JP2005322972A - Antenna module, radio module, radio system, and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna module technology, having at least two functions from among multiple-frequency handling, polarization switching and directivity control. <P>SOLUTION: The antenna module has three functions of multiple frequency adaptation, polarization switching and directivity control. It comprises an antenna array composed of nine radiation elements (conductors) 11, three feed points (A12, B13 and C14), a matching circuit 15 for matching the input impedance of the antenna with the characteristic impedance of feed wires, 12 pieces of first switches 16 for controlling the interconnection between the plurality of adjacent radiation elements 11 and three pieces of second switches 17 for switching over the three feed points. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antenna module technology, and more particularly to an antenna module technology capable of a frequency switching function, a polarization switching function, and a directivity control function.

  Currently, mobile phones are second-generation mobile phones such as PDC (Personal Digital Celluler), FOMA, CDMA2000, PHS (Personal Handyphone System), and wireless LANs are IEEE802.11a, 802.11b, 802.11g, Bluetooth, etc., ITS (Intelligent Transport Systems (GPS) uses multiple frequencies corresponding to wireless standards such as GPS (Global Positioning System), VICS (Vehicle Information Communication System), ETC (Electronic Toll Collection System), etc., and multiple frequencies will coexist in the future. The environment is expected to continue.

  However, since a single-frequency antenna is used in conventional wireless communication, a wireless device corresponding to a plurality of frequencies needs to be provided with a plurality of single-frequency antennas, which is increased in size.

  In addition, the area where radio waves can be transmitted and received satisfactorily on the surface of the wireless device is limited, and there is a limit to installing all antennas in a favorable radio wave environment. Therefore, in recent years, multi-frequency (multi-band) compatible antennas that can handle a plurality of frequencies with one antenna have attracted attention.

  As a conventional example of a multiband antenna, one has a structure in which a radiation element corresponding to a plurality of frequencies is provided in the antenna. For example, as a structure using a plurality of radiating elements having different resonance lengths, a design and measurement result of a three-frequency resonance antenna having a multilayer plate configuration (Technical Report of IEICE, AP2002-141, p41-46, 2003) (Non-Patent Document 1), "Multifrequency Microstrip Patch Antenna Using Multiple Stacked Elements (IEEE Microwave and Wireless Components Letters, vol.13, No.3, p123-124, 2003)" (Non-Patent Document 2), "2 A study on a configuration method of a frequency shared microstrip antenna (2003 IEICE Communication Society Conference, Lecture No. B-1-161) ”(Non-patent Document 3) and the like.

  However, the above antenna has a structure in which a plurality of antennas are arranged in one place, and since a region where radio waves can be transmitted and received satisfactorily on the surface of the wireless device is limited, it is difficult to transmit and receive all desired radio waves satisfactorily. there were.

  A structure in which one radiating element has a plurality of resonance lengths has also been proposed. For example, "A Study on Radiation Characteristics of Modified Sirpinski Type Microstrip Antenna (2003 IEICE Communication Society Conference, Lecture Number B-1-162)" (Non-Patent Document 4), "Double Frequency Slot Bowtie Antenna" (2003 IEICE Communication Society Conference, Lecture No. B-1-176) ”(Non-Patent Document 5).

  However, the modified Sirpinski-type microstrip antenna has a problem that radiation patterns are different in the three bands, and three frequencies cannot be transmitted and received under the same conditions in the same area. Also, it seems that the dual-frequency slot bow tie antenna can only handle up to about three frequencies.

  Thus, many methods for switching the resonance length of the antenna with a switch have been proposed. For example, JP-A-2000-236209 (Patent Document 1), JP-A-2002-261533 (Patent Document 2), JP-A-2003-124730 (Patent Document 3), US Pat. No. 6,198,438 (Patent Document 4), "GTRI Prototype Reconfigurable Aperture Design (2002 IEEE Antenna and Propagation Society International Symposium Digest, p473-476)" (Non-Patent Document 6), "The GTRI Prototype Reconfigurable Aperture Design (2003 IEEE Antenna and Propagation Society International Symposium Digest, p683)" ˜686) ”(Non-Patent Document 7).

  In Japanese Patent Laid-Open No. 2000-236209 (Patent Document 1), as shown in FIG. 22, a metal piece 101 is connected by a PIN diode 102 to form a dipole antenna. A bias is applied to the PIN diode 102 to switch the conduction / cutoff of the PIN diode 102 to change the resonance length. The dipole antenna used in Japanese Unexamined Patent Publication No. 2000-236209 (Patent Document 1) needs to be excited with a balanced current.

  However, the line used for the RF circuit often uses an unbalanced current such as a microstrip line or a coplanar line. When a balanced current is required, a balun must be provided between the antenna and the line.

  In general, since the balun has a narrow band, it cannot cope with a plurality of frequencies, and one balun is required for each frequency. Therefore, in order to support multiband, it is necessary to arrange baluns in the vicinity of the feeding point of the dipole antenna as many as the number of multibands, and the number of multibands is limited by the balun installation area. Therefore, Japanese Patent Laid-Open No. 2000-236209 (Patent Document 1) can be used when there are few frequency bands such as a dual band, but cannot be applied to multibands with many frequency bands.

  In Japanese Patent Laid-Open No. 2002-261533 (Patent Document 2), as shown in FIG. 23, one feeding point (feeding pattern) 219 and a plurality of grounding points (grounding patterns) 220a, 220b, and 220c are included in the antenna element pattern 218. , 220d, and these grounding points 220a, 220b, 220c, 220d are respectively switched by switches SW221a, SW221b, SW221c, SW221d to change the resonance length. Reference numeral 211 denotes an antenna unit, 212 denotes a wiring board, 213 denotes a ground pattern, and 214 denotes an RF module.

  However, in Japanese Patent Laid-Open No. 2002-261533 (Patent Document 2), since the short-circuit point is switched by a switch, the input impedance of the antenna changes at each frequency. Therefore, the ground point can be moved only within a matching range, and it seems that the frequency range that can be varied in multiband cannot be increased.

  Actually, the variable frequency band disclosed in Japanese Patent Laid-Open No. 2002-261533 (Patent Document 2) is 1.55 to 2.2 GHz, which is as small as 30% with respect to the center frequency of 1.8 GHz. Therefore, it is possible to cope with the case of using a relatively close frequency band such as a cellular phone, but it is not possible to cope with the case of using the 2.4 GHz band and the 5 GHz band like a wireless LAN.

  In Japanese Patent Laid-Open No. 2003-124730 (Patent Document 3), as shown in FIGS. 24A and 24B, the first radiating element 320, the second radiating element 330, and the third radiating element 340 are switched. The power feeding point and the short-circuit point are shared, and four frequency bands are realized by switching the power feeding point and the short-circuit point by the switches SW360 and SW362. 300 is an antenna structure, 305 is a short-circuit plane, 310 is a sub-antenna structure, 322 is a first end, 324 is a feed line, 332 is a second end, 334 is an interval, 342 is a third end, 350 Is a feed line, 370 and 372 are radio frequency modules, and A1 and A2 are openings.

  However, in Japanese Patent Laid-Open No. 2003-124730 (Patent Document 3), it is necessary to arrange the three radiating elements 320, 330, and 340 on the same plane, and the area where radio waves can be transmitted and received satisfactorily on the surface of the wireless device is limited. Therefore, it is difficult to transmit and receive all four radio waves satisfactorily.

  In US Pat. No. 6,1984,438 (Patent Document 4), as shown in FIG. 25, element elements 400 arranged in a matrix are connected by MEMS switches 420, respectively.

  When all the MEMS switches 420 are turned off (shut off state), one side of each element element has a resonance length and corresponds to a high frequency. On the other hand, when all the MEMS switches are turned on (conducting state), the individual element elements are connected to form one rectangular radiating element as a whole and resonate at a low frequency.

  Here, in US Pat. No. 6,1984,438 (Patent Document 4), in order to match the characteristic impedance of the line (usually using 50Ω), a high-frequency feed point 405 (provided for each individual element) and a low-frequency feed point 410 ( A different point is used). Therefore, there is a drawback that the number of multibands that can be handled is limited by the number of feeding points that can be arranged in the array antenna arranged in a matrix.

  Further, there is a drawback that it is difficult to provide a feeding point on the MEMS switch 420. In the example of FIG. 25, the high-frequency feeding point 405 that resonates with one element element and the low-frequency feeding point 410 that resonates with the entire 3 × 3 array can be arranged on the element element (radiating element 400). When resonance is desired, the feeding point comes on the MEMS switch, so even if a 3 × 3 array is used, only two frequencies can be handled.

  Furthermore, since the conductor width connected by the MEMS switch 420 is smaller than the width of the adjacent element elements, when all the MEMS switches 420 are turned on to form one rectangular radiating element, the inside of the entire radiating element There is a large gap in the. As a result, the current flowing through the radiating element is limited by the air gap, the bandwidth is reduced, and it becomes difficult to secure the bandwidth necessary for communication.

  In the GTRI Prototype Aperture Antenna, as shown in FIG. 26 (see Non-Patent Document 7), element elements 510 arranged in a matrix are connected by FET switches 520 and excited at a single feeding point by a balanced current. It has a structure.

  The GTRI Prototype Aperture Antenna can switch the frequency and directivity by changing the shape of the radiating element by the combination of ON and OFF of the FET switch 520. However, in this case, since the FET switch 520 is selected ON / OFF using a genetic algorithm, the arithmetic circuit becomes complicated.

  Further, there is only one feeding point 530, and it is necessary to match the input impedance of the radiating element 510 with the characteristic impedance of the feeding line, and the degree of freedom of the shape of the radiating element 510 is small, and the frequency range that can be varied may be limited. Is expensive.

  Actually, the variable frequency range reported in the above-mentioned literature was about 1 to 2 GHz, which was enough to handle a bandwidth of about ± 50%. In addition, since it is excited by a balanced current, a balun is required for connection to a microstrip line or coplanar line widely used in RF circuits. Therefore, there is a problem that the number of multibands is limited depending on the installation area of the balun.

  A matching circuit may be provided to match the antenna input impedance to the characteristic impedance of the line. As a matching circuit, a method of resistance conversion using a λ / 4 line, a circuit in which an inductor and a capacitor are configured in a π type or a T type, a circuit including a phase shifter and a capacitor, and the like are known.

  However, since the line length of λ / 4 line is uniquely determined by the frequency, it is not suitable for adjusting the input impedance fluctuation of the antenna. Conventionally, constants such as matching circuit inductors, capacitors, phase shifters, etc. are input to the antenna. An automatic matching circuit that varies depending on impedance has been proposed.

  For example, in the tuning of mobile phone base stations and hams, a system is adopted in which the constants of a variable capacitor and a variable coil are adjusted by a motor. However, since a driving unit such as a motor is required, the matching circuit becomes large and cannot be installed in a portable terminal, a wireless LAN terminal, or an ITS terminal.

  Recently, research aimed at a small automatic matching circuit has also been actively conducted. For example, “A matching circuit in an automatic antenna matching system (Journal of the Institute of Electronics, Information and Communication Engineers B, vol.J85-B, No. 11, (p1977-1980, 2002) ”(Non-patent document 8),“ Matching circuit in automatic antenna matching system (2003 IEICE General Conference, Lecture No. B-1-62) ”(Non-patent document 9) and“ Automatic matching of human proximity antennas by the steepest descent method (Technical Report of IEICE, AP2003-31, p31-36, 2003) ”(Non-patent Document 10).

  In the automatic antenna matching system, an automatic matching circuit is configured by three variable capacitors and a fixed-length line, and constants of the variable capacitors are determined in advance in each region on the Smith chart, and the constants are switched according to the input impedance of the antenna. Has proposed. In this method, it has been reported that the VSWR can be matched to almost 2 or less even when the input impedance of the antenna fluctuates in the range of VSWR (Voltage Standing Wave Ratio) ≦ 6.5.

  In the above "Matching circuit in antenna automatic matching system (2003 IEICE General Conference, Lecture No. B-1-62)" (Non-Patent Document 9), an automatic matching circuit is constructed with a variable phase shifter and a variable capacitor. It is reported that the antenna input impedance can be matched to 50Ω at f = 2000MHz.

  In addition, the automatic matching circuit of a human body proximity active antenna is composed of a parallel varactor, a series varactor, and a 4: 1 transformer using a balun. It has been reported that the resonance frequency of a commercial radio antenna shifts by 7 to 8 MHz when it is close to the human body, but it can be excited at a predetermined frequency of 160 MHz with a good VSWR by using an automatic matching circuit.

  However, the above examples are all intended to fix the frequency and match when the input impedance of the antenna varies depending on the external environment, and the possibility of multiband is not specified. Since the element constants of the matching circuit operate at 1 / ωC and ωL, for example, when the frequency is halved, the L and C constants are doubled to match the same input impedance.

  For the purpose of downsizing the matching circuit, it is desired to match the input impedance fluctuation of the multiband antenna with a single automatic matching circuit. To that end, a small inductor, capacitor, and shifter with a wide variable range are required. A phaser is required.

  Since the above-mentioned method has a fixed frequency, the variable range of the element constant is expected to be narrow, and it seems difficult to apply it to the input impedance fluctuation of the multiband antenna. Further, the combination of the variable phase shifter and the variable capacitor has a drawback that the matching locus on the Smith chart becomes long and the matching band becomes narrow when the resistance component of the input impedance of the antenna is larger than 50Ω.

  Looking at small elements having a large variable range, a variable capacitor already has a variable range of two digits or more in the region of 1 to 20 GHz by a varactor. However, in the millimeter wave region, there is a concern that leaks in the varactor increase and cannot be handled by the varactor.

  As the variable inductor, a chip-type variable inductor is commercially available in which a core material such as an iron core is mechanically inserted and removed from a coil. However, the self-resonant frequency of the chip-type variable inductor is not higher than GHz, and it will be difficult to increase the self-resonant frequency with the conventional structure in the future, and it cannot cope with the microwave to millimeter wave region at all.

  As for variable phase shifters, variable phase shifters using ferrite and GaAs semiconductors are commercially available and researched and developed, but the compatible frequencies are 30 GHz or less for ferrite and 60 GHz or less for GaAs semiconductor. Use ferrite and GaAs semiconductor. It is considered that the conventional phase shifter cannot be applied to an automatic matching circuit of a multiband antenna that covers the millimeter wave region.

  On the other hand, liquid crystal is attracting attention as a material that can cope with a high frequency of about 100 GHz, and a variable delay line using nematic liquid crystal has been studied. For example, “A Study on the Design of Microwave Variable Delay Line Using Liquid Crystal and Its Insertion Loss (The IEICE Transactions C, vol.J84-C, No.2, p90-96, 2001)” Patent Document 11), “Modeling Synthesis and Characterization of a Millimeter-Wave Multilayer Microstrip Liquid Crystal Phase Shifter, (Japanese Journal of Applied Physics, vol. 36, p4409 to 4413, 1997)” (Non-patent Document 12) However, a general liquid crystal material has a dielectric loss tangent of about 0.01 to 0.11, which is two orders of magnitude larger than that of an inorganic material. When a variable delay line is formed of a liquid crystal material, there is a disadvantage that a dielectric loss increases.

  Recently, a high-frequency signal can be cut off well up to about 100 GHz, insertion loss is small, and power consumption is low.

  For example, in a variable capacitor, “Distributed MEMS true-time delay phase shifters and wideband switches (IEEE Transactions and Microwave Theory and Techniques, vol. 46, No. 11, p1881 to 1890, 1998)” (Non-patent Document 13), “A low power / low voltage electrostatic actuator for RF MEMS applications (Solid-State Sensors and Actuator Workshop, p246-249, 2000)” (Non-Patent Document 14).

  A variable capacitor by MEMS forms a capacitance by the air gap between the upper and lower electrodes and the air gap between the comb electrodes facing each other, and one electrode is operated by electrostatic attraction to change the air gap to change the capacitance. And However, the variable range of the capacitance is limited by the parasitic capacitance between the substrate and the electrode and the parasitic capacitance due to the minute gap when the upper and lower electrodes covered with the insulating film are in contact with each other. At present, the variable range is limited to about one digit. .

  On the other hand, as an example of a variable inductor, Japanese Patent Application Laid-Open No. 2003-68571 (Patent Document 5), “Development of an On-Chip RF Variable Inductor (Technical Report of the Institute of Electronics, Information and Communication Engineers, SDM2002-231, p23-28, 2003)” (Non-Patent Document 15), “Self-Asembling MEMS Variable and Fixed RF Inductor (IEEE Transactions and Microwave Theory and Techniques, vol. 49, No. 11, p2093-2098, 2001)” (Non-Patent Document 16), etc. is there.

  In Japanese Patent Laid-Open No. 2003-68571 (Patent Document 5), as shown in FIG. 27, a plurality of conductor plates 642 and 643 are provided below a transmission line (spiral inductor) 691, and switches 630 (SW1 ′, SW2 ′) are provided. The inductance is varied by switching the conductor plate to be grounded.

  The method disclosed in Patent Document 5 is a method of changing the characteristic impedance of the line constituting the transmission line by changing the position of the ground plane with a switch. The amount of change in inductance reported here is 2.5 to 4.8. nH, and a large variable range is not expected.

  As shown in FIG. 28, the on-chip RF variable inductor mechanically pushes a spring-like coil floating from the substrate to change the coil height, and changes the magnetic flux leaking from the side surface of the coil to make the inductance variable.

  In the Self-Asembling MEMS Variable Inductor disclosed in Non-Patent Document 16, as shown in FIG. 29, two upright loops are heated, and one of the loops is largely curled so that a magnetic flux leaking between the loops is generated. Change the inductor to be variable.

  Both the above-described on-chip RF variable inductor and Self-Asembling MEMS Variable Inductor are methods of varying the inductance using leakage magnetic flux from the side surface of the inductor. The variable range reported in these documents is the on-chip RF variable inductor. About 3% and about 50% for the Self-Asembling MEMS Variable Inductor, it is considered that a large variable range cannot be realized even if such a method is used.

  Therefore, the on-chip RF variable inductor and the Self-Asembling MEMS Variable Inductor disclosed in the above-mentioned Patent Document 5, Non-Patent Document 15 and Non-Patent Document 16 are components of an automatic matching circuit of a multiband antenna. Is considered inappropriate.

  When many communication standards coexist, a method for improving communication capacity by controlling not only the frequency but also the polarization has been taken. In the past, a single linear polarization was used, but polarization diversity and circular polarization that switch between horizontal polarization and vertical polarization are attracting attention. Already, GPS (Global Positioning System), ETC (Electronic Toll Collection System) , SADARS (Satellite Digital Audio Radio Services) and the like employ circular polarization.

  In the above-described conventional example, the GPS antenna and the ETC antenna correspond to circular polarization in the three-frequency resonance antenna having a multilayer plate configuration. However, in a three-frequency resonant antenna having a multilayer plate configuration, one radiating element corresponds to one frequency, and one frequency becomes one polarization and does not have a function of switching the polarization itself. Therefore, when switching the polarization at the same frequency, the number of radiating elements corresponding to the polarization is required, and there is a disadvantage that the antenna becomes large.

  Further, in Patent Documents 1 to 4 that disclose a method of switching the resonance length of an antenna with a switch, circularly polarized waves are not realized and the function of switching polarizations is not provided.

  As antennas specialized in polarization switching, "Polarization Reconfigurable Patch Antenna using Microelectromechanical System (MEMS) Actuators (2002 IEEE Antenna and Propagation Society International Symposium Digest, p6-9)" (Non-Patent Document 17), The polarization-switching microstrip antenna used (2003 IEICE Communication Society Conference, Lecture No. B-1-137) ”(Non-patent Document 18) and the like.

  As shown in FIG. 30, the Polarization Reconfigurable Patch Antenna of Non-Patent Document 17 has a notch formed on two orthogonal sides of the patch antenna 600, and a MEMS actuator 601 having a metal stub is provided on one of the notches. . The feed line 602 is made from the apex of the patch antenna 600.

  In FIG. 30, when the MEMS actuator 601 is OFF, the phase difference becomes 90 degrees in the two excited directions, and circularly polarized waves are radiated. When the MEMS actuator 601 is ON, since the metal stub is connected to the antenna, one of the resonance lengths is extended, and the phase difference between the two excitation directions is shifted from 90 degrees, and elliptical polarization or linear polarization is radiated.

  In the polarization switching microstrip antenna of Non-Patent Document 18, as shown in FIG. 31, two slots for electromagnetic coupling (701 and 702) corresponding to two excitation directions are provided on the ground plane of the microstrip antenna. A Y-shaped microstrip line 710 is arranged underneath, and PIN diodes D1 (703) and D2 (704) opposite to the Y-shaped line are provided to short-circuit with the ground plane. Since one electromagnetic coupling slot can be selected by turning on and off the PIN diode, two orthogonally polarized waves can be switched.

  The above two antennas can switch the polarization, but have only one frequency and cannot support multiband. A multi-band antenna that supports two or three bands using the same structure as Polarization Reconfigurable Patch Antenna is “Microelectromechanical Systems (MEMS) Actuators for Antenna Reconfigurability (2001 IEEE MTT-S. Digest, p215-218)” (Non-patent document 19). However, all the radio waves radiated from the antenna are linearly polarized waves, and both multiband and polarization switching cannot be achieved.

  As more communication standards coexist in the future, a method of spatially separating radio waves will be necessary. Conventionally, an omnidirectional antenna has been generally used. However, if a directional antenna is used, radio waves can be spatially separated in the same area, so that the communication capacity in the area can be dramatically improved.

  In addition, since the gain of the directivity control antenna is improved in comparison with the non-directional antenna in the direction in which the beam is radiated, the reception power increases when used on the receiving side, and high-speed transmission is possible. When used on the transmission side, less power is required to send the same information, and a reduction in power consumption can be expected. Therefore, research on directivity control antennas has been actively conducted.

  As an example of a directional antenna, a cellular phone base station employs a method of spatially separating communication paths by a sector antenna. However, it is necessary to prepare a plurality of antennas with narrowed beam widths and to direct the individual antennas in different directions, and the size of the antenna increases, making it difficult to introduce it into a portable terminal or a wireless LAN.

  The Yagi / Uda antenna is well known as a directional antenna. The Yagi / Uda antenna is designed to provide directivity by placing a director with a shorter electrical length than the dipole antenna and a reflector with a longer electrical length than the dipole antenna before and after the dipole antenna. As an example in which the principle of the Yagi / Uda antenna is used for two-dimensional directivity control, there is JP-A-2001-36337 (Patent Document 6).

  In Patent Document 6, as shown in FIG. 32, a plurality of parasitic elements 801 are arranged around a feeding element 800, and a switch circuit 804 that conducts a capacitor 802 and a ground plane 803 is provided in parallel to the parasitic element 801. By turning on or off the circuit 804, the parasitic element 801 acts as a director or reflector to control the directivity.

  In the configuration of Patent Document 6, the area occupied by the antenna is reduced because a director and a reflector are used in common, but since the monopole antenna is used for the feeding element 800 and the parasitic element 801, the antenna becomes three-dimensional and portable. Introduction to terminals and wireless LAN terminals is difficult.

  As another method for controlling directivity, for example, there is JP-A-6-112727 (Patent Document 7). The antenna structure used in Patent Document 7 is shown in FIG. 33 (a), and the radiation pattern is shown in FIGS. 33 (b) and 33 (c).

  In the one disclosed in Patent Document 7, as shown in FIG. 33A, an annular radiating conductor in which a ground plate 811 is provided on the back surface of a dielectric 810 and an outer peripheral portion is short-circuited to the ground plate 811 on the surface of the dielectric 810. 812 is provided, and a diode that is short-circuited to the ground plane 810 is disposed inside the annular conductor 812.

  Then, two excitation modes (TM110 mode (FIG. 33 (b)) and TM210 mode (FIG. 33 (c)) can be selected by turning on and off the diode. When the TM110 mode and the TM210 mode are set to the same frequency, two radiation modes are emitted. However, in Patent Document 7, the number of radiation patterns that can be selected is limited to two, fine directivity control is impossible, and the pattern can be used only for limited applications.

  There is also a method for controlling directivity by combining radiation patterns from a plurality of antennas, such as a phased array antenna or an adaptive array antenna. Phased array antennas require as many phase shifters and front-end circuits as the number of antennas, and arithmetic circuits that control the phase shifters are also required, making wireless modules more complex and larger, and currently used as radar. However, it is difficult to introduce it into a portable terminal or a wireless LAN. In addition, there is a drawback in that transmission / reception power is reduced due to insertion loss of the phase shifter.

  An adaptive antenna requires an arithmetic circuit for vector synthesis and baseband circuits and front-end circuits as many as the number of antennas when vector synthesis is performed in the baseband, and the number of antennas when vector synthesis is performed at the front-end. Only a front-end circuit is required, and the wireless module is inevitably complicated and enlarged.

  However, an ESPAR antenna that synthesizes signals by spatial beam forming has been proposed, and an arithmetic circuit for vector synthesis is necessary. However, since only one baseband circuit and one front-end circuit are required, great expectation is gathered.

  As conventional examples of ESPAR antennas, there are, for example, JP-A-10-154911 (Patent Document 8) and JP-A-2002-325012 (Patent Document 9). In the ESPAR antenna disclosed in these, as shown in FIG. 34, a parasitic element 821 loaded with a plurality of variable reactances Xi is arranged around a feeding element 820 made of a monopole antenna, and the reactance of the parasitic element 821 is increased. Directivity is controlled by switching with a switch.

  However, in these Patent Documents 8 and 9, it is necessary to dispose many parasitic elements around the feeding elements, and there is a limit to miniaturization of the antenna. In addition, since the monopole antenna is used, the antenna is three-dimensional, and it is difficult to introduce it into a portable terminal or a wireless LAN terminal.

  As a method of controlling directivity using a planar antenna, “Electronically Steering Yagi-Uda Microstrip Patch Antenna array (1995 IEEE Antenna and Propagation Society International Symposium, p1870)” (Non-patent Document 20), “Electronic beam steering using” "switched parasitic patch elements (Electronics Letters, vol.33, No.1, p7-8, 1997)" (Non-patent Document 21), "Beam-forming microstrip array antenna (2002 IEICE General Conference, Lecture) No. B-1-234) ”(Non-Patent Document 22),“ Two-dimensional beam shaping with X-shaped array microstrip array antenna (2003 IEICE General Conference, Lecture No. B-1-248) ”(Non-Patent Document 22) Patent Document 23) and the like.

  In Non-Patent Document 20 (Electronically Steering Yagi-Uda Microstrip Patch Antenna Array), as shown in FIG. 35, a microstrip antenna is used, a reflector is used in common and Yagi and Uda antennas are configured in four directions, and a feed element is formed. By switching, directivity control in four directions is realized.

  In Non-Patent Document 21 (Electronic beam steering using switched parasitic patch elements), as shown in FIG. 36, microstrip antennas are arranged in the E-plane direction, the central element is a feeding element, and both end elements are parasitic elements. The parasitic element is provided with a switch that is short-circuited to the ground plane. One parasitic element is short-circuited to the ground plane to function as a reflector, and directivity control in the E-plane direction can be performed.

  In Non-Patent Document 22 (beam forming microstrip array antenna), as shown in FIG. 37, a parasitic element (P-MSA) in which variable reactances are loaded at both ends of a feeding element (F-MSA) made of a microstrip antenna. ) To change the reactance of the parasitic element and perform directivity control on the H plane. The X-shaped array microstrip array antenna utilizes the above-described effect, and a parasitic element loaded with variable reactances is arranged around the feeding element in four directions to realize directivity control in two dimensions. .

  Since the above example uses a microstrip antenna, unlike the antenna of Patent Document 6 (Japanese Patent Laid-Open No. 2001-36337) and the ESPAR antenna of Patent Documents 8 and 9, the antenna is downsized. Is advantageous.

  However, in the sector antenna, Yagi / Uda antenna, phased array antenna, ESPAR antenna, electronic beam steering using switched parasitic patch elements, and beam shaping microstrip array antenna, the resonance length of the feed element is one, so the frequency is one. It is limited to.

  Therefore, when multiband or polarization switching is performed using the above antenna structure, it is necessary to arrange the antennas by the number of bands and polarizations, and there is a disadvantage that the installation area of the antenna becomes very large. If a certain installation area can be secured, it will be possible to switch between two to three frequencies and polarization switching at one frequency. However, in portable terminals and wireless LAN terminals, the antenna installation area is limited, so multiband compatibility and polarization are possible. Switching is expected to be virtually impossible.

  In Patent Document 7 (Japanese Patent Laid-Open No. 6-112727), since excitation is originally performed in two modes, the frequencies of the two modes can be made different to be two frequencies. It becomes impossible to control directivity by frequency and cannot be used as a directivity control antenna.

  In addition, the GTRI Prototype Aperture Antenna described above can change the shape of the radiating element according to the combination of ON and OFF of the FET switch, and can support multi-frequency and directivity control. However, GTRI Prototype Aperture Antenna uses a genetic algorithm to switch FET switches ON / OFF using a genetic algorithm, and requires a balun for the number of bands to supply power with balanced current, and the variable frequency range is 1-2 GHz. The frequency variable performance is very poor compared to an antenna specialized in multi-frequency, which has drawbacks such as degree and narrowness.

  As described above, communication standards will increase in the future, and antennas and wireless modules will be required to have three new functions: multi-frequency support, polarization switching, and directivity control. An antenna having one function is not proposed at all, and only a GTRI Prototype Aperture Antenna having two functions is proposed. The GTRI Prototype Aperture Antenna also has a significant problem in terms of its practical use because the multi-frequency function has a significantly lower performance than a single-function antenna.

  The applicant has filed a patent application regarding the tapered slot antenna. For example, JP-A-10-13141 (Patent Document 10), JP-A-10-13143 (Patent Document 11), JP-A-10-173432 (Patent Document 12), JP-A-11-163626 (Patent Document) Reference 13). The tapered slot antenna has a constant input impedance over a wide band, and is classified into a wide band antenna. Although it can transmit and receive in a wide frequency band, it does not have polarization switching and directivity control functions.

JP 2000-236209 A JP 2002-261533 A JP 2003-124730 A USP 6198438 JP 2003-68571 A JP 2001-36337 A JP-A-6-112727 Japanese Patent Laid-Open No. 10-154911 JP 2002-325012 A Japanese Patent Laid-Open No. 10-13141 Japanese Patent Laid-Open No. 10-13143 Japanese Patent Laid-Open No. 10-173432 JP 11-163626 A Design and measurement results of a three-frequency resonant antenna with a multi-layer configuration (Technical Report of IEICE, AP2002-141, p41-46, 2003) Multifrequency Microstrip Patch Antenna Using Multiple Stacked Elements (IEEE Microwave and Wireless Components Letters, vol.13, No.3, p123-124, 2003) A study on the configuration method of dual-band microstrip antenna (2003 IEICE Communication Society Conference, Lecture No. B-1-161) A Study on Radiation Characteristics of Modified Sirpinski Type Microstrip Antenna (2003 IEICE Communication Society Conference, Lecture No. B-1-162) Dual Frequency Slot Bowtie Antenna (2003 IEICE Communication Society Conference, Lecture No. B-1-176) GTRI Prototype Reconfigurable Aperture Design (2002 IEEE Antenna and Propagation Society International Symposium Digest, p473-476) The GTRI Prototype Reconfigurable Aperture Antenna (2003 IEEE Antenna and Propagation Society International Symposium Digest, p683 ~ 686) Matching circuit in an automatic antenna matching system (The IEICE Transactions B, vol. J85-B, No. 11, p1977-1980, 2002) Matching circuit for automatic antenna matching system (2003 IEICE General Conference, Lecture No. B-1-62) Automatic matching of active antennas in proximity to human body by steepest descent method (Technical Report of IEICE, AP2003-31, p31-36,2003) A Study on Design of Microwave Variable Delay Line Using Liquid Crystal and Its Insertion Loss (The IEICE Transactions C, vol.J84-C, No.2, p90-96, 2001) Modeling Synthesis and Characterization of a Millimeter-Wave Multilayer Microstrip Liquid Crystal Phase Shifter, (Japanese Journal of Applied Physics, vol.36, p4409-4413, 1997) Distributed MEMS true-time delay phase shifters and wideband switches (IEEE Transactions and Microwave Theory and Techniques, vol.46, No.11, p1881-1890, 1998) A low power / low voltage electrostatic actuator for RF MEMS applications (Solid-State Sensors and Actuator Workshop, p246-249, 2000) "Development of on-chip RF variable inductor (Technical Report of IEICE, SDM2002-231, p23-28, 2003)" Self-Asembling MEMS Variable and Fixed RF Inductor (IEEE Transactions and Microwave Theory and Techniques, vol. 49, No. 11, p2093-2098, 2001) Polarization Reconfigurable Patch Antenna using Microelectromechanical System (MEMS) Actuators (2002 IEEE Antenna and Propagation Society International Symposium Digest, p6-9) Polarization-switching microstrip antenna using a diode (2003 IEICE Communication Society Conference, Lecture No. B-1-137) Microelectromechanical Systems (MEMS) Actuators for Antenna Reconfigurability (2001 IEEE MTT-S. Digest, p215-218) Electronically Steering Yagi-Uda Microstrip Patch Antenna array (1995 IEEE Antenna and Propagation Society International Symposium, p1870) Electronic beam steering using switched parasitic patch elements (Electronics Letters, vol.33, No.1, p7-8, 1997) Microstrip array antenna for beam forming (2002 IEICE General Conference, Lecture No. B-1-234) Two-dimensional beam shaping with X-shaped array microstrip array antenna (2003 IEICE General Conference, Lecture No. B-1-248)

  In the background art described above, the prior art and its problems have been described. The present invention solves such problems, and the antenna module technology has at least two functions of multi-frequency compatibility, polarization switching, and directivity control. The purpose is to provide. The purpose of each claim is described below.

  The object of the present invention is to provide a structure of an antenna module having at least two functions of multi-frequency support, polarization switching, and directivity control. Furthermore, in addition to the above object, the inventions according to claims 6 and 10 have an object to provide an antenna module structure capable of expanding the band.

  The invention according to claim 11 provides a configuration of a small matching circuit for performing good transmission and reception in the antenna module of the present invention having at least two functions of multi-frequency support, polarization switching, and directivity control. The purpose is that.

  It is an object of the present invention to provide a variable inductor structure having a wide control range.

  An object of the present invention is to provide a structure for realizing a small antenna module.

  The object of the present invention is to provide a structure for realizing a low-loss and low-cost antenna module.

  An object of the present invention is to provide a structure for realizing an antenna module having a wide bandwidth.

  The object of the present invention is to provide a structure for easily giving directivity.

  It is an object of the present invention to provide a structure of a small wireless module that can support a plurality of wireless standards and has at least two functions of multi-frequency support, polarization switching, and directivity control. Yes.

  An object of the invention described in claim 20 is to provide a configuration of a small wireless system that can support a plurality of wireless standards and has at least two functions of multi-frequency support, polarization switching, and directivity control.

  It is an object of the present invention to provide a method for controlling an antenna module having at least two functions of multi-frequency support, polarization switching, and directivity control.

In order to achieve the above object, the present invention has the following configuration. That is,
(1) The invention described in claim 1 is an antenna module having at least two functions among three functions of frequency switching, polarization switching, and directivity control, and an antenna array including a plurality of radiating elements; A plurality of feeding points that feed power to a plurality of radiating elements, a first switch that selectively controls connection / disconnection between adjacent radiating elements among the plurality of radiating elements, and a feeding line is selected as the plurality of feeding points And a matching circuit capable of changing a constant for matching the input impedance of the antenna to the characteristic impedance of the feeder line.

(2) The invention according to claim 2 is the antenna module according to claim 1, wherein the antenna array forms a plurality of radiating elements having different resonance lengths by a combination of conduction / cutoff states of the first switch. And the same switch is selected from a plurality of feed points by the second switch, and further, by the combination of the conduction / cut-off state of the first switch by the matching circuit. The input impedance of the radiating element to be formed is matched with the characteristic impedance of the feeder line.

(3) The invention according to claim 3 is the antenna module according to claim 1 or 2, characterized in that the antenna array is a microstrip antenna array comprising a plurality of rectangular conductors arranged in a matrix. To do.

(4) The invention according to claim 4 is the antenna module according to claim 3, wherein the antenna array forms a plurality of rectangular radiating elements having different resonance lengths by a combination of conduction / cutoff states of the first switch. When the linearly polarized wave having the same excitation direction is radiated, the side perpendicular to the excitation direction of the rectangular radiating element formed by the conduction of the first switch is supplied from the plurality of feeding points. The same feeding point on the perpendicular of the middle point is selected by the second switch.

(5) The invention according to claim 5 is the antenna module according to claim 3, wherein the antenna array forms a plurality of rectangular radiating elements having different resonance lengths according to a combination of conduction / cutoff states of the first switch. And having the same turning direction and radiating elliptically polarized waves in the same turning direction, the same feeding that is on the diagonal line of the rectangular radiating element formed by conduction of the first switch from the plurality of feeding points A point is selected by the second switch.

(6) The invention according to claim 6 is the antenna module according to any one of claims 3 to 5, wherein the first switch has a structure in which the first switch is electrically connected or cut off over substantially the entire side of the adjacent rectangular conductor. It is characterized by that.

(7) The invention according to claim 7 is the antenna module according to claim 1 or 2, wherein the antenna array is a slot antenna array having a plurality of rows of a plurality of slots linearly arranged in two orthogonal directions. It is characterized by that.

(8) According to an eighth aspect of the present invention, in the antenna module according to the seventh aspect, the antenna array has a plurality of strips having different resonance lengths depending on a combination of conduction / cutoff states of the first switch in two orthogonal directions. A strip-shaped radiating element formed by connecting the first switch from the plurality of feeding points when the linearly polarized wave having the same excitation direction is radiated. The same feeding point in the short direction is selected by the second switch.

(9) The invention according to claim 9 is the antenna module according to claim 7, wherein the antenna array has a plurality of strips having different resonance lengths depending on a combination of conduction / cutoff states of the first switch in two orthogonal directions. In the case of radiating elliptically polarized waves, a strip-shaped radiating element having the same resonance length is formed in two orthogonal directions, and the plurality of feeding points Each feeding point in the short direction of the two strip-shaped radiating elements formed by connection of one switch is selected by the second switch.

(10) The invention according to claim 10 is the antenna module according to any one of claims 7 to 9, wherein the slot adjacent by the first switch is connected to almost the entire short surface of the slot. It is characterized by.

(11) The invention according to claim 11 is the antenna module according to any one of claims 1 to 10, wherein the matching circuit is composed of a combination of a variable inductor and a variable capacitor by MEMS, and the inductance or capacitance is changed. The input impedance of the antenna is matched with the characteristic impedance of the feeder line.

(12) The invention according to claim 12 is the antenna module according to claim 11, wherein the variable inductor is a spiral inductor composed of a movable wiring and a fixed wiring, and the inner diameter of the spiral inductor is increased by moving the movable wiring. It has a structure in which at least one of the diameter and the pitch of the spiral is variable.

(13) The invention according to claim 13 is the antenna module according to claim 11 or 12, wherein the variable inductor is separated from the first inductor and the first inductor through which a high-frequency signal to be transmitted or received passes. It comprises two inductors, and has a structure in which the distance between the first inductor and the second inductor is variable.

(14) The invention according to claim 14 is the antenna module according to any one of claims 1 to 13, wherein the antenna array and the first switch are provided on a first board, and the matching is provided on a second board. There is a circuit and the second switch, and the first substrate and the second substrate are stacked.

(15) The invention according to claim 15 is the antenna module according to claim 14, wherein the first substrate is a glass substrate.

(16) The invention according to claim 16 is the antenna module according to any one of claims 1 to 15, wherein each of the first switches has a V-shaped tip portion facing the other first switch. And the gap between the four first switches facing each other is X-shaped.

(17) The invention according to claim 17 is the antenna module according to any one of claims 1 to 6 and 11 to 16, further comprising a ground plane, wherein the plurality of radiating elements are selectively connected to the ground plane. 3 switches are provided.

(18) The invention according to claim 18 is characterized in that the second substrate of the antenna module according to any one of claims 14 to 17 includes at least a part of a front end circuit and a baseband circuit.

(19) According to the nineteenth aspect of the present invention, a third substrate is laminated on the antenna module according to any one of the fourteenth to seventeenth aspects or the wireless module according to the sixteenth aspect, and the third substrate. Has at least a part of a front-end circuit and a baseband circuit.

(20) The invention according to claim 20 is characterized in that the antenna module according to any one of claims 1 to 19 or the radio module according to any one of claims 16 to 17 is used.

(21) The invention according to claim 21. An antenna array including a plurality of radiating elements; a plurality of feeding points that feed power to the plurality of radiating elements; and a first switch that selectively controls connection / disconnection between adjacent radiating elements among the plurality of radiating elements; And a second switch for selectively switching the feed line to the plurality of feed points, and a matching circuit for matching the input impedance of the antenna to the characteristic impedance of the feed line, and frequency switching, polarization switching, directivity A method for controlling an antenna module having at least two functions among the three functions of control, wherein a plurality of radiating elements having different resonance lengths are formed by a combination of conduction / cutoff states of a first switch; A step of selecting the same feeding point from a plurality of feeding points by means of a switch and radiating the same polarization, and a conduction / It characterized by having a step of matching the characteristic impedance of the feed line input impedance of the radiating element formed by the combination of the cross-sectional state.

(22) In the invention described in claim 22, an antenna array composed of a plurality of radiating elements, a plurality of feeding points that feed power to the plurality of radiating elements, and an adjacent radiating element among the plurality of radiating elements are selectively selected. A first switch for connecting / disconnecting to the power supply, a second switch for selectively switching the feed line to the plurality of feed points, and a matching circuit for matching the input impedance of the antenna to the characteristic impedance of the feed line. And a method for controlling an antenna module having at least two of the three functions of frequency switching, polarization switching, and directivity control, wherein a plurality of resonance lengths can be obtained by a combination of conduction / cutoff states of the first switch. A step of forming different rectangular radiating elements; and an excitation direction of the rectangular radiating element formed by conduction of the first switch from the plurality of feeding points. Characterized by a step of emitting the same linear polarization of the excitation direction by selecting the same feeding point located on a perpendicular line at the midpoint of the interlinking sides by said second switch.

(23) In the invention described in claim 23, an antenna array composed of a plurality of radiating elements, a plurality of feeding points that feed power to the plurality of radiating elements, and an adjacent radiating element among the plurality of radiating elements are selectively selected. A first switch for connecting / disconnecting to the power supply, a second switch for selectively switching the feed line to the plurality of feed points, and a matching circuit for matching the input impedance of the antenna to the characteristic impedance of the feed line. A method for controlling an antenna module having at least two of three functions of frequency switching, polarization switching, and directivity control, wherein a plurality of resonance lengths are obtained by a combination of conduction / cutoff states of the first switch. A step of forming different rectangular radiating elements, and a diagonal line of the rectangular radiating elements formed by conduction of the first switch from the plurality of feeding points Characterized by having a step of radiating the elliptically polarized in the same turning direction by selecting the same feeding point and the second switch in.

  According to the antenna module of the first and second aspects, a plurality of radiating elements having different resonance lengths can be formed by a combination of the conduction / cutoff states of the first switch, so that it is possible to cope with multiple frequencies. In addition, polarization switching is realized by selecting the feeding point for supplying current in the direction of generating the desired polarization to the radiating element formed by the combination of the conduction / cutoff state of the first switch. it can.

  Furthermore, since the parasitic element can be arranged adjacent to the radiating element including the feeding point by the combination of the conduction / cutoff state of the first switch, directivity control is possible. Therefore, it can have at least two functions of multi-frequency support, polarization switching, and directivity control.

  In addition, since the matching circuit that can change the constant is provided, the input impedance of the antenna can be matched with the characteristic impedance of the feeder line for a plurality of radiating elements formed by the combination of the conduction / cutoff state of the first switch. As a result, efficient transmission / reception is possible.

  Furthermore, since the same feeding point can be used when radiating the same polarization, the number of feeding points can be reduced.

  According to the antenna module of the third aspect, a plurality of radiating elements having different external shapes can be formed by a combination of conduction / cutoff of the first switch. Here, when the feeding point is selected by the second switch so that the X-direction side has the excitation length for the plurality of radiating elements, linearly polarized waves in the X direction having different frequencies can be radiated.

  Further, when the feeding point is selected by the second switch so that the Y-direction side has the excitation length for the plurality of radiating elements, linearly polarized waves in the Y-direction having different frequencies can be radiated.

  Further, when the feeding point is selected by the second switch so as to excite the elliptically polarized wave with respect to the plurality of radiating elements, elliptically polarized waves having different frequencies can be radiated. As described above, the structure of the present claim enables multi-frequency / polarized wave switching.

  Further, a parasitic element composed of a microstrip antenna can be arranged adjacent to the radiating element including the feeding point by the combination of conduction / cutoff of the first switch. Therefore, changing the shape of the feed element and the shape of the parasitic element to operate the parasitic element as a reflector, loading the reactance to the adjacent parasitic element, and shorting the adjacent parasitic element to the ground plane Directivity control can be realized by the method.

  Furthermore, since the antenna array is composed of a microstrip antenna, the radiating element formed by the combination of the conduction / cutoff state of the first switch can also have a microstrip antenna structure, and the antenna module can be lowered (planarized). .

  In addition, since the microstrip antenna can be excited by an unbalanced current such as a microstrip line or a coplanar line, it can be easily connected to a front-end circuit.

  According to the antenna module of claim 4, the feeding point is on the perpendicular of the midpoint of the side perpendicular to the excitation direction of the radiating element with respect to the rectangular radiating element formed by the combination of conduction and cutoff of the first switch. Therefore, it is possible to efficiently suppress the polarization orthogonal to the desired linear polarization and radiate a good linear polarization.

  Furthermore, since the same feeding point is used, the number of feeding points when radiating linearly polarized waves having different frequencies can be reduced.

  In order to select the same feeding point, the position where the inset feeding is performed changes in the plurality of rectangular radiating elements formed by combining the first switch with the conduction / cutoff state. The radiating element can match the input impedance with the characteristic impedance of the feeder line by appropriately selecting the constant of the matching circuit.

  According to the antenna module of claim 5, when the rectangular radiating element is formed by combining the first switch with the conduction / cutoff state, the feeding point is on the diagonal line of the radiating element, Can emit elliptically polarized waves in the same swiveling direction.

  Furthermore, since the same feeding point can be selected, the number of feeding points can be reduced and more multibands can be handled.

  In order to select the same feeding point, the position where the inset feeding is performed changes in the plurality of rectangular radiating elements formed by combining the first switch with the conduction / cutoff state. The radiating element can match the input impedance with the characteristic impedance of the feeder line by appropriately selecting the constant of the matching circuit.

  According to the antenna module of claim 6, when a rectangular or rectangular radiating element is formed by a combination of conduction / cutoff states of the first switch, the gap surrounded by the four first switches inside the radiating element. Is smaller than in the case of claim 5. As a result, the band of the radiating element can be expanded as compared with the structures of claims 3 to 5.

  According to the antenna module of the seventh aspect, a plurality of strip-shaped radiating elements having different lengths in the longitudinal direction can be formed in two directions of X and Y depending on the combination of conduction / cutoff of the first switch. Here, when the feeding point on the short side is selected by the second switch for the plurality of strip-shaped radiating elements in the X direction, linearly polarized waves in the X direction having different frequencies can be radiated.

  In addition, if a short feed point is selected by the second switch for the plurality of strip-shaped radiation elements in the Y direction, linearly polarized waves in the Y direction having different frequencies can be radiated.

  Furthermore, two strip-shaped radiating elements having the same length in the X and Y directions are simultaneously formed by the combination of conduction / cutoff of the first switch, and a feeding point at the short side of each radiating element. When is selected and a phase difference is given to the current flowing through the feeding point, elliptically polarized waves are emitted. Even in the case of forming elliptically polarized waves, the two strip-shaped radiating elements in the X and Y directions can change the excitation length by the combination of conduction / cutoff of the first switch, and thus can cope with multiple frequencies. As described above, the structure of the present claim enables multi-frequency / polarized wave switching.

  Further, a parasitic element made up of a slot antenna can be arranged adjacent to the radiating element including the feeding point by a combination of conduction / cutoff of the first switch. Therefore, directivity control can be realized by a method of operating the parasitic element as a reflector by changing the shape of the feeder element and the parasitic element.

  Furthermore, since the antenna array is composed of slot antennas, the radiating elements formed by the combination of the conduction / cutoff states of the first switch can also have a slot antenna structure, and the antenna module can be lowered (planarized).

  In addition, since the slot antenna can be excited by an unbalanced current such as a microstrip line or a coplanar line by electromagnetic coupling, it can be easily connected to the front end circuit.

  According to the antenna module of claim 8, the feeding point is in the short direction of the strip-shaped radiating element formed by the combination of the conduction / cutoff state of the first switch. The strip-shaped radiating element formed by the connection of one switch can be excited.

  In addition, since the same feeding point is used, feeding points when linearly polarized waves having different frequencies are radiated can be reduced.

  Further, the strip-shaped radiating element formed by the combination of the conduction / cutoff state of the first switch is connected to a matching circuit whose constant can be changed via the second switch. By appropriate selection, the radiating element can match the input impedance with the characteristic impedance of the feeder line.

  According to the antenna module of claim 9, the two feeding points are in the short direction of the two strip-shaped radiating elements formed by the combination of the conduction / cutoff state of the first switch. Thus, the two strip-shaped radiating elements formed by the connection of the first switch can be excited by the feeding point. Here, when a phase difference is given to the currents flowing through the two feeding points, elliptically polarized waves can be emitted. Even in the case of elliptically polarized waves, the two strip-shaped radiating elements in the X and Y directions can change the excitation length by the combination of conduction / cutoff of the first switch, and thus can cope with multiple frequencies.

  Further, since each feeding point in the short direction of the two strip-shaped radiating elements is selected by the second switch, when radiating elliptically polarized waves having the same turning direction and different frequencies, The number can be reduced.

  Further, the two strip-shaped radiating elements formed by the combination of the conduction / cutoff states of the first switch are connected to a matching circuit whose constant can be changed via the second switch. By appropriately selecting the constants, the radiating element can match the input impedance with the characteristic impedance of the feeder line.

  According to the antenna module of claim 10, when the strip-shaped radiating element is formed by a combination of connection and cutoff states of the first switch, the short dimension of the slot is also provided in the region where the first switch is provided. Is not limited by the width of the first switch and is almost the same as the short slot, and the flow of magnetic current is not limited. Therefore, the band of the radiating element can be expanded more than the structure of claims 7-9.

  According to the antenna module of the eleventh aspect, both the inductor and the capacitor, which are elements constituting the matching circuit, can be varied, and the impedance matching range can be made wider than that of the conventional automatic matching circuit. Also, since a variable phase shifter is not used, if a π-type or T-type matching circuit is configured with a variable inductor and variable capacitor, even if the resistance component of the input impedance of the antenna is greater than 50Ω, the matching locus on the Smith chart is displayed. It can be made relatively short and the matching band is not narrowed.

  In addition, since the variable inductor and the variable capacitor are configured by MEMS, the insertion loss is small, so that efficient transmission / reception is possible. Furthermore, since a fine inductor and capacitor can be realized by MEMS, the matching circuit can be mounted on the back surface of the antenna, and the antenna module can be miniaturized. Furthermore, since the variable capacitor by MEMS can cut off a high frequency signal satisfactorily, it functions as a good variable capacitor even for a signal of about 100 GHz, and a circuit capable of matching to the millimeter wave region can be configured.

  According to the antenna module of the twelfth aspect, the magnetic flux passing through the spiral inductor and the magnetic flux leaking from the spiral inductor can be greatly changed. Therefore, a variable range with a large inductance can be realized.

  According to the antenna module of the thirteenth aspect, since the distance between the first inductor and the second inductor is variable, when the distance between the first inductor and the second inductor is close, the second inductor The generated magnetic flux is transmitted or received through a high-frequency signal, that is, through the first inductor that is a component of the matching circuit, and the interaction between the first inductor and the second inductor is increased, and the apparent The inductance of the upper first inductor increases. On the other hand, when the distance between the first inductor and the second inductor is increased, the interaction between the first inductor and the second inductor is reduced, and the inductance of the first inductor is apparently reduced.

  Thus, the magnitude of mutual coupling can be efficiently changed by controlling the distance between the first inductor and the second inductor. Therefore, the inductance of the first inductor that is a component of the matching circuit can be controlled in a wide range.

  The antenna module according to claim 14, wherein the antenna array and the first switch are provided on a first board, the matching circuit and the second switch are provided on a second board, and the first board and The second substrate is laminated.

  In general, the size of a MEMS switch, variable capacitor, and variable inductor is 1 mm □ or less. On the other hand, since the size of the antenna array is often several mm □ or more, the antenna array and the first switch are provided on the first substrate, and the matching circuit and the second switch are provided on the second substrate. When the substrate and the second substrate are stacked, the matching circuit and the second switch can be integrated in an area corresponding to the area occupied by the antenna array on the second substrate, and the antenna module can be downsized.

  According to the antenna module of the fifteenth aspect, since the first substrate is a glass substrate, and the glass substrate is a substrate capable of performing a MEMS process and has a low dielectric loss tangent, an antenna module with a small loss can be formed. Further, since the glass material is low in cost, the cost of the antenna module can be reduced.

  According to the antenna module of the sixteenth aspect, a structure for realizing an antenna module with a wide bandwidth can be realized, and according to the antenna module according to the seventeenth aspect, a structure for easily giving directivity can be realized.

  According to the radio module of the eighteenth aspect, at least a part of the front end circuit and the baseband circuit is provided on the second substrate. The antenna module is small because the area occupied by the antenna array is almost determined. Therefore, even when at least part of the front-end circuit and the baseband circuit is provided on the second substrate constituting the antenna module, a wireless module that is smaller than the existing wireless module can be realized.

  In addition, since the antenna module has at least two functions of multi-frequency support, polarization switching, and directivity control, the wireless module has the same function. Therefore, a single wireless module can support a plurality of wireless standards. In addition, since directivity can also be controlled, a high gain can be realized by directing a radiation pattern in a predetermined direction even when using one frequency / polarized wave, and good transmission / reception can be performed. Furthermore, good transmission and reception can be performed constantly by switching the frequency, polarization, and directivity depending on the radio wave condition.

  According to the wireless module of the nineteenth aspect, the third substrate is laminated on the antenna module or the wireless module, and the third substrate includes at least a part of the front end circuit and the baseband circuit. The antenna module of the present invention is small because the occupation area is determined by the antenna array. Therefore, even if a third substrate is stacked below the second substrate constituting the antenna module and at least a part of the front-end circuit and baseband circuit is provided, a wireless module that is smaller than existing wireless modules can be realized. it can.

  In addition, since the antenna module has at least two functions of multi-frequency support, polarization switching, and directivity control, the wireless module has the same function. Therefore, a single wireless module can support a plurality of wireless standards. In addition, since directivity can also be controlled, a high gain can be realized by directing a radiation pattern in a predetermined direction even when using one frequency / polarized wave, and good transmission / reception can be performed. Furthermore, good transmission and reception can be performed constantly by switching the frequency, polarization, and directivity depending on the radio wave condition.

  The radio system according to claim 20 has at least two functions of multi-frequency support, polarization switching, and directivity control. Therefore, a single wireless system can support a plurality of wireless standards. In addition, since directivity can also be controlled, a high gain can be realized by directing a radiation pattern in a predetermined direction even when using one frequency / polarized wave, and good transmission / reception can be performed. Furthermore, good transmission and reception can be performed constantly by switching the frequency, polarization, and directivity depending on the radio wave condition.

  According to the control method of claims 21 to 23, an antenna module control method having at least two functions of multi-frequency support, polarization switching, and directivity control can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Example 1>
A first embodiment of the present invention will be described.
FIG. 1A is a diagram illustrating an example of an antenna module of the present invention. FIG. 4A is a top view and FIG. 4B is a cross-sectional view.

  The antenna module according to the present embodiment is an antenna module having three functions of frequency switching, polarization switching, and directivity control. The antenna module includes an antenna array including nine radiating elements (conductors) 11 and three power feeds. In order to match the point (feeding point A12, feeding point B13, feeding point C14) and the input impedance of the antenna with the characteristic impedance of the feeding line, the connection between the plurality of adjacent radiating elements 11 is controlled. There are three first switches 16 and three second switches 17 for switching the three feeding points.

  The matching circuit 15 includes (a) π-type, (b) T-type, and (c) L-type inductance and capacitor connection as shown in FIG. 1D, for example, and the inductance and the constant of the capacitor are variable. It has a configuration. The antenna array is a microstrip antenna array composed of a plurality of rectangular conductors arranged in a matrix.

  When the configuration of the antenna module is described in detail, a ground plane 18 made of a Cu layer is formed on the lower surface of the first substrate 10 made of quartz having a relative dielectric constant of 3.9, and a second ground made of alumina is formed under the ground plane 18. A substrate 19 is laminated. On the upper surface of the first substrate 10, nine rectangular conductors 11 made of a Cu layer are arranged in a matrix. All nine conductors 11 have the same outer shape, the length in the X direction is W1, and the length in the Y direction is L1.

  A first switch 16 made of a MEMS switch is provided between the conductors 11. As shown in detail in FIG. 1-B (a) and its cross-sectional view (b), the first switch 16 has a hinge 163 connected to the upper electrode 161, the lower electrode 162, and the upper electrode 161, and a bias voltage. The upper electrode 161 has a structure that can be moved by a hinge 163, and the nine conductors 11 that constitute the antenna array can be connected by the first switch 16. Yes.

  More specifically, when a bias is applied to the upper electrode 161 of the first switch 16 from the bias line, an electrostatic attractive force is generated between the upper electrode 161 and the lower electrode 162, and the upper electrode 161 moves downward to cause a conductor. 11 is in contact with each other and the adjacent conductors 11 become conductive.

  On the other hand, when the bias of the upper electrode 161 is cut off, the electrostatic attractive force between the upper and lower electrodes disappears, and the upper electrode 161 moves upward due to the rigidity of the hinge 163 and is cut off from the conductor 11 and the adjacent conductors 11 are cut off. . The twelve first switches 16 have the same outer shape and are formed on the first substrate 10.

  Further, three of the nine conductors are provided with feeding points A12 to C14, respectively, and each feeding point is connected to the second substrate 19 by a via penetrating the first substrate 10 and the second substrate 19, and the second feeding point A12 to C14. It is connected to the second switch 17 formed on the substrate 19 and then connected to one matching circuit 15 to supply power.

  The second switch 17 has the same configuration as the first switch 16 and includes a MEMS switch. The second switch 17 includes an upper electrode 171, a lower electrode 172, a hinge connected to the upper electrode 171, and a bias line. Moves by a hinge to switch the feeding point. In the figure, the upper electrode of the second switch is located below the lower electrode, but in this specification, the movable electrode is referred to as the upper electrode.

  When a bias is applied to the upper electrode 171 of the second switch 17 from the bias line, an electrostatic attractive force is generated between the upper electrode 171 and the lower electrode 172, and the upper electrode 171 moves upward to come into contact with the feeder line 20, A desired feeding point can be selected. FIG. 1-C is a diagram showing this state.

  When the bias of the upper electrode 171 is cut off, the electrostatic attractive force between the upper and lower electrodes disappears, and the upper electrode 171 moves downward due to the rigidity of the hinge and is cut off from the power supply line 20. In that case, another feeding point can be selected by bringing another second switch connected to another feeding point into a conductive state.

  The feeding point A12 includes three radiating elements (radiating elements) having different resonance lengths that radiate linearly polarized waves in the Y direction among a plurality of rectangular radiating elements formed by a combination of conduction / cutoff states of the first switch 16. This is a feeding point used for the elements A to C, the details of which will be described with reference to FIG. 2, and is on the vertical line of the midpoint of the side orthogonal to the excitation direction of the three radiating elements A to C.

  The feeding point B13 includes three radiating elements (radiating elements) having different resonance lengths that radiate linearly polarized waves in the X direction among a plurality of rectangular radiating elements formed by a combination of conduction / cutoff states of the first switch 16. D to F, the details of which are used in FIG. 3), which are on the perpendicular line of the midpoint of the side perpendicular to the excitation direction of the three radiating elements D to F.

  The feeding point C14 includes three radiating elements having different resonance lengths (radiation) that radiate elliptically polarized waves in the same turning direction among a plurality of rectangular radiating elements formed by a combination of conduction / cutoff states of the first switch 16. This is a feeding point used for the elements G to I, the details of which are shown in FIG.

The matching circuit 15 is a circuit in which a MEMS variable inductor and a variable capacitor are combined in a π type, and has a structure in which the constant can be varied.
In this embodiment, it is assumed that the second switch 17, the matching circuit 15, and the feeder line 20 are all formed on the second substrate 19.

  Next, the operation of the first switch and the second switch when dealing with multiband and polarization switching will be described in detail.

  In the antenna of the present invention, an array antenna is constituted by nine conductors 11, and has a structure that can form a plurality of rectangular radiating elements having different resonance lengths by a combination of conduction / cutoff states of the first switch 16. When the same polarized wave is radiated, the second switch 17 selects the same feeding point from a plurality of feeding points, and further includes a matching circuit 15 that can change a constant (capacitor capacity and inductor inductance). Therefore, the input impedance of the radiating element formed by the combination of the conduction and cutoff states of the first switch 16 can be matched with the characteristic impedance of the feeder line.

  More specifically, when the linearly polarized wave having the same excitation direction is radiated, the midpoint of the side orthogonal to the excitation direction of the rectangular radiating element formed by the conduction of the first switch 16 from the three feeding points The same feeding point on the vertical line is selected by the second switch 17.

  In addition, when radiating elliptically polarized waves in the same turning direction, the same feeding point on the diagonal line of the rectangular radiating element formed by the conduction of the first switch 16 from the three feeding points A12 to C14. It is selected by the second switch 17.

  For example, the case of emitting linearly polarized waves in the Y direction will be described with reference to FIG. Among the rectangular radiating elements formed by the combination of the conduction / cutoff states of the first switch 16, the rectangular radiating element A including the feeding point A12 and including one conductor in the X direction and one conductor in the Y direction, the feeding point A12. A rectangular radiating element B including three conductors in the X direction and two Y directions, and a rectangular radiating element C including three conductors in the X direction and three Y directions including the feeding point A12 are considered.

  Of the three feeding points, the feeding point A12 is on the perpendicular of the midpoint of the X-direction side of the illustrated conductor, that is, the X of the rectangular radiating element A composed of one conductor in the X direction and one conductor in the Y direction. The feed point B13 is provided on the perpendicular of the midpoint of the Y direction side of any one conductor among the nine conductors, and is provided on the perpendicular of the midpoint of the direction side (that is, W1). Is provided on the diagonal of any one of the nine conductors.

  Considering the size of the three radiating elements formed by the combination of conduction / cutoff of the first switch 16, the length of the radiating elements A, B, C in the excitation direction (that is, the length in the Y direction) is L1, Since L2 and L3, the radiating element A operates as a radiating element having L1 as a half wavelength, the radiating element B operates as a radiating element having approximately L2 as a half wavelength, and the radiating element C has approximately L3 as a half wavelength. Operating as a radiating element. Strictly speaking, in the radiating elements B and C, the opening surrounded by the four first switches inside the radiating element contributes as an inductance component, so that L2 and L3 deviate from a half wavelength.

  The length of the side perpendicular to the excitation direction of the radiating elements A, B, and C (that is, the length in the X direction) is W1 for the radiating element A, and W3 for the radiating elements B and C.

  Further, since the outer shapes of the nine conductors 11 and the twelve first switches 16 are the same, the perpendicular of the midpoint of the side orthogonal to the excitation direction of the radiating element A (that is, W1), the radiating element B The perpendicular of the midpoint of the side orthogonal to the excitation direction (ie, W3) and the perpendicular of the midpoint of the side orthogonal to the excitation direction of the radiating element C (ie, W3) all coincide.

  Here, the feeding point A12 is provided on the vertical line of the midpoint of the side in the X direction of the radiating element A (that is, W1), and the X direction coincides with the direction orthogonal to the excitation direction. It is provided on the perpendicular line of the midpoint of the side orthogonal to the excitation direction of the radiating element A.

  Further, since the perpendicular of the midpoint of the side orthogonal to the excitation direction of the radiating element A and the perpendicular of the midpoint of the side orthogonal to the excitation direction of the radiating elements B and C are common, the feeding point A12 is the radiating element B, It is on the perpendicular of the midpoint of the side orthogonal to the excitation direction with respect to C.

  Therefore, all the first switches 16 are cut off to form the radiating element A, the second switch 17 connected to the feeding point A12 is turned on, and the other second switches 17 are cut off to turn off the feeding point A12. When selected, the feed point A12 is on the perpendicular of the midpoint of the side orthogonal to the excitation direction of the radiating element A, and therefore, the polarization orthogonal to the linear polarization in the Y direction is efficiently suppressed and a good linear polarization is achieved. Can emit waves.

  Even when the input impedance of the radiating element A is different from the characteristic impedance of the feeder line 20, the constant of the radiating element A such as the capacitance of the capacitor and the inductance of the inductor can be changed via the second switch 17. Since the matching circuit 15 is connected, the input impedance of the radiating element A can be matched with the characteristic impedance of the feeder line 20 by appropriately selecting the constant of the matching circuit 15.

  Further, the radiating element B is formed by the combination of the conduction / cutoff state of the first switch 16, the second switch 17 connected to the feeding point A12 is turned on, and the other second switch 17 is cut off to feed power. When the point A12 is selected, the feeding point A12 is on the perpendicular of the midpoint of the side orthogonal to the excitation direction of the radiating element B, and therefore, the polarization orthogonal to the linear polarization in the Y direction is efficiently suppressed and good Can radiate simple linearly polarized waves.

  Further, since the radiating element B has a different input impedance from that of the radiating element A, the radiating element B has an input impedance different from that of the radiating element A. Therefore, the input impedance of the radiating element B can be matched with the characteristic impedance of the feeder line by appropriately selecting the constant of the matching circuit 15.

  Further, the first switch 16 is all turned on to form the radiating element C, the second switch 17 connected to the feeding point A12 is turned on, the other second switch 17 is cut off, and the feeding point A12 is turned off. When selected, the feed point A12 is on the perpendicular of the midpoint of the side orthogonal to the excitation direction of the radiating element C. Therefore, the polarization orthogonal to the linearly polarized wave in the Y direction is efficiently suppressed to achieve a good linear polarization. Can emit waves.

  Further, since the radiating element C has a different input impedance from the radiating elements A and B, the radiating element C has an input impedance different from that of the radiating elements A and B. Therefore, the input impedance of the radiating element C can be matched with the characteristic impedance of the feeder line by appropriately selecting the constant of the matching circuit 15.

Next, the case of emitting linearly polarized waves in the X direction will be described with reference to FIG.
Among the rectangular radiating elements formed by the combination of the conduction / cutoff states of the first switch 16, the rectangular radiating element D including the feeding point B13 and including one conductor in the X direction and one conductor in the Y direction, the feeding point B13. A rectangular radiating element E including two conductors in the X direction and three in the Y direction, and a rectangular radiating element F including three feeders in the X direction and three in the Y direction including the feeding point B13 are considered.

  As for the feeding point, as in FIG. 2, the feeding point A12 is on the vertical line of the midpoint of the X direction of any one of the nine conductors, and the feeding point B13 is the Y of the conductor shown in the figure. Provided on the perpendicular of the midpoint of the direction side (ie, L1), that is, on the perpendicular of the midpoint of the side in the Y direction (ie, L1) of the rectangular radiating element D composed of one conductor in the X direction and one conductor in the Y direction. The feeding point C14 is provided on the diagonal line of any one of the nine conductors.

  Considering the size of the three radiating elements formed by the conduction / cutoff combination of the first switch 16, the length of the radiating elements D, E, F in the excitation direction (that is, the length in the X direction) is W1, Since W2 and W3, the radiating element D operates as a radiating element having W1 as a half wavelength, the radiating element E operates as a radiating element having W2 as a half wavelength, and the radiating element F generally has W3 as a half wavelength. Operating as a radiating element.

  Strictly speaking, in the radiating elements E and F, the opening surrounded by the four first switches 16 inside the radiating element contributes as an inductance component, so that W2 and W3 deviate from a half wavelength.

  The length of the side perpendicular to the excitation direction of the radiating elements D to F (that is, the length in the Y direction) is L1 for the radiating element D, and L3 for the radiating elements E and F.

  Since the nine conductors 11 and the twelve first switches 16 have the same external shape, the perpendicular to the midpoint of the side perpendicular to the excitation direction of the radiating element D (that is, L1) is the same as in FIG. The perpendicular of the midpoint of the side orthogonal to the excitation direction of the radiating element E (ie, L3) and the perpendicular of the midpoint of the side orthogonal to the excitation direction of the radiating element F (ie, L3) all coincide.

  Therefore, when the linearly polarized wave in the X direction is radiated, the feeding point B13 is on the perpendicular of the midpoint of the side orthogonal to the excitation direction of the rectangular radiating elements D to F.

  Accordingly, the radiating elements D, E, and F are respectively formed by combining the first switch 16 with the conduction / cutoff state, the second switch 17 connected to the feeding point B13 is conducted, and the other second switch 17 is established. Is selected and the feed point B13 is selected, the feed point B13 is on the perpendicular of the midpoint of the side perpendicular to the excitation direction of the radiating elements D, E, F. Waves can be suppressed efficiently and good linearly polarized waves can be emitted.

  Further, even when the input impedances of the radiating elements D, E, and F are different from the characteristic impedance of the feeder line, the radiating elements D, E, and F are connected to the matching circuit 15 whose constant can be varied via the second switch 17. Therefore, the input impedance of the radiating elements D, E, and F can be matched with the characteristic impedance of the feeder line by appropriately selecting the constant of the matching circuit 15.

Next, the case of radiating elliptically polarized waves will be described with reference to FIG.
Of the rectangular radiating elements formed by the combination of the conduction / cutoff states of the first switch, the rectangular radiating element G and the feeding point C14 including one feeding point C14 and one conductor in the X direction including the feeding point C14. Consider a rectangular radiating element H that includes two conductors in the X direction and two conductors in the Y direction, and a rectangular radiating element I that includes three conductors in the X direction and three conductors in the Y direction, including the feeding point C14.

  Further, the feeding point A12 is on the perpendicular of the midpoint of the side in the X direction of any one of the nine conductors, and the feeding point B13 is in the Y direction of any one of the nine conductors. The feeding point C14 is provided on the diagonal of the conductor of the illustrated conductor, that is, on the diagonal of the rectangular radiating element G composed of one conductor in the X direction and one conductor in the Y direction. .

  When the microstrip antenna is fed diagonally, two modes are excited with resonance lengths at two orthogonal sides of the microstrip antenna. If the outer shape of the antenna is rectangular, a phase difference occurs between the two modes, and elliptically polarized waves are radiated. Since the radiating element G of the present embodiment has a rectangular outer shape and is fed from a diagonal line, it radiates elliptically polarized waves.

  Considering the size of the three rectangular radiating elements formed by the combination of the conduction / cutoff state of the first switch 6, the lengths of the radiating elements G, H, and I in the Y direction are L1, L2, and L3. The lengths in the X direction are W1, W2, and W3.

  Further, since the nine conductors and the twelve first switches have the same external shape, the diagonal line of the radiating element G, the diagonal line of the radiating element H, and the diagonal line of the radiating element I are on one line.

  Here, since the feeding point C14 is provided on the diagonal line of the rectangular radiating element G composed of one conductor in the X direction and one conductor in the Y direction, the feeding point C14 is also provided for the rectangular radiating elements H and I. It is provided on each diagonal line.

  Therefore, the radiating elements G, H, and I are respectively formed by combining the first switch 16 with the conduction / cutoff state, the second switch 16 connected to the feeding point C14 is turned on, and the other second switch 17 is turned on. When the feeding point C14 is selected by shutting off, the feeding point C14 is on the diagonal line of the radiating elements G, H, and I, and thus can emit elliptically polarized waves in the same turning direction.

  Further, even when the input impedances of the radiating elements G, H, and I are different from the characteristic impedance of the feeder line 20, the radiating elements G, H, and I are connected to the matching circuit 15 whose constant can be changed via the second switch 17. Since they are connected, the input impedance of the radiating elements G, H, and I can be matched with the characteristic impedance of the feeder line 20 by appropriately selecting the constant of the matching circuit 15.

  Note that when the length in the X direction and the length in the Y direction of the rectangular radiating element formed by the connection of the first switch 16 are appropriately adjusted and the phase difference between the two modes is 90 degrees, circularly polarized light is radiated. it can.

  As described above, in the antenna module of the present embodiment, a common feeding point can be used for three rectangular or rectangular radiating elements having different resonance lengths and the same polarization plane, and therefore, as disclosed in Patent Document 4 (USP6198438). In comparison, the number of feeding points can be reduced. Therefore, it can cope with more multibands.

  Further, by switching the feeding point with the second switch 17, it is possible to switch between two directions of linearly polarized waves and elliptically polarized waves while maintaining the multiband function.

  Further, since the matching circuit 15 having a variable constant is provided, the input impedance of the rectangular or rectangular radiating element formed by the combination of the conduction / cutoff state of the first switch 16 is matched with the characteristic impedance of the feeder line 20. Can be efficiently transmitted and received.

  Furthermore, since the rectangular or rectangular radiating element formed by the combination of the conduction / cutoff states of the first switch 16 has a microstrip antenna structure, the antenna module can be lowered (planarized). In addition, it can be excited by an unbalanced current such as a microstrip line or a coplanar line, and can be easily connected to a front-end circuit.

  In FIGS. 1 to 4 described above, the nine conductors and the twelve first switches have the same outer shape, but the conductors constituting the antenna array may be different as long as the outer shape is rectangular. When the plurality of rectangular radiating elements formed by the conduction of the first switch 16 radiate the same linearly polarized wave in the excitation direction, the feeding point is in the side perpendicular to the excitation direction of the plurality of rectangular radiating elements. When a plurality of rectangular radiating elements provided so as to lie on the vertical line of the point and radiating elliptically polarized waves in the same turning direction when a plurality of rectangular radiating elements formed by conduction of the first switch 16 radiate, It is sufficient that one rectangular radiation element is provided on the diagonal line.

  In the present embodiment, a structure capable of supporting three polarized waves and three frequencies by using nine conductors and three feeding points is shown. However, the number of rectangular conductors arranged in a matrix is increased. Then, it becomes possible to apply to more bands.

  In this embodiment, the three linearly polarized waves in the Y direction are fed from the feeding point A12, the three linearly polarized waves in the X direction are fed from the feeding point B13, and the three elliptically polarized waves are fed from the feeding point C14. However, if the number of conductors arranged in a matrix becomes very large, the constant variable range of the matching circuit becomes very wide if all the radiation elements with the same polarization plane are fed from one feeding point. Is not realistic.

  In such a case, a plurality of rectangular radiating elements that are formed by conduction of the first switch 16 and radiate linearly polarized waves in the same excitation direction are blocked in a certain frequency range, and a plurality of rectangles that fall within the block are included. For one radiating element, one feeding point is provided on the perpendicular of the midpoint of the side orthogonal to the excitation direction, and for different blocks, the sides orthogonal to the excitation direction for a plurality of rectangular radiating elements that fall within the corresponding block When a single feed point different from the above is provided on the vertical line of the center point and a radio wave having the same linear polarization is radiated, the feed point may be switched by the second switch.

  Also, when radiating elliptically polarized waves, a plurality of rectangular radiating elements that radiate elliptically polarized waves in the same turning direction are formed in a certain frequency range, as formed by conduction of the first switch as described above, One feeding point is provided on a diagonal line for a plurality of rectangular radiating elements that fall within the block, and one different from the above that is located diagonally for a plurality of rectangular radiating elements that fall within the corresponding block in a different block Even when a radio wave having a plane of polarization in the same turning direction is radiated, the feed point may be selected by the second switch. By such a method, the number of feeding points can be remarkably reduced as compared with Patent Document 4 (USP 6198438), and a very large number of bands can be handled.

Next, a method for controlling directivity will be specifically described.
In the antenna module of the present invention, since the rectangular conductors are arranged in a matrix, a parasitic element can be arranged around the radiating element to be fed by conduction / cutoff of the first switch.

  As a means for switching the directivity, there are a method of changing the shape of the feeding element and the shape of the parasitic element, a method of loading a variable reactance on the parasitic element arranged around the feeding element, and a method of shorting the parasitic element to the ground plane The antenna module of the present invention is known and can adopt the above-described method.

A method for controlling directivity will be described in detail by taking the radiating element D as an example.
FIG. 5 is a diagram for explaining a method of changing the shape of the feeding element and the shape of the parasitic element.

  All four first switches 16 connected to the conductor having the feeding point B13 are cut off to form a rectangular radiating element D, the second switch 17 connected to the feeding point B13 is turned on, and the other When the second switch 17 is cut off and the feeding point B13 is selected, a linearly polarized wave in the X direction with W1 as a half wavelength is radiated.

  Here, when the two first switches that connect the three conductors surrounded by the one-dot chain line in FIG. 5 are turned on, unpaid electrons composed of the three conductors are formed. Since the parasitic element is much longer in the excitation direction than the radiating element D, it operates as a reflector 23 with respect to the radiating element D, and tilts the beam of the radiating element D in the + Y direction from the zenith. As shown in FIG. 5, if the reflector is configured by connecting conductors not connected to the radiating element D by the first switch, the directivity can be controlled in two dimensions of X and Y.

FIG. 6 is a diagram for explaining a method of controlling directivity by loading a variable reactance to a parasitic element arranged around a feeding element.
All four first switches 16 connected to the conductor 11 having the feeding point B13 are cut off to form a rectangular radiating element D, and the second switch 17 connected to the feeding point B13 is turned on. When the second switch 17 is cut off and the feeding point B13 is selected, linearly polarized waves in the X direction with W1 as a half wavelength are emitted.

  Further, the variable reactance 24 is loaded on four conductors adjacent to the radiating element D in the X direction and the Y direction, that is, four conductors surrounded by a one-dot chain line in the drawing.

  When one of the variable reactances 24 loaded on two conductors adjacent to the radiating element D in one direction is inductive and the other is capacitive, the radiating pattern of the radiating element D is the non-inductive side from the zenith direction. Tilt toward the feed element.

  Thus, by loading the variable reactance 24 on the conductor adjacent to the radiating element D and reversing the sign of the variable reactance 24 loaded on the two conductors adjacent to the radiating element D in one direction, , Y can control the directivity in two dimensions. The variable reactance 24 can be configured by connecting a variable capacitor using a varactor or MEMS and a line in series.

  FIG. 7 is a diagram for explaining a method of controlling directivity by short-circuiting a parasitic element arranged around a feeder element with a ground plane.

  All four first switches 16 connected to the conductor having the feeding point B13 are cut off to form a rectangular radiating element D, the second switch 17 connected to the feeding point B13 is turned on, and the other When the second switch 17 is cut off and the feeding point B13 is selected, a linearly polarized wave in the X direction with W1 as a half wavelength is radiated.

  In addition, a third switch 25 that is short-circuited to the ground plane is provided on four conductors adjacent to the radiating element D in the X direction and the Y direction, that is, four conductors surrounded by a one-dot chain line in the drawing.

  When only the third switch 25 on one side of the two conductors adjacent to the radiating element D in one direction is made conductive and short-circuited to the ground plane, the radiation pattern of the radiating element D is not short-circuited to the ground plane from the zenith direction. Tilt to the opposite side of the feed element.

  Thus, by providing the third switch 25 that is short-circuited to the ground plane on the conductor adjacent to the radiating element D, and by short-circuiting only one of the two conductors adjacent to the radiating element D in one direction with the ground plane, X , Y can control the directivity in two dimensions. The third switch 25 can be configured by a PIN diode or a MEMS switch.

  5 to 7 describe the method of controlling the directivity with respect to the radiating element D. However, in the case where the directivity is controlled with the radiating elements A, B, C, E, F, G, H, and I, there are nine methods. The rectangular conductors connected to each other by the first switch 16 are arranged in a matrix form in addition to the conductors of the radiating elements A, B, C, E, F, G, H, and I in FIG. Or a variable reactance is loaded on four parasitic elements adjacent to the radiating element as shown in FIG. 6, or four parasitic elements adjacent to the radiating element as shown in FIG. What is necessary is just to provide the 3rd switch which short-circuits with a ground plane.

  As described above, the antenna module of the present invention has three functions of a multi-frequency switching function, a polarization switching function, and a directivity control function.

  Next, a matching circuit with a variable constant used in the antenna module of this embodiment will be described. The matching circuit of this embodiment is a circuit in which a variable inductor and a variable capacitor by MEMS are combined in a π type.

  In general, the impedance range that can be matched by one matching circuit is determined by the variable range of each element of the matching circuit. Conventional automatic matching circuits are often fixed in a fixed manner, such as a variable capacitor (varactor) and line, or a combination of varactor and balun, and the range that can be matched with one matching circuit is relatively narrow.

  In addition, there are cases where each element is variable, such as a combination of a variable capacitor (varactor) and a variable phase shifter. However, if the resistance component of the input impedance of the antenna is larger than 50Ω, there is a drawback that the matching band becomes narrow. .

  Since both the inductor and the capacitor, which are elements constituting the matching circuit of this embodiment, are variable, the impedance matching range can be made wider than that of the conventional automatic matching circuit.

  In addition, since the matching circuit of this embodiment does not use a variable phase shifter and a π-type matching circuit is configured with a variable inductor and a variable capacitor, even if the resistance component of the antenna input impedance is greater than 50Ω, Smith is required. Since the locus of matching on the chart can be made relatively short, there is an advantage that the band that can be matched is not narrowed.

  Moreover, since the variable inductor and the variable capacitor by MEMS have a small insertion loss, efficient transmission / reception becomes possible.

  Further, since a fine inductor and capacitor can be realized by MEMS, the matching circuit can be mounted on the back surface of the antenna, and the antenna module can be miniaturized.

  Furthermore, since the variable capacitor by MEMS can cut off a high-frequency signal satisfactorily by the capacity due to the air gap, it can function as a good variable capacitor even for a signal of about 100 GHz, and a circuit capable of matching to the millimeter wave region can be configured.

  In this embodiment, a π-type matching circuit is used. However, a T-type matching circuit may be configured by a variable inductor and a variable capacitor using MEMS. Furthermore, when the variation range of the input impedance of the antenna is small, there is a case where it can be applied even with an L-type matching circuit using a variable inductor by MEMS and a variable capacitor, and the matching circuit of the present invention is not necessarily limited to a π-type (FIG. 1). -D).

  Next, the variable capacitor by MEMS which constitutes the matching circuit of this embodiment will be described.

  The variable capacitor of the present embodiment requires a wide variable range in order to cope with a multiband matching circuit, but the conventional MEMS variable capacitor has a variable range of about one digit.

  Therefore, in this embodiment, a plurality of MEMS variable capacitors having different capacitance values are provided on the second substrate, and a method of switching the MEMS variable capacitors by a fourth switch (not shown) is adopted. As a result, a variable capacitor having a variable range of several digits can be easily realized.

  Next, the variable inductor by MEMS which constitutes the matching circuit of this embodiment will be described.

  A variable inductor also requires a wide variable range to support a multi-band matching circuit. However, since a conventional variable inductor can only achieve a variable range of several tens of percent, a plurality of variable inductors such as the MEMS variable capacitor described above can be used. The method of switching the variable inductor with a switch is not realistic.

  A feature of the present invention is that a variable inductor is formed by a spiral inductor composed of a movable wiring and a fixed wiring, and at least one of an inner diameter, an outer diameter or a spiral pitch of the spiral inductor can be varied by moving the movable wiring. is there.

FIG. 8 is a diagram illustrating an example of a variable inductor in the present embodiment.
As shown in the figure, there is a fixed wiring 28 composed of two loops A26 and B27 which are electrically separated and have the same orientation. One end of the loop A26 is connected to a line 29, and one end of the loop B27 is a via hole 30. Is connected to the line 31 in another layer.

  Both ends of the loop A26 and the loop B27 that are not connected to the line are in contact with the movable wiring 32 formed of the loop C opposite to the loop A26 and the loop B27. The movable wiring 32 has a structure that is rubbed in the Y direction within the same plane by a MEMS actuator (not shown).

  When the movable wiring 32 is at the tip of the loop A26 and the loop B27 (FIG. 8A), the outer diameter of the spiral inductor is maximized. Therefore, the magnetic flux that can pass through the spiral inductor is increased to give a large inductor.

  On the other hand, when the movable wiring is rubbed in the + Y direction (FIG. 8B), the outer diameter of the spiral inductor is reduced, the magnetic flux that can pass through the spiral inductor is reduced, and the inductance is reduced.

  Thus, in the structure of FIG. 8, the outer diameter of the spiral inductor can be changed efficiently depending on the position of the movable wiring, so that the magnetic flux passing through the spiral inductor can be greatly changed. Therefore, a larger variable range than the conventional MEMS variable inductor can be obtained.

FIG. 9 is a diagram illustrating another example of the variable inductor.
As shown in the figure, there is a fixed wiring 33 composed of a three-turn spiral inductor, the outer end of the fixed wiring 33 is connected to a line 34, and the inner end is connected to a movable wiring 35 provided above the spiral. -Connected in a bridge structure, the movable wiring 35 is structured to be rubbed in the Y direction in the same plane by a MEMS actuator (not shown) while contacting the area surrounded by the ellipse in the spiral inductor diagram. ing.

  When the movable wiring 35 is at the end of the spiral inductor (FIG. 9A), the inner diameter of the spiral inductor is maximized. As a result, the magnetic flux passing through the spiral inductor increases, giving a large inductance.

  On the other hand, when the movable wiring 35 is rubbed in the −Y direction (FIG. 9B), the inner diameter of the spiral inductor is reduced and the inductance is reduced.

  As described above, in the structure of FIG. 9, the inner diameter of the spiral inductor can be changed efficiently depending on the position of the movable wiring 35, so that the magnetic flux passing through the spiral inductor can be greatly changed. Therefore, a large variable range can be realized.

FIG. 10 is a diagram illustrating another example of the variable inductor.
As shown in the figure, there is a fixed wiring composed of two large and small loops A36 and B37 connected in series and having different directions, and one end of the loop A36 is connected to a line 39 in another layer via a via hole 38. ing.

  One end of the loop B 37 is in contact with one end of the movable wiring 40 formed of the loop C in the same direction as the loop A 36, and the other end of the movable wiring 40 is in contact with the line 41.

  The movable wiring 40 has a structure that can be rubbed in the Y direction on the same plane by a MEMS actuator (not shown).

  When the movable wiring (loop C) 40 is located at the end of the loop B37 (FIG. 10A), the spiral pitch of the spiral inductor is maximized. As a result, the magnetic flux leaking from the spiral inductor increases, resulting in a small inductance.

  On the other hand, when the movable wiring 40 is rubbed in the −Y direction (FIG. 10B), the spiral pitch is reduced, the leakage magnetic flux is reduced, and the inductance is increased.

  In the structure of FIG. 10, since the pitch of the spiral inductor can be efficiently changed depending on the position of the movable wiring 40, the magnetic flux leaking from the spiral inductor can be greatly changed. Therefore, a large variable range is realized.

  The variable inductor of the present invention includes a first inductor through which a high-frequency signal to be transmitted or received passes and a second inductor separated from the first inductor, and the distance between the first inductor and the second inductor is determined. A variable structure may be adopted. FIG. 11 is a diagram showing an example of a variable inductor based on this principle.

  In FIG. 11, a first inductor 42 formed of a loop inductor is a component of a matching circuit, and a high-frequency signal to be transmitted or received passes therethrough. Above the first inductor 42 is a second inductor 43 comprising a loop inductor separated from the first inductor 42, and the second inductor 43 is connected to a current source 45 via a series resistor 44. .

  The second inductor 42 is structured to move in the vertical direction (Z direction) by a MEMS actuator (not shown), and the distance between the first inductor 42 and the second inductor 43 can be varied.

  When the distance between the first inductor 42 and the second inductor 43 is close, the magnetic flux generated by the second inductor 43 passes through the first inductor 42 that is a component of the matching circuit. The interaction between the inductor 42 and the second inductor 43 is increased, and the inductance of the first inductor 42 is apparently increased.

  On the other hand, if the distance between the first inductor 42 and the second inductor 43 is increased, the interaction between the first inductor 42 and the second inductor 43 becomes smaller, and the inductance of the first inductor 42 apparently decreases.

  Thus, in the structure of FIG. 11, the magnitude of the mutual coupling can be efficiently changed by controlling the distance between the first inductor 42 and the second inductor 43. Therefore, the inductance of the first inductor 42 that is a component of the matching circuit can be controlled in a wide range.

  When the matching circuit is configured by the variable inductor having the structure shown in FIGS. 8 to 11 and the MEMS variable capacitor described above, both the inductor and the capacitor can have a large variable range, and therefore the matching is performed in a wide impedance range. It becomes possible.

  As a result, the input impedance of the radiation elements A to I of the present embodiment formed by the combination of the conduction / cutoff state of the first switch can be sufficiently matched with the characteristic impedance of the feeder line.

  The variable inductors in FIGS. 8 to 11 have a structure in which the inductance is controlled by changing one of the outer diameter, inner diameter, spiral pitch of the variable inductor, or the distance from the adjacent second inductor. It does not matter if two or more parameters are controlled at the same time. In that case, the magnetic flux passing through the variable inductor can be changed more greatly by simultaneously controlling two or more parameters, so that a larger variable range can be realized.

  The antenna module according to the present embodiment includes an antenna array in which nine conductors 11 are arranged in a matrix on the first substrate 10 and twelve first switches 16 as described with reference to FIG. The second substrate 19 includes a matching circuit 15 having a variable constant consisting of at least a variable capacitor and a variable inductor by MEMS and a second switch 17 for switching the feeding points A12 to C14. The substrate 19 is laminated.

  In general, the size of a MEMS switch, variable capacitor, and variable inductor is 1 mm □ or less. On the other hand, when considering the size of the antenna array, when one conductor is compatible with 60 GHz millimeter waves, when the relative permittivity of the first substrate 10 is 3.9, it is about 1 mm □, and in the case of nine arrays, the minimum is 3 mm. A degree is required, and the matching circuit 15 and the second switch 17 can all be integrated on the second substrate 19 in an area corresponding to the area occupied by the antenna array.

  If the relative permittivity of the first substrate 10 is increased to increase the wavelength shortening, the size of the antenna array also decreases, but the radiation efficiency of the antenna also decreases at the same time, which is not preferable, and there is a limit to the reduction of the antenna array, The area occupied by the matching circuit 15 and the second switch 17 formed on the second substrate 19 does not significantly increase from the area occupied by the antenna array.

  As described above, in the present embodiment, the first substrate 10 has the antenna array and the first switch 16, and the second substrate 19 has the variable constant matching circuit 15 and the second switch 17, Since the first substrate 10 and the second substrate 19 are laminated, the area of the antenna module is almost determined by the area occupied by the antenna array on the first substrate 10, and the antenna module can be made smaller.

<Example 2>
Next, a second embodiment of the present invention will be described.
FIG. 12 is a diagram showing another example of the antenna module of the present invention. FIG. 4A is a top view of the antenna module, and FIG. 4B is a cross-sectional view thereof.

  The antenna module of the present embodiment is an antenna module having two functions of frequency switching and polarization switching. The antenna module includes an antenna array including nine radiating elements (conductors) 11 and three feeding points A12 to A12. C14, a matching circuit 15 that can change the constant, twelve first switches 16a that connect the radiating elements, and three second switches 17 that switch the three feeding points. ing.

  The feature of the present embodiment is that the first switch has a structure in which the first switch is electrically connected or cut off over almost the entire side of the adjacent rectangular conductor. The antenna array is a microstrip antenna array composed of a plurality of rectangular conductors arranged in a matrix.

  When the configuration of the antenna module is described in detail, a ground plane 18 made of a Cu layer is formed on the lower surface of the first substrate 10 made of Pyrex (registered trademark) glass having a relative dielectric constant of 4.5, and alumina is formed under the ground plane 18. A second substrate 19 made of is laminated. On the upper surface of the first substrate 10, nine rectangular conductors 11 made of a Cu layer are arranged in a matrix.

  All nine conductors have the same outer shape, the length in the X direction is W1, and the length in the Y direction is L1. In addition, a first switch 16 a made of a MEMS switch is provided between the conductors 11.

  The first switch 16a includes an upper electrode 161a, a lower electrode 162a, a hinge (not shown) connected to the upper electrode, and a bias line (not shown). The upper electrode 161a is a side of the adjacent rectangular conductor 11. The nine conductors constituting the antenna array can be connected to each other by the first switch 16a. The twelve first switches 16a have the same outer shape and are formed on the first substrate.

  Further, three of the nine conductors 11 are provided with feeding points A12 to C14, and each feeding point is provided by a via 21 penetrating the first substrate 10 and the second substrate 19 to provide a first feeding point A12 to C14. It is connected to the second switch 17 formed on the second substrate 19 and then connected to one matching circuit 15 to supply power.

  The second switch 17 has the same structure as that of the first embodiment, and includes an upper electrode 171, a lower electrode 172, a hinge (not shown) connected to the upper electrode 171, and a bias line (not shown). Is switched. For the structure of the hinge, refer to FIG.

  Further, among the three feeding points in the antenna array of the present embodiment, the feeding point A12 is the Y direction among the plurality of rectangular radiating elements formed by the combination of the conduction / cutoff state of the first switch 16a. A feeding point used for three radiating elements (radiating elements A to C having the same shape as in FIG. 2) having different resonance lengths that radiate linearly polarized waves, and a side orthogonal to the excitation direction of the three radiating elements A to C It is on the perpendicular of the midpoint.

  The feeding point B13 includes three radiating elements (radiating elements) having different resonance lengths that radiate linearly polarized waves in the X direction among a plurality of rectangular radiating elements formed by a combination of conduction / cutoff states of the first switch 16a. D to F, the same feeding point used in FIG. 3), and is on the vertical line of the middle point of the side orthogonal to the excitation direction of the three radiating elements D to F.

  The feeding point C14 includes three radiating elements (radiating elements G) having different resonance lengths that radiate elliptically polarized waves in the same turning direction among a plurality of rectangular radiating elements formed by a combination of conduction / cutoff states of the first switch. To I, the same shape as in FIG. 4, and is provided on diagonal lines of the three radiating elements G to I.

  In addition, the matching circuit 15 of the present embodiment also includes a circuit in which a variable inductor and a variable capacitor by MEMS are combined in a π type, and has a structure in which a constant can be varied.

  Also in this embodiment, the second switch 17, the matching circuit 15, and the feeder line 20 are all formed on the second substrate 19.

  The operation of the first switch 16a will be described in detail. When a bias is applied from the bias line to the upper electrode 161a of the first switch 16a, an electrostatic attractive force is generated between the upper electrode 161a and the lower electrode 162a, and the upper electrode 161a. Moves downward and contacts the conductor 11.

  Here, since the upper electrode 161a has substantially the same length as the side of the adjacent rectangular conductor 11, the first switch 16a conducts on almost the entire side of the adjacent rectangular conductor 11.

  On the other hand, when the bias of the upper electrode 161a is cut off, the electrostatic attractive force between the upper and lower electrodes disappears, and the upper electrode 161a moves upward by the rigidity of the hinge and is cut off from the conductor 11.

  Here, since the upper electrode 161a has substantially the same length as the side of the adjacent rectangular conductor 11, the first switch 16a is cut off on almost the entire side of the adjacent rectangular conductor 11.

  Therefore, when the rectangular or rectangular radiating elements B, C, E, F, H, and I are formed by the combination of the connection / cutoff states of the first switch 161a as in the first embodiment, that is, linear polarization in the Y direction. A rectangular radiating element B comprising three conductors in the X direction and two conductors in the Y direction, including the feeding point A12, and radiating linearly polarized waves in the Y direction and including the feeding point A12, and three in the X direction. Rectangular radiating element C composed of three conductors 11 in the Y direction, rectangular radiating element E radiating linearly polarized waves in the X direction and including the feeding point B13 and composed of two conductors 11 in the X direction and three conductors in the Y direction, A rectangular radiating element F that radiates linearly polarized waves in the X direction and includes the feed point B and includes three conductors in the X direction and three conductors in the Y direction, two radiating elements that radiate elliptically polarized waves and include the feed point C in the X direction And a rectangular radiating element H consisting of two conductors in the Y direction, radiating elliptically polarized waves In addition, when the rectangular radiating element I including the feeding point C and including three conductors in the X direction and three in the Y direction is formed, the gap surrounded by the four first switches is formed in the radiating element. Smaller than the case. Therefore, the band of the radiating element can be expanded as compared with the first embodiment.

  In this embodiment, the first substrate 10 forming the antenna array is Pyrex (registered trademark) glass. Pyrex (registered trademark) glass is a substrate on which a MEMS process can be performed in the same manner as quartz, and has a dielectric constant equivalent to that of quartz and a low dielectric loss tangent, so that an antenna module with low loss can be formed.

  In addition, since the cost is lower than that of quartz, the cost of the antenna module can be reduced as compared with the first embodiment. Blue plate glass can also be used in the same manner because it can perform a MEMS process and has a dielectric constant equivalent to quartz and a low dielectric loss tangent.

  Since this embodiment also has the matching circuit 15 including the variable capacitor and the variable inductor by the same MEMS as in the first embodiment, the impedance matching range can be made wider than that of the conventional automatic matching circuit.

  Therefore, the input impedance of the radiation elements A to I of this embodiment formed by the combination of the conduction / cutoff state of the first switch can be sufficiently matched with the characteristic impedance of the feeder line.

  In the antenna module of this embodiment, as described with reference to FIG. 12, the first substrate 10 includes an antenna array and a first switch 16a, and the second substrate 19 includes a variable capacitor and a variable inductor formed by MEMS. There are a matching circuit 15 having a variable constant and a second switch 17 for switching the feeding point. Since the first substrate 10 and the second substrate 19 are laminated, the antenna module can be reduced in size.

  Although not described in the present embodiment, when the directivity is controlled by the antenna module of FIG. 12, the method of FIGS. 5 to 7 described in the first embodiment may be used.

  In the present embodiment, as described above, since the upper electrode 161a has substantially the same length as the side of the adjacent rectangular conductor 11, the gap surrounded by the four first switches inside the radiating element is formed in the first embodiment. However, as shown in FIG. 12C, the shape of the tip portion where the four first switches 16a face each other is extended to a V shape, and the gap between the four first switches 16a is increased. By making the X form an X shape, the gap surrounded by the four first switches can be substantially eliminated, and the band can be expanded, which is effective in improving the characteristics.

<Example 3>
Next, a third embodiment of the present invention will be described.
FIG. 13 is a diagram showing another example of the antenna module of the present invention. FIG. 4A is a top view of the antenna module of the present embodiment, and FIG.

  The antenna module of the present embodiment is an antenna module having three functions of frequency switching, polarization switching, and directivity control. The antenna module includes an antenna array including 18 radiating elements (slots) 51 and two antenna modules. Feeding points A52 and B53, a matching circuit 54 capable of changing a constant, and twelve first switches 55 for connecting the radiation elements, and two second switches for switching the two feeding points A switch 56 is provided. The antenna array is a slot antenna array in which three rows of three slots linearly arranged in two orthogonal directions are arranged in three rows.

  When the configuration of the antenna module is described in detail, a ground plate 57 made of a Cu layer is formed on the upper surface of a first substrate 50 made of quartz having a relative dielectric constant of 3.9, and aluminum nitride is formed under the first substrate 50. A second substrate 58 is stacked.

  The base plate 57 has three rows of three slots 51 arranged linearly in two orthogonal directions (that is, two directions of X and Y). The eighteen slots 51 all have the same outer shape, the length in the longitudinal direction is L1, and the length in the short direction is W.

  Further, a first switch 55 made of a MEMS switch is provided between the three slots 51 arranged linearly, and the three slots 51 can be connected by the first switch 55. .

  The first switch 55 includes an upper electrode 551, a lower electrode 552, and a hinge and a bias line connected to the upper electrode 551. The upper electrode 551 has a structure movable by the hinge. . The configuration of the hinge is the same as in FIG.

  The operation of the first switch 55 will be described. When a bias is applied to the upper electrode 551 of the first switch 55 from the bias line, an electrostatic attractive force is generated between the upper electrode 551 and the lower electrode 552, and the upper electrode 551 is moved. It moves downward and short-circuits with the ground plane 57 at both ends of the slot 51 in the short direction, and the slots 51 are separated.

  On the other hand, when the bias of the upper electrode 551 is cut off, the electrostatic attractive force between the upper and lower electrodes disappears, the upper electrode 551 moves upward due to the rigidity of the hinge and is cut off from the ground plane 57, and the adjacent slots are connected. . The external shapes of the twelve first switches 55 are the same and are formed on the first substrate 50.

  A line 59 formed on the surface of the second substrate 58 is provided perpendicular to the slot 51 below the slot 51 in the center of the slot antenna array arranged in three rows in each of the X and Y directions. The slots 51 are electromagnetically coupled to form feed points A52 and BB53.

  The feeding point A52 is connected to a second switch 56 formed on the second substrate 58, and further connected to a matching circuit 54 to supply power. The feeding point B53 is also connected to another second switch 56 on the second substrate 58, and then connected to another matching circuit 54 to supply power.

  In this embodiment, a line that reaches the feeding point via the matching circuit 54 and the second switch 56 is expressed as a feeding line 60. Since the feeder line 60 is surrounded by a second ground plane 61 provided on the lower surface of the second substrate 58 and a ground plane 57 on the upper surface of the first substrate 50, it has a triplate line structure.

  The second switch 56 is also a MEMS switch, and includes a hinge and a bias line connected to the upper electrode 561, the lower electrode 562, and the upper electrode 561. The upper electrode 561 is moved by the hinge and switches a feeding point. That is, when a bias is applied to the upper electrode 561 of the second switch 56 from the bias line, an electrostatic attractive force is generated between the upper electrode 561 and the lower electrode 562, and the upper electrode 561 moves upward to contact the line 59, A desired feeding point can be selected.

  When the bias of the upper electrode 561 is cut off, the electrostatic attractive force between the upper and lower electrodes disappears, and the upper electrode 561 moves downward due to the rigidity of the hinge and is cut off from the line 59.

  In that case, another feeding point can be selected by bringing another second switch connected to the other feeding point into a conductive state. Further, when the two second switches 56 are turned on, two feeding points can be selected simultaneously, and two-point feeding is possible.

  In addition, the matching circuit 54 of this embodiment is composed of a circuit in which a variable inductor and a variable capacitor by MEMS are combined in a T type, and has a structure in which a constant can be varied.

  In this embodiment, it is assumed that the second switch 56, the matching circuit 54, and the feeder line 60 are all formed on the second substrate 58.

  Next, operations of the first switch 55 and the second switch 56 in the case of dealing with multiband and polarization switching will be described.

  The antenna module of the present embodiment is composed of 18 slots 51, and a plurality of strip-shaped radiating elements having different resonance lengths can be formed by a combination of conduction / cutoff states of the first switch 55 in two orthogonal directions. When the same linearly polarized wave in the excitation direction is radiated, the same feeding point in the short direction of the strip-shaped radiating element formed by the connection of the first switch 55 is connected to the second feeding point from the two feeding points. Since the matching circuit 54 which can be selected by the switch 56 and can further change the constant is provided, the input impedance of the radiating element formed by the combination of the conduction / cutoff state of the first switch 55 is set to the power supply line 60. It can be matched to the characteristic impedance.

  In addition, a plurality of strip-shaped radiating elements having different resonance lengths can be formed by a combination of conduction / cutoff states of the first switch 55 in two orthogonal directions. When elliptically polarized light is radiated, resonance occurs in two orthogonal directions. The strip-shaped radiating elements having the same length are formed, and the feeding points in the short direction of the two strip-shaped radiating elements formed by the connection of the first switch 55 are formed from the plurality of feeding points. The matching circuit 54 that can be selected by the switch 56 and can further change the constant can match the input impedance of the radiating element formed by the combination of the conduction / cutoff state of the first switch 55 with the characteristic impedance of the feeder line 60. It is a feature.

  For example, the case of emitting linearly polarized waves in the Y direction will be described with reference to FIG. A feed point A52 in FIG. 14 intersects a slot and a line (not shown, but the line is arranged as shown in FIG. 13) at the center of the slot antenna array arranged in three rows in the Y direction. The feed point B53 is a feed point that is electromagnetically coupled, and the feed point B53 is a feed point that is electromagnetically coupled by intersecting another slot with a slot at the center of the slot antenna array arranged in three rows in the X direction.

  Among strip-shaped radiating elements formed by a combination of conduction / cut-off states of the first switch 55, that is, radiating elements composed of slots connected by the first switch 55, the feed point A52 is included and the Y direction 1 A strip-shaped radiating element A composed of a plurality of slots, a strip-shaped radiating element B composed of two slots 51 including the feeding point A52, and a strip-shaped radiating element B composed of three slots 51 including the feeding point A52. Consider a radiating element C.

  Considering the size of the three radiating elements formed by the combination of the conduction / cutoff state of the first switch 55, the length of the radiating elements A, B, C in the excitation direction (that is, the length in the Y direction) is L1. , L2 and L3, the radiating element A operates as a radiating element having L1 as a half wavelength, the radiating element B operates as a radiating element having approximately L2 as a half wavelength, and the radiating element C approximately has L3 as a half wavelength. It operates as a radiating element. Strictly speaking, since the magnetic current of the radiating elements B and C is limited by the cut-off width when the first switch is cut off from the ground plane, the half wavelength shifts from L2 and L3.

  Here, the line 59 constituting the feeding point A52 is disposed orthogonally to the slot at the center of the slot antenna array disposed in each of the three rows in the Y direction, and is electromagnetically coupled. Therefore, even when the radiating elements B and C are formed by the combination of the conduction / cutoff states of the first switch 55, the line 59 constituting the feeding point A52 is arranged orthogonal to the slots of the radiating elements B and C. Thus, power can be supplied by electromagnetic coupling.

  In other words, all the first switches 55 are short-circuited with the ground plane 57 to form the radiating element A, the second switch 56 connected to the feeding point A52 is turned on, and the other second switches 56 are cut off to feed power. When the point A52 is selected, the feeding point A52 is electromagnetically coupled to the radiating element A, so that a good linearly polarized wave in the Y direction can be emitted.

  Further, even when the input impedance of the radiating element A is different from the characteristic impedance of the feeder line, the radiating element A is connected to the matching circuit 54 whose constant can be changed via the second switch 56. By appropriately selecting the constant, the input impedance of the radiating element A can be matched with the characteristic impedance of the feeder line.

  Further, the radiating element B is formed by the combination of the conduction / cutoff state of the first switch 55, and more specifically, between the three slots in the middle row of the slot antenna array arranged in three rows in the Y direction. Of the two first switches 55 to be connected, the switch in the −Y direction is disconnected from the ground plane 57, and the switch in the + Y direction and all other first switches 55 are short-circuited to the ground plane 57 to connect the radiating element B. When the power supply point A52 is selected when the power supply point A52 is selected by turning on the second switch 56 connected to the power supply point A52 and shutting off the other second switch 56, the power supply point A52 is electromagnetically coupled. A good linearly polarized wave in the Y direction can be emitted.

  Further, since the radiating element B is also connected to the matching circuit 54 whose constant can be changed via the second switch 56, the input impedance of the radiating element B can be set to the power supply line 60 by appropriately selecting the constant of the matching circuit 54. Can be matched with characteristic impedance.

  Further, the radiating element C is formed by a combination of the conduction / cutoff states of the first switch 55, that is, two connecting the three slots in the middle row of the slot antenna array arranged in three rows in the Y direction. Only the first switch 55 is cut off from the ground plate 57, and all the other first switches 55 and the ground plate 57 are short-circuited to form the radiating element C, and the second switch 56 connected to the feeding point A52 is conducted. However, when the other second switch 56 is cut off and the feeding point A52 is selected, the feeding point A52 is electromagnetically coupled with the radiating element C, so that a good linearly polarized wave in the Y direction can be radiated.

  Since the radiating element C is also connected to the matching circuit 54 whose constant can be changed via the second switch 56, the input impedance of the radiating element C can be set to the power supply line 60 by appropriately selecting the constant of the matching circuit 54. Can be matched with characteristic impedance.

  Next, the case of emitting linearly polarized waves in the X direction will be described with reference to FIG. In the figure, feed points A52 are feed points in which slots in the center of the slot antenna array arranged in three rows in the Y direction and the line 59 intersect and electromagnetically coupled, and feed points B53 are arranged in three rows in the X direction. The slot at the center of the slot antenna array is a feeding point where another line (not shown, but the line is arranged as shown in FIG. 13) intersects and is electromagnetically coupled.

  Of the strip-shaped radiating elements formed by the combination of the conduction / cut-off states of the first switch 55, the strip-shaped radiating element D including the feeding point B53 and including one slot in the X direction, the feeding point B53 and the X Consider a strip-shaped radiating element E composed of two slots in the direction, and a strip-shaped radiating element F composed of three slots in the X direction including the feeding point B53.

  Since the length of the three radiating elements D, E, and F formed by the combination of the conduction / cutoff states of the first switch 55 (that is, the length in the X direction) is L1, L2, and L3, radiation is performed. The element D operates as a radiating element having L1 as a half wavelength, the radiating element E operates as a radiating element having L2 as a half wavelength, and the radiating element F operates as a radiating element having L3 as a half wavelength. Strictly speaking, since the magnetic current of the radiating elements E and F is limited by the first switch 55, the half wavelength is shifted from L2 and L3.

  Here, the lines 59 constituting the feeding point B53 are arranged orthogonally to the slots at the center of the slot antenna array arranged in three rows in the X direction, and are electromagnetically coupled. Therefore, even when the radiating elements E and F are formed by the combination of the conduction / cutoff state of the first switch 55, the line 59 constituting the feeding point B53 is arranged orthogonal to the slots of the radiating elements E and F. Thus, power can be supplied by electromagnetic coupling.

  That is, the radiating elements D, E, and F are formed by the combination of conduction / cutoff of the first switch 55, the second switch connected to the feeding point B53 is turned on, and the other second switches are cut off. When the feeding point B is selected, the feeding point B53 is electromagnetically coupled to each of the radiating elements D, E, and F, so that a good linearly polarized wave in the X direction can be emitted.

  Also, when the input impedance of the radiating elements D, E, and F is different from the characteristic impedance of the feeder line, the radiating elements D, E, and F are connected to a matching circuit whose constant can be varied via the second switch. Therefore, the input impedance of the radiating elements D, E, and F can be matched with the characteristic impedance of the feeder line by appropriately selecting the constant of the matching circuit.

Next, the case of emitting elliptically polarized waves will be described with reference to FIG.
14 and 15, the feeding point A52 is a feeding point where a slot at the center of the slot antenna array arranged in each of the three rows in the Y direction intersects with a line (not shown) and is electromagnetically coupled, and the feeding point B53 Is a feed point where a slot at the center of the slot antenna array arranged in three rows in the X direction crosses another line (not shown) and is electromagnetically coupled.

  Among the strip-shaped radiating elements formed by the combination of the conduction / cutoff states of the first switch 55, the strip-shaped radiating element A including the feeding point A52 and including one slot in the Y direction, the feeding point A including Y A strip-shaped radiating element B composed of two slots in the direction, a strip-shaped radiating element C composed of three slots in the Y direction including the feeding point A52, and a strip composed of one slot in the X direction including the feeding point B53. Let us consider a strip-shaped radiating element E including two radiating elements D, a feeding point B53 and two slots in the X direction, and a strip-shaped radiating element F including three feeding slots B53 and the three slots in the X direction.

  The length in the excitation direction (that is, the length in the Y direction) of the three radiating elements A, B, and C that are formed by the combination of the conduction / cutoff state of the first switch 55 and radiate linearly polarized waves in the Y direction is L1. , L2 and L3, the radiating element D operates as a radiating element having L1 as a half wavelength, the radiating element E operates as a radiating element having approximately L2 as a half wavelength, and the radiating element F approximately has L3 as a half wavelength. It operates as a radiating element.

  On the other hand, the lengths of the three radiating elements D, E, and F that radiate linearly polarized waves in the X direction (that is, the lengths in the X direction) are L1, L2, and L3. Radiate linearly polarized waves orthogonal to each other at the same resonance frequency, radiating element E radiates orthogonally polarized waves orthogonal to the radiating element B at the same resonance frequency, and radiating element F is a straight line orthogonal to the radiating element C at the same resonance frequency. It can be seen that it emits polarized light.

  Therefore, a strip-shaped radiating element having the same resonance length is formed by the combination of the conduction / cutoff state of the first switch 55 in two orthogonal directions, and the two switch points A52 and B53 When two feed points A52 and B53 in the short direction of the two strip-shaped radiating elements formed by conduction are selected by the second switch, two orthogonal modes can be excited.

  Here, when a phase difference is given to the currents flowing through the feeding points A52 and B53, the two orthogonal modes generate a phase difference and can radiate elliptically polarized waves. If the phase difference between the currents flowing through the feeding points A52 and B53 is 90 degrees, circular polarization is obtained.

  In addition, the two strip-shaped radiating elements having the same resonance length formed in two orthogonal directions are connected to different matching circuits each having a variable constant, and therefore by appropriately selecting the matching circuit constants. The input impedance of the two strip-shaped radiating elements formed by the combination of the conduction / cutoff state of the first switch in two orthogonal directions can be matched with the characteristic impedance of the feeder line.

  That is, all the first switches 55 are short-circuited to the ground plane 57 to form the radiating element A and the radiating element D in two orthogonal directions, and the feed point A52 in the short direction of the radiating element A and the short side of the radiating element D are formed. When the feeding point B53 in the direction is selected at the same time, two orthogonal modes with L1 as a half wavelength can be excited. Here, when a phase difference is given to the currents flowing through the feeding points A52 and B53, the linearly polarized waves of the radiating elements A and D are combined into an elliptically polarized wave.

  Further, the radiating element B and the radiating element E are formed in two orthogonal directions by a combination of conduction / cutoff of the first switch 55, and the feeding point A 52 in the short direction of the radiating element B and the short direction of the radiating element E When the feeding point B53 at the same time is simultaneously selected and a phase difference is given to the currents flowing through the feeding points A52 and B53, elliptically polarized waves having a resonance frequency different from that of the elliptically polarized waves produced by the radiating elements A and D can be radiated.

  Further, the radiating element C and the radiating element F are formed in two orthogonal directions by the combination of conduction / cutoff of the first switch 55, and the feed point A 52 in the short direction of the radiating element C and the short direction of the radiating element F When the feeding point B53 in the above is simultaneously selected and a phase difference is given to the currents flowing through the feeding points A and B, an ellipse having a resonance frequency different from the elliptical polarization generated by the radiating elements A and D and the radiating elements B and E Polarized light can be emitted.

  Further, since the radiating elements A and D, the radiating elements B and E, and the radiating elements C and F are connected to different matching circuits, the radiating elements A and D, the radiating elements B and E, and the radiating elements C and F are connected. Both can match the input impedance of the antenna with the characteristic impedance of the feeder.

  As described above, in the antenna module of this embodiment, the three strip-shaped radiating elements having different resonance lengths and the same linear polarization polarization can use a common feeding point, and have elliptical polarization in the same turning direction. A common feeding point can also be used when radiating elements having different resonance lengths are formed. Therefore, the number of feeding points can be reduced as compared with Patent Document 4 (USP6198438), and more multibands can be handled.

  Further, by switching the feeding point with the second switch, it is possible to switch the two directions of linearly polarized waves while maintaining the multiband function. Furthermore, if two feeding points are selected simultaneously and a phase difference is given to the current flowing through the feeding point, elliptically polarized waves can be emitted. Thus, the antenna module of the present embodiment can realize multiband and polarization control by a combination of conduction / cutoff of the first switch and the second switch.

  In addition, since it has a matching circuit that can change the constant, the input impedance of the strip-shaped radiating element formed by the combination of the conduction and cutoff states of the first switch can be matched with the characteristic impedance of the feeder line, which is efficient. Can be sent and received.

  Furthermore, since the strip-shaped radiating element formed by the combination of the conduction / cutoff state of the first switch 55 has a slot antenna structure, the antenna module can be lowered (planarized). In addition, it can be excited by an unbalanced current by using electromagnetic coupling, and can be easily connected to the front-end circuit.

  13 to 16, the eighteen slots 51 and the twelve first switches 55 have the same outer shape, but the slots constituting the antenna array need not have the same outer shape.

  In the present embodiment, a structure capable of supporting three polarizations and three frequencies by using 18 slots 51 and two feeding points is shown. However, if the number of slots arranged in two orthogonal directions is increased. It can be applied to more bands.

  In this embodiment, the three linearly polarized waves in the Y direction are fed from the feeding point A52, the three linearly polarized waves in the X direction are fed from the feeding point B53, and the three elliptically polarized waves are fed from the feeding points A52 and B53. Although it is structured to be fed, if the number of slots arranged in two orthogonal directions is very large, feeding all radiating elements with the same polarization plane from one feeding point will result in a very constant variable range of the matching circuit. Widen and not realistic.

  In such a case, a strip-shaped radiating element which is formed by conduction of the first switch 55 and radiates linearly polarized waves in the same excitation direction is blocked in a certain frequency range, and a plurality of strip-shaped elements entering the block are formed. Provide one common feed point in the short direction for the radiating element, and provide another common feed point in the short direction for multiple strip-shaped radiating elements that fall within the corresponding block in different blocks. When the same linearly polarized wave is radiated, the feeding point may be switched by the second switch.

  Even when elliptically polarized waves are radiated, a pair of strip-shaped radiating elements that radiate elliptically polarized waves in the same turning direction are blocked in a certain frequency range, and a common feeding point is provided for each block. Even when a radio wave having a wavefront is radiated, the feeding point may be switched by the second switch.

  If such a method is used, the number of feeding points becomes very small, and more bands can be handled.

Next, a method for controlling directivity will be described.
Since the antenna module of the present embodiment has a plurality of rows of a plurality of slots linearly arranged in two orthogonal directions, parasitic elements are arranged on both sides of the radiating element to be fed by conduction / cutoff of the first switch. be able to. Therefore, directivity control can be realized by changing the shape of the feed element and the shape of the parasitic element.

  Taking the radiating element D as an example, a method for controlling directivity according to FIG. 17 will be described in detail. The two first switches 55 connected to the slot 51 having the feeding point B52 are all short-circuited with the ground plane 57 to form a strip-shaped radiating element D, and the second switch connected to the feeding point B53 is made conductive. When the other second switch is cut off and the feeding point B53 is selected, linearly polarized waves in the X direction with L1 as a half wavelength are radiated.

  Here, when the two first switches 55 connecting the three slots surrounded by the one-dot chain line in the figure are disconnected from the ground plane 57, unpaid electrons consisting of the three slots are formed.

  Since the parasitic element is much longer in the excitation direction than the radiating element D, it operates as a reflector with respect to the radiating element D, and tilts the beam of the radiator D in the + Y direction from the zenith. As shown in FIG. 17, when the reflectors are configured by connecting slots having the same orientation as the radiating element D by the first switch 55, the directivity can be switched in the X direction.

  When directivity is controlled in the X direction, the number of slots 51 arranged in a straight line is increased, and the first switch 55 is turned on / off in the X direction with respect to the feed element by the conduction / cutoff combination. An element is formed, and the excitation length of the parasitic element may be longer than the excitation length of the feed element.

  For the radiating element A, the above-described method can be used, and when it is desired to switch the directivity in two dimensions in all of the radiating elements A to F, parasitic elements adjacent to the feeding element in the X direction and the Y direction can be used. The number and arrangement of the slots and the length in the longitudinal direction may be adjusted so that the parasitic element is formed longer than the feeder element.

  As described above, the antenna module of the present invention can simultaneously realize the three functions of multi-frequency switching, polarization switching, and directivity control.

  Since this embodiment also has a matching circuit composed of a variable capacitor and a variable inductor by MEMS as in the first and second embodiments, the impedance matching range can be made wider than that of a conventional automatic matching circuit.

  Therefore, the input impedance of the radiation elements A to F of the present embodiment formed by the combination of the conduction / cutoff state of the first switch 55 can be sufficiently matched with the characteristic impedance of the feeder line.

  Also in the antenna module of this embodiment, the first substrate has an antenna array and a first switch, and the second substrate has a matching circuit having a variable constant consisting of a variable capacitor and a variable inductor by MEMS and a power supply. There is a second switch for switching the points, and the first substrate and the second substrate are stacked, so that the antenna module can be reduced in size.

<Example 4>
Next, a fourth embodiment of the present invention will be described.
FIG. 18 is a diagram showing another example of the antenna module of the present invention. FIG. 5A is a top view of the antenna module of the present embodiment, and FIG.

  The antenna module of this embodiment is also an antenna module having two functions of frequency switching and polarization switching. The antenna module includes an antenna array including 18 radiating elements (slots) 51, and two feeding points A52 and B53. And having 12 matching first switches 55a for connecting between the radiating elements and 2nd second switches 56 for switching between the two feeding points. Yes.

  A feature of this embodiment is that the first switch 55a has a structure in which adjacent slots are connected to almost the entire short surface of the slot.

  When the configuration of the antenna module is described in detail, when the configuration of the antenna module is described in detail, a ground plane 57 made of a Cu layer is formed on the upper surface of the first substrate 50 made of Pyrex (registered trademark) having a relative dielectric constant of 4.5. A second substrate 58 made of alumina is laminated under the first substrate 50.

  The base plate 57 has three rows of three slots 51 arranged linearly in two orthogonal directions (that is, two directions of X and Y). The eighteen slots 51 all have the same outer shape, the length in the longitudinal direction is L1, and the length in the short direction is W.

  In addition, a first switch 55a composed of a MEMS switch is provided between three linearly arranged slots, and the three slots 51 can be connected by the first switch 55a.

  The first switch 55a separates the slots 51, and includes an upper electrode 551a, a lower electrode 552a, a hinge connected to the upper electrode 551a, and a bias line made of a conductor having substantially the same length as the short side of the slot. It has a function to connect or separate between slots arranged in a straight line. The external shapes of the twelve first switches 55a are all the same and are formed on the first substrate 50.

  Also, feed points A52 and B53 that are electromagnetically coupled to the line 59 formed on the surface of the second substrate 58 are provided below the slots at the center of the slot antenna array arranged in three rows in the X and Y directions. is there.

  The feeding points A52 and B53 are connected to respective second switches 56 formed on the second substrate 58, and are further connected to different matching circuits 54 to supply power.

  In this embodiment, the line 59 that reaches the feeding point via the matching circuit 54 and the second switch 56 is also expressed as a feeding line 60. Since the feeder line 60 is surrounded by a second ground plane 61 provided on the lower surface of the second substrate 58 and a ground plane 57 on the upper surface of the first substrate 50, it has a triplate line structure.

  The second switch 56 is also a MEMS switch, and includes a hinge and a bias line connected to the upper electrode 561, the lower electrode 562, and the upper electrode 561, and has a function of switching a feeding point. Further, when the two second switches 56 are turned on, two feeding points can be selected at the same time, and two-point feeding is possible.

  Similarly to the third embodiment, the matching circuit 54 is composed of a circuit in which a variable inductor and a variable capacitor by MEMS are combined in a T type, and has a structure in which a constant can be varied.

  In this embodiment, it is assumed that the second switch 56, the matching circuit 54, and the feeder line 60 are all formed on the second substrate 58.

  The operation of the first switch 55a will be described in detail. When a bias is applied from the bias line to the upper electrode 551a of the first switch 55a, an electrostatic attractive force is generated between the upper electrode 551a and the lower electrode 552a. 551a moves downward, and short-circuits with the ground plane 57 at both ends in the short direction of the slot, so that each slot 51 is separated.

  On the other hand, when the bias of the upper electrode 551a is cut off, the electrostatic attractive force between the upper and lower electrodes disappears, the upper electrode 551a moves upward due to the rigidity of the hinge and is cut off from the ground plane, and the adjacent slots are connected.

  Here, since the upper electrode 551a is made of a conductor having substantially the same length as the short slot, adjacent slots are connected to almost the entire short slot.

  Therefore, as in the third embodiment, when the strip-shaped radiating elements B, C, E, and F are formed by the combination of the connection / cutoff state of the first switch 55a, that is, the linearly polarized wave in the Y direction is radiated and A strip-shaped radiating element B including the feeding point A and including two slots in the Y direction, and a strip-shaped radiating element radiating linearly polarized waves in the Y direction and including the feeding point A and including three slots in the Y direction. C, a strip-shaped radiating element E that radiates linearly polarized waves in the X direction and includes the feeding point B and includes two slots in the X direction, radiates linearly polarized waves in the X direction and includes the feeding point B, and the X direction 3 When the rectangular rectangular radiating element F is formed of the slots, the short dimension of the slot is not limited by the width of the first switch even in the region where the first switch is provided, and is almost W. Magnetic flow is less likely to be restricted. Therefore, the band of the radiating element can be expanded as compared with the third embodiment.

  In this embodiment, the first substrate 50 forming the antenna array is Pyrex (registered trademark) glass. Pyrex (registered trademark) glass is a substrate on which a MEMS process can be performed in the same manner as quartz, and has a dielectric constant equivalent to that of quartz and a low dielectric loss tangent, so that an antenna module with low cost and low loss can be formed.

  Furthermore, since this embodiment also has a matching circuit composed of a variable capacitor and a variable inductor using the same MEMS as in the first to third embodiments, the impedance matching range can be made wider than that of a conventional automatic matching circuit.

  Therefore, the input impedance of the radiation elements A to F of the present embodiment formed by the combination of the conduction / cutoff state of the first switch can be sufficiently matched with the characteristic impedance of the feeder line.

  Also, in the antenna module of this embodiment, as described with reference to FIG. 18, the first substrate 50 has an antenna array and a first switch 55a, and the second substrate 58 includes a variable capacitor by MEMS and a variable inductor. There are a matching circuit 54 having a variable constant and a second switch 56 for switching the feeding point. Since the first substrate 50 and the second substrate 58 are laminated, the antenna module can be reduced in size.

  Also in the antenna module of the present embodiment, the method of FIG. 17 described in the third embodiment can be used to control the directivity.

<Example 5>
Next, an embodiment of the wireless module of the present invention will be described.
FIG. 19 is a diagram illustrating an example of a wireless module according to the present invention. This embodiment has a structure in which a third substrate 62 made of a porous polyimide substrate is laminated on the lower layer of the antenna module shown in FIG. 7, and the front-end circuit 63 is formed on the third substrate 62 using chip parts. The front end circuit 63 and the antenna module are connected by a via hole 64 that is configured and penetrates the third substrate 62.

  That is, the antenna array and the first switch 16 are provided on the first substrate 10, the matching circuit 15 and the second switch 17 are provided on the second substrate 19, and the third substrate 62 is provided. The front end circuit 63 is configured using chip parts, and the first, second, and third substrates are stacked.

  In the antenna module used in this embodiment, the third switch 62 that is short-circuited to the ground plane is formed on a conductor adjacent to the radiating element D only, but the radiating element D can be controlled in directivity. Since the radiating elements A, B, C, E, F, G, and I do not have the above structure, the directivity cannot be switched.

  Since the radio module of the present embodiment uses the anten module of FIG. 7, it is possible to cope with multiple frequencies, switch polarization, and control directivity. Therefore, a single wireless module can support a plurality of wireless standards.

  Further, in this embodiment, a third substrate 62 is stacked below the antenna module, that is, below the second substrate 19, and the first substrate 16 is formed on the third substrate 62 by a combination of conduction / cutoff states. Since the front end circuit 63 for the radiating elements A to I is provided, a small wireless module can be realized.

  In the present embodiment, only the front end circuit 63 is mounted on the third substrate 62. However, both the front end circuit 63 and the baseband circuit may be mounted, or a part of the front end circuit 63 and the baseband circuit may be mounted. Even if is mounted, the wireless module can be reduced in size.

  In the present embodiment, a third substrate 62 is stacked below the second substrate 19, and the radiation elements A to I are formed on the third substrate 62 by a combination of conduction / cutoff states of the first switch 16. However, if there is a space on the second substrate 19, the same effect can be expected even if the front end circuit 63 and a part of the baseband circuit are mounted on the second substrate 19. it can.

Next, the wireless system of the present invention will be described.
FIG. 20 is a diagram illustrating an example of a wireless system according to the present invention. In this embodiment, the antenna module of FIG. 7 is used, and the antenna module 70 is connected to a transmission / reception changeover switch 74 for switching between a multi-frequency transmission system and a reception system.

  According to the desired frequency, polarization, and directivity, the control circuit 75 sets the conduction / cutoff combination of the first, second, and third switches and the constants of the variable capacitor and variable inductor of the π-type matching circuit.

  Thereafter, a control signal A is supplied from the control circuit 75 to the bias generation circuit 78 of the first switch to generate a predetermined bias, the first switch is turned on / off, and the radiating elements A to I are formed in the antenna array. To do.

  Further, a control signal B is supplied from the control circuit 75 to the bias generation circuit 79 of the second switch to generate a predetermined bias, and the second switch is turned on or off to remove one from the feeding points A, B, C. Select and determine the direction of polarization.

  Further, a control signal C is supplied from the control circuit 75 to the bias generating circuit 80 of the third switch for the radiating element D to generate a predetermined bias, the third switch is turned on and off, and is short-circuited to the ground plane. The parasitic element is switched to perform beam switching in the XY directions.

  The control signal D is supplied from the control control circuit 75 to the variable capacitor / variable inductor control circuit 76.

  In the variable capacitor control circuit, a bias for controlling only a fourth switch connected to a desired variable capacitor and a bias for controlling a constant of the variable capacitor are generated, and a desired variable is selected from a plurality of variable capacitors by the fourth switch. Select a capacitor and change the constant.

  Further, the variable inductor control circuit generates a predetermined bias and drives a MEMS actuator attached to the movable wiring of the variable inductor to obtain a desired inductor. Thereby, the constant of the matching circuit is changed to match the input impedance of the radiating elements A to I with the characteristic impedance of the feeder line.

  Further, in consideration of the transmission or reception mode, a control signal E is supplied from the control circuit 75 to the transmission / reception selector switch control circuit 77 to generate a predetermined bias, and the switch 74 corresponding to transmission or reception of the radiating elements A to I is turned on. The antenna module 70 and the front end circuit 63 are electrically connected to perform transmission / reception.

  In the above embodiment, the bias generation circuits 78 to 80 are provided to control the first to third switches. However, such a bias generation circuit is not provided, and the control signals A to C from the control circuit 75 are provided. Thus, the connection / cutoff control of the first to third switches may be performed directly.

  As described above, the wireless system of the present embodiment supports three frequencies and three polarizations, and the directivity can be switched for some radio waves. Therefore, one radio system can cope with the standards of three frequencies and three polarizations, and the radio system itself can be downsized.

  In addition, since directivity can also be controlled, a high gain can be realized by directing a radiation pattern in a predetermined direction even when using one frequency / polarized wave, and good transmission / reception can be performed. Furthermore, good transmission and reception can be performed continuously by switching the frequency, polarization, and directivity according to the radio wave condition.

Another example of the wireless system according to the present invention will be described.
FIG. 21 is a diagram illustrating another example of the wireless system of the present invention. In FIG. 21, when a plurality of radiating elements are formed by a combination of conduction / cutoff states of the first switch, a control signal D is supplied from the control circuit 75 to the variable capacitor / variable inductor control circuit 76 and the constants of the variable capacitor and the variable inductor. In the transmission mode, the reflected wave from the antenna array 71 is detected by the reflected wave detection circuit 151, and the optimum constant of the matching circuit 15 is obtained by the automatic impedance control circuit 152 according to the reflected wave, and the matching circuit An automatic matching circuit 150 for controlling the constants of 15 variable capacitors and variable inductors is provided.

  In the wireless system of FIG. 21, even when the input impedance of the antenna array changes due to the external environment, the input impedance of the antenna array 71 can be matched with the characteristic impedance of the feeder line by the automatic matching circuit 150. become able to.

  Although the present embodiment has been described with respect to a wireless system capable of transmitting and receiving, since the effect of the present invention can be expected even with a reception-only wireless system, a reception-only and transmission-only wireless system is also included in the present invention. To do.

It is a figure which shows an example of the antenna module of this invention. It is a figure which shows the structure of a hinge. It is a figure which shows the connection of a feeding point, a 2nd switch, and a matching circuit. It is a figure which shows the structural example of the matching circuit which consists of a variable capacitor and a variable inductor. It is a figure explaining the multi-frequency response | compatibility of the antenna module of Example 1, and polarization switching. It is a figure explaining the multi-frequency response | compatibility of the antenna module of Example 1, and polarization switching. It is a figure explaining the multi-frequency response | compatibility of the antenna module of Example 1, and polarization switching. It is a figure explaining the directivity control of the antenna module of Example 1. FIG. It is a figure explaining the directivity control of the antenna module of Example 1. FIG. It is a figure explaining the directivity control of the antenna module of Example 1. FIG. It is a figure which shows an example of the variable inductor of this invention. It is a figure which shows another example of the variable inductor of this invention. It is a figure which shows another example of the variable inductor of this invention. It is a figure which shows another example of the variable inductor of this invention. It is a figure which shows another example of the antenna module of this invention. It is a figure which shows another example of the antenna module of this invention. It is a figure explaining the multi-frequency response | compatibility of the antenna module of Example 3, and polarization switching. It is a figure explaining the multi-frequency response | compatibility of the antenna module of Example 3, and polarization switching. It is a figure explaining the multi-frequency response | compatibility of the antenna module of Example 3, and polarization switching. It is a figure explaining the directivity control of the antenna module of Example 3. FIG. It is a figure which shows another example of the antenna module of this invention. It is a figure which shows another example of the radio | wireless module of this invention. It is a figure which shows an example of the radio | wireless system of this invention. It is a figure which shows another example of the radio | wireless system of this invention. It is a figure which shows the prior art example (Unexamined-Japanese-Patent No. 2000-236209) of an antenna. It is a figure which shows the prior art example (Unexamined-Japanese-Patent No. 2002-261533) of an antenna. It is a figure which shows the prior art example (Unexamined-Japanese-Patent No. 2003-124730) of an antenna. It is a figure which shows the prior art example (USP (US Patent) 6198438) of an antenna. It is a figure which shows the prior art example (GTRI Prototype Aperture Antenna) of an antenna. It is a figure which shows the prior art example (Unexamined-Japanese-Patent No. 2003-68571) of a variable inductor. It is a figure which shows the prior art example (on-chip RF variable inductor) of a variable inductor. It is a figure which shows the conventional example (Self-Asembling MEMS Variable Inductor) of a variable inductor. It is a figure which shows the prior art example (Polarization Reconfigurable Patch Antenna) of an antenna. It is a figure which shows the prior art example (polarization switching microstrip antenna) of an antenna. It is a figure which shows the prior art example (Unexamined-Japanese-Patent No. 2001-36337) of an antenna. It is a figure which shows the prior art example (Unexamined-Japanese-Patent No. 6-112727) of an antenna. It is a figure which shows the prior art example (Unexamined-Japanese-Patent No. 10-154911, Unexamined-Japanese-Patent No. 2002-325012) of an antenna. It is a figure which shows the prior art example (Electronically Steering Yagi-Uda Microstrip Patch Antenna array) of an antenna. It is a figure which shows the prior art example (Electronic beam steering using switched parasitic patch elements) of an antenna. It is a figure which shows the prior art example (microstrip array antenna for beam shaping | molding) of an antenna.

Explanation of symbols

10, 50: First substrate 11: Radiation element (conductor)
12, 52: Feeding point A
13, 53: Feeding point B
14: Feed point C
15, 54: Matching circuit 16, 16a, 55, 55a: First switch 161, 161a, 551, 551a: Upper electrode 162, 162a, 552, 552a: Lower electrode 163: Hinge 17, 17a, 56: Second Switches 171, 171a, 561: Upper electrodes 172, 172a, 562: Lower electrodes 18, 57: Ground plate 19, 58: Second substrate 20, 60: Feed line 24: Variable reactance 25: Third switches 26, 36: Loop A
27, 37: Loop B
28, 33: Fixed wiring 29, 34, 41, 59: Line 30, 38: Via hole 31, 39: Line in other layer 32, 40: Movable wiring (loop C)
42: first inductor 43: second inductor 44: resistor 45: current source 51: slot 61: second ground plane 62: third substrate 63: front end circuit 64: via 70: antenna module 71: microstrip Antenna array 72: Radiation elements A to I transmission system 73: Radiation elements A to I reception system 74: Transmission / reception changeover switch 75: Control circuit 76: Variable capacitor, variable inductor control circuit 77: Transmission / reception changeover switch control circuit 78: First Switch bias generation circuit 79: Bias generation circuit of the second switch 80: Bias generation circuit of the third switch 150: Automatic matching circuit 151: Reflected wave detection circuit 152: Automatic impedance control circuit 101: Metal strip 102: PIN diode 211: Antenna part 212: Wiring board 213: Gras De Pattern 214: RF module 218: antenna element pattern 219: feed point (feed pattern)
220a to 220d: grounding points 221a to 221d: switch 300: antenna structure 305: short-circuit plane 310: sub-antenna structure 320: first radiating element 322: first end 324: feed line 330: second radiating element 332 : Second end 334: spacing 340: third radiating element 342: third end 350: feed line 360, 362: switch 370, 372: radio frequency module A 1, A 2: aperture 400: radiating element 405: High-frequency feeding point 410: Low-frequency feeding point 420: MEMS switch 500: Insulating substrate 510: Conductor (radiating element)
520: FET switch 530: Feed point 600: Patch antenna 601: MEMS actuator 602: Feed line 616a, 616b: Connection terminal 622: Insulator layer 630: Switch element 640A: Variable inductor 642, 643: Conductor plate 691: Transmission line (Spiral inductor)
700: Patch 701, 702: Slot 703, 704: Diode 710: Microstrip line 800: Feeding element 801: Parasitic element 802: Capacitor 803: Ground plane 804: Switch circuit 810: Dielectric 811: Ground plane 812: Toroidal radiation conductor 813: Diode 820: Feeding element 821: Parasitic element

Claims (23)

An antenna module having at least two functions among the three functions of frequency switching, polarization switching, and directivity control,
An antenna array including a plurality of radiating elements; a plurality of feeding points that feed power to the plurality of radiating elements; and a first switch that selectively controls connection / disconnection between adjacent radiating elements among the plurality of radiating elements; An antenna comprising: a second switch that selectively switches a feeding line to the plurality of feeding points; and a matching circuit that can vary a constant for matching the input impedance of the antenna to the characteristic impedance of the feeding line. module. The antenna module according to claim 1, wherein
The antenna array has a structure in which a plurality of radiating elements having different resonance lengths are formed by a combination of conduction / cutoff states of the first switch, and when the same polarization is radiated, Selecting the same feeding point from a plurality of feeding points, and further matching the input impedance of the radiating element formed by the combination of the conduction / cutoff state of the first switch by the matching circuit with the characteristic impedance of the feeding line. A featured antenna module. The antenna module according to claim 1 or 2,
The antenna module is a microstrip antenna array comprising a plurality of rectangular conductors arranged in a matrix. The antenna module according to claim 3, wherein
The antenna array has a structure in which a plurality of rectangular radiating elements having different resonance lengths are formed by a combination of conduction / cutoff states of the first switch and radiates linearly polarized waves having the same excitation direction. From the plurality of feeding points, the same feeding point that is on the perpendicular of the midpoint of the side perpendicular to the excitation direction of the rectangular radiating element formed by the conduction of the first switch is selected by the second switch. An antenna module characterized by that. The antenna module according to claim 3, wherein
The antenna array has a structure in which rectangular radiation elements having different resonance lengths are formed by a combination of conduction / cutoff states of the first switch and radiates elliptically polarized waves in the same turning direction. The antenna module, wherein the second switch selects the same feed point on a diagonal line of a rectangular radiating element formed by conduction of the first switch from the plurality of feed points. The antenna module according to any one of claims 3 to 5,
The antenna module according to claim 1, wherein the first switch has a structure in which the first switch is electrically connected or cut off over substantially the entire side of the adjacent rectangular conductor. The antenna module according to claim 1 or 2,
2. The antenna module according to claim 1, wherein the antenna array is a slot antenna array having a plurality of rows of a plurality of slots linearly arranged in two orthogonal directions. The antenna module according to claim 7, wherein
The antenna array has a structure in which a plurality of strip-like radiating elements having different resonance lengths are formed by a combination of conduction / cutoff states of the first switch in two orthogonal directions, and the linearly polarized waves having the same excitation direction When the second switch is used, the same feeding point in the short direction of the strip-shaped radiation element formed by the connection of the first switch is selected from the plurality of feeding points. A featured antenna module. The antenna module according to claim 7, wherein
The antenna array has a structure in which a plurality of strip-shaped radiating elements having different resonance lengths are formed by a combination of conduction / cutoff states of the first switch in two orthogonal directions, and radiates elliptically polarized waves Forms a strip-shaped radiating element having the same resonance length in two orthogonal directions, and further, a short of the two strip-shaped radiating elements formed by connecting the first switch from the plurality of feeding points. An antenna module, wherein each feeding point in a hand direction is selected by the second switch. The antenna module according to any one of claims 7 to 9,
An antenna module having a structure in which slots adjacent to each other by the first switch are connected to almost the entire short surface of the slot. The antenna module according to any one of claims 1 to 10,
The antenna module is configured by a combination of a variable inductor and a variable capacitor by MEMS, and adjusts an input impedance of the antenna to a characteristic impedance of the feeder line by changing an inductance or a capacitance. The antenna module according to claim 11, wherein
The variable inductor is a spiral inductor composed of a movable wiring and a fixed wiring, and has a structure in which at least one of an inner diameter, an outer diameter, or a spiral pitch of the spiral inductor is changed by moving the movable wiring. module. The antenna module according to claim 11 or 12,
The variable inductor includes a first inductor through which a high-frequency signal to be transmitted or received passes and a second inductor separated from the first inductor, and varies a distance between the first inductor and the second inductor. An antenna module having a structure. The antenna module according to any one of claims 1 to 13,
The first substrate includes the antenna array and the first switch, the second substrate includes the matching circuit and the second switch, and the first substrate and the second substrate are stacked. A featured antenna module. The antenna module according to claim 14, wherein
The antenna module, wherein the first substrate is a glass substrate. The antenna module according to any one of claims 1 to 15,
In each of the first switches, the shape of the tip portion facing the other first switch is extended to a V shape so that the gap between the four first switches facing each other is X-shaped. An antenna module. The antenna module according to any one of claims 1 to 6 and 11 to 16,
An antenna module comprising a ground plate, wherein a third switch for selectively connecting the plurality of radiating elements to the ground plate is provided.   18. A radio module, wherein the second substrate of the antenna module according to claim 14 has at least a part of a front end circuit and a baseband circuit.   A third substrate is stacked on the antenna module according to any one of claims 14 to 17 or the wireless module according to claim 16, and at least a front end circuit and a baseband circuit are disposed on the third substrate. A wireless module characterized in that there is a part.   A radio system using the antenna module according to any one of claims 1 to 19 or the radio module according to any one of claims 16 to 17. An antenna array including a plurality of radiating elements; a plurality of feeding points that feed power to the plurality of radiating elements; and a first switch that selectively controls connection / disconnection between adjacent radiating elements among the plurality of radiating elements; And a second switch for selectively switching the feed line to the plurality of feed points, and a matching circuit for matching the input impedance of the antenna to the characteristic impedance of the feed line, and frequency switching, polarization switching, directivity A method for controlling an antenna module having at least two of the three functions of control,
Forming a plurality of radiating elements having different resonance lengths by a combination of conduction / cutoff states of the first switch;
Selecting the same feeding point from a plurality of feeding points by the second switch to radiate the same polarization; and
A method for controlling an antenna module, comprising: matching an input impedance of the radiating element formed by a combination of a conduction / cutoff state of a first switch by the matching circuit with a characteristic impedance of a feeder line. An antenna array including a plurality of radiating elements; a plurality of feeding points that feed power to the plurality of radiating elements; and a first switch that selectively controls connection / disconnection between adjacent radiating elements among the plurality of radiating elements; And a second switch for selectively switching the feed line to the plurality of feed points, and a matching circuit for matching the input impedance of the antenna to the characteristic impedance of the feed line, and frequency switching, polarization switching, directivity A method for controlling an antenna module having at least two of the three functions of control,
A step of forming a plurality of rectangular radiating elements having different resonance lengths by a combination of conduction / cutoff states of the first switch, and a rectangular radiation formed by conduction of the first switch from the plurality of feeding points. Radiating linearly polarized waves having the same excitation direction by selecting the same feeding point on the perpendicular of the midpoint of the side orthogonal to the excitation direction of the element by the second switch. Control method of antenna module. An antenna array including a plurality of radiating elements; a plurality of feeding points that feed power to the plurality of radiating elements; and a first switch that selectively controls connection / disconnection between adjacent radiating elements among the plurality of radiating elements; And a second switch for selectively switching the feed line to the plurality of feed points, and a matching circuit for matching the input impedance of the antenna to the characteristic impedance of the feed line, and frequency switching, polarization switching, directivity A method for controlling an antenna module having at least two of the three functions of control,
Forming a plurality of rectangular radiating elements having different resonance lengths by a combination of conduction / cutoff states of the first switch; and rectangular radiation formed by conduction of the first switch from the plurality of feeding points. A method for controlling an antenna module, comprising the step of radiating elliptically polarized waves in the same turning direction by selecting the same feeding point on the diagonal line of the element by the second switch.

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