JP2006340235A - Antenna device, wireless communication apparatus, control method thereof, computer processable program, and recording medium thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To select a combination of components of a rectangle patch antenna so as to be capable of configuring three kinds of linearly polarized wave antenna, a right-handed rotatory polarized wave antenna, and a left-handed rotatory polarized wave antenna with one structure, and also to achieve MIMO communication suitable for a radio wave environment by utilizing the rectangle patch antenna set to an optimum state. <P>SOLUTION: A device includes: a conductive main exciting element 51 located on an octagonal insulation board 29; sub exciting elements P1 to P4 for polarized wave control located at four corners in diagonal line directions of the main exciting element 51; and control electrodes 52a to 52d respectively arranged to the sub exciting elements P1 to P4, and controls the sub exciting elements P1 to P4 to be conductive or insulating to switch polarized waves emitted from the rectangle patch antenna. Since the antenna system can separately control the conductivity/insulation of the sub exciting elements P1 to P4, the antenna system can combine the main exciting element 51 and the sub exciting elements P1 to P4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is an antenna device suitable for application to a multi-input multi-output (hereinafter referred to as MIMO) communication system that transmits and receives signals simultaneously using a plurality of planar antennas, a radio communication device, and a control method thereof, The present invention relates to a computer-processable program and its recording medium. Specifically, with respect to the antenna device, the planar antenna main body and the small piece are controlled by controlling the DC bias voltage to the control electrode provided on the semiconductive small piece for polarization control disposed in the diagonal direction of the planar antenna main body. The combination of the antenna and the antenna can be selected, and the radiation polarization of the planar antenna can be switched so that three types of antennas of linear polarization, right-handed polarization and left-handed polarization can be configured with one structure. At the same time, a multi-input multi-output communication suitable for a radio wave environment can be realized by using a planar antenna set in an optimum state.

  In recent years, not only information processing equipment such as personal computers and mobile phone, and communication terminal equipment such as PDA (Personal Digital Assistance), but also various consumer electronic equipment such as audio products, video equipment, camera equipment, printers or entertainment. Robots and the like are often equipped with a wireless communication function. In addition to electronic devices, wireless communication functions include, for example, wireless LAN (Local Area Network) access points, PCMCIA (Personal Computer Memory Card International Association) specification cards, compact flash (registered trademark) cards, mini PCI ( In many cases, so-called small accessory cards such as peripheral component interconnection cards are also mounted. A wireless card module having such a storage function and a wireless communication function is configured.

  Currently, the IEEE 802.11a system using a carrier frequency of 5.2 GHz band and the IEEE 802.11b / g system using a carrier frequency of 2.4 GHz band are mainly used for home wireless LANs. These IEEE802.11a and IEEE802.11g have a data transmission rate of 54 Mbps, but recently, with the increase in the amount of data (information) to be handled, research on wireless systems for realizing higher transmission rates.・ Development is active.

  One of the methods that are attracting attention as a method that enables such high-speed transmission is a MIMO (Multi Input Multi Output) communication method. The MIMO communication system is a system that performs communication using a plurality of spatial propagation channels using a plurality of antennas. Currently, IEEE802.11a and IEEE802.11g used in wireless LANs use OFDM (Orthogonal Frequency Division Multiplexing) as a modulation method. By adopting this OFDM, transmission on each subcarrier can be regarded as substantially flat fading. Therefore, even in a relatively wideband communication system such as IEEE (Institute of Electrical and Electronics Engineers) 802.11a or IEEE 802.11g, the MIMO propagation path can be expressed with a somewhat simple model. Is becoming possible.

  With regard to this type of MIMO communication system antenna, Patent Document 1 discloses a wireless communication apparatus. According to this wireless communication apparatus, an antenna cluster including n antennas is provided. The antenna is capable of transmitting and receiving signals with relatively low correlation between signals, and includes a number of antenna ports connected to a single signal processing device. The antenna is configured to operate within a space volume in which the maximum linear dimension of the pair of antenna ports is λ / 3 or less. By configuring the antenna in this way, it is possible to provide an antenna cluster that can simultaneously transmit and receive an uncorrelated signal in a MIMO communication system applicable to a portable wireless terminal device.

  Patent Document 2 discloses an antenna array. According to this antenna array, an antenna group having two pairs of antennas is provided, and each antenna pair has an orthogonally polarized antenna. An antenna circuit is connected to the antenna group, and the antenna array is operated based on the beamforming / steering mode, the MIMO mode, and the diversity mode. Configuring the antenna array in this way can provide an antenna array in which beamforming / steering, MIMO and diversity operations can be performed on transmitted and received signals without using additional antennas.

  Furthermore, Patent Document 3 discloses a diversity system, a base station apparatus, and a diversity control method. According to this system, a plurality of antenna elements are provided, and multiple incoming waves are separated into a plurality of paths for each angle based on received signals obtained from these antenna elements, and the mutual relationship between the separated paths is measured. Then, a plurality of transmission directions for transmission diversity are determined based on the measured correlation, and the transmission weights of the antenna elements that transmit in the determined transmission direction are calculated. By configuring the system in this way, fading can be suppressed to improve the attenuation of received signals, and inter-signal interference can be suppressed.

  FIG. 24 is a diagram illustrating a configuration example at the time of signal propagation by the MIMO communication method according to the conventional example. According to the MIMO communication scheme shown in FIG. 24, the transmission terminal device 2 is provided with a transmission system 2a, and this transmission system 2a is provided with m (m is an integer) transmission antennas. The receiving terminal device 4 is provided with a receiving unit 4a, and the receiving unit 4a is provided with n (n is an integer) receiving antennas. Communication between the transmission terminal device 2 and the reception terminal device 4 is performed using a plurality of radio wave propagation channels 3 as media.

  For example, the transmission signal input to the transmission unit 2a is subjected to spatial multiplexing coding and modulated, and the modulated transmission radio wave is radiated (radiated) from the m antennas to the radio wave propagation channel 3. In the receiving terminal device 4, the received radio waves that arrive via the radio wave propagation channel 3 are received by n antennas. In the receiving unit 4a, the received radio wave is subjected to space-time decoding processing, and the received signal is demodulated and output.

  As a demodulation method in MIMO, channel information is unknown on the transmission side and linear operation only on the reception side, such as zero forcing and V-BLAST (Vertical Bell Labs Layered Space-Time). Demodulation method, MLD (Maximum Likelihood Detection) method to demodulate by non-linear operation, STBC (Space Time Block Coding) method to give orthogonality to two transmission signals, and transmission side However, various schemes such as eigen-mode MIMO for transmitting and receiving channel information in advance and performing transmission and reception by performing appropriate power distribution and phase vector synthesis according to the channel information have been proposed.

  In this MIMO communication system, in principle, the transmission rate increases linearly with the number of antennas. The MIMO communication method is a communication method using a radio wave propagation environment of each signal transmitted and received in a plurality of radio wave propagation channels 3, that is, a multipath environment in which reflection, scattering, diffraction, and shielding are mixed. Since the spatial correlation characteristic accompanying this greatly affects the information transmission capability, conventionally, a method for reducing interference between signals as much as possible has been considered in the MIMO communication system. As for this inter-signal interference reduction method, for example, Non-Patent Document 1 shows an “Orthogonal Tripolarized MIMO Transmission Experiment in a Multipath Environment”.

  FIG. 25 is a perspective view showing an example of mounting an antenna for linear polarization in the MIMO communication system. According to the linearly polarized antenna mounting example shown in FIG. 25, as seen in Non-Patent Document 1, two of the vertically polarized antenna 5a and the horizontally polarized antenna 5b are attached to the set box 5 or the like. For example, the horizontally polarized antenna 5b and the vertically polarized antenna 5a are arranged so as to be orthogonal to each other.

  FIG. 26 is a perspective view showing an example of mounting an antenna for circular polarization in the MIMO communication system. According to the circularly polarized antenna mounting example shown in FIG. 26, as seen in Non-Patent Document 1, the right-handed polarized antenna 6a and the left-handed polarized antenna 6b are attached to the set box 5 or the like. For example, the right-hand polarized antenna 6a and the left-hand polarized antenna 6b are arranged so as to be orthogonal to each other. Thus, in the antenna device for linearly polarized waves and circularly polarized waves, the quality of MIMO transmission is improved by making the respective polarized waves orthogonal.

Japanese Patent Laying-Open No. 2002-280826 (5th page, FIG. 5) Japanese Patent Laying-Open No. 2002-290148 (FIG. 1 on page 4) Japanese Patent Laying-Open No. 2003-204295 (page 3 in FIG. 2) Das Nirmol Kumar et al., "Transmission experiment using orthogonal three polarized waves in multipath environment", IEICE General Conference, SB-1-7, 2004

  However, in the MIMO communication schemes such as those found in Patent Documents 1 to 3 and Non-Patent Document 1, it is not always easy to make each polarization orthogonal. In wireless LANs used indoors and in mobile communications used outdoors, cases where radio waves are transmitted and received in line-of-sight (LOS) are rare. This is because transmission and reception are often performed in a multipath rich environment (NLOS: Non Line of Sight). According to the MIMO communication system that performs communication using such a multipath environment, there is a possibility that polarized waves that are initially orthogonalized may cause interference due to the influence of a reflector (thing).

  FIG. 27 is a conceptual diagram showing an example of reception in the reception terminal device 4 when the transmission terminal device = right-handed / right-handed polarized wave setting. According to the transmission terminal device 2 shown in FIG. 27, two antennas are provided, both of which are set to right-handed polarization, and the radiated radio wave from one antenna is reflected once by the reflector. It is an example of reception in the receiving terminal device 4 in the case of having performed. When the light is reflected once by the reflector, the polarization becomes a reverse rotation, and thus the reception terminal device 4 receives the left-handed polarization. In this way, even if both antennas of the transmission terminal device 2 are radiated with the same polarization, if there is a reflector on one side and the reflection is received, the polarization becomes a reverse polarization. For this reason, the receiving terminal device 4 may not cause interference.

  FIG. 28 is a conceptual diagram illustrating a reception example in the reception terminal device 4 when the transmission terminal device = right-handed / left-handed polarized wave setting. The two antennas provided in the transmission terminal device 2 shown in FIG. 28 are cases where one is set to right-handed polarization and the other is set to left-handed polarization, and the radiated radio wave from one antenna It is an example of reception in the receiving terminal device 4 when is reflected by the reflector once. When the light is reflected once by the reflector, the polarization becomes a reverse rotation, and thus the reception terminal device 4 receives the right-hand polarization. As described above, when the right-handed and left-handed polarized waves are separately radiated from both antennas of the transmission terminal device 2, there is a reflector on one side, and when the reflection is received, the polarization is Due to the reverse rotation, interference occurs in the receiving terminal device 4.

  In this way, the polarization changes variously in a multipath-rich environment, and even if orthogonality is given at the time of radiation, it may not necessarily be advantageous for communication characteristics depending on the radio wave environment. There is. In order to cope with this, if antennas for linearly polarized waves and right-handed / left-handed polarized waves are provided and these antennas are switched and used, in the MIMO communication system, it is not necessary. Although many antennas are required, there are problems that the number of antennas is increased, which leads to an increase in cost and occupies a large space for mounting the antenna to the set box 5.

  Therefore, the present invention solves such a conventional problem, and allows the selection of a combination of antenna members, so that three types of linearly polarized waves, right-handed polarized waves, and left-handed polarized waves can be selected. ANTENNA DEVICE, RADIO COMMUNICATION DEVICE, AND METHOD FOR CONTROLLING THE SAME TO CONFIGURE AN ANTENNA WITH ONE STRUCTURE AND AVAILABLE TO IMPROVE MIMO COMMUNICATIONS CONTAINED FOR RADIO WAVE ENVIRONMENT An object of the present invention is to provide a computer-processable program and a recording medium thereof.

  The above-described problems include a conductive planar antenna main body portion having a predetermined shape and disposed on a dielectric substrate, and a semiconductive piece for polarization control disposed in a diagonal direction of the planar antenna main body portion. This is solved by an antenna device comprising: a portion and a control electrode provided on the small piece portion, wherein the radiation polarization of the planar antenna is switched by controlling a DC bias voltage supplied to the control electrode.

  According to the antenna device of the present invention, the conductive planar antenna main body having a predetermined shape is disposed on the dielectric substrate, and in the diagonal direction of the planar antenna main body, polarization control is performed. A semiconductive piece is placed. A control electrode is provided on the small piece portion, and a DC bias voltage supplied to the control electrode is controlled.

  For example, in the planar antenna main body, small pieces having control electrodes are arranged at two diagonal corners, respectively, and a forward bias voltage is supplied to the control electrodes of the two small pieces in one diagonal direction. When a reverse bias voltage is supplied to the control electrodes of the two diagonal pieces, the planar antenna body is electrically connected to one diagonal piece, and the other diagonal piece is insulated. Thus, the circularly polarized antenna showing the characteristics of right-handed polarization or left-handed polarization can be configured with one structure. Further, when a forward bias voltage is supplied to all the control electrodes at the four corners in the diagonal direction, a linearly polarized antenna body can be configured.

  As described above, since the conductivity / insulation of the small piece portion can be controlled by controlling the DC bias voltage to the control electrode, the combination of the planar antenna main body portion and the small piece portion can be selected. Therefore, the radiation polarization of the planar antenna can be switched, and three types of antennas of linear polarization, right-handed polarization, and left-handed polarization can be configured with one structure.

  The wireless communication device according to the present invention controls two or more antenna devices and two or more transmission / reception circuits connected to each of the antenna devices and transmitting / receiving signals using a multi-input / multi-output communication scheme, Each of the antenna devices includes a dielectric substrate, a conductive planar antenna body having a predetermined shape and disposed on the substrate, and a diagonal direction of the planar antenna body. A semi-conductive small piece for polarization control and a control electrode provided on the small piece, and switching the radiation polarization of the planar antenna by controlling the DC bias voltage supplied to the control electrode It is what.

  According to the wireless communication device of the present invention, the antenna device according to the present invention is applied, and the DC bias to the control electrode of the semiconductive small piece for polarization control arranged in the diagonal direction of the planar antenna body portion By controlling the voltage, the radiation polarization of the planar antenna body is switched.

  For example, in the planar antenna main body, small pieces having control electrodes are arranged at two diagonal corners, respectively, and a forward bias voltage is supplied to the control electrodes of the two small pieces in one diagonal direction. When a reverse bias voltage is supplied to the control electrodes of the two small pieces in the diagonal direction, one of the small pieces in the diagonal direction changes to conductivity, and the planar antenna main body and the small piece changed to conductivity become electrically The other small piece in the diagonal direction that is connected is insulative, so that a circularly polarized antenna body exhibiting the characteristics of right-handed polarization or left-handed polarization can be formed. Further, when a forward bias voltage is supplied to all the control electrodes at the four corners in the diagonal direction, a linearly polarized antenna body can be configured.

  Therefore, it is possible to select three types of antenna bodies constituted by the combination of the planar antenna main body portion and the small piece portion, and to transmit / receive signals of linearly polarized wave, right-handed polarization, and left-handed polarization. Thereby, multi-input multi-output communication suitable for the radio wave environment can be realized.

  A method for controlling a wireless communication apparatus according to the present invention includes a conductive planar antenna body having a predetermined shape and disposed on a dielectric substrate, and polarization control disposed in a diagonal direction of the planar antenna body. A semi-conductive small piece for use and a control electrode provided on the small piece, and an antenna device for switching the radiated polarization of a planar antenna by controlling the DC bias voltage supplied to the control electrode and having multiple inputs A method of controlling a wireless communication device that transmits and receives signals by a multi-output communication method, comprising a step of setting a DC bias voltage to a control electrode of an antenna device and a plane constituted by the set DC bias voltage to the control electrode Detecting the communication quality of the antenna, holding the setting of the DC bias voltage to the control electrode based on the detected communication quality of the planar antenna, and the held control It is characterized in that a step of executing communication by setting the DC bias voltage to the electrode.

  According to the control method of the wireless communication apparatus according to the present invention, the antenna apparatus according to the present invention is applied to the control electrode of the semiconductive small piece part for polarization control arranged in the diagonal direction of the planar antenna body part. By controlling the direct current bias voltage, the radiation polarization of the planar antenna main body is switched.

  For example, when holding the setting of the DC bias voltage to the control electrode, the DC bias voltage to the control electrode is set, and the communication quality of the planar antenna configured by the DC bias voltage to the control electrode set here Is detected, and it is determined whether or not the communication quality of the detected planar antenna is optimal, and the setting of the DC bias voltage to the control electrode determined to be optimal is updated and held.

  Therefore, a linearly polarized wave and a right-handed polarized wave are selected using a planar antenna selected from three types of antenna bodies composed of a combination of a planar antenna body and a small piece, and set to an optimum state. And a signal of left-handed polarization can be transmitted and received. Thereby, multi-input multi-output communication suitable for the radio wave environment can be realized.

  A computer-processable program according to the present invention includes a conductive planar antenna body having a predetermined shape and disposed on a dielectric substrate, and a polarization control disposed in a diagonal direction of the planar antenna body. Having a semi-conductive small piece portion and a control electrode provided on the small piece portion, and having an antenna device for switching a radiation polarization of a planar antenna by controlling a DC bias voltage supplied to the control electrode. A control program for a wireless communication device that transmits and receives signals in accordance with an output communication method, and includes a step configured to set a DC bias voltage to a control electrode of an antenna device and a DC bias voltage to the set control electrode A step of detecting the communication quality of the antenna and a step of maintaining the setting of the DC bias voltage to the control electrode based on the detected communication quality of the planar antenna. When, is characterized in that a step of executing communication by setting the DC bias voltage to the held control electrode.

  A recording medium for a computer-processable program according to the present invention has a conductive planar antenna body having a predetermined shape and disposed on a dielectric substrate, and is disposed in a diagonal direction of the planar antenna body. A semi-conductive small piece for polarization control and a control electrode provided on the small piece, and an antenna device for switching the radiation polarization of the planar antenna by controlling the DC bias voltage supplied to the control electrode. A recording medium in which a control program for a wireless communication apparatus that transmits and receives signals in a multi-input multi-output communication system is described, and is configured by describing the program according to claim 14 and / or 15. It is what.

  According to the computer-processable program and the recording medium thereof according to the present invention, for example, a program that can be executed by a microcomputer, CPU, signal processing LSI, etc. Using a planar antenna selected from three types of antenna bodies and set in an optimum state, signals of linearly polarized wave, right-handed polarized wave and left-handed polarized wave can be transmitted and received.

  According to the antenna device of the present invention, the conductive small piece for polarization control is arranged in the diagonal direction of the planar antenna main body, and the direct current bias voltage supplied to the small piece is controlled to control the radiation deviation of the planar antenna. The wave is to be switched.

  With this configuration, a combination of the planar antenna main body portion and the small piece portion can be selected, so that three types of antennas of linearly polarized waves, right-handed polarized waves, and left-handed polarized waves can be configured with one structure. Therefore, the antenna device with the radiation polarization switching function can be sufficiently applied to a multi-input multi-output communication system suitable for a radio wave environment.

  According to the wireless communication device and the control method thereof according to the present invention, the antenna device according to the present invention is applied, and the control electrode of the semiconductive small piece for polarization control disposed in the diagonal direction of the planar antenna body portion By controlling the direct current bias voltage, the radiation polarization of the planar antenna main body is switched.

  With this configuration, using a planar antenna selected from three types of antennas composed of a combination of a planar antenna body and a small piece, and using a planar antenna set to an optimum state, linear polarization, clockwise rotation Polarized and left-hand polarized signals can be transmitted and received. Therefore, multi-input multi-output communication suitable for the radio wave environment can be realized.

  According to the computer-processable program and its recording medium according to the present invention, it is selected from three types of antenna bodies constituted by a combination of a planar antenna main body portion and a small piece portion, and is set in an optimum state. Using a planar antenna, signals of linearly polarized wave, right-handed polarized wave and left-handed polarized wave can be transmitted and received.

  Next, an embodiment of an antenna device, a wireless communication device, a control method thereof, a computer processable program and a recording medium thereof according to the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a configuration example of an antenna device 100 as a first embodiment according to the present invention.

  The antenna device 100 shown in FIG. 1 is applied to an antenna that simultaneously transmits and receives signals using a multi-input multi-output (hereinafter referred to as MIMO) communication method using a plurality of planar antennas and a wireless communication device that applies the antenna. It is preferable. The antenna device 100 is configured by disposing a conductive main excitation element 11, which is an example of a planar antenna main body, on an insulating substrate 19. The main excitation element 11 has, for example, an octagonal rectangular patch pattern shape with four corners cut off. The substrate 19 has a length L and a width W. The main excitation element 11 has a length L ′ (L ′ <L) and a width W ′ (W ′ <W). The main excitation element 11 is made of a metal material such as copper having a thickness t, white copper, phosphor bronze, brass, SUS, or gold, and the main excitation element 11 is formed by etching a copper foil substrate or metal plating on a resin. It is formed by a method, a metal foil attaching technique, or the like.

  In the diagonal direction of the main excitation element 11, a triangular auxiliary excitation element (degenerate separation element or perturbation element: notch part) for polarization control, which is an example of a small piece part, is disposed across the insulating region. The sub excitation elements 12 a to 12 d are made of the same metal material as that of the main excitation element 11. The auxiliary excitation elements 12a to 12d are formed by, for example, separating the elements so that the lower insulating substrate 19 is exposed by cutting out the four corners of the square main excitation element 11. The notch may be any method such as etching or a method of cutting a groove by a grinder.

  In this example, switches SW1 to SW4 are mounted (connected) between the main excitation element 11 and the auxiliary excitation elements 12a to 12d at the four corners, and the planar antenna ( The radiation polarization of the rectangular patch antenna) is switched. The switches SW1 to SW4 are composed of semiconductor active elements. As the semiconductor active element, a p-type or n-type field effect transistor or an npn-type or pnp-type bipolar transistor is used. In addition to the semiconductor active elements, the switches SW1 to SW4 may be switches having a mechanical driving mechanism, for example, a micro electromechanical system (MEMS) switch.

  When field effect transistors are used for the switches SW1 to SW4, for example, the source is connected to the main excitation element 11, and the drain is connected to the sub excitation element 12a and the like. The source / drain connection method may be reversed. The on / off control is executed by controlling the gate voltage. When bipolar transistors are used for the switches SW1 to SW4, for example, the collector is connected to the main excitation element 11, and the emitter is connected to the sub excitation element 12a and the like. The collector-emitter connection method may be reversed. The on / off control is executed by controlling the base current.

  The substrate 19 is provided with four control terminals 13a to 13d. The control terminal 13a is connected to the control electrode (gate or base) of the switch SW1 via the choke coil 14a. A bypass capacitor 15a is connected between the control electrode and a ground (GND) pattern (not shown). The choke coil 14a, the bypass capacitor (pass capacitor) 15a, and the like constitute a filter for preventing a high-frequency current from entering and is connected to a DC line as necessary, and the filter is laid out (arranged) at an appropriate position. .

  The ground pattern is provided on the back side of the substrate. The bypass capacitor 15a is connected to the ground pattern through a through hole. Similarly, the other control terminals 13b to 13d are connected to the control electrodes of the switches SW2 to SW4 via the choke coils 14b, 14c, 14d and the like, respectively. The bypass capacitors 15b, 15c, and 15d are connected in the same manner. The above-described switches SW1 to SW4, the main excitation element 11 of the rectangular patch antenna, the sub excitation elements 12a to 12d, the DC line, the ground pattern, and other control terminals 13a to 13d are mounted by face bonding by wire bonding or bumps. Connected by face-down mounting method or the like.

  A DC voltage for driving the switches SW1 to SW4 (hereinafter referred to as switch drive voltage or switch control signals S11 to S14, S21 to S24) is supplied between the control electrode and the ground pattern. A control unit (switch controller) (not shown) is connected to the control terminals 13a to 13d and the ground pattern. With respect to the switches SW1 to SW4, switch driving voltages are paired as in the diagonal switches SW1, SW3, SW2, and SW4. Is made to supply. This rectangular patch antenna, for example, emits circularly polarized radiation such as right-handed and left-handed polarized waves as shown in Hiroyuki Arai, “New Antenna Engineering”, General Electronic Publishing (1996), and linearly polarized radiation. To be made.

  2A and 2B are a top view showing a structural example of the antenna device 100 and a cross-sectional view taken along line X1-X1 thereof. 3A to 3C are exploded top views showing examples of the laminated structure of the antenna device 100. FIG.

  2A, the antenna device 100 includes switches SW1 to SW4, a square-shaped insulating substrate 19, an octagonal main excitation element 11, and triangular sub-excitation elements 12a to 12d. In FIG. 2B, the switches SW1 to SW4 are arranged so as to bridge an insulating region between the main excitation element 11 and the sub excitation elements 12a to 12d.

  The antenna device 100 shown in FIG. 3A has a three-layer structure. The first layer includes an insulating substrate 19, a conductive main excitation element 11, sub-excitation elements 12a to 12d, and switches SW1 to SW4. Have. The main excitation element 11 and the sub excitation elements 12a to 12d are disposed on the insulating substrate 19a of the first layer, and switches SW1 to SW4 are provided between the main excitation element 11 and each of the sub excitation elements 12a to 12d. Connected and configured. An RF feed point (through hole 16e) is provided below the main excitation element 11.

  In the second layer shown in FIG. 3B, an insulating substrate 19b and a microstrip line 18 are provided. The main excitation element 11 is connected to the main excitation element 11 through a through hole 16e provided in the first insulating substrate 19a. Connected. The microstrip line 18 has a characteristic impedance of 50Ω and is arranged in a state sandwiched between the first and second insulating substrates 19a and 19b. The microstrip line 18 is provided with a power supply terminal (power supply circuit), and is connected to a high-frequency circuit or the like of the wireless communication device so as to supply a transmission signal or draw a reception signal. The third layer shown in FIG. 3C includes a ground pattern 17 (GND layer) provided on the entire back surface of the second insulating substrate 19b. Accordingly, the antenna device 100 having a three-layer structure is configured.

  Here, a manufacturing method of the antenna device 100 having a three-layer structure will be described. First, a square single-sided copper foil substrate having a copper foil on one surface of an insulating substrate was prepared, and an octagonal shape for the main excitation element and a triangular shape for the auxiliary excitation element on this copper foil. A resist is applied to the substrate and patterned. In order to secure an insulating region between the main excitation element 11 and the sub excitation elements 12a to 12d, a resist is not applied. Using these resists as a mask, excess copper foil is removed with a predetermined etching solution. Thereby, a single-sided copper foil board | substrate can be element-separated into the octagon-shaped main excitation element 11 and the triangular-shaped sub excitation elements 12a-12d.

  Next, a through hole having a predetermined diameter reaching the main excitation element 11 is formed. The through hole is opened by a drill or the like. The diameter of the through hole 16e only needs to ensure a level that can form a conductive member. Thus, the first substrate 19a having the main excitation element 11 and the sub excitation elements 12a to 12d on one surface and the through hole 16e having a predetermined diameter from the main excitation element 11 to the back surface is formed. be able to.

  Next, a square double-sided copper foil substrate having copper foil on both sides of an insulating substrate is prepared, and a resist of a predetermined shape is applied to the copper foil on one side for patterning and patterned. . The resist is applied in alignment with the through hole 16e described above. The copper foil on the other surface is coated with a resist on the entire surface. Using these resists as a mask, excess copper foil is removed with a predetermined etching solution. Thereby, the second substrate 19b having the microstrip line 18 on one surface and the ground pattern 17 on the other surface can be formed. Of course, the present invention is not limited to this, and a copper foil or the like equivalent to a microstrip line may be attached to the surface of the single-sided copper foil substrate on which the copper foil is not formed.

  Thereafter, the first substrate 19a having the main excitation element 11, the sub excitation elements 12a to 12d, and the through hole 16e, and the second substrate 19b having the microstrip line 18 and the ground pattern 17 are bonded with a predetermined adhesive. Use them together. The bonding surfaces are a surface that does not have the main excitation element 11 and the sub excitation elements 12a to 12d on the first substrate 19a, and a surface that has the microstrip line 18 on the second substrate 19b. Further, a conductive member is filled in the through hole or plated to electrically connect the main excitation element 11 and the microstrip line 18.

  Next, the switches SW1 to SW4 are connected between the main excitation element 11 and the sub excitation elements 12a to 12d. For the switches SW1 to SW4, semiconductor active elements such as p-type or n-type field effect transistors or npn-type or pnp-type bipolar transistors are used. The switches SW1 to SW4 are not limited to semiconductor active elements, and may be configured using switches having a mechanical drive mechanism (see Example 2). These elements are connected by face-up mounting using wire bonding or face-down mounting using bumps. Thereby, the antenna device 100 having a three-layer structure can be manufactured.

  Thus, according to the antenna device 100 having the three-layer structure as the first embodiment, the switches SW1, SW2, SW3, and SW4 are arranged at the respective corners in the two diagonal directions in the main excitation element 11, and one diagonal line is provided. The two switches SW1 and SW3 in the direction are turned on, and the two switches SW2 and SW4 in the other diagonal direction are turned off. When the switches SW1 to SW4 are controlled to be turned on / off in this way, the main excitation element 11 and one of the diagonal sub-excitation elements 12a and 12c are electrically connected, and the other diagonal sub-excitation element 12b and 12d. Since they are in an insulated state, a circularly polarized antenna body exhibiting the characteristics of right-handed polarization or left-handed polarization can be formed.

  Further, when all the switches SW1 to SW4 at the four corners in the diagonal direction are turned on, a linearly polarized antenna body in which the horizontal polarization and the vertical polarization are orthogonal to each other can be configured. By such on / off control of the switches SW1 to SW4, the main excitation element 11 and the sub excitation elements 12a to 12d can be combined, and three types of antennas of linearly polarized wave, right-handed polarized wave, and left-handed polarized wave are provided. A single structure can be used. As a result, the antenna device 10 with the radiation polarization switching function can be sufficiently applied to a MIMO communication system suitable for a radio wave environment.

  FIG. 4 is a top view illustrating a configuration example of the antenna device 200 as the second embodiment. In the antenna device 200 shown in FIG. 4, MEMS (Micro Electromechanical Systems) switches SW1 ′ to SW4 ′ are mounted (connected) as switch elements between the main excitation element 11 and the sub excitation elements 12a to 12d. SW1 ′ to SW4 ′ are turned on / off to switch the radiation polarization of the rectangular patch antenna. In addition, since the thing of the same name and code | symbol as 1st Example has the same function, the description is abbreviate | omitted.

5A to 5C are a top view and a cross-sectional view showing a configuration example and an operation example of the MEMS switch SW1 ′ and the like.
The MEMS switch SW1 ′ illustrated in FIG. 5A is provided in an insulating region between the main excitation element 11 and each of the sub excitation elements 12a to 12d. For example, the MEMS switch SW1 ′ includes a silicon (Si) substrate 21, a movable portion 22, a voltage application electrode 23, and contacts 24a and 24b. One end side of the movable portion 22 is attached to the Si substrate 21 and has, for example, a diaphragm structure that can move up and down with the one end as a fulcrum. A contact 24a is provided on the other end side of the movable portion 22, and the contact 24a is electrically connected to the auxiliary excitation element 12a and the like. A contact 24 b is also provided on the Si substrate side, and this contact 24 b is electrically connected to the main excitation element 11. The contact 24b on the Si substrate side is provided at a position facing the contact 24a on the movable part side.

  A voltage application electrode (control electrode) 23 is provided on the Si substrate 21, and a switch drive voltage is applied to the voltage application electrode 23. When a predetermined switch drive voltage is applied to the voltage application electrode 23, the movable portion 22 is drawn to the voltage application electrode side by the Coulomb force. As a result, the contact 24a on the movable portion side contacts with the contact 24b on the Si substrate side, and the main excitation element 11 and the sub excitation element 12a are electrically connected.

  As described above, according to the antenna device 200 as the second embodiment, the MEMS switch SW1 'is connected between the main excitation element 11 and the sub excitation elements 12a to 12d at the four corners. As a result, as in the first embodiment, an antenna device that emits circularly polarized waves such as right-handed and left-handed polarized waves and linearly polarized radiation can be configured.

  FIG. 6 is a diagram illustrating a configuration example of an antenna device 300 as the third embodiment. The antenna apparatus 300 shown in FIG. 6 is suitable for application to an antenna that simultaneously transmits and receives signals in a MIMO communication scheme using a plurality of planar antennas and a radio communication apparatus to which the antenna is applied. The antenna device 300 is configured by disposing a conductive main excitation element 31 on an insulating substrate 19. The main excitation element 31 has a circular shape. The substrate 19 has a length L and a width W. The diameter of the main excitation element 31 is Dφ (Dφ <L, W). The material of the main excitation element 31 and the manufacturing method thereof are as described in the first embodiment.

  When the origin is defined in the diagonal direction of the insulating substrate 19 and at the center of the circular main excitation element 31, on the circumference of every 90 ° along the diagonal direction with respect to the origin ( In a predetermined position), rectangular control sub-excitation elements 12a to 12d (or perturbation elements: notch portions) for polarization control, which are examples of small pieces, are arranged with an insulating region interposed therebetween. The sub excitation elements 12 a to 12 d are made of the same metal material as the main excitation element 31. For example, the sub-excitation elements 12a to 12d are formed by separating the elements so that the lower insulating substrate 19 is exposed by cutting out a predetermined position of the circular main excitation element 31 in a U shape. Done. The notch may be any method such as etching or a method of cutting a groove by a grinder.

  In this example, switches SW1 to SW4 are mounted (connected) between the main excitation element 31 and the auxiliary excitation elements 12a to 12d at respective positions on the circumference, and the switches SW1 to SW4 are controlled to be turned on / off. Thus, the radiation polarization of a planar antenna (hereinafter referred to as a circular patch antenna) is switched. The switches SW1 to SW4 are composed of semiconductor active elements as in the first embodiment. As the semiconductor active element, a p-type or n-type field effect transistor or an npn-type or pnp-type bipolar transistor is used. Of course, the switches SW1 to SW4 may be a switch having a mechanical drive mechanism or the MEMS switch SW1 'described in the second embodiment in addition to the semiconductor active element.

  As in the first embodiment, the insulating substrate 19 is provided with four control terminals 13a to 13d. The control terminal 13a is connected to the control electrode (gate or base) of the switch SW1 via the choke coil 14a. A bypass capacitor 15a is connected between the control electrode and a ground pattern 17 (not shown). The choke coil 14a, the bypass capacitor 15a, and the like constitute a filter for preventing a high-frequency current from being sneak in, and are connected to a DC system line as necessary, and the filter is laid out at an appropriate position.

  The ground pattern 17 is provided on the back side of the substrate as in the first embodiment. The bypass capacitor 14a is connected to the ground pattern 17 through the through hole 16a. Similarly, the other control terminals 13b to 13d are connected to the control electrodes of the switches SW2 to SW4 via choke coils 14b, 14c, and 14d, respectively. The bypass capacitors 15b, 15c, and 15d are connected in the same manner. The above-described switches SW1 to SW4, the main excitation element 31 of the rectangular patch antenna, the sub excitation elements 12a to 12d, the DC line, the ground pattern 17, and the like control terminals 13a to 13d are face-up mounted or bumped by wire bonding. It is connected by the face down mounting method or the like.

  A DC voltage for driving the switches SW <b> 1 to SW <b> 4 (hereinafter referred to as a switch driving voltage or a switch control signal) is supplied between the control electrode and the ground pattern 17. A switch control unit (switch controller) (not shown) is connected to the control terminals 13a to 13d and the ground pattern 17, and the switches SW1 to SW4 are switched in pairs such as diagonal switches SW1, SW3, SW2, and SW4. A drive voltage is supplied. This circular patch antenna is also adapted to radiate circularly polarized waves such as right-handed and left-handed polarized waves, linearly polarized radiation, etc. as described in the first embodiment.

  As described above, since the main excitation element 31 according to the third embodiment is configured by a circular patch pattern, the present invention is not limited to the rectangular patch antenna described in the first embodiment, and is based on the concept of the present invention. The present invention can be applied to various types of wireless communication devices based on the antenna device 300 having a circular patch antenna.

FIG. 7 is a block diagram illustrating a configuration example of a wireless communication device 400 as a fourth embodiment to which the antenna device 100 is applied.
In this embodiment, N (N is an integer of 2 or more) antenna devices and transmission / reception circuits are applied to appropriately control the radiation polarization of the antenna devices, and the MIMO communication (transmission) system suitable for the usage environment Is made to realize. In this example, the antenna device 100 described in the first embodiment is used for each of the antennas ANT1 and ANT2.

  The wireless communication device 400 shown in FIG. 7 is applied to a home wireless LAN such as an IEEE802.11a system using a carrier frequency of 5.2 GHz band or an IEEE802.11b / g system using a carrier frequency of 2.4 GHz band. It is preferable. The wireless communication apparatus 400 includes a communication control unit 40, a high frequency unit 43, a memory unit 48, two (= N) antennas ANT1 and ANT2, and two transmission / reception changeover switches 41 and 42, thereby realizing a MIMO communication system. Is. The high frequency unit 43 includes two receiving circuits 44a and 44b and two transmitting circuits 45a and 45b.

  Transmission / reception changeover switches 41 and 42 are connected to the antenna ANT1. The transmission / reception change-over switches 41, 42 are configured to connect either one of the reception circuits 44a, 44b or the transmission circuits 45a, 45b in the high-frequency unit 43 to the power supply terminal (through hole 16e) of the antenna ANT1. The power supply terminal is connected to the main excitation element 11 of the antenna ANT1 through the microstrip line 18, and supplies a transmission signal or receives (draws) a reception signal.

  The reception circuit 44a and the transmission circuit 45a constitute a transmission / reception circuit for transmitting / receiving a signal by a MIMO communication method using the first antenna ANT1. The reception circuit 44a is connected to the antenna ANT1 via the transmission / reception changeover switch 41, takes in a reception signal from the antenna ANT1 via the transmission / reception changeover switch 41, and performs reception processing by the MIMO communication method.

  The transmission circuit 45a is connected to the antenna ANT1 via the transmission / reception changeover switch 41, processes the transmission signal by the MIMO communication method, and feeds the transmission signal to the antenna ANT1 via the transmission / reception changeover switch 41.

  A transmission / reception selector switch 42 is connected to the antenna ANT2. The transmission / reception changeover switch 42 is configured to connect either the reception circuit 44b or the transmission circuit 45b to the power supply terminal (through hole 16e) of the antenna ANT2. The power supply terminal is connected to the main excitation element 11 of the antenna ANT2 through the microstrip line 18, and supplies a transmission signal or receives (draws) a reception signal.

  The reception circuit 44b and the transmission circuit 45b constitute a transmission / reception circuit for transmitting / receiving a signal by the MIMO communication method using the second antenna ANT2. The reception circuit 44b is connected to the antenna ANT2 via the transmission / reception changeover switch 42, receives a reception signal from the antenna ANT2 via the transmission / reception changeover switch 42, and performs reception processing by the MIMO communication method.

  The transmission circuit 45b is connected to the antenna ANT2 via the transmission / reception changeover switch 42, processes the transmission signal by the MIMO communication method, and feeds the transmission signal to the antenna ANT2 via the transmission / reception changeover switch 42.

  The communication control unit 40 is connected to the antennas ANT1 and ANT2 and the high frequency unit 43 described above, and the switches SW1 to SW4 of the antenna ANT1 are controlled to be turned on / off according to the quality of the signal received by the receiving circuit 44a. The switches SW1 to SW4 of the antenna ANT2 are turned on / off according to the quality of the signal received by the circuit 44b.

  The communication control unit 40 includes a control device 46 and a switch control circuit 47. A switch control circuit 47 is connected to the antennas ANT1 and ANT2. The switch control circuit 47 is connected to the control device 46. The control device 46 uses a CPU (Central Processing Unit), MPU (Micro Processing Unit), A / D converter, D / A converter, modulation / demodulation (BB) circuit, MAC circuit, user interface, etc. (not shown). The

  The control device 46 controls the antennas ANT1 and ANT2 through the high frequency unit 43 and the switch control circuit 47. For example, the transmission / reception switching switch 41 outputs a switch switching signal SS1 to switch the transmission / reception function of the antenna ANT1, or the transmission / reception switching switch 42 outputs a switch switching signal SS2 to switch the transmission / reception function of the antenna ANT2.

  Further, the control device 46 turns on / off the switches SW1 to SW4 connected between the main excitation element 11 and the four sub excitation elements 12a to 12d in accordance with the quality of the reception signals received by the reception circuits 44a and 44b. It controls OFF. For example, the receiving circuits 44a and 44b measure reception sensitivity (Received Signal Strength Indicator; hereinafter referred to as RSSI). In the case of the IEEE 802.11a system, the reception sensitivity can be obtained by monitoring an AGC (automatic gain control) signal before quadrature detection. Of course, the present invention is not limited to this, and the reception sensitivity may be obtained by detection of decoded data or the like.

  The control device 46 determines whether the RSSI is within a certain range. When the RSSI is not within a certain range, for example, when the RSSI is lower than the lower limit threshold or when the RSSI exceeds the upper limit threshold, the control device 46 instructs the switch control circuit 47 to switch the polarization. The switch control data D11 is output. As a result, the radiation polarization of the antennas ANT1 and ANT2 can be controlled by the switch control circuit 47 (polarization diversity).

  The control device 46 controls the subcarrier modulation method of the transmission signal fed (transmitted) from the transmission circuits 45a and 45b to the antennas ANT1 and ANT2 according to the quality of the reception signals received by the reception circuits 44a and 44b. Made. Through this control of the subcarrier modulation scheme, a MIMO communication (transmission) scheme suitable for the usage environment can be realized.

  A memory unit 48 as an example of a recording medium is connected to the control device 46. As the memory unit 48, a read-only memory (ROM), a memory (RAM) in which information can be written and read at any time, a read memory (EEPROM) in which information can be electrically erased and written, or a hard disk device (HDD) are used. The The memory unit 48 stores a control program for a wireless communication device that transmits and receives signals using the MIMO communication method.

  In this control program, the communication quality of a rectangular patch antenna constituted by the step of setting on / off of each of the switches SW1 to SW4 of the antennas ANT1 and ANT2 and the on / off of the switches SW1 to SW4 set here. , A step of holding the settings of the switches SW1 to SW4 based on the communication quality of the square patch antenna detected here, and a step of executing communication according to the settings of the switches SW1 to SW4 held here Is included.

  By using the control program stored in the memory unit 48, three types of rectangular patch antennas constituted by combinations of the main excitation element 11 and the sub excitation elements 12a to 12d are selected, and the optimum state is obtained. Using the set rectangular patch antenna, signals of linearly polarized wave, right-handed polarized wave and left-handed polarized wave can be transmitted and received.

  The switch control circuit 47 described above receives switch control data D11 from the control device 46, generates switch selection signals S11 to S14 and S21 to S24 based on the switch control data D11, and outputs the switch selection signal S11 for the antenna ANT1. The switch SW1 is supplied, and the switch selection signal S12 is supplied to the switch SW2. The switch selection signal S13 is supplied to the switch SW3, and the switch selection signal S14 is supplied to the switch SW4. Based on these switch selection signals S11 to S14, the switches SW1 to SW4 of the antenna ANT1 can be ON / OFF controlled.

  The switch control circuit 47 receives the switch control data D11 from the control device 46, supplies the switch selection signal S21 to the switch SW1 and the switch selection signal S22 to the switch SW2 with respect to the antenna ANT2. The switch selection signal S23 is supplied to the switch SW3, and the switch selection signal S24 is supplied to the switch SW4. Based on these switch selection signals S21 to S24, the switches SW1 to SW4 of the antenna ANT2 can be ON / OFF controlled.

  In this example, switches SW1, SW2, SW3, SW4 are arranged clockwise in the respective corners of the two diagonal directions in the main excitation element 11, and the two switches SW1 and SW3 in one diagonal direction are turned on, and the other The two switches SW2 and SW4 in the diagonal direction are turned off. In two diagonal directions, turning on the two switches SW2 and SW4 on one diagonal and turning off the other two switches SW1 and SW3 enables selection of right / left rotation of circular polarization. . By turning on all the switches SW1 to SW4 arranged at the respective corners in the two diagonal directions with the main excitation element 11, linearly polarized waves can be selected.

表１は、４個のスイッチＳＷ１〜ＳＷ４の組み合わせと、そのアンテナ装置の動作例を示している。表１によれば、アンテナＡＮＴ１による方形パッチアンテナのスイッチＳＷ１及びＳＷ３がＯＮで、ＡＮＴ１のスイッチＳＷ２及びＳＷ４がＯＦＦである場合は、ＡＮＴ１が右旋偏波（ＲＨＣＰ）となる。アンテナＡＮＴ２による方形パッチアンテナ（以下ＡＮＴ２という）のスイッチＳＷ１及びＳＷ３がＯＦＦで、ＡＮＴ２のスイッチＳＷ２及びＳＷ４がＯＮである場合は、ＡＮＴ２が左旋偏波（ＬＨＣＰ）となる。

Table 1 shows a combination of four switches SW1 to SW4 and an operation example of the antenna device. According to Table 1, when the switches SW1 and SW3 of the rectangular patch antenna by the antenna ANT1 are ON and the switches SW2 and SW4 of the ANT1 are OFF, ANT1 is right-handed polarized wave (RHCP). When the switches SW1 and SW3 of the rectangular patch antenna (hereinafter referred to as ANT2) by the antenna ANT2 are OFF and the switches SW2 and SW4 of ANT2 are ON, ANT2 is left-handed polarized wave (LHCP).

  Further, when the switches SW1 and SW3 of ANT1 are OFF and the switches SW2 and SW4 of ANT1 are ON, ANT1 is left-handed polarized wave (LHCP). When the switches SW1 and SW3 of ANT2 are ON and the switches SW2 and SW4 of ANT2 are OFF, ANT2 is right-handed polarized wave (RHCP).

  Further, when all the switches SW1 to SW4 of ANT1 are ON, ANT1 is linearly polarized (LINEAR). When all the switches SW1 to SW4 of ANT2 are ON, ANT2 is linearly polarized (LINEAR). The case of “ON” described above is a state in which the main excitation element 11 such as the antennas ANT1 and ANT2 and the sub excitation elements 12a to 12d are electrically connected. In the geometric equivalent pattern, the main excitation element 11 and the sub excitation elements 12a to 12d are integrated on the same plane. On the other hand, the state is the opposite of the case of “OFF”. In the equivalent pattern, the corners of the main excitation element 11 are missing, and the sub excitation elements 12a to 12d are not electrically visible on the same plane.

In this way, if all the four switches SW1 to SW4 are set to “ON”, the circularly polarized wave is eliminated and the linearly polarized wave is obtained. That is, in the rectangular patch antenna using the antennas ANT1 and ANT2, three types of right-handed polarized wave, left-handed polarized wave, and linearly polarized wave can be selected. If these three radiation polarizations are selected so that the communication state is the best, transmission most suitable for the propagation environment used by the user can be performed.
Then, the control method of the radio | wireless communication apparatus which concerns on this invention is demonstrated. FIG. 8 is a flowchart illustrating a control example of the wireless communication device 400 to which the antenna device 100 is applied.

  In this embodiment, a conductive main excitation element 11 having an octagonal shape and disposed on an insulating substrate 19 and a polarization control element disposed in the diagonal direction of the main excitation element 11 with an insulating region interposed therebetween. The antennas ANT1 and ANT2 that switch the radiation polarization of the rectangular patch antenna by controlling on / off control of the switches SW1 to SW4 connected to the sub-excitation elements 12a to 12d are used to transmit and receive signals according to the MIMO communication system. Assumes the case.

  According to the MIMO communication system of this example, the switch switching combination is changed in N (i = 1 to N) ways to extract (find) a setting that maximizes the transmission rate. Furthermore, the subcarrier modulation is set to M (j = 1 to M), for example, 64QAM → 16QAM → 8PSK → QPSK, and the state of the antenna that maximizes the transmission speed is set by changing the subcarrier. Transmission / reception processing with the wireless communication apparatus is executed.

  On the premise of such operation setting conditions, the subcarrier is set to j = 1 in step A1 of the flowchart shown in FIG. For example, the subcarrier is set to 64QAM. Thereafter, in step A2, the combination of the switches SW1 to SW4 of each antenna ANT1 and ANT2 is set to i = 1. The transmission rate at these settings j = 1 and i = 1 is measured in step A3. For example, the reception circuits 44a and 44b measure reception sensitivity (reception strength RSSI or the like).

  Thereafter, the process proceeds to step A4, where it is determined (detected) whether or not the transmission rate is maximized. At this time, the maximum value of the transmission rate is detected, and when the maximum value of the transmission rate is detected, the process proceeds to step A5 and the setting of the combination of the switches SW1 to SW4 of each ANT1 and ANT2 is stored (registered). .

  Thereafter, the process proceeds to step A6, and the switch switching combination number is incremented by one (i = i + 1), and the process proceeds to step A7. In step A7, it is determined whether or not N combinations of switch switching have been completed. If N switches are not executed, that is, if i <N, the process returns to step A3 to measure the transmission rate. Thereafter, the discrimination, recording and incrementing of steps A4 to A6 are repeated.

  If the switch switching combination is i = N in step A6, the process proceeds to step A8, and the subcarrier variable step is incremented by j = j + 1. For example, the subcarrier is switched from 64QAM to 16QAM.

  Thereafter, the process proceeds to step A9, and if M variable steps are not executed, that is, if j <M, the process returns to step A2. In step A2, the combination of the switches SW1 to SW4 of each antenna ANT1 and ANT2 is set to i = 1. The transmission rate at these settings j = 2 and i = 1 is measured in step A3.

  Thereafter, the process proceeds to step A4, where it is detected whether the transmission rate is maximum in order to determine whether the communication quality of the rectangular patch antenna is optimal. When the transmission rate is the maximum, the process proceeds to step A5, and the setting of the combination of the switches SW1 to SW4 of each of the antennas ANT1 and ANT2 having the optimum detected communication quality is held (extracted). Thereafter, the process proceeds to step A6. Steps A2 to A7 for updating and holding the settings of the switches SW1 to SW4 determined to be optimal in this way are sequentially repeated.

  If the combination of switching is i = N in step A7, the process proceeds to step A8, j = j + 1 is performed in the subcarrier variable step, and if j <M in step A9, Returning to A2, the above-described processing is repeated. When j = M is reached in step A9, the process proceeds to step A10 to fix the setting. Thereby, communication can be executed by setting the switches SW1 to SW4 in which the optimum communication quality is detected, and by using the polarization method at that time, it is possible to realize wireless communication processing by the MIMO communication method suitable for the use environment. It becomes like this.

9A and 9B are diagrams illustrating an example of transmission / reception during non-reflection between the wireless communication apparatuses 401 and 402 in the MIMO communication scheme.
In this embodiment, it is assumed that a MIMO communication scheme is realized using two antennas ANT1 and ANT2 in data transmission and reception processing, and the communication processing is executed using a multipath environment. And For example, the wireless communication device 401 shown in FIG. 7 is applied to the wireless communication device 401 shown in FIG. 9A, and the antenna device 100, 200, or 300 described in the first, second, or third embodiment is applied 2. Two rectangular patch antennas ANT1 and ANT2 are arranged.

  In this example, the antenna ANT1 of the wireless communication apparatus 401 is set to right-handed polarization with the switches SW1 and SW3 turned on and the other switches SW2 and SW4 turned off. In terms of a geometric equivalent pattern, a rectangular patch pattern in which the upper right and lower left of the antenna ANT1 are missing is obtained. The antenna ANT1 radiates (radiates) right-hand polarized data Da.

  The antenna ANT2 is set to left-handed polarized wave with the switches SW2 and SW4 turned on and the other switches SW1 and SW3 turned off. In terms of a geometric equivalent pattern, a square patch pattern in which the upper left and lower right of the antenna ANT2 are missing is obtained. The antenna ANT2 radiates left-hand polarized data Db.

  The wireless communication apparatus 402 shown in FIG. 7 is applied to the wireless communication apparatus 402 shown in FIG. 9B, and two antenna apparatuses 100, 200, or 300 described in the first, second, or third embodiments are applied. Rectangular patch antennas ANT1 and ANT2 are arranged. In this example, the antenna ANT1 of the wireless communication device 402 is set to right-handed polarization with the switches SW1 and SW3 turned on and the other switches SW2 and SW4 turned off. In terms of a geometric equivalent pattern, a rectangular patch pattern in which the upper right and lower left of the antenna ANT1 are missing is obtained. The antenna ANT1 radiates (radiates) right-hand polarized data Da.

  The antenna ANT2 is set to left-handed polarized wave with the switches SW2 and SW4 turned on and the other switches SW1 and SW3 turned off. In terms of a geometric equivalent pattern, a square patch pattern in which the upper left and lower right of the antenna ANT2 are missing is obtained. The antenna ANT2 radiates left-hand polarized data Db.

  In the MIMO communication system in which the polarization is set in this way, when there is no reflecting object or the like in a multipath environment, the antenna ANT1 of the wireless communication device 401 transmits the right-hand polarized data Da to the right rotation by the wireless communication device 402. Data Da is received and processed by the antenna ANT1 set for polarization reception. Similarly, the antenna ANT2 of the wireless communication apparatus 401 receives and processes the data Db of the left-handed polarized wave data Db by the antenna ANT2 set to receive the left-handed polarized wave by the wireless communication apparatus 402.

  10A and 10B are diagrams illustrating an example of transmission / reception when a reflector 403 is present between the wireless communication apparatuses 401 and 202 in the MIMO communication scheme.

  In this embodiment, according to the MIMO communication system, there is a case where the polarized waves which are initially orthogonalized may cause interference due to the influence of the reflection by the reflector 403 in a multipath environment. Taking the example shown in FIGS. 9A and 9B, when the radiated radio wave from one antenna ANT1 is reflected once, the polarized wave becomes a reverse rotation, so when radiating from the antennas ANT1 and ANT2, In spite of the distinction between circularly polarized waves and counterclockwise polarized waves, they eventually become the same wave and cause interference. On the other hand, even if both antennas ANT1 and ANT2 radiate with the same rotational wave, there is a reflector 403 on one side, and the polarized wave becomes a reverse rotational wave despite being affected by the reflection. , May cause no interference.

  In this way, the polarization changes variously in a multipath rich environment, and even if it has orthogonality at the time of radiation, it may not necessarily be a superior result for communication characteristics depending on the radio wave environment There is. For example, the left-hand polarized wave data Db radiated from the antenna ANT2 of the wireless communication device 401 shown in FIG. 10A is received as a direct wave by the wireless communication device 402 shown in FIG. 10B. The right-hand polarized data Da radiated from the antenna ANT1 of the wireless communication device 401 is received as a reflected wave by the wireless communication device 402 shown in FIG. 9B.

  In such a case, the following two methods can be considered as methods for improving the quality of the received signal. The first method detects the reception sensitivity (reception strength RSSI, etc.) and feeds back to the transmission side. The setting of the antenna ANT2 of the wireless communication device 401 on the transmission side is left as it is, and only the antenna ANT1 is rotated from right to left. Switch to polarization mode. That is, the switch SW1, SW3 of the antenna ANT1 of the wireless communication apparatus 401 is switched from ON to OFF, and further, the switch SW2, SW4 is switched from OFF to ON. At the time of transmission, transmission is performed from both antennas with the same polarization. As a result, the reception side becomes a reverse wave due to reflection, and interference does not occur. According to the first method, when the signal level necessary for demodulation on the receiving side cannot be obtained, the reception level is increased even if the interference is prepared.

  In the second method, the antenna ANT2 of the wireless communication device 402 on the receiving side is set as it is, and only the antenna ANT1 is switched from right-handed to left-handed polarized wave according to reception sensitivity (reception strength RSSI, etc.). It is to select whether to use as it is without switching. According to the second method, the signal level necessary for demodulation on the receiving side is obtained, but rather the level of the interference signal is lowered by reducing the receiving sensitivity to improve the signal quality. It is.

  In this example, the reception sensitivity (reception intensity RSSI, etc.) is detected, and the radio communication device 402 on the reception side can easily switch the polarization from right to left or left to right as appropriate according to this RSSI. Made. Below, the Example regarding this RSSI detection is described.

  FIG. 11 is a RSSI detection level diagram showing an example of threshold setting at the time of switch (polarization) switching control. FIG. 12 is a flowchart illustrating an example of control at the time of polarization switching in the radio communication device 402 on the receiving side.

  In this example, when the polarization is switched from right-handed to left-handed or left-handed to right-handed in the wireless communication device 402 on the receiving side in accordance with RSSI, as shown in FIG. It is assumed that a threshold value Lth1 and an upper limit threshold value Lth2 (Lth1 <Lth2) are set, and the right-handed and left-handed polarized waves are switched based on the lower and upper limit threshold values Lth1 and Lth2.

  In this example, when the relationship between RSSI and upper limit threshold Lth2 is RSSI> Lth2, and when the relationship between RSSI and lower limit threshold Lth1 is that RSSI <Lth1, switches SW1 to SW4 are switched. Executes polarization switching setting. Note that, when the relationship between the RSSI and the lower and upper thresholds Lth1 and Lth2 is Lth1 ≦ RSSI <Lth2, a case where the current reception state is maintained without performing polarization switching will be described as an example.

  With these as switch (polarization) switching conditions, RSSI is detected in step B1 of the flowchart shown in FIG. The RSSI is detected by the receiving circuits 44 a and 44 b and the RSSI detection data is output to the control device 46. Next, in step B2, the control device 46 compares the RSSI and the upper limit threshold Lth2 based on the RSSI detection data, and determines whether RSSI> Lth2. When RSSI> Lth2, the process proceeds to step B3 to switch the switches SW1 to SW4 and execute the polarization switching setting (see FIGS. 10A and 10B).

  Thereafter, the process proceeds to step B4, and the control device 46 determines whether or not the relationship between the lower limit and upper limit thresholds Lth1 and Lth2 is Lth1 ≦ RSSI <Lth2. When the relationship between the RSSI, the lower limit and the upper limit thresholds Lth1 and Lth2 is Lth1 ≦ RSSI <Lth2, the current reception state is maintained.

  When RSSI> Lth2 is not satisfied in Step B2 described above, that is, when RSSI is Lth2 or less, the process proceeds to Step B6. If the relationship between the RSSI, the lower limit and the upper limit thresholds Lth1 and Lth2 is not Lth1 ≦ RSSI <Lth2 in step B4, the process proceeds to step B5, the switch switching setting is restored, and then the process proceeds to step B6. In step B6, the control device 46 compares the RSSI and the lower threshold Lth1, and determines whether RSSI ≦ Lth1.

  When RSSI ≦ Lth1, the process proceeds to step B8, and the control device 46 switches the switches SW1 to SW4 to execute the polarization switching setting. Thereafter, the process proceeds to step B9, and the control device 46 determines whether or not the relationship between the RSSI, the lower limit and the upper limit thresholds Lth1 and Lth2 is Lth1 ≦ RSSI <Lth2. When Lth1 ≦ RSSI <Lth2, the current reception state is maintained.

  If the relationship between the RSSI, the lower limit and the upper limit thresholds Lth1 and Lth2 is not Lth1 ≦ RSSI <Lth2 in step B9, the process proceeds to step B10, the switch switching setting is restored, and the process proceeds to step B11. Change career. Thereafter, the process returns to step B1 to repeat the above-described processing.

  As described above, according to the radio communication apparatus and the control method thereof as the fourth embodiment, the rectangular patch antennas ANT1 and ANT2 according to the present invention are applied, and between the main excitation element 11 and the sub excitation elements 12a to 12d. By switching on / off the switches SW1 to SW4 connected to, the radiation polarization of the main excitation element 11 is switched.

  In this example, when the switches SW1 to SW4 are controlled to be turned on / off, the main excitation element 11 and one diagonal sub-excitation element 12a to 12d are electrically connected, and the other diagonal sub-excitation element 12a to 12d. Since 12d is in an insulated state, a circularly polarized antenna body exhibiting the characteristics of right-handed polarization or left-handed polarization can be formed. Further, when all the switches SW1 to SW4 at the four corners in the diagonal direction are turned on, a linearly polarized antenna body can be configured.

  Therefore, it is possible to select three types of antenna bodies constituted by combinations of the main excitation element 11 and the sub excitation elements 12a to 12d, and transmit / receive signals of linearly polarized waves, right-handed polarized waves, and left-handed polarized waves. . As a result, the wireless communication process can be executed by the MIMO communication method suitable for the radio wave environment.

  Further, for the purpose of cost reduction or the like, for example, the switches SW1 to SW4 are not provided at all four corners on the diagonal line between the main excitation element 11 and the sub excitation elements 12a to 12d, but only on one diagonal line. The other diagonal corner is not cut away. Then, by switching ON / OFF of these switches SW1 to SW4, it is possible to switch between circularly polarized waves (right or left) and linearly polarized waves to detect optimum communication quality. .

  In this embodiment, the case where the rectangular patch antennas ANT1 and ANT2 described in the first embodiment are applied has been described. However, the present invention is not limited to this, and the MEMS switch SW1 ′ described in the second embodiment is used. The wireless communication device 400 in which a plurality of antenna devices 200 and the antenna device 300 having the circular patch pattern described in the third embodiment are mounted may be configured. The same effect as in the fourth embodiment can be obtained.

  FIG. 13 is a diagram illustrating a configuration example of an antenna device 500 as the fifth embodiment. An antenna device 500 shown in FIG. 13 is applied to an antenna that simultaneously transmits and receives signals using a multi-input multi-output (hereinafter referred to as MIMO) communication method using a plurality of planar antennas, and a wireless communication device that applies the antenna. It is preferable. The antenna device 500 is configured by disposing a conductive main excitation element 51, which is an example of a planar antenna main body, on a dielectric substrate 29. The main excitation element 51 has, for example, an octagonal rectangular patch pattern shape with four corners cut off. The substrate 29 has a length L and a width W. The main excitation element 51 has a length L ′ (L ′ <L) and a width W ′ (W ′ <W). The main excitation element 51 is made of a metal material such as copper having a thickness t, white copper, phosphor bronze, brass, SUS, or gold, and the main excitation element 51 is formed by etching a copper foil substrate or metal plating on a resin. It is formed by a method, a metal foil attaching technique, or the like.

  In the diagonal direction of the main excitation element 51, a triangular sub-excitation element (degenerate separation element or perturbation element) for polarization control, which is an example of a small piece, is disposed. Unlike the main excitation elements 51, the sub excitation elements P1 to P4 are made of a semiconductive resin material. For example, the auxiliary excitation elements P1 to P4 are made of any conductive plastic of polyacetylene, polythiophene, polyaniline, polypyrrole, or polyazulene.

  For example, the auxiliary excitation elements P1 to P4 are formed by joining a triangular conductive (semiconductive) plastic on the lower dielectric substrate 29 continuously to the four corners of the octagonal main excitation element 51. Created by. A predetermined adhesive is used for the connecting portion. In this example, the finished shape of the main excitation element 51 including the auxiliary excitation elements P1 to P4 has a quadrangular shape.

  The sub excitation element P1 is provided with a control electrode 52a made of metal so as to supply a DC bias voltage. Similarly, control electrodes 52b, 52c and 52d are provided in the other sub-excitation elements P2 to P4 so as to supply a DC bias voltage. In this example, the direct-current bias voltage supplied to the control electrodes 52a, 52b, 52c, and 52d is controlled to switch the radiation polarization of the rectangular patch antenna.

  For the above-mentioned dielectric substrate 29, a solid electrolyte member of any one of silicon gel, acrylonitrile gel or polysaccharide polymer is used. The substrate 29 is provided with four control terminals 13a to 13d. The control terminal 13a is connected to the control electrode 52a of the auxiliary excitation element P1 via the choke coil 14a. A bypass capacitor 15a is connected between the control electrode 52a and a ground (GND) pattern (not shown). The choke coil 14a, the bypass capacitor (pass capacitor) 15a, and the like constitute a filter for preventing a high-frequency current from entering and is connected to a DC line as necessary, and the filter is laid out (arranged) at an appropriate position. .

  The ground pattern 17 is provided on the back side of the substrate. The bypass capacitor 15a is connected to the ground pattern 17 through a through hole. Similarly, the other control terminals 13b to 13d are connected to the control electrodes 52b, 52c and 52d of the sub-excitation elements P2 to P4 via the choke coils 14b, 14c and 14d, respectively. The bypass capacitors 15b, 15c, and 15d are connected in the same manner.

  The DC bias voltage (hereinafter also referred to as function control signals S31 to S14 and S21 to S24) for selecting the conductive or insulating function of the sub-excitation elements P1 to P4 includes the control electrodes 52a, 52b, 52c and 52d and the ground pattern. 17 is supplied. A communication control unit (function control circuit or the like) (not shown) is connected to the control terminals 13a to 13d and the ground pattern 17, and with respect to the sub excitation elements P1 to P4, the sub excitation elements P1, P3, P2, and P4 in the diagonal direction, etc. In this way, a DC bias voltage is supplied to the pair. This rectangular patch antenna, for example, emits circularly polarized radiation such as right-handed and left-handed polarized waves as shown in Hiroyuki Arai, “New Antenna Engineering”, General Electronic Publishing (1996), and linearly polarized radiation. To be made.

  14A and 14B are a top view showing a structure example of the antenna device 500 and a cross-sectional view taken along line X1-X1 thereof. 15A to 15C are exploded top views showing examples of the laminated structure of the antenna device 500. FIG.

  In FIG. 14A, the antenna device 500 includes sub-excitation elements P1 to P4, a square-shaped dielectric substrate 29, an octagonal main excitation element 51, and triangular sub-excitation elements P1 to P4. In FIG. 14B, the sub excitation elements P1 to P4 are configured so as to be continuous from the four corners of the main excitation element 51 so that the finished shape of the main excitation element 51 including the sub excitation elements P1 to P4 is a square shape. .

  15A to 15C are exploded top views showing examples of the laminated structure of the antenna device 500. FIG. The antenna device 500 shown in FIG. 15A has a three-layer structure, and the first layer includes a dielectric substrate 29, a main excitation element 51, and auxiliary excitation elements P1 to P4. A main excitation element 51 and auxiliary excitation elements P1 to P4 are arranged on the first dielectric substrate 29a. An RF feeding point (through hole 16e) is provided below the main excitation element 51.

  In the second layer shown in FIG. 15B, a dielectric substrate 29b and a microstrip line 18 are provided, and the main excitation element 51 is connected to the main excitation element 51 through a through hole 16e provided in the first layer of the dielectric substrate 29a. Connected. The microstrip line 18 has a characteristic impedance of 50Ω, and is arranged in a state sandwiched between the first and second dielectric substrates 29a and 19b. The microstrip line 18 is provided with a power supply terminal (power supply circuit), and is connected to a high-frequency circuit or the like of the wireless communication device so as to supply a transmission signal or draw a reception signal. The third layer shown in FIG. 15C includes a ground pattern 17 (GND layer) provided on the entire back surface of the second dielectric substrate 29b. Thus, the antenna device 500 having a three-layer structure is configured.

  Here, a manufacturing method of the antenna device 500 having a three-layer structure will be described. First, a square single-sided copper foil substrate having a copper foil on one surface of a dielectric substrate is prepared, and an octagonal resist is applied and patterned on the copper foil as a main excitation element. Using this resist as a mask, excess copper foil is removed with a predetermined etching solution. Thereby, the octagonal main excitation element 51 can be formed on the single-sided copper foil substrate. Thereafter, a triangular semiconductive plastic member is bonded onto the lower dielectric substrate 29 continuously to the four corners of the octagonal main excitation element 51. Thereby, the sub excitation elements P1-P4 can be formed. A predetermined adhesive is used for bonding the plastic member onto the substrate 29. It should be noted that the conductive plastic is formed into a triangular shape and joined so that the finished shape of the main excitation element 51 including the secondary excitation elements P1 to P4 is a square shape.

  Next, a through hole having a predetermined diameter reaching the main excitation element 51 is formed. The through hole is opened by a drill or the like. The diameter of the through hole 16e only needs to ensure a level that can form a conductive member. Thus, the first substrate 29a having the main excitation element 51 and the sub excitation elements P1 to P4 on one surface and the through hole 16e having a predetermined diameter from the main excitation element 51 to the back surface is formed. be able to.

  Next, a square-shaped double-sided copper foil substrate having copper foil on both sides of a dielectric substrate is prepared, and a resist having a predetermined shape is applied to the copper foil on one side for patterning and patterned. . The resist is applied in alignment with the through hole 16e described above. The copper foil on the other surface is coated with a resist on the entire surface. Using these resists as a mask, excess copper foil is removed with a predetermined etching solution. Thereby, the second substrate 29b having the microstrip line 18 on one surface and the ground pattern 17 on the other surface can be formed. Of course, the present invention is not limited to this, and a copper foil or the like equivalent to a microstrip line may be attached to the surface of the single-sided copper foil substrate on which the copper foil is not formed.

  Thereafter, the first substrate 29a having the main excitation element 51, the sub excitation elements P1 to P4 and the through hole 16e and the second substrate 29b having the microstrip line 18 and the ground pattern 17 are bonded with a predetermined adhesive. Use them together. The bonding surface is a surface that does not have the main excitation element 51 and the sub excitation elements P1 to P4 on the first substrate 29a and a surface that has the microstrip line 18 on the second substrate 29b. Further, a conductive member is filled in the through hole or plated to electrically connect the main excitation element 51 and the microstrip line 18.

16A and 16B are cross-sectional views showing control examples for making the sub-excitation element P1 and the like conductive or insulating.
The junction structure shown in FIG. 16A is obtained by extracting a part of the sub excitation element P1 on the dielectric substrate 29 shown in FIG. For the dielectric substrate 29, a solid electrolyte member made of silicon gel, acrylonitrile gel, polysaccharide polymer, or the like is used. This solid electrolyte member is a member that easily induces negative (negative) ions. The sub excitation element P1 is made of a semiconductive resin material, for example, a conductive plastic such as polyacetylene, polythiophene, polyaniline, polypyrrole, or polyazulene.

  In the junction structure shown in FIG. 16A, a forward bias voltage is supplied between the control electrode 52a of the sub excitation element P1 and the ground pattern 17 on the back surface of the substrate. When such a bias voltage is supplied, negative ions (electrons) are injected (doping) from the dielectric substrate 29 in which the sub-excitation element P1 and the like are solid electrolytes to the semi-conductive plastic sub-excitation element. The sub-excitation element P1 changes to conductivity and changes to the property of conducting electricity well like a metal.

  On the other hand, when a reverse bias voltage is supplied between the control electrode 52a of the sub-excitation element P1 and the ground pattern 17 on the back surface of the substrate in the junction structure shown in FIG. 16B, the negative ions are converted into semiconductive plastic. Since it is extracted (dedoped) from the auxiliary excitation element P1 or the like to the dielectric substrate 29, the auxiliary excitation element P1 changes to insulation and changes to a property that makes it difficult to improve electricity like an insulator.

  In this example, in the junction structure of a solid electrolyte and a semiconductive plastic, the property of changing to conductivity or insulation by doping / dedoping depending on the application direction of the DC bias voltage described above is a sub-excitation for polarization control. This is applied to the element P1 and the like.

  Thus, according to the antenna device 500 having the three-layer structure as the fifth embodiment, the sub excitation elements P1, P2, P3, and P4 are arranged at the respective corners in the two diagonal directions in the main excitation element 51, while The two sub-excitation elements P1 and P3 in the diagonal direction are made conductive, and the two sub-excitation elements P2 and P4 in the other diagonal direction are made insulating. When the auxiliary excitation elements P1 to P4 are functionally controlled to be conductive or insulative as described above, the main excitation element 51 and one of the diagonal excitation elements P1 and P3 are electrically connected, and the other diagonal direction is applied. Since the sub-excitation elements P2 and P4 are in an insulated state, a circularly polarized antenna body exhibiting the characteristics of right-handed polarization or left-handed polarization can be formed.

  Further, if all the sub-excitation elements P1 to P4 at the four corners in the diagonal direction are made conductive, a linearly polarized antenna body can be formed. By controlling the functions of the sub-excitation elements P1 to P4 to be conductive or insulating, the main excitation element 51 and the sub-excitation elements P1 to P4 can be combined. Three types of polarized antennas can be configured with one structure. As a result, the antenna device 500 with the radiation polarization switching function can be sufficiently applied to a MIMO communication system suitable for a radio wave environment.

  FIG. 17 is a diagram illustrating a configuration example of an antenna device 600 according to the sixth embodiment. The antenna device 600 shown in FIG. 17 is suitable for application to an antenna that simultaneously transmits and receives signals by a MIMO communication method using a plurality of planar antennas and a wireless communication device to which the antenna is applied. The antenna device 600 is configured by disposing a conductive main excitation element 61 on a dielectric substrate 29. The main excitation element 61 has a circular shape. The substrate 29 has a length L and a width W. The diameter of the main excitation element 61 is Dφ (Dφ <L, W). The material of the main excitation element 61 and the manufacturing method thereof are as described in the fifth embodiment.

  When the origin is defined at the center of the circular main excitation element 61 in the diagonal direction of the dielectric substrate 29, the circumference is 90 ° along the diagonal direction with respect to the origin (see FIG. At predetermined positions, rectangular sub-excitation elements P1 ′ to P4 ′ (degenerate separation elements or perturbation elements) for polarization control, which are an example of small pieces, are arranged. Unlike the main excitation element 61, the auxiliary excitation elements P1 'to P4' are made of a semiconductive plastic member. The auxiliary excitation elements P1 ′ to P4 ′ are, for example, separated from each other so that the lower dielectric substrate 29 is exposed by cutting out a predetermined position of the circular main excitation element 61 into a U shape. It is formed by joining semiconductive plastic members so as to fill the letter-shaped notch.

  In this example, the sub excitation elements P1 ′ to P4 ′ are mounted (joined) at positions on the circumference of the main excitation element 61, and the sub excitation elements P1 to P4 are controlled to be conductive / insulating. The radiation polarization of a planar antenna (hereinafter referred to as a circular patch antenna) is switched.

  As in the fifth embodiment, the dielectric substrate 29 is provided with four control terminals 13a to 13d. The control terminal 13a is connected to the control electrode 62a of the auxiliary excitation element P1 via the choke coil 14a. A bypass capacitor 15a is connected between the control electrode 62a and a ground pattern 17 (not shown). The choke coil 14a, the bypass capacitor 15a, and the like constitute a filter for preventing a high-frequency current from being sneak in, and are connected to a DC system line as necessary, and the filter is laid out at an appropriate position.

  The ground pattern 17 is provided on the back side of the substrate in the same manner as in the fifth embodiment. The bypass capacitor 14a is connected to the ground pattern 17 through the through hole 16a. Similarly, the other control terminals 13b to 13d are connected to the control electrodes 62b, 62c and 62d of the sub excitation elements P2 'to P4' via the choke coils 14b, 14c and 14d, respectively. The bypass capacitors 15b, 15c, and 15d are connected in the same manner.

  A DC bias voltage (function control signal) for selecting the function of the auxiliary excitation elements P1 'to P4' is supplied between the control electrodes 62a, 62b, 62c, 62d and the ground pattern 17. A function control unit (function controller) (not shown) is connected to the control terminals 13a to 13d and the ground pattern 17, and with respect to the sub excitation elements P1 'to P4', diagonal sub-excitation elements P1 ', P3' and P2 ' A DC bias voltage is supplied to the pair, such as every P4 ′. As described in the fifth embodiment, this circular patch antenna also emits circularly polarized radiation such as right-handed and left-handed polarized waves, linearly polarized radiation, and the like.

  As described above, since the main excitation element 61 according to the sixth embodiment is configured by a circular patch pattern, the present invention is not limited to the rectangular patch antenna described in the fifth embodiment, and is based on the concept of the present invention. The present invention can be applied to various types of wireless communication devices based on the antenna device 600 having a circular patch antenna.

FIG. 18 is a block diagram illustrating a configuration example of a wireless communication apparatus 700 as a seventh embodiment to which the antenna apparatus 500 is applied.
In this embodiment, N (N is an integer of 2 or more) antenna devices and transmission / reception circuits are applied to appropriately control the radiation polarization of the antenna devices, and the MIMO communication (transmission) system suitable for the usage environment Is made to realize. In this example, the antenna device 500 described in the fifth embodiment is used for each of the antennas ANT1 ′ and ANT2 ′.

  18 includes a communication control unit 40 ′, a high frequency unit 43, a memory unit 48, two (= N) antennas ANT1 ′ and ANT2 ′, and two transmission / reception changeover switches 41 and 42. The MIMO communication method is realized. The high frequency unit 43 includes two receiving circuits 44a and 44b and two transmitting circuits 45a and 45b.

  A transmission / reception selector switch 41 is connected to the antenna ANT1 '. The transmission / reception changeover switch 41 is configured to connect either the reception circuit 44a or the transmission circuit 45a in the high-frequency unit 43 to the power supply terminal (through hole 16e) of the antenna ANT1 '. The power feeding terminal is connected to the main excitation element 51 of the antenna ANT1 'through the microstrip line 18, and feeds a transmission signal or receives (draws) a reception signal.

  The reception circuit 44a and the transmission circuit 45a constitute a transmission / reception circuit for transmitting / receiving a signal by a MIMO communication method using the first antenna ANT1 '. The reception circuit 44a is connected to the antenna ANT1 'via the transmission / reception changeover switch 41, takes in a reception signal from the antenna ANT1' via the transmission / reception changeover switch 41, and performs reception processing by the MIMO communication method.

  The transmission circuit 45a is connected to the antenna ANT1 'via the transmission / reception changeover switch 41, processes the transmission signal by the MIMO communication method, and feeds the transmission signal to the antenna ANT1' via the transmission / reception changeover switch 41.

  A transmission / reception changeover switch 42 is connected to the antenna ANT2 '. The transmission / reception changeover switch 42 is configured to connect either the reception circuit 44b or the transmission circuit 45b to the power supply terminal (through hole 16e) of the antenna ANT2 '. The power feeding terminal is connected to the main excitation element 51 of the antenna ANT2 'through the microstrip line 18, and feeds the transmission signal or receives (draws) the reception signal.

  The reception circuit 44b and the transmission circuit 45b constitute a transmission / reception circuit for transmitting / receiving a signal by the MIMO communication method using the second antenna ANT2 '. The reception circuit 44b is connected to the antenna ANT2 'via the transmission / reception changeover switch 42, takes in a reception signal from the antenna ANT2' via the transmission / reception changeover switch 42, and performs reception processing by the MIMO communication method.

  The transmission circuit 45b is connected to the antenna ANT2 'via the transmission / reception changeover switch 42, processes the transmission signal by the MIMO communication method, and feeds the transmission signal to the antenna ANT2' via the transmission / reception changeover switch 42.

  A communication control unit 40 ′ is connected to the antennas ANT1 ′, ANT2 ′ and the high frequency unit 43 described above, and the communication control unit 40 ′ has the antennas ANT1 and ANT2 according to the quality of the signals received by the receiving circuits 44a and 44b. The DC bias voltage to each control electrode 52a, 52b, 52c, 52d is controlled. For example, the auxiliary excitation elements P1 to P4 of the antenna ANT1 ′ are controlled to be conductive or insulating according to the quality of the signal received by the receiving circuit 44a, and the antenna is selected according to the quality of the signal received by the receiving circuit 44b. The auxiliary excitation elements P1 to P4 of ANT2 ′ are controlled to be conductive or insulating.

  The communication control unit 40 ′ includes a control device 46 and a function control circuit 57 for the auxiliary excitation element. A function control circuit 57 is connected to the antennas ANT1 'and ANT2'. The function control circuit 57 is connected to the control device 46. The control device 46 uses a CPU (Central Processing Unit), MPU (Micro Processing Unit), A / D converter, D / A converter, BB circuit, MAC circuit, user interface, etc. (not shown).

  The control device 46 controls the antennas ANT1 'and ANT2' through the high frequency unit 43 and the function control circuit 57. For example, the function switching signal SS1 is output to the transmission / reception switching switch 41 to switch the transmission / reception function of the antenna ANT1 ′, or the function switching signal SS2 is output to the transmission / reception switching switch 42 to switch the transmission / reception function of the antenna ANT2 ′. .

  In addition, the control device 46 controls the conductivity or insulation of the four sub excitation elements P1 to P4 provided continuously to the main excitation element 51 according to the quality of the reception signals received by the reception circuits 44a and 44b. To do. In the case of the IEEE 802.11a system, the quality of the received signal can be obtained by monitoring an AGC (automatic gain control) signal before quadrature detection. Of course, the present invention is not limited to this, and the quality of the received signal may be determined by detecting the decoded data.

  For example, the control device 46 determines whether the RSSI is within a certain range. When the RSSI is not within a certain range, for example, when the RSSI is lower than the lower limit threshold or when the RSSI exceeds the upper limit threshold, the control device 46 instructs the function control circuit 57 to switch the polarization. Function control data D21 is output. As a result, the radiation polarization of the antennas ANT1 'and ANT2' can be controlled (polarization diversity).

  As in the fourth embodiment, the control device 46 feeds (transmits) power from the transmission circuits 45a and 45b to the antennas ANT1 ′ and ANT2 ′ in accordance with the quality of the reception signals received by the reception circuits 44a and 44b. The subcarrier modulation scheme of the transmission signal is controlled. Through this control of the subcarrier modulation scheme, a MIMO communication (transmission) scheme suitable for the usage environment can be realized.

  The control device 46 is connected to a memory unit 48 that is an example of a recording medium, and stores a control program for a wireless communication device that transmits and receives signals according to the MIMO communication method. As the memory unit 48, a read-only memory (ROM), a memory (RAM) in which information can be written and read at any time, a read memory (EEPROM) in which information can be electrically erased and written, or a hard disk device (HDD) are used. The

  In this control program, a step of setting a DC bias voltage to the control electrodes 52a, 52b, 52c, 52d of the antennas ANT1 ′ and ANT2 ′, and a DC to the control electrodes 52a, 52b, 52c, 52d set here are set. The step of detecting the communication quality of the rectangular patch antenna constituted by the bias voltage and the setting of the DC bias voltage to the control electrodes 52a, 52b, 52c, and 52d based on the detected communication quality of the rectangular patch antenna are held. And a step of executing communication by setting a DC bias voltage to the control electrodes 52a, 52b, 52c, and 52d held here.

  By using the control program stored in the memory unit 48, three types of rectangular patch antennas configured by combinations of the main excitation element 51 and the sub excitation elements P1 to P4 are selected, and the optimum state is obtained. Using the set rectangular patch antenna, signals of linearly polarized wave, right-handed polarized wave and left-handed polarized wave can be transmitted and received.

  The function control circuit 57 receives the function control data D21 from the control device 46, generates function selection signals (DC bias voltages) S31 to S34 and S41 to S44 based on the function control data D21, and relates to the antenna ANT1 ′. The function selection signal S31 is supplied to the sub excitation element P1, and the function selection signal S32 is supplied to the sub excitation element P2. Further, the function selection signal S33 is supplied to the auxiliary excitation element P3, and the function selection signal S34 is supplied to the auxiliary excitation element P4. Based on these function selection signals S31 to S34, the sub excitation elements P1 to P4 of the antenna ANT1 'can be controlled to be conductive or insulating.

  The function control circuit 57 receives the function control data D21 from the control device 46, supplies the function selection signal S41 to the auxiliary excitation element P1 and supplies the function selection signal S42 to the auxiliary excitation element P2 with respect to the antenna ANT2 '. Further, the function selection signal S43 is supplied to the auxiliary excitation element P3, and the function selection signal S44 is supplied to the auxiliary excitation element P4. Based on these function selection signals S41 to S44, the sub excitation elements P1 to P4 of the antenna ANT2 'can be controlled to be conductive / insulating.

  In this example, sub excitation elements P1 to P4 having control electrodes 52a, 52b, 52c, and 52d are respectively arranged clockwise in the respective corners of the two diagonal directions in the main excitation element 51. A forward bias voltage is supplied to the control electrodes 52a and 52c of the two auxiliary excitation elements P1 and P3, and a reverse bias voltage is supplied to the control electrodes 52b and 52d of the other two auxiliary excitation elements P2 and P4 in the diagonal direction. . When such a bias voltage is supplied, one of the two sub-excitation elements P1 and P3 changes to conductivity (doping), and the other two sub-excitation elements P2 and P4 change to insulation (undoping).

  Conversely, a reverse bias voltage is supplied to the control electrodes 52a and 52c, and a forward bias voltage is supplied to the control electrodes 52b and 52d. As a result, the auxiliary excitation elements P1 and P3 become insulative, and the auxiliary excitation elements P2 and P4 become conductive. Thereby, it is possible to select right-handed / left-handed circularly polarized waves depending on the conductivity or insulation of the sub-excitation elements P1 to P4. By supplying a forward bias voltage to all the control electrodes 52a, 52b, 52c, and 52d, all the sub-excitation elements P1 to P4 can be made conductive and a linearly polarized wave can be selected.

表２は、４個の副励振素子Ｐ１〜Ｐ４の組み合わせと、そのアンテナ装置５００の動作例を示している。表２によれば、アンテナＡＮＴ１’による方形パッチアンテナの副励振素子Ｐ１及びＰ３が導電性で、ＡＮＴ１’の副励振素子Ｐ２及びＰ４が絶縁性である場合は、ＡＮＴ１’が右旋偏波（ＲＨＣＰ）となる。アンテナＡＮＴ２’による方形パッチアンテナ（以下ＡＮＴ２’という）の副励振素子Ｐ１及びＰ３が絶縁性で、ＡＮＴ２’の副励振素子Ｐ２及びＰ４が導電性である場合は、ＡＮＴ２’が左旋偏波（ＬＨＣＰ）となる。

Table 2 shows a combination of four sub excitation elements P1 to P4 and an operation example of the antenna device 500. According to Table 2, when the sub-excitation elements P1 and P3 of the rectangular patch antenna by the antenna ANT1 ′ are conductive and the sub-excitation elements P2 and P4 of the ANT1 ′ are insulative, ANT1 ′ is a right-hand polarized wave ( RHCP). When the sub-excitation elements P1 and P3 of the rectangular patch antenna (hereinafter referred to as ANT2 ') by the antenna ANT2' are insulative and the sub-excitation elements P2 and P4 of the ANT2 'are conductive, the ANT2' is left-hand polarized (LHCP). )

  Further, when the auxiliary excitation elements P1 and P3 of ANT1 'are insulative and the auxiliary excitation elements P2 and P4 of ANT1' are conductive, ANT1 'is left-handed polarized wave (LHCP). When the sub excitation elements P1 and P3 of the ANT 2 'are conductive and the sub excitation elements P2 and P4 of the ANT 2' are insulative, the ANT 2 'is right-handed polarized wave (RHCP).

  Furthermore, when all of the sub-excitation elements P1 to P4 of ANT1 'are conductive, ANT1' is linearly polarized (LINEAR). When all of the auxiliary excitation elements P1 to P4 of ANT2 'are conductive, ANT2' is linearly polarized (LINEAR). The case of “conductive” described above is a state in which the main excitation elements 51 such as the antennas ANT1 ′ and ANT2 ′ and the sub excitation elements P1 to P4 are electrically connected. In a geometric equivalent pattern, the main excitation element 51 and the sub excitation elements P1 to P4 are integrated on the same plane. On the other hand, the state is the opposite of the “insulating” case. In the equivalent pattern, the corners of the main excitation element 51 are missing and the sub excitation elements P1 to P4 are not electrically visible on the same plane.

Thus, if all the four sub-excitation elements P1 to P4 are made “conductive”, they are not circularly polarized but linearly polarized. That is, in the rectangular patch antenna using the antennas ANT1 ′ and ANT2 ′, three types of right-handed polarized wave, left-handed polarized wave, and linearly polarized wave can be selected. If these three radiation polarizations are selected so that the communication state is the best, transmission most suitable for the propagation environment used by the user can be performed.
Then, the control method of the radio | wireless communication apparatus which concerns on this invention is demonstrated. FIG. 19 is a flowchart illustrating a control example of the wireless communication device 700 to which the antenna device 500 is applied.

  In this embodiment, a conductive main excitation element 51 having an octagonal shape and disposed on a dielectric substrate 29, and sub excitation elements P1 to P4 for polarization control in the diagonal direction of the main excitation element 51, The antennas ANT1 ′ and ANT2 ′ for switching the radiation polarization of the rectangular patch antenna using its conductivity or insulation by controlling the DC bias voltage supplied to the control electrodes 52a, 52b, 52c and 52d It is assumed that a signal is transmitted and received by the MIMO communication method.

  According to the MIMO communication system of this example, the conductive or insulating combination of the sub excitation elements P1 to P4 is changed in N (i = 1 to N) ways, and transmission is performed in the same manner as in the fourth embodiment. Extract (find) the setting that maximizes the speed. Furthermore, the subcarrier modulation is set to M (j = 1 to M), for example, 64QAM → 16QAM → 8PSK → QPSK, and the state of the antenna that maximizes the transmission speed is set by changing the subcarrier. Transmission / reception processing with the wireless communication apparatus is executed.

  On the premise of such operation setting conditions, the subcarrier is set to j = 1 in step C1 of the flowchart shown in FIG. For example, the subcarrier is set to 64QAM. Thereafter, in step C2, the combination of conductivity / insulation of the sub-excitation elements P1 to P4 of the antennas ANT1 'and ANT2' is set to i = 1. At this time, the DC bias voltage to the control electrodes 52a, 52b, 52c, 52d of the antennas ANT1 'and ANT2' is set. The transmission rate at these settings j = 1 and i = 1 is measured in step C3. For example, reception sensitivity (reception strength RSSI) is measured. This is to detect the communication quality of the rectangular patch antenna constituted by the DC bias voltage applied to the set control electrodes 52a, 52b, 52c, and 52d.

  Thereafter, the process proceeds to step C4, where it is determined (detected) whether or not the transmission rate is maximized. When the transmission speed reaches the maximum, the process proceeds to step C5 to record (register) the setting of the conductive or insulating combination of the auxiliary excitation elements P1 to P4 of the antennas ANT1 'and ANT2'. At this time, the setting of the DC bias voltage to the control electrodes 52a, 52b, 52c, and 52d based on the communication quality of the square patch antenna that has been previously issued is maintained.

  Thereafter, the process proceeds to step C6, and the conductive or insulating combination number of the auxiliary excitation elements P1 to P4 is incremented by one (i = i + 1). Thereafter, the process proceeds to step C7, and it is determined whether the combination of conductivity or insulation of the N types of auxiliary excitation elements P1 to P4 has been executed. If the combination is i <N, the process returns to step C3 to measure the transmission rate. Thereafter, the determination of the maximum value in step C4 is repeated.

  If the combination of conductivity or insulation of the sub-excitation elements P1 to P4 becomes i = N in step C7, the process proceeds to step C8 where j = j + 1 (increment) the subcarrier variable step. For example, the subcarrier is switched from 64QAM to 16QAM, and the process returns to Step C2.

  In step C2, the combination of conductivity or insulation of the sub-excitation elements P1 to P4 of the antennas ANT1 'and ANT2' is set to i = 1. The transmission rate at these settings j = 2 and i = 1 is measured in step C3. Thereafter, the process proceeds to step C4, where it is detected whether or not the transmission rate is maximized in order to determine whether or not the communication quality of the rectangular patch antenna is optimal. When the transmission rate reaches the maximum, the process proceeds to step C5, and the setting of the combination of the conductive or insulating properties of the antennas ANT1 and ANT2 that are detected in advance and has the optimum communication quality is recorded (registered). Thereafter, the process proceeds to step C6. Steps C2 to B7 for updating and holding the settings of the sub excitation elements P1 to P4 determined to be optimal in this way are sequentially repeated.

  Then, in step C7, when the combination of conductivity or insulation of the sub-excitation elements P1 to P4 is i = N, the process proceeds to step C8 where j = j + 1 is performed in the subcarrier variable step. If j <M in C9, the process returns to step C2 and the above-described processing is repeated. If j = M is reached in step C9, the process proceeds to step C10 to fix the setting. As a result, communication can be executed using the antenna ANT1 ′ or ANT2 ′ combined by setting the DC bias voltage to the sub-excitation elements P1 to P4 in which the optimum communication quality is detected, and the polarization method at that time is used. By doing so, it becomes possible to realize wireless communication processing by the MIMO communication method suitable for the use environment.

FIGS. 20A and 20B are diagrams illustrating an example of transmission and reception during non-reflection between the wireless communication apparatuses 701 and 702 in the MIMO communication scheme.
In this embodiment, in the data transmission and reception processing, the MIMO communication scheme is realized using two antennas ANT1 ′ and ANT2 ′, and the communication processing is executed using a multipath environment. Assuming For example, the radio communication apparatus 701 shown in FIG. 20A is applied with the radio communication apparatus 700 shown in FIG. 18, and two rectangular patch antennas using the antenna apparatus 500 or 600 described in the fifth or sixth embodiment are applied. ANT1 ′ and ANT2 ′ are arranged.

  In this example, the antenna ANT1 'of the wireless communication apparatus 701 is set to right-handed polarization, with the sub-excitation elements P1 and P3 made conductive and the other sub-excitation elements P2 and P4 made insulating. In terms of a geometric equivalent pattern, a rectangular patch pattern in which the upper right and lower left of the antenna ANT1 'are missing is obtained. The antenna ANT1 'radiates (radiates) right-hand polarized data Da.

  Further, the antenna ANT2 'is set to left-handed polarized waves with the sub-excitation elements P2 and P4 made conductive and the other sub-excitation elements P1 and P3 made insulating. In terms of a geometric equivalent pattern, a square patch pattern in which the upper left and lower right of the antenna ANT2 'are missing is obtained. The antenna ANT2 'radiates left-hand polarized data Db.

  The wireless communication apparatus 700 shown in FIG. 18 is applied to the wireless communication apparatus 702 shown in FIG. 20B, and two rectangular patch antennas ANT1 to which the antenna apparatus 500 or 600 described in the fifth or sixth embodiment is applied. “And ANT2” are arranged. In this example, the antenna ANT1 'of the wireless communication device 702 is set to right-handed polarized waves with the sub-excitation elements P1 and P3 made conductive and the other sub-excitation elements P2 and P4 made insulating. In terms of a geometric equivalent pattern, a rectangular patch pattern in which the upper right and lower left of the antenna ANT1 'are missing is obtained. The antenna ANT1 'radiates (radiates) right-hand polarized data Da.

  Further, the antenna ANT2 'is set to left-handed polarized waves with the sub-excitation elements P2 and P4 made conductive and the other sub-excitation elements P1 and P3 made insulating. In terms of a geometric equivalent pattern, a square patch pattern in which the upper left and lower right of the antenna ANT2 'are missing is obtained. The antenna ANT2 'radiates left-hand polarized data Db.

  In the MIMO communication system in which the polarization is set in this way, when there is no reflector or the like in a multipath environment, the antenna ANT1 ′ of the wireless communication device 701 transmits the right-hand polarized data Da to the right by the wireless communication device 702. Data Da is received and processed by the antenna ANT1 ′ set to receive the circularly polarized wave. Similarly, the antenna ANT2 'of the wireless communication apparatus 701 receives and processes the left-hand polarized wave data Db by the antenna ANT2' set to receive the left-handed polarized wave by the wireless communication apparatus 702.

  FIGS. 21A and 21B are diagrams illustrating a transmission / reception example when a reflector 403 exists between the wireless communication apparatuses 701 and 702 in the MIMO communication scheme.

  In this embodiment, according to the MIMO communication system, there is a case where the polarized waves which are initially orthogonalized may cause interference due to the influence of the reflection by the reflector 403 in a multipath environment. In the example shown in FIGS. 20A and 20B, when the radiated radio wave from one antenna ANT1 ′ is reflected once, the polarized wave becomes a reverse rotation, and thus the radiation from the antennas ANT1 ′ and ANT2 ′. In some cases, the right-handed polarization and the left-handed polarized wave are distinguished, but eventually they become the same and cause interference. On the other hand, even if both antennas ANT1 ′ and ANT2 ′ radiate with the same rotation wave, there is a reflector 403 on one side and the polarization is reversed to a reverse rotation wave despite being affected by the reflection. Therefore, interference may not occur.

  In this way, the polarization changes variously in a multipath rich environment, and even if it has orthogonality at the time of radiation, it may not necessarily be a superior result for communication characteristics depending on the radio wave environment There is. For example, the left-hand polarized data Db radiated from the antenna ANT2 'of the wireless communication device 701 shown in FIG. 21A is received as a direct wave by the wireless communication device 702 shown in FIG. 21B. The right-hand polarized wave data Da radiated from the antenna ANT1 'of the wireless communication apparatus 701 is received as a reflected wave by the wireless communication apparatus 702 shown in FIG. 20B.

  In such a case, the setting of the antenna ANT2 'of the radio communication apparatus 702 on the reception side is left as it is, and only the antenna ANT1' is switched from right-handed to left-handed polarized wave. That is, the auxiliary excitation elements P1 and P3 of the antenna ANT1 ′ of the wireless communication apparatus 702 are switched from conductive to insulating, and further, the auxiliary excitation elements P2 and P4 are switched from insulating to conductive. May not wake up. In this example, the reception sensitivity (reception strength RSSI, etc.) is detected, and the radio communication device 702 on the reception side easily switches the polarization from right-handed to left-handed or left-handed to right-handed according to this RSSI. Made.

  FIG. 22 is a RSSI detection level diagram showing a threshold setting example during DC bias voltage (polarization) switching control. FIG. 23 is a flowchart illustrating an example of control at the time of polarization switching in the radio communication device 702 on the reception side.

  In this example, when the polarization is switched from right-handed to left-handed or left-handed to right-handed by the receiving-side wireless communication device 702 or the like in accordance with RSSI, as shown in FIG. The lower limit threshold value Lth1 and the upper limit threshold value Lth2 (Lth1 <Lth2) are set for the RSSI detection level, and it is assumed that the right-handed and left-handed polarized waves are switched based on the lower and upper threshold values Lth1 and Lth2. .

  In this example, when the relationship between RSSI and the upper threshold Lth2 is RSSI> Lth2, and when the relationship between the RSSI and the lower threshold Lth1 is RSSI <Lth1, the auxiliary excitation elements P1 to P4 Polarization switching setting is executed by switching the DC bias voltage to the control electrodes 52a to 52d. Note that, when the relationship between the RSSI and the lower and upper thresholds Lth1 and Lth2 is Lth1 ≦ RSSI <Lth2, a case where the current reception state is maintained without performing polarization switching will be described as an example.

  Under these DC bias voltage (polarization) switching conditions, RSSI is detected at step E1 of the flowchart shown in FIG. The RSSI is detected by the reception circuits 44 a and 44 b of the wireless communication device 702 and the RSSI detection data is output to the control device 46. Next, in step E2, the control device 46 compares RSSI with the upper limit threshold Lth2 based on the RSSI detection data and determines whether RSSI> Lth2. When RSSI> Lth2, the process proceeds to step E3 to switch the DC bias voltage to the control electrodes 52a to 52d of the auxiliary excitation elements P1 to P4 and execute the polarization switching setting (see FIGS. 21A and 21B).

  Thereafter, the process proceeds to step E4, and the control device 46 determines whether or not the relationship between the lower limit and upper limit threshold values Lth1 and Lth2 is Lth1 ≦ RSSI <Lth2. When the relationship between the RSSI, the lower limit and the upper limit thresholds Lth1 and Lth2 is Lth1 ≦ RSSI <Lth2, the current reception state is maintained.

  If RSSI> Lth2 is not satisfied in step E2 described above, that is, if RSSI is equal to or less than Lth2, the process proceeds to step E6. If the relationship between the RSSI, the lower limit and the upper limit thresholds Lth1 and Lth2 is not Lth1 ≦ RSSI <Lth2 in step E4, the process proceeds to step E5, and after the DC bias voltage switching setting is restored, the process returns to step E6. Transition. In step E6, the control device 46 compares the RSSI and the lower threshold Lth1, and determines whether RSSI ≦ Lth1.

  When RSSI ≦ Lth1, the process proceeds to step E8, and the control device 46 executes the polarization switching setting by switching the DC bias voltage. Thereafter, the process proceeds to step E9, and the control device 46 determines whether or not the relationship between the RSSI, the lower limit and the upper limit thresholds Lth1 and Lth2 is Lth1 ≦ RSSI <Lth2. When Lth1 ≦ RSSI <Lth2, the current reception state is maintained.

  If the relationship between the RSSI, the lower limit and the upper limit thresholds Lth1 and Lth2 is not Lth1 ≦ RSSI <Lth2 in step E9, the process proceeds to step E10, the DC bias voltage switching setting is restored, and the process proceeds to step E11. And change the subcarrier. Thereafter, the process returns to step E1 to repeat the above-described processing.

  Thus, according to the radio communication apparatus and the control method thereof as the seventh embodiment, the antennas ANT1 ′ and ANT2 ′ according to the present invention are applied, and the dielectric substrate 29 has an octagonal shape. A conductive main excitation element 51 is arranged, and in the diagonal direction of the main excitation element 51, semiconductive sub excitation elements P1 to P4 for polarization control are arranged. The auxiliary excitation elements P1 to P4 are provided with control electrodes 52a, 52b, 52c, and 52d, and the DC bias voltage supplied to the control electrodes 52a, 52b, 52c, and 52d is controlled.

  In the above-described example, the forward bias voltage is supplied to the control electrodes 52a and 52c of the two sub-excitation elements P1 and P3 in one diagonal direction, and the control electrodes 52b of the two sub-excitation elements P2 and P4 in the other diagonal direction. , 52d is supplied with a reverse bias voltage, the main excitation element 51 and the sub excitation elements P1, P3 are electrically connected, and the other diagonal sub excitation elements P2, P4 are in an insulated state. In addition, a circularly polarized antenna body that exhibits right-handed polarization characteristics can be configured.

  Further, when a reverse bias voltage is supplied to the control electrodes 52a and 52c of the sub excitation elements P1 and P3 and a forward bias voltage is supplied to the control electrodes 52b and 52d of the sub excitation elements P2 and P4, the main excitation element 51 and the sub excitation elements 51 The excitation elements P2 and P4 are electrically connected, and the other diagonal sub-excitation elements P1 and P3 are in an insulated state, thereby forming a circularly polarized antenna body exhibiting left-handed polarization characteristics. be able to.

  Further, when a forward bias voltage is supplied to the two control electrodes 52a, 52b, 52c, and 52d at the four corners in the diagonal direction, a linearly polarized antenna body can be configured. As described above, since the conductivity or insulation of the sub-excitation elements P1 to P4 can be controlled separately by controlling the DC bias voltage to the control electrodes 52a, 52b, 52c, and 52d, the main excitation element 51 and the sub-excitation element P1. ~ P4 and a combination of conductivity or insulation can be selected. Accordingly, the radiation polarization of the rectangular patch antenna can be switched, and three types of antennas of linear polarization, right-handed polarization, and left-handed polarization can be configured with one structure as in the fourth embodiment. become.

  Further, for the purpose of cost reduction, for example, the main excitation element 51 and the four sub excitation elements P1 to P4 continuous to the main excitation element 51 are not provided at all the four corners on the diagonal line, but only at two places on one diagonal line. The corner of the main excitation element 51 is left on the other diagonal line without being cut out. Then, by switching the conductivity or insulation of these two sub-excitation elements P1 and P3, switching between circular polarization (right-handed or left-handed) and linearly polarized light is performed, and the optimum communication quality is detected. , And so on.

  In this embodiment, the case where the rectangular patch antennas ANT1 ′ and ANT2 ′ described in the fifth embodiment are applied has been described. However, the present invention is not limited to this, and the circular patch pattern described in the sixth embodiment is used. You may comprise the radio | wireless communication apparatus 700 which mounted the antenna device 600 which it has. The same effect as in the seventh embodiment can be obtained.

  The present invention is extremely suitable when applied to a MIMO communication system that transmits and receives signals simultaneously using a plurality of rectangular patch antennas.

It is a figure which shows the structural example of the antenna apparatus 100 as a 1st Example which concerns on this invention. (A) And (B) is the top view which shows the structural example of the antenna apparatus 100, and its X1-X1 arrow sectional drawing. (A)-(C) are the exploded top views which show the laminated structure example of the antenna apparatus 100. FIG. It is a top view which shows the structural example of the antenna apparatus 200 as a 2nd Example. FIGS. 7A to 7C are a top view and a cross-sectional view illustrating a configuration example and an operation example of the MEMS switch SW <b> 1 ′ and the like. It is a figure which shows the structural example of the antenna apparatus 300 as a 3rd Example. It is a block diagram which shows the structural example of the radio | wireless communication apparatus 400 as a 4th Example to which the antenna apparatus 100 is applied. 4 is a flowchart illustrating a control example of a wireless communication device 400 to which the antenna device 100 is applied. (A) And (B) is a figure which shows the example of transmission / reception at the time of the non-reflection between the radio | wireless communication apparatuses 401 and 402 in a MIMO communication system. (A) And (B) is a figure which shows the example of transmission / reception in case the reflector 403 exists between the radio | wireless communication apparatuses 401 and 202 in a MIMO communication system. It is a detection level figure of RSSI which shows the example of a threshold setting at the time of switch (polarization) change control. 10 is a flowchart illustrating a control example at the time of polarization switching in the radio communication device 402 on the receiving side. It is a figure which shows the structural example of the antenna apparatus 500 as a 5th Example. (A) And (B) is the top view which shows the structural example of the antenna apparatus 500, and its X1-X1 arrow sectional drawing. (A)-(C) are the exploded top views which show the laminated structure example of the antenna apparatus 500. FIG. (A) And (B) is sectional drawing which shows the example of control which makes subexcitation element P1 etc. electroconductive or insulative. It is a figure which shows the structural example of the antenna apparatus 600 as a 6th Example. It is a block diagram which shows the structural example of the radio | wireless communication apparatus 700 as a 7th Example to which the antenna apparatus 500 is applied. 10 is a flowchart illustrating a control example of a wireless communication device 700 to which the antenna device 500 is applied. (A) And (B) is a figure which shows the example of transmission / reception at the time of the non-reflection between the radio | wireless communication apparatuses 701 and 702 in a MIMO communication system. (A) And (B) is a figure which shows the example of transmission / reception when the reflector 403 exists between the radio | wireless communication apparatuses 701 and 702 in a MIMO communication system. It is a detection level figure of RSSI which shows the example of a threshold setting at the time of direct-current bias voltage (polarization) switching control. 10 is a flowchart illustrating an example of control at the time of polarization switching in the wireless communication device 702 on the reception side. It is a figure which shows the structural example at the time of the signal propagation by the MIMO communication system concerning a prior art example. It is a perspective view which shows the antenna attachment example for a linearly polarized wave in a MIMO communication system. It is a front view which shows the example of antenna attachment for circular polarization in a MIMO communication system. It is a conceptual diagram which shows the example of reception in the receiving terminal device at the time of transmission terminal device = right-handed rotation / right-handed polarization setting. It is a conceptual diagram which shows the example of reception in the receiving terminal device at the time of transmission terminal device = right-handed rotation / left-handed polarization setting.

Explanation of symbols

11, 31, 51, 61 ... main excitation elements, 12a to 12d, P1 to P4 ... auxiliary excitation elements, 13a to 13d ... control terminals, 17 ... grounding patterns 17, 18 ... strips Line, 19 ... insulating substrate, 29 ... dielectric substrate, 40, 40 '... communication control unit, 41, 42 ... transmission / reception changeover switch, 44a, 44b ... receiving circuit, 45a, 45b ... transmission circuit, 46 ... control device, 47 ... switch control circuit, 52a-52d ... control electrode, 57 ... function control circuit, 100, 200, 300, 500, 600 ... Antenna device, 400, 401, 402, 700, 701, 702 ... Wireless communication device

Claims (16)

A conductive planar antenna body having a predetermined shape and disposed on a dielectric substrate;
A semi-conductive small piece for polarization control disposed in a diagonal direction of the planar antenna body, and
A control electrode provided on the small piece,
An antenna device characterized by switching a radiation polarization of a planar antenna by controlling a DC bias voltage supplied to the control electrode. Small pieces each having a control electrode are arranged at two diagonal corners of the planar antenna body,
The forward bias voltage is supplied to one of the control electrodes of the two small pieces in the diagonal direction, and the reverse bias voltage is supplied to the control electrode of the other two pieces in the diagonal direction. The antenna device according to 1. Small pieces each having a control electrode are arranged at two diagonal corners of the planar antenna body,
2. The antenna device according to claim 1, wherein a forward bias voltage is supplied to all the control electrodes of the small pieces. When making the small piece conductive, ions are implanted from the dielectric substrate into the small piece by a forward bias voltage,
2. The antenna device according to claim 1, wherein when the small piece portion is made insulative, ions are extracted from the small piece portion to the dielectric substrate by a reverse bias voltage.   The antenna device according to claim 1, wherein the planar antenna main body is formed of a square patch pattern or a circular patch pattern. The semiconductive piece is
2. The antenna device according to claim 1, wherein the antenna device is made of a resin member of any one of polyacetylene, polythiophene, polyaniline, polypyrrole, and polyazulene. The dielectric substrate includes
2. The antenna device according to claim 1, wherein a solid electrolyte member of any one of silicon gel, acrylonitrile gel, or polysaccharide polymer is used. Two or more antenna devices;
Two or more transmission / reception circuits that are connected to each of the antenna devices and transmit / receive signals by a multi-input multi-output communication method,
A communication control circuit for controlling the antenna device and the transmission / reception circuit;
Each of the antenna devices is
A dielectric substrate, and a conductive planar antenna body having a predetermined shape and disposed on the substrate;
A semi-conductive small piece for polarization control disposed in a diagonal direction of the planar antenna body, and
A control electrode provided on the small piece,
A radio communication apparatus characterized by switching a radiation polarization of a planar antenna by controlling a DC bias voltage supplied to the control electrode. The communication control circuit includes:
9. The wireless communication apparatus according to claim 8, wherein a DC bias voltage to the control electrode of the antenna apparatus is controlled according to the quality of the signal received by the transmission / reception circuit. The communication control circuit includes:
The radio communication apparatus according to claim 8, wherein a subcarrier modulation scheme of a signal transmitted by the transmission / reception circuit is controlled according to a quality of the signal received by the transmission / reception circuit. The transceiver circuit is
A receiving circuit for receiving a signal by the multi-input multi-output communication method;
A transmission circuit for transmitting a signal by the multi-input multi-output communication method;
A feeding circuit in which one is connected to the receiving circuit and the transmitting circuit and the other is connected to the antenna device;
The wireless communication apparatus according to claim 8, further comprising: a switch that switches a connection destination of each of the power feeding circuits to either the reception circuit or the transmission circuit. A conductive planar antenna body having a predetermined shape and disposed on a dielectric substrate; a semi-conductive small piece for polarization control disposed in a diagonal direction of the planar antenna body; and A control electrode provided on the small piece, and having an antenna device for switching the radiation polarization of the planar antenna by controlling a DC bias voltage supplied to the control electrode, and transmitting and receiving signals by a multi-input multi-output communication method A method for controlling a wireless communication device, comprising:
Setting a DC bias voltage to the control electrode of the antenna device;
Detecting communication quality of a planar antenna constituted by a set DC bias voltage to the control electrode;
Holding a setting of a DC bias voltage to the control electrode based on the detected communication quality of the planar antenna;
And a step of executing communication by setting a DC bias voltage to the held control electrode. When holding the setting of the DC bias voltage to the control electrode,
Setting a DC bias voltage to the control electrode;
Detecting communication quality of a planar antenna constituted by a set DC bias voltage to the control electrode;
Determining whether the detected communication quality of the planar antenna is optimal; and
The method of controlling a wireless communication device according to claim 12, wherein the step of updating and holding the setting of the DC bias voltage to the control electrode determined to be optimal is sequentially repeated. A conductive planar antenna body having a predetermined shape and disposed on a dielectric substrate; a semi-conductive small piece for polarization control disposed in a diagonal direction of the planar antenna body; and A control electrode provided on the small piece, and having an antenna device for switching the radiation polarization of the planar antenna by controlling a DC bias voltage supplied to the control electrode, and transmitting and receiving signals by a multi-input multi-output communication method A control program for a wireless communication device,
Setting a DC bias voltage to the control electrode of the antenna device;
Detecting communication quality of a planar antenna constituted by a set DC bias voltage to the control electrode;
Holding a setting of a DC bias voltage to the control electrode based on the detected communication quality of the planar antenna;
And a step of executing communication by setting a DC bias voltage to the held control electrode. In the step of holding the setting of the DC bias voltage to the control electrode,
Setting a DC bias voltage of the control electrode;
Detecting communication quality of a planar antenna constituted by a set DC bias voltage to the control electrode;
Determining whether the detected communication quality of the planar antenna is optimal; and
15. The computer-processable program according to claim 14, further comprising a step of sequentially repeating the step of updating and holding the setting of the DC bias voltage to the control electrode determined to be optimal. A conductive planar antenna body having a predetermined shape and disposed on a dielectric substrate; a polarization-controlling semi-conductive piece disposed in a diagonal direction of the planar antenna body; and A radio having a control electrode provided on a small piece portion and having an antenna device for switching a radiation polarization of a planar antenna by controlling a DC bias voltage supplied to the control electrode and transmitting / receiving a signal by a multi-input multi-output communication method A recording medium describing a control program for a communication device,
16. A computer-processable program recording medium comprising the program according to claim 14 or / and 15 described therein.

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