This application is based upon and claims the benefit of priority from Japanese patent application No. 2019-174875, filed on Sep. 26, 2019, the disclosure of which is incorporated herein in its entirety by reference.
The present disclosure relates to a polarized wave shared array antenna and a method for manufacturing the same.
The rapid spread of radio communication has led to a problem that there is a shortage in frequency bands used for radio communication. One of techniques for effectively using a frequency band is beamforming. Beamforming is a technique in which interference with other radio systems is prevented while signal quality is maintained by radiating radio waves having directivity, thereby enabling radio communication with a predetermined communication target.
A typical technique for achieving beamforming is phased array. Phased array is a technique for enhancing a signal in a desired direction by adjusting the phases of radio signals fed to a plurality of planar antennas in a transmitter and combining radio waves radiated from each of the planar antennas in space.
In recent years, an integral-type module in which a planar antenna such as a patch antenna and a high-frequency unit of a transceiver are mounted on each of both sides of a substrate has been receiving attention in terms of reducing the size of an antenna module. It is desired that a plurality of planar antennas in the phased array be disposed at intervals of about a half wavelength of a carrier wave. Therefore, as the frequency becomes higher, the intervals between the antennas become shorter. Consequently, the size of the above-described integral-type module becomes small.
Giving a millimeter-wave band as an example, the half wavelength is 5 mm at 30 GHz (a wavelength of 10 mm), and the half wavelength is 2.5 mm at 60 GHz band (a wavelength of 5 mm). It is necessary to mount a transmission and reception unit in these about half-wavelength regions in order to implement an integral-type module, and accordingly it becomes essential to integrate a plurality of transceivers including a phase shifter.
Further, in the phased array, if the characteristics of the individual arrays deviate from the assumed weighting of phases, the beam deviates from the desired direction. Therefore, it is desired that the wiring layouts of all arrays from the transmission and reception unit to the feeding point of an antenna have the same shape.
Japanese Unexamined Patent Application Publication No. 2019-047238 discloses two four-element arrays, each of which is composed of four radiating elements. One of these arrays is formed on each of the two sub-arrays, and power is supplied by running feed lines between the four element arrays and wiring one of the feed lines to each radiating element, the wirings being equal in length to each other. In Japanese Unexamined Patent Application Publication No. 2019-047238, in order to reduce the number of side lobes, feeding points to the two sub-arrays are provided at both ends of a printed circuit board and the directions in which power is supplied to the two sub-arrays are made opposite to each other. Further, Published Japanese Translation of PCT International Publication for Patent Application, No. 2000-508144 discloses a technique for reducing leakage to orthogonal polarized waves by arranging feeding points at a mirror symmetrical position in a two-polarized-waves shared patch antenna.
Polarization diversity and polarization multiple-input and multiple-output (MIMO) that use two types of orthogonal polarized waves may be used in order to improve communication quality. When two types of polarized waves are generated simultaneously by one planar antenna, two transmission and reception units integrated in an integrated circuit are respectively connected to two feeding points disposed at positions different from each other in the one planar antenna.
When power is supplied to two-polarized-waves shared planar antennas, it is required that wirings to respective feed points of the same polarized waves be made equal in length in order to make the characteristics of the same polarized waves between the planar antennas equal. However, in order to make wirings from respective transmission and reception units to the corresponding feeding points equal in length, wirings of complicated shapes are required, which causes a problem that wiring loss increases and a man-hour for designing increases.
The present disclosure has been made in view of the above-described problem and an object thereof is to provide a polarized wave shared array antenna in which wirings from a plurality of transmission and reception units integrated in an integrated circuit to respective feeding points of polarized wave shared planar antennas are equal in length without making the shapes of the wirings complicated, and a method for manufacturing the same.
A polarized wave shared array antenna according to an aspect of the present disclosure includes: a first planar antenna and a second planar antenna provided adjacent to each other on one surface of an antenna substrate, each of the first and the second planar antennas being configured to generate two polarized waves of a first polarized wave and a second polarized wave orthogonal to each other; a first feeding point for generating the first polarized wave and a second feeding point for generating the second polarized wave, the first and the second feeding points being provided in the first planar antenna; a third feeding point for generating the first polarized wave and a fourth feeding point for generating the second polarized wave, the third and the fourth feeding points being provided in the second planar antenna; and an integrated circuit including a first transmission and reception unit to a fourth transmission and reception unit provided on the other surface of the antenna substrate, the first to the fourth transmission and reception units, respectively, being connected to the first to the fourth feeding points via a first wiring to a fourth wiring, respectively, in which in a plan view, with respect to a first axis that passes through a center of the first and the second planar antennas, the first and the second feeding points, respectively, are disposed symmetrical to the third and the fourth feeding points, and the first and the second transmission and reception units, respectively, are disposed symmetrical to the third and the fourth transmission and reception units.
A method for manufacturing a polarized wave shared array antenna according to an aspect of the present disclosure includes: providing a first planar antenna and a second planar antenna so as to be adjacent to each other on one surface of an antenna substrate, each of the first and the second planar antennas being configured to generate two polarized waves of a first polarized wave and a second polarized wave orthogonal to each other; providing a first feeding point for generating the first polarized wave and a second feeding point for generating the second polarized wave in the first planar antenna; providing a third feeding point for generating the first polarized wave and a fourth feeding point for generating the second polarized wave in the second planar antenna; providing an integrated circuit including a first transmission and reception unit to a fourth transmission and reception unit on the other surface of the antenna substrate, the first to the fourth transmission and reception units, respectively, being connected to the first to fourth feeding points via a first wiring to a fourth wiring, respectively; and disposing the first and the second feeding points, respectively, so as to be symmetrical to the third and the fourth feeding points with respect to a first axis that passes through a center of the first and the second planar antennas in a plan view, and disposing the first and the second transmission and reception units, respectively, so as to be symmetrical to the third and the fourth transmission and reception units with respect to the first axis that passes through the center of the first and the second planar antennas in the plan view.
The above and other aspects, features and advantages of the present disclosure will become more apparent from the following description of certain exemplary embodiments when taken in conjunction with the accompanying drawings, in which:
Hereinafter, with reference to the drawings, example embodiments of the present disclosure will be described. For the clarification of the explanation, the following description and drawings are omitted or simplified as appropriate. Note that in the figures showing a polarized wave shared array antenna viewed in plan from the side thereof in which an integrated circuit is formed, in order to explain the positional relation between the planar antenna and the integrated circuit, an antenna substrate is made invisible and thus the entirety of the planar antenna and the integrated circuit can be seen.
Example embodiments relate to a polarized wave shared planar array antenna that generates two orthogonal linear polarized waves. Prior to describing the example embodiments, a problem of a comparative example is described.
As shown in
Further, an integrated circuit 20 is mounted on the other surface of the antenna substrate 1. The integrated circuit 20 includes four transmission and reception units integrated therein, the PADs of transmission and reception units (hereinafter simply referred to as transmission and reception units 21a to 21d), respectively, are connected to wirings 13a to 13d via solder 2. Vias 3 are formed in the antenna substrate 1. The wirings 13a to 13d are connected to the feeding points 12a to 12d of the planar antennas 5a to 5d via the vias 3, respectively.
In
Between the antennas (the planar antennas 5a and 5c and the planar antennas 5b and 5d) adjacent to each other in the polarized wave direction, the positions of the feeding points are shifted in directions opposite to each other. However, the positions can be corrected by shifting the phase by 180° with a phase shifter included in each of the transmission and reception units of the integrated circuit 20. By doing so, it is possible to maintain the design symmetry excluding variations in the manufacturing and the mounting, thereby improving the accuracy of beamforming.
Regarding four planar antennas 6a to 6d, each of which radiates a polarized wave (a V polarized wave) parallel to the vertical direction in the figure as shown by a double-headed arrow in
Two transmission and reception units integrated in the integrated circuit 20 are respectively connected to two feeding point disposed at positions different from each other in one planar antenna, in order to generate two types of polarized waves simultaneously in each of the planar antennas 11a to 11d. For example, in the one planar antenna 11a, the two transmission and reception units 21a and 22a are respectively connected to the two feeding points 12a and 14a disposed at positions different from each other.
In order to make the characteristics of the two polarized waves of each planar antenna equal when the above-described polarized wave shared planar antennas in which one planar antenna generates two orthogonal polarized waves are arranged in an array, it is desired that all wirings to respective feeding points be made equal in length.
However, as shown in
To address the above problem, the inventors have conceived the polarized wave shared array antenna described below.
The feeding point 12a for generating the H polarized wave and the feeding point 14a for generating the V polarized waves are provided in the planar antenna 11a. Further, the feeding point 12b for generating the H polarized wave and the feeding point 14b for generating the V polarized waves are provided in the planar antenna 11b. The integrated circuit 20 is provided on the other surface of the antenna substrate. The transmission and reception units 21a, 22a, 21b, and 22b are formed on the integrated circuit 20 and these units, respectively, are connected to the feeding points 12a, 14a, 12b, and 14b via the wirings 13a, 15a, 13b, and 15b, respectively.
It is assumed in this example that an axis passing through the center of the planar antennas 11a and 11b is an axis A1. In the example of
In the planar antenna 11a, the feeding point 12a is disposed in the −x direction, and the feeding point 14a is disposed in the +y direction orthogonal to the −x direction. Further, in the planar antenna 11b, the feeding point 12b is disposed in the −x direction, and the feeding point 14b is disposed in the −y direction opposite to the +y direction.
The transmission and reception units 22a, 21a, 21b, and 22b are disposed in the integrated circuit 20 so as to be arranged in this order in a straight line orthogonal to the axis A1 in a direction from the planar antenna 11a toward the planar antenna 11b. The feeding point 12a is further away from the line where the transmission and reception units 22a, 21a, 21b, and 22b are arranged than the feeding point 14a is. Further, the feeding point 12a is closer to the axis A1 than the feeding point 14a is.
It is assumed in this example that an axis passing through the center of the planar antennas 11a and 11c is an axis A2. In the example of
In the planar antenna 11a, the feeding point 12a is disposed in the −x direction, and the feeding point 14a is disposed in the +y direction orthogonal to the −x direction. Further, in the planar antenna 11c, the feeding point 12c is disposed in the +x direction opposite to the −x direction, and the feeding point 14c is disposed in the +y direction.
The transmission and reception units 22a and 21a are arranged on a straight line parallel to the axis A2 on the planar antenna 11a side of the integrated circuit 20, and the transmission and reception units 22c and 21c are arranged on a straight line parallel to the axis A2 on the planar antenna 11c side of the integrated circuit 20.
By arranging the feeding points and the transmission and reception units that contribute to the respective polarized waves so as to be line-symmetrical to each other, it is possible to make wirings from a plurality of transmission and reception units integrated in the integrated circuit to the respective feeding points of the polarized wave shared planar antennas equal in length without making the shapes of the wirings complicated. Specific example embodiments will be described below.
The feeding point 12c for generating the H polarized wave and the feeding point 14c for generating the V polarized waves are provided in the planar antenna 11c. Further, the feeding point 12d for generating the H polarized wave and the feeding point 14d for generating the V polarized waves are provided in the planar antenna 11d.
Each antenna is a patch antenna, and is a microstrip antenna including a radiation conductor, a ground conductor, and a dielectric layer interposed between the radiation conductor and the ground conductor. The planar antennas 11a to 11d are radiation conductors that radiate radio waves and are formed on one surface of the antenna substrate 1 by a conductive layer. Note that a ground conductor is provided on the other surface of the antenna substrate 1 although it is not shown in the figure. The ground conductor functions as a ground of the microstrip antenna and is formed by a conductive layer.
As shown in
The polarized wave direction of each of the planar antennas 11a to 11d is the same as the direction in which the array is arranged. That is, the H polarized wave direction is the same as the direction in which the planar antennas 11a and 11c are arranged, and the V polarized wave direction is the same as the direction in which the planar antennas 11a and 11b are arranged.
Further, the integrated circuit 20 is mounted on the other surface of the antenna substrate 1. The transmission and reception units 21a to 21d and the transmission and reception units 22a to 22d are disposed in the integrated circuit 20. The integrated circuit 20 has a rectangular shape and is disposed so that left and right sides thereof are orthogonal to a straight line A1.
The transmission and reception units 22a, 21a, 21b, and 22b are disposed on the left side (the −x side) of the integrated circuit 20 so as to be arranged in this order in a straight line orthogonal to the axis A1 in the direction from the planar antenna 11a toward the planar antenna 11b. The feeding point 12a is further away from the line where the transmission and reception units 22a, 21a, 21b, and 22b are arranged than the feeding point 14a is. Further, the feeding point 12a is closer to the axis A1 than the feeding point 14a is.
The transmission and reception units 22c, 21c, 21d, and 22d are disposed on the left side (the +x side) of the integrated circuit 20 so as to be arranged in this order in a straight line orthogonal to the axis A1 in the direction from the planar antenna 11c toward the planar antenna 11d. The feeding point 12c is further away from the line where the transmission and reception units 22c, 21c, 21d, and 22d are arranged than the feeding point 14c is. Further, the feeding point 12c is closer to the axis A1 than the feeding point 14c is.
It is assumed in this example that an axis passing through the center of the planar antennas 11a and 11c and the planar antennas 11b and 11d is the axis A1, and an axis passing through the center of the planar antennas 11a and 11b and the planar antennas 11c and 11d is the axis A2. In
Further, in a plan view, with respect to the axis A1, the transmission and reception units 21a and 22a, respectively, are disposed so as to be symmetrical to the transmission and reception units 21b and 22b, and the transmission and reception units 21c and 22c, respectively, are disposed so as to be symmetrical to the transmission and reception units 21d and 22d. Further, in a plan view, with respect to the axis A2, the transmission and reception units 21a and 22a, respectively, are disposed so as to be symmetrical to the transmission and reception units 21c and 22c, and the transmission and reception units 21b and 22b, respectively, are disposed so as to be symmetrical to the transmission and reception units 21d and 22d.
As described above, the feeding points and the transmission and reception units of the same polarized waves are disposed symmetrical to each other with respect to the axes A1 and A2. This configuration makes it possible to connect the feeding points to the corresponding transmission and reception units without intersecting the wirings. Thus, it is possible to form the wirings 13a to 13d so that they are equal in length and have the same shape, and similarly, it is possible to form the wirings 15a to 15d so that they are equal in length and have the same shape. Accordingly, it is possible to make the characteristics of the same polarized waves between the planar antennas constituting the array equal.
As shown in
Further, the transmission and reception units 21c, 22c, 22d, and 21d are disposed on the left side (the +x side) of the integrated circuit 20 so as to be arranged in this order in a straight line orthogonal to the axis A1 in the direction from the planar antenna 11c toward the planar antenna 11d. The feeding point 12c is further away from the line where the transmission and reception units 21c, 22c, 22d, and 21d are arranged than the feeding point 14c is. Further, the feeding point 12c is closer to the axis A1 than the feeding point 14c is.
By changing the positions in which the transmission and reception units 21a to 21d and the transmission and reception units 22a to 22d are disposed in accordance with the change in the positional relation between the feeding points 12a to 12d and the feeding points 14a to 14d in this way, as in the case of the first example embodiment, it is possible to connect the feeding points to the corresponding transmission and reception units without intersecting the wirings. Thus, it is possible to form the wirings 13a to 13d so that they are equal in length and have the same shape and form the wirings 15a to 15d so that they are equal in length and have the same shape, whereby it is possible to make the characteristics of the same polarized waves between the planar antennas constituting the array equal.
As described above, according to the example embodiments, it is possible to form the wirings of the same polarized waves that connect the feeding units to the transmission and receptions unit of the planar antennas in the same shape, whereby it is possible to make the characteristics of the two polarized waves equal and to reduce the loss due to an increase in the wiring length. The example embodiments are used for radio communication devices and are effective particularly in the case of a phased array antenna.
Note that the present disclosure is not limited to the aforementioned example embodiments and may be changed as appropriate without departing from the spirit of the present disclosure. In the aforementioned examples, although a square planar antenna is used, a circular planar antenna or the like may be used. In the above-described figures, all the wirings are bent at right angles, but they may be bent at any angle.
According to the present disclosure, it is possible to provide a polarized wave shared array antenna in which wirings from a plurality of transmission and reception units integrated in an integrated circuit to respective feeding points of polarized wave shared planar antennas are equal in length without making the shapes of the wirings complicated, and a method for manufacturing the same.
The first and second example embodiments can be combined as desirable by one of ordinary skill in the art.
While the disclosure has been particularly shown and described with reference to embodiments thereof, the disclosure is not limited to these example embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the claims.
Number | Date | Country | Kind |
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JP2019-174875 | Sep 2019 | JP | national |
Number | Name | Date | Kind |
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20190221947 | Zihir | Jul 2019 | A1 |
20200153116 | Onaka | May 2020 | A1 |
20200412025 | Oshima | Dec 2020 | A1 |
20210098895 | Oshima | Apr 2021 | A1 |
Number | Date | Country |
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2000-508144 | Jun 2000 | JP |
2019-047238 | Mar 2019 | JP |
Number | Date | Country | |
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20210098895 A1 | Apr 2021 | US |