TWI600209B - Antenna reset circuit - Google Patents

Description

Antenna reset circuit

The present invention pertains to communication antenna technology, and more particularly to an antenna reset circuit for a handheld device that is capable of resetting an antenna pattern.

Nowadays, as the microwave frequency band has been used up by many application fields, it has prompted all circles to compete in the development of related systems in the millimeter wave (mm-wave) band. Because the millimeter wave is transmitting, its diffraction attenuation is far. It is more serious than microwave, so the antenna for transmitting millimeter waves needs to have high gain characteristics, and in order to enable the field pattern generated by the antenna to be comprehensively covered, the conventional method adopts an antenna system with a plurality of antennas. The effect of changing the field pattern is achieved by selectively turning on a different number of antennas.

However, when a different number of antennas are turned on, the input impedance of the antenna system changes. Therefore, in order to achieve impedance matching when a different number of antennas are turned on, the conventional method is various in the antenna system. The impedance matching circuit of the group selects a suitable impedance matching circuit through the switching device. In addition, in addition to the multiple impedance matching circuits, the antenna system needs to design an additional control circuit to match the appropriate impedance of each group. The matching circuit makes the overall structure of the conventional antenna system too large and the circuit is complicated. Furthermore, conventional impedance matching circuits are implemented using lumped elements, However, the lumped element suitable for the millimeter wave has high cost, large error, and instability, and the production yield of the impedance matching circuit is lowered when mass production is performed.

The microstrip line is a printed conductor separated by a dielectric on the ground plane, which is a strip conductor (signal line). Is isolated from the ground plane by a dielectric. The thickness and width of the printed conductor, the distance between the conductor and the formation, and the dielectric constant of the dielectric determine the characteristic impedance of the microstrip line. If the thickness, width, and distance from the ground plane are controllable, its characteristic impedance is also controllable. The propagation delay time per unit length of the microstrip line depends only on the dielectric constant and is independent of the width or spacing of the lines. The main functions of the microstrip line are two: one is to transmit the high-frequency signal more efficiently; the other is to form a matching network with other solid devices such as inductors and capacitors, so that the signal output end is well matched with the load. Advantages of the microstrip line include: small size, light weight, frequency bandwidth, high reliability, and low manufacturing cost. Microstrip lines and microstrip-like lines are typically fabricated using a thin film process. The dielectric substrate is made of a material having a high dielectric constant and low microwave loss, such as alumina ceramics, garnet ferrite, and quartz. The conductor should have the characteristics of high conductivity, good stability, and strong adhesion to the substrate.

In order to improve the disadvantages of the prior art, the present invention provides an antenna reset circuit which is disposed in a multi-antenna system having a plurality of antennas for switching the overall radiation pattern generated by the antennas. The circuit includes a feed portion, a complex power distribution link, and a plurality of switch units. The feeding portion is configured to feed a telecommunication signal; the power distribution link is divided into Optionally, the antenna is coupled between the antenna and the feeding portion to form a transmission path of the electrical signal between each of the antennas and the feeding portion; and the switching units are respectively disposed correspondingly to the antennas And a power distribution link for selectively cutting or turning on the electrical signal path between each of the antennas and the feeding portion. Thereby, the overall field pattern of the antennas can be easily adjusted through the design of the switching units to improve signal reception quality.

Another object of the present invention is to provide an antenna reset circuit capable of simultaneously matching single or multiple antennas, and to provide an antenna reset circuit having stable characteristics and high production yield. The present invention is applicable to an antenna device device of a millimeter wave band. In an embodiment of the present invention, the bandwidth includes a frequency band of 36 to 40 GHz, but is not limited to the millimeter wave band and the foregoing frequency band, and is well known to those skilled in the art. The content changes disclosed in the present invention can be applied to antenna communication purposes in different frequency bands. In an embodiment of the present invention, the antenna reset circuit and the multi-antenna system can be implemented on a printed circuit, and the antenna reset circuit can be ensured except that the deficiencies of the lumped component design can be eliminated. The stability of the response and the production yield of the antenna reset circuit are improved.

In an embodiment of the present invention, each of the switch units is correspondingly disposed from a coupling position of the power distribution link and the feed portion, and conforms to a position of one-half wavelength of a resonance frequency of the antenna. By switching the switching units to achieve switching of various field types, the field type can be transformed with directivity, omnidirectionality and orientation, and the appropriate antenna field type and pointing can be selected to enhance the mobile device. Set the communication quality.

In an embodiment of the invention, each of the switching units is a Micro Electro Mechanical Systems (MEMS) switch or a radio frequency diode.

In an embodiment of the invention, the feeding portion is not connected to one of the power distribution link ends to a matching unit, and the matching unit is a microstrip line.

In an embodiment of the present invention, the multi-antenna system has four sets of antennas, and the number of the power distribution links is four, and the power distribution links are disposed on the same plane, and are centered on the feed portion. Extending outwardly, and extending directions of adjacent power distribution links are perpendicular to each other.

In an embodiment of the invention, each of the switch units is coupled to a bias input line, and a bias is selectively input through the bias input line to turn the switch unit on or off.

In an embodiment of the present invention, each of the power distribution links is respectively provided with a grounding wire, and the electrical length of the grounding wire is n times of a quarter wavelength of the resonant frequency of the antenna, wherein the n system is positive Integer.

In one embodiment of the invention, the power distribution links are implemented in microstrip lines.

In an embodiment of the invention, the feed portion and the power distribution link are connected by a stepped microstrip line.

The antenna reset circuit of the present invention is matched with a set of feeding parts The plurality of sets of power distribution links and the design of the switch unit are respectively disposed on each of the power distribution links, so that the antenna reset circuit can not only match a single antenna, but also can simultaneously match multiple antennas, and can greatly reduce the antenna. By resetting the required size of the circuit, the user can easily adjust the overall field type of the antenna to improve signal reception quality. Moreover, the antenna reset circuit is implemented by replacing the lumped component with a printed circuit. Even if there is a slight error in the line width or line length of the printed circuit during mass production, the response characteristics of the antenna reset circuit can be maintained, and the stability of the response of the antenna reset circuit can be ensured and the antenna reset can be improved. The production yield of the circuit.

The above summary, the following detailed description and the accompanying drawings are intended to further illustrate the manner, the Other objects and advantages of the present invention will be described in the following description and drawings.

1, 1', 1" ‧ ‧ multi-antenna system

10, 10', 10" ‧ ‧ antenna reset circuit

110‧‧‧Feeding Department

121, 122, 123, 124‧‧‧ power distribution links

121', 122', 123', 124'‧‧‧ power distribution links

121", 122", 123", 124"‧‧‧ power distribution links

131, 132, 133, 134‧‧‧ switch units

141, 142, 142, 144‧‧‧ bias input lines

151, 152, 153, 154‧‧‧ grounding wire

21, 22, 23, 24‧‧‧ antenna

30‧‧‧Connecting Department

301‧‧‧Connected column

302‧‧‧Matching unit

1 is a schematic view of various angles of a first embodiment of an antenna reset circuit of the present invention.

2 is a perspective view of a second embodiment of the antenna reset circuit of the present invention.

FIG. 3 is a schematic view showing the perspective of a third embodiment of the antenna reset circuit of the present invention.

Figure 4 is a graph showing the frequency response of reflection coefficients of the first, second and third embodiments of the present invention.

Figure 5 is a cross-sectional view of a plurality of field-type switching radiation patterns of the first, second and third embodiments of the present invention.

The embodiments of the present invention are described below by way of specific examples, and those skilled in the art can readily appreciate other advantages and functions of the present invention from the disclosure herein.

In the prior art, since the millimeter wave spatial transmission attenuation is extremely large, the antenna must use a high gain pointing antenna field type, and in order to achieve comprehensive coverage, the conventional technology adopts a multi-antenna system to achieve high by selectively opening different numbers of antennas. The gain points to a change in the field pattern. In order to achieve matching for different antennas, different matching circuits are required, so the multi-antenna switching architecture has multiple sets of impedance matching circuits with the same number of antennas, and then selects an appropriate impedance matching structure through an additional switching device, so the device volume Too large, complicated circuit structure, and a large number of components are not conducive to design and control operations. Moreover, the matching circuit of the prior art is mostly realized by the lumped component, the cost and the operational instability will be improved, and the lumped component itself will have an error, which will reduce the yield when mass production is performed. In order to improve the shortcomings of the prior art, the present invention proposes an antenna reset circuit that only needs to use a set of resettable circuits to simultaneously control and select a complex array antenna to transmit signals, which can match all situations simultaneously, and in all modes of operation. There are broadband responses below. The antenna reset circuit of the present invention is realized by a transmission line (microstrip line), and is matched with a printed circuit structure, which can greatly reduce the production cost, and has high operational stability and high quality signal strength.

Please refer to FIG. 1 , which is a perspective view of the first embodiment of the antenna reset circuit of the present invention. In this embodiment, the antenna reset circuit 10 is configured. In a multi-antenna system 1 having a two-layer three-dimensional structure, FIG. 1(a) is a top view of the first layer substrate of the multi-antenna system 1, and FIG. 1(b) is the first of the multi-antenna system 1. FIG. 1(c) is a schematic diagram of a second layer substrate of the multi-antenna system 1, and FIG. 1(d) is a schematic diagram of a combination of a first layer substrate and a second layer substrate of the multi-antenna system 1. Where the substrates are printed circuit boards.

The antenna reset circuit 10 includes a feed portion 110, four power distribution links 121, 122, 123, and 124, and four switch units 131, 132, 133, and 134. The antenna reset circuit 10 can be combined with four directional antennas 21, 22, 23, 24 to form a multi-antenna system 1. The types of the antennas 21, 22, 23, and 24 having directivity may be selected according to design requirements. In this embodiment, the antennas 21, 22, and 24 may be quasi-Yakumu Uda antennas (Quasi Yagi- Uda antenna), and the antenna 23 adopts a rectangular patch antenna; further, the positions of the antennas 21, 22, 23, and 24 are selected such that the field pattern of the entire antenna can cover the design requirements as much as possible. Set to receive/send the direction of the signal. In this embodiment, the multi-antenna system 1 is capable of achieving omnidirectional signal coverage. Therefore, the antennas 21, 22, 23, and 24 are respectively disposed on the upper, lower, left, and right sides (in terms of the substrate perpendicular to the ground plane). ) in four directions. It should be noted that the type, the number, and the setting position of the antenna of the present invention may be adjusted according to design requirements, and are not limited to the embodiment.

The feed portion 110 can be used to feed a signal (not shown) to drive the antennas 21, 22, 23, 24. In this embodiment, the multi-antenna system 1 adopts a two-layer three-dimensional structure, and one end of the feeding portion 110 and the same function The rate distribution links 121, 122, 123, and 124 are coupled to each other, and the other end is coupled to a communication portion 30 disposed on the second layer substrate. Referring to FIG. 1(c) together, the communication portion 30 can be Having a connecting post 301 and a matching unit 302, the antenna reset circuit 1 can be coupled to the matching unit 302 or an external circuit (not shown) disposed on one of different planes through the connecting portion 30 and The electrical signal transmission is performed, so that the first embodiment of the present invention can achieve the effect of controlling multiple sets of antennas with a set of matching circuits.

The power distribution links 121, 122, 123, and 124 are respectively coupled between the antennas 21, 22, 23, and 24 and the feed portion 110 to be in the antennas 21, 22, and 23, A transmission path of the electrical signal is formed between the 24 and the feeding portion 110. The power distribution links 121, 122, 123, and 124 can be implemented by substantially the same microstrip line, that is, the electrical length and line width of the power distribution links 121, 122, 123, and 124 are designed. The specifications are substantially the same, and by this design, the power of the electrical signals input by the feeding unit 110 can be evenly distributed to the power distribution links 121, 122, 123, and 124.

The switch units 131, 132, 133, and 134 are respectively disposed on the power distribution links 121, 122, 123, and 124, respectively, so that the power distribution links 121, 122, 123, and 124 are respectively set. There is a switch unit, and the switch units 131, 132, 133, and 134 are used to selectively cut or turn on the electrical signal path between the antennas 21, 22, 23, and 24 and the feed portion 110. In order for some of the switching units to be selectively turned off to cut off the corresponding electrical signal paths, the input impedance of the power distribution link that is cut off the electrical path is equivalent to an open circuit, so each of the switching units The setting positions of 131, 132, 133, and 134 are calculated from the coupling positions of the power distribution links 121, 122, 123, and 124 and the feeding portion 110, and conform to the antennas 21, 22, 23, and 24; At a position one-half of the wavelength of the resonant frequency, this design method does not have energy loss in the power distribution link that is cut off the electrical signal path under ideal conditions, and can complete the energy of the electrical signal. An antenna coupled to each of the power distribution links that is turned on, and in this embodiment, the resonant frequencies of the antennas 21, 22, 23, and 24 are 38 GHz, and thus the switching units 131 and 132 The 133 and 134 are disposed at a position of about 3.95*10 ^-3 meters from the feeding portion 110. Furthermore, the switching units 131, 132, 133, 134 are respectively coupled to a bias input line 141, 142, 142, 144, and the bias input lines are connected to an external control unit (not shown) And letting the control unit selectively switch the on or off states of the switch units 131, 132, 133, 134. The switch units 131, 132, 133, and 134 may be Micro Electro Mechanical Systems (MEMS) switches or radio frequency diodes.

In addition, the power distribution links 121, 122, 123, and 124 are respectively provided with grounding lines 151, 152, 153, and 154, and the grounding lines 151, 152, 153, and 154 are respectively used for the power distribution. The links 121, 122, 123, 124 are grounded. The location of the grounding lines 151, 152, 153, and 154 is not limited, but those skilled in the art can understand that the control unit for inputting the control bias (not shown) The RF signal of the multi-antenna system 1 is not affected, and the electrical length of the stub (such as the grounding wire) whose terminal is short-circuited is designed to be a quarter wavelength, so that the input impedance of the stray is equivalent to an open circuit, and thus does not affect The characteristics of the radio frequency signals of the multi-antenna system 1, that is, the electrical lengths of the ground lines 151, 152, 153, 154 can be designed to be n times the quarter-wavelength of the resonant frequency of the antenna, wherein n is A positive integer. In this embodiment, the resonant frequencies of the antennas 21, 22, 23, and 24 are 38 GHz, so the electrical lengths of the grounding wires 151, 152, 153, and 154 may be 1.96*10 ^-3 *n meters. .

The first embodiment of the present invention is a two-layer substrate three-dimensional structure, but the antenna reset circuit of the present invention can also be implemented on a single substrate to meet the demand for the miniaturization of electronic devices.

2 is a top view of the second embodiment of the antenna reset circuit of the present invention, FIG. 2(a) is a top view of the second embodiment, and FIG. 2(b) is a second embodiment. view. The multi-antenna system 1 of the second embodiment adopts a two-layer design as compared with the first embodiment, and the multi-antenna system 1' of the second embodiment adopts a single-layer design. Different from the first embodiment, the matching unit is disposed on the second layer substrate. To realize the single layer antenna system 1', the power distribution link 121', 122' of the antenna reset circuit 10' of the second embodiment 123', 124' adopts a stepped microstrip line design to achieve the matching effect, and a portion of the front portion close to the feeding portion 110 has a narrow line width first, and then connects to the power distribution links 121', 122. Portions of ', 123', 124' have a slightly wider line width. With this design, although the second embodiment is not additionally connected to a matching unit, only the antennas 21, 22, When one of 23, 24 is driven to be turned on (ie, only one of the switching units 131, 132, 133, 134 is in an open state), it will have a higher input impedance, but the antennas 21, 22, 23 The response bandwidth of 24 is still within an acceptable range. As the number of enabled antennas 21, 22, 23, 24 is increased, the overall equivalent input impedance of the antenna system 1' is reduced, and is designed as a high impedance power distribution link 121', 122' 123', 124' will compensate for the reduced input impedance so that when different numbers of antennas 21, 22, 23, 24 are turned on, the response bandwidth can meet the design requirements. The second embodiment has the functions of the feed portion 110, the switching units (131, 132, 133, 134), the bias input lines (141, 142, 142, 144) and the ground lines (151, 152, 153, 154). The principles and effects are the same as those of the first embodiment, and therefore will not be described again.

3 is a perspective view of a third embodiment of the antenna reset circuit of the present invention, FIG. 3(a) is a top view of the third embodiment, and FIG. 3(b) is a third embodiment. view. Similar to the multi-antenna system 1' of the second embodiment, the multi-antenna system 1" of the third embodiment also adopts a single-layer design, which differs from the second embodiment in the power distribution links 121", 122" The layout of the 123", 124" is different. The antenna reset circuit 10 different from the first embodiment and the antenna reset circuit 10' of the second embodiment are both used when the electrical signal is fed. For the design of the fourth embodiment, the antenna reset circuit 10" of the present embodiment is composed of three T-type splitters, that is, the T-wave splitter of the first group is transmitted after the electrical signal is fed. Divided into two points, and then divided the power into four by the other two sets of T-type splitter, and then become four sets of power distribution links 121", 122", 123", 124", this design is the same as the second embodiment in a single layer design, but due to the difference in circuit layout, the third embodiment has additional board space to set another matching unit. (not shown), or alternatively, the manner of the second embodiment is adopted, and a stepped microstrip line design is adopted between the feeding portion and the power distribution links 121", 122", 123", 124" to achieve the matching effect ( As shown in FIG. 3(a), the line width of the microstrip line of the feed portion to the power distribution link varies, so that the third embodiment can have a wider response bandwidth than the second embodiment, and also ensures When different numbers of antennas 21, 22, 23, 24 are turned on, the response bandwidth can meet the design requirements. The third embodiment has the feeding portion 110, the switching unit (131, 132, 133, 134), and the partial The principle and function of the pressure input lines (141, 142, 142, 144) and the ground lines (151, 152, 153, 154) are the same as those of the first embodiment, and therefore will not be described again.

Please refer to FIG. 4, which are reflection coefficient frequency response diagrams of the first, second and third embodiments of the present invention, respectively. 4(a) is a first embodiment, FIG. 4(b) is a second embodiment, and FIG. 4(c) is a third embodiment. In the first embodiment, the multi-antenna system 1 has a two-layer stereo structure, so that the antennas 21, 22, 23, and 24 can have a relatively wide bandwidth reflection coefficient frequency response when the antennas 21, 22, 23, and 24 are turned on; For example, the multi-antenna system 1' is a single-layer design, and the width of the power distribution links 121', 122', 123', 124' is changed to achieve matching, so that the multi-antenna system 1' is produced. This is easier, but the response bandwidth of the multi-antenna system 1' of the second embodiment is narrower than the response bandwidth of the multi-antenna system 1. The multi-antenna system 1" of the third embodiment is also a single-layer design and is composed of three T-types. The power splitting links 121", 122", 123", 124" formed by the splitter, the response bandwidth of the multi-antenna system 1" is between the response bandwidth of the multi-antenna system 1 and the multi-antenna system 1' Between the response bandwidths, those skilled in the art can implement the configurations of the above three embodiments according to actual needs, and all of the advantages and effects of the present invention can be achieved.

Referring to FIG. 5, the radiation field type measurement diagrams of the plurality of field type switchings of the first, second, and third embodiments of the present invention, respectively, and FIG. 5(a) is the multi-antenna system 1 of the first embodiment. 5(b) is a multi-antenna system 1' of the second embodiment, and FIG. 5(c) is a radiation field type measurement diagram of switching of various field types of the multi-antenna system 1" of the third embodiment.

When the antenna reset circuit of the present invention has n links, the ends of the n links are respectively connected to the antenna, and then the switching circuit is used to control the conduction of the n links, and the architecture enables the field type to reach (2 ⁿ -1). The changes are roughly divided into three types of directional, omnidirectional and bidirectional field-type changes, and then integrated with high-gain antennas, which can achieve the functions of high gain and beam switching. In the first, second, and third embodiments of the present invention, the multi-antenna systems 1, 1', 1" are respectively provided with the antenna reset circuits 10, 10', 10" of the present invention, through which the The switching units 131, 132, 133, 134 enable the multi-antenna systems 1, 1 ', 1" to achieve various field switching effects. By switching between the switching units 131, 132, 133, 134, The multi-antenna system 1, 1 ', 1" field type can switch between directivity, omnidirectionality and oppositeism, and its field pattern is shown in Figures 5(a) to (c), whereby The use environment of the multi-antenna systems 1, 1 ', 1" further selects an appropriate antenna field type and orientation to improve the communication quality of the mobile device.

In summary, the antenna reset circuit of the present invention is provided with the switching unit through the power distribution links and the power distribution links, so that the antenna reset circuit can not only match a single antenna, but also It can be used to match multiple antennas at the same time, which can greatly reduce the structure size required by the antenna reset circuit, and can more easily adjust the overall field type of the antennas to improve the signal receiving quality. Moreover, the antenna reset circuit system By replacing the lumped component with a printed circuit, even if there is a slight error in the line width or line length of the printed circuit during mass production, the response characteristics of the antenna reset circuit can be maintained, and the antenna reset can be ensured. The stability of the response of the circuit and the production yield of the antenna reset circuit.

The above-described embodiments are merely illustrative of the features and functions of the present invention, and are not intended to limit the scope of the technical scope of the present invention. Modifications and variations of the above-described embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as set forth in the scope of the claims described below.

1‧‧‧Multi-antenna system

10‧‧‧Antenna reset circuit

110‧‧‧Feeding Department

121, 122, 123, 124‧‧‧ power distribution links

131, 132, 133, 134‧‧‧ switch units

141, 142, 142, 144‧‧‧ bias input lines

151, 152, 153, 154‧‧‧ grounding wire

21, 22, 23, 24‧‧‧ antenna

Claims (8)

An antenna reset circuit is disposed in a multi-antenna system having a plurality of antennas for switching an overall radiation pattern generated by the antennas, the antenna reset circuit comprising: a feed portion for feeding a The plurality of power distribution links are respectively coupled between the antennas and the feeding portion for forming a transmission path of the electrical signal between each of the antennas and the feeding portion; and a plurality of switching units Correspondingly disposed on each of the power distribution links, respectively, for selectively cutting or turning on the electrical signal path between each antenna and the feeding portion; wherein each of the switching units is correspondingly set from the power distribution The coupling position of the link and the feed portion is at a position corresponding to one-half wavelength of the resonance frequency of the antenna. The antenna reset circuit of claim 1, wherein each of the switch units is a MEMS switch or a radio frequency diode. The antenna reset circuit of claim 1, wherein the number of the power distribution links is four, and the power distribution links are disposed on the same plane, and are centered on the feed portion. Extending, and the direction of extension of adjacent power distribution links is perpendicular to each other. The antenna reset circuit of claim 1, wherein each of the switch units is coupled to a bias input line, and a bias is selectively input through the bias input line to turn the switch unit on or off. . The antenna reset circuit of claim 1, wherein the power distribution link is respectively provided with a ground line, and the electrical length of the ground line is a quarter wavelength of the resonant frequency of the antenna. Times, n is a positive integer. The antenna reset circuit of claim 1, wherein the power distribution link is a microstrip line. The antenna reset circuit of claim 1, wherein the antenna is a rectangular patch antenna or a quasi-Yakura Uda antenna. The antenna reset circuit of claim 1, wherein the feed portion is not connected to a matching unit with one of the power distribution link connections.