JP2003087049A - Two-frequency resonance planar patch antenna, and design method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-frequency resonance planar patch antenna, which can transmit and receive circularly polarized waves and linearly polarized waves, using a single antenna. SOLUTION: This patch antenna is composed of an oblong patch body 12 and a ground plate 14 where the above patch plate 12 is superposed via a dielectric, and this has on the above patch body 12, the first slot 16a and the second slot 16b which are provided in close vicinity to the opposed sides S2 and S3 of the patch body 12, and a power supply point 18 on the diagonal of a virtual square 22, which has the same center point as the patch body 12 and has sides S1', S2', S3', and S4' in parallel with the four sides S1, S2, S3, and S4 of the patch main body 12. As a result, transmission and reception of the circularly polarized waves of relatively lower frequency and linearly polarized waves of frequency higher than the frequency of the circularly polarized waves, in question with a single patch antenna 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual-frequency resonant planar patch antenna and its design method, and more particularly to a dual-frequency resonant planar patch antenna capable of transmitting and receiving both circularly polarized waves and linearly polarized waves with a single antenna and its design. Regarding the method.

[0002]

2. Description of the Related Art Conventionally, flat antennas such as patch antennas are well known. Planar antennas are relatively easy to reduce cost and weight, and are widely used in fields such as radar and communication systems. Conventional patch antennas include those for single frequency circular polarization and those for single frequency linear polarization. Further, with respect to the patch antenna, there is a demand for transmitting and receiving a plurality of frequencies with a single antenna because of its excellent low cost, light weight, and compatibility, and various developments have been made. For example, it is an antenna for dual frequency linearly polarized waves, and two linearly polarized waves of different frequencies can be transmitted and received by etching a pair of slots in a portion near two parallel radiation sides of a planar patch antenna. With this antenna, good impedance matching and gain performance can be obtained simultaneously at both resonance frequencies.

By the way, in recent years, GPS (Global pos
general purpose users of communication systems have become popular with the spread of car navigation systems using the ition system). In addition, in recent navigation systems, V that provides various information in real time is not only the vehicle position and the destination and the route between them.
ICS (Vehicle information & Communic)
ation System), for example, presenting recommended routes that allow you to move to your destination without getting caught in traffic, providing information about facilities on the travel route (facility reservation status, availability, etc.), and various entertainment information. The use of complex systems that realize a more comfortable drive is also increasing with the provision of such services.

[0004]

As described above, in the navigation system, GPS and VICS are now being used.
The combined use of (registered trademark) has become indispensable, but 1.575 GHz circular polarization is used in GPS. On the other hand, in VICS (registered trademark), 2.5
GHz linear polarization is used. In other words, despite the same car navigation device, GPS and VIC
Since S (registered trademark) is used, there is a problem that separate antennas having different characteristics are required. Therefore, the system configuration may be complicated, and the design of the object on which the antenna is mounted may be impaired.

The present invention has been made to solve the above problems, and a dual-frequency resonant planar patch antenna capable of transmitting and receiving circularly polarized waves and linearly polarized waves with a single antenna, and It is an object of the present invention to provide a design method capable of easily performing the design.

[0006]

In order to achieve the above-mentioned object, the present invention relates to a rectangular patch, a ground plate larger than the patch for laminating the patches via a dielectric, and a patch on the patch. A pair of slots provided close to opposite long sides of the patch, and a feeding point formed on a diagonal line of a virtual square having the same center as the patch and having four sides parallel to the four sides of the patch, It is characterized in that it can transmit and receive a circularly polarized wave having a relatively low frequency and a linearly polarized wave having a frequency higher than the frequency of the circularly polarized wave.

In order to achieve the above-mentioned object, the present invention provides a dual frequency resonance plane capable of transmitting and receiving a circularly polarized wave having a relatively low frequency and a linearly polarized wave having a frequency higher than the frequency of the circularly polarized wave. A method for designing a patch antenna, wherein a line passing through a center point of a square patch and parallel to an arbitrary first side of the patch is offset toward a second side orthogonal to the first side. A first step of providing a temporary feeding point to form a patch antenna capable of transmitting and receiving linearly polarized waves of frequency f1, and the second step between the temporary feeding point and the second side with respect to the patch antenna of the first step. A first slot formed along a side and a second slot formed symmetrically to the first slot with the center point of the patch interposed therebetween are formed on the patch, and a frequency f lower than the frequency f1 is formed.
1'and a second step of shifting to a dual-frequency linear polarization patch antenna capable of transmitting and receiving linear polarization of frequency f2 'higher than the frequency f1, and the second side with respect to the patch antenna of the second step From the first slot to the first slot and the distance from the second side to the third side of the patch opposite to the second side, while reducing the distance between the first slot and the second slot. A third step of re-adjusting the frequency f1 ′ changed in step to a frequency f1 and shifting to a dual-frequency linear polarization patch antenna capable of transmitting and receiving linear polarization of the frequency f1 and the changed frequency f2 ″; For the patch antenna of the third step, the lengths of the first slot and the second slot are adjusted, and the frequency f2 ″ is readjusted to the frequency f2,
A fourth step of shifting to a dual-frequency linearly polarized patch antenna capable of transmitting and receiving linearly polarized waves of frequency f1 and frequency f2, and the patch having the same center point as the patch of the patch antenna of the fourth step is formed. The provisional feeding point is moved to a diagonal line of a virtual square having four sides parallel to the four sides, and the first slot and the second slot with respect to the center point are moved.
While maintaining the positional relationship of the slots, the first side and the fourth side opposite to the first side are extended by the same length, and the frequency f
A fifth step of shifting to a dual-frequency resonant planar patch antenna capable of transmitting and receiving the circularly polarized wave of 1 and the linearly polarized wave of frequency f2.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments (hereinafter referred to as embodiments) of a dual-frequency resonant flat patch antenna of the present invention will be described below with reference to the drawings.

FIG. 1 shows a dual-frequency resonant planar patch antenna (hereinafter, simply referred to as patch antenna) 10 of the present embodiment.
A top view and a side view are shown. Patch antenna 1
Reference numeral 0 is composed of a patch body 12 made of, for example, copper foil, and a ground plate 14 made of, for example, copper foil on which the patch body 12 is mounted via a dielectric such as ceramics.

The patch main body 12 has a rectangular outer shape, and a pair of slots 16a and 16b are formed along the edges of the patch main body 12 at a position close to a pair of long sides of each side forming the patch main body 12. Has been done. Also, the ground plate 1
Reference numeral 4 denotes a through hole 14a which is formed to be larger than the patch body 12 and which penetrates a core wire 20a (for example, a core wire portion of a coaxial cable) of a power supply probe 20 connected to a power supply point 18 formed at a predetermined position on the patch body 12. have.
Therefore, the core wire 20a is connected to the patch body 12 by a connecting means such as soldering, and the outer shield part is connected to the ground plate 14. The power supply probe 20 is connected to a transceiver (not shown).

Generally, in the case of a dual-frequency linearly polarized patch antenna, the feeding point 18 is adjusted while being shifted from the center of the patch body 12 toward either the slot 16a or the slot 16b while adjusting the two different points. Frequency, and good impedance matching and gain can be obtained at both resonance frequencies at the same time.

However, in the present embodiment, the position of the feeding point 18 is changed in order to enable good circular polarization transmission / reception. In the present embodiment, the patch body 12
And four sides S1 ', S2', which have the same center point C0 and are parallel to the four sides S1, S2, S3, S4 of the patch body 12.
The feeding point 18 is formed at a position offset from the center point C0 on the diagonal line 22a of the virtual square 22 having S3 'and S4'. By arranging such feeding points 18, the patch antenna 10 having two polarizations capable of transmitting and receiving a circularly polarized wave having a relatively low frequency and a linearly polarized wave having a frequency higher than the frequency of the circularly polarized wave can be provided. Obtainable.

FIGS. 2A to 2E are explanatory views for explaining the design procedure of the patch antenna 10 having dual polarization. FIG. 2 shows a design procedure of the patch antenna 10 that enables transmission and reception of a relatively low circular polarization frequency f1 and a linear polarization frequency f2 higher than the circular polarization frequency f1.

First, in the first step shown in FIG. 2A, the patch antenna 24 capable of linearly polarized wave of the frequency f1 is formed. That is, an arbitrary first side (for example, side S1) that passes through the center point C0 of the square patch body (side S1 = S2 = S3 = S4) 26 and constitutes the patch body 26
A patch antenna 24 capable of transmitting and receiving linearly polarized waves of frequency f1 by providing a temporary feeding point C1 at a position offset on a line parallel to the second side (S2) orthogonal to the side S1.
To form.

Next, in the second step shown in FIG. 2B, the patch antenna 24 of the first step is moved to the patch antenna 28 capable of transmitting and receiving linearly polarized waves of different frequencies. That is, between the temporary feeding point C1 and the side S2, the first slot 30a having a predetermined length and width on the line L1 set along the side S2, and the center point C0 of the patch body 26.
With the second slot 30 having a predetermined length and width on the line L2 set at the symmetrical position of the first slot 30a.
b (the same size as the first slot 30a) is formed. As a result, the patch body 26 in the first step moves to the dual-frequency linear polarization patch antenna 28 capable of transmitting and receiving the linear polarization of the frequency f1 ′ lower than the frequency f1 and the frequency f2 ′ higher than the frequency f1. At this time, the low resonance frequency f1 ′ is determined by the size of the outer shape of the patch body 26, and the higher resonance frequency f2 ′ is determined by the two first slots 30a and the second slots 3 on the patch body 26.
It is determined by the size and position of 0b.

Next, in the third step shown in FIG. 2C, the frequency f1 'changed in the second step due to the formation of the first slot 30a and the second slot 30b is readjusted to the frequency f1. . That is, the frequency f1 is obtained by readjusting the size of the patch body 26. That is, the distance W1 from the S2 side to the first slot 30a and the third side (side S
3) and the distance W2 from the second slot 30b to the first slot 30a and the second slot 3 while maintaining the distance W2 (W1 = W2).
The distance W3 between 0b (Fig. 2 (b)) is reduced to
The distance W4 is set as shown in (c). That is, the area of the patch body 32 is reduced to adjust the frequency. As a result, the frequency f1 ′ changed in the second step is the frequency f1
Is re-adjusted. At this time, the frequency f2 ′ determined in the second step also changes in conjunction with each other and becomes the frequency f2 ″. Therefore, at this stage, the frequency f1
And the dual-frequency linearly polarized patch antenna 30 capable of transmitting and receiving the linearly polarized wave of the changed frequency f2 ″.

Next, in the fourth step shown in FIG. 2D, the frequency f which has changed due to the change in the size of the patch body 32 in the third step.
2 ″ is readjusted to the desired linearly polarized frequency f2. That is, the higher frequency f2 is obtained by increasing or decreasing the size (length) of the first slot 30a and the second slot 30b. In the example of FIG. 2D, the first slot 30
Re-adjustment to the higher resonance frequency f2 is performed by extending both ends of a and the second slot 30b in the longitudinal direction by the same length W5 to form the first slot 16a and the second slot 16b. As a result, it shifts to the dual-frequency linearly polarized patch antenna 34 capable of transmitting and receiving the linearly polarized waves of the frequencies f1 and f2.

Finally, in the fifth step shown in FIG. 2 (e), the temporary feeding point C1 is moved so that the patch antenna 34 of the fourth step can transmit and receive circularly polarized waves. When the temporary feeding point C1 is moved, as shown in FIG. 1, the patch main body 32 has the same center point C0 as the patch main body 32 of the patch antenna 34 formed in the fourth step.
A virtual square 22 having four sides S1 ', S2', S3 ', S4' parallel to the four sides S1, S2, S3, S4 forming
The provisional feeding point C1 is moved to a position offset from the center point C0 on the diagonal line 22a, and the feeding point 18 capable of transmitting and receiving circularly polarized waves is determined. At this time, while maintaining the positional relationship of the first slot 16a and the second slot 16b with respect to the center point C0 at the same time, while performing the fine adjustment to extend the sides S1 and S4 by the same length, the circular polarization of the frequency f1 is obtained. And a dual frequency resonant planar patch antenna 10 capable of transmitting and receiving linearly polarized waves of frequency f2.

In this way, the dual-frequency resonant planar patch antenna 10 capable of transmitting and receiving the circularly polarized wave of the frequency f1 and the linearly polarized wave of the frequency f2 can be easily designed.

FIG. 3 shows the measured return loss when the patch antenna 10 designed as described above is fed from a 50Ω coaxial cable. In FIG. 3, 2
1.575 GHz and 2.5 where two resonant frequencies are desired
It has been achieved at the frequency of GHz, and the return loss is f1.
= -17 dB at 1.575 GHz, f2 =
At 2.5 GHz, since it is -27 dB, it can be seen that good impedance matching is obtained at the same time. Needless to say, these frequencies are GPS and VICS
(Registered trademark).

Therefore, GPS and VICS (registered trademark)
It is possible to transmit and receive necessary signals with a single antenna even in a communication system that utilizes multiple antennas, and it is possible to simplify the communication system, and at the same time, an object equipped with the antenna, such as an automobile The influence on the design can be minimized.

For example, a patch antenna 1 for GPS and VICS (registered trademark) designed and created as described above.
To install 0 in a car, for example, patch antenna 1
0 is covered with a resin case and mounted on the instrument panel in front of the passenger seat or on the roof so that it is installed horizontally so as to match the polarization direction of the VICS (registered trademark) antenna provided on the roadside. Is desirable.

In this embodiment, FIG. 2 (a)
It is needless to say that the design procedure of the patch antenna 10 is only shown in (e) and that the two-frequency resonant planar patch antenna of a desired frequency can be obtained by appropriately changing each dimension. A patch antenna can be designed. In addition, each dimension may be selected individually while confirming the frequency.In an environment where the antenna simulation can be sufficiently performed, for example, on a computer, change each dimension as a parameter and confirm the resonance frequency. However, it is also preferable to design.

[0024]

As described above, according to the present invention,
A dual-frequency resonant planar patch antenna capable of transmitting and receiving circularly polarized waves and linearly polarized waves with a single antenna can be obtained. Moreover, the design can be easily performed.

[Brief description of drawings]

1A and 1B are a plan view and a side view of a dual-frequency resonant planar patch antenna according to the present invention.

FIG. 2 is an explanatory diagram illustrating a design procedure of a dual frequency resonant flat patch antenna according to the present invention.

FIG. 3 is a graph showing measured return loss of the dual-frequency resonant planar patch antenna according to the present invention.

[Explanation of symbols]

10 dual frequency resonance plane patch antenna (patch antenna), 12 patch body, 14 ground plate, 16a 1st
Slot, 16b second slot, 18 feeding point, 20
Feed probe, 22 virtual squares, S1, S2, S3,
S4, S1 ', S2', S3 ', S4' sides.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01Q 21/30 H01Q 21/30 (72) Inventor Hidekazu Oishibashi 3-30, Shimomarket-cho, Toyota-shi, Aichi Kojima Press Kogyo Co., Ltd. F-term (reference) 5J012 CA11 CA21 CA01 FA01 5J021 AA01 AB05 AB06 DB07 HA07 HA10 JA03 JA06 5J045 AA03 AA12 AB05 BA01 CA01 CA04 DA06 DA10 FA02 GA01 HA06 JA02 JA15 NA02 NA06

Claims (2)

[Claims] 1. A rectangular patch, a ground plate that is larger than the patch and is formed by stacking the patches via a dielectric, and a pair of slots provided on the patch in proximity to opposite long sides of the patch. , A feeding point formed on a diagonal line of a virtual square having the same center as the patch and having four sides parallel to the four sides of the patch, and A dual-frequency resonant planar patch antenna capable of transmitting and receiving linearly polarized waves of a frequency higher than the frequency. 2. A method of designing a dual-frequency resonant planar patch antenna capable of transmitting and receiving a circularly polarized wave having a relatively low frequency and a linearly polarized wave having a frequency higher than the frequency of the circularly polarized wave, the method comprising: A provisional feed point is provided at a position offset on a line passing through the center point and parallel to an arbitrary first side forming the patch toward a second side orthogonal to the first side, and linearly polarized waves of frequency f1 are transmitted and received. A first step of making a possible patch antenna; a first slot formed along the second side between the temporary feeding point and the second side with respect to the patch antenna of the first step; The first point across the center point of the patch
A dual-frequency linearly polarized wave capable of transmitting and receiving a linearly polarized wave having a frequency f1 ′ lower than the frequency f1 and a frequency f2 ′ higher than the frequency f1 by forming a slot and a second slot formed at a symmetrical position on the patch. A second step of shifting to a patch antenna; and a second step for the patch antenna of the second step.
The distance between the first slot and the second slot is maintained while maintaining the distance from the side to the first slot and the distance between the third side of the patch facing the second side and the second slot, and reducing the distance between the first slot and the second slot. A third step of re-adjusting the frequency f1 ′ changed in two steps to a frequency f1 and moving to a patch antenna for dual frequency linear polarization capable of transmitting and receiving linear polarization of the frequency f1 and the changed frequency f2 ″, For the patch antenna of the third step, the first
Adjusting the lengths of the slots and the second slot, readjusting the frequency f2 ″ to the frequency f2, and shifting to a dual-frequency linearly polarized patch antenna capable of transmitting and receiving linearly polarized waves of the frequencies f1 and f2. 4 steps, moving the temporary feeding point on a diagonal line of a virtual square having the same center point as the patch of the patch antenna of the fourth step and having four sides parallel to the four sides forming the patch, and While the positional relationship between the first slot and the second slot is maintained, the first side and the fourth side opposite to the first side are extended by the same length, and a circular polarization of frequency f1 and a straight line of frequency f2 are obtained. A fifth step of migrating to a dual-frequency resonant planar patch antenna capable of transmitting and receiving polarized waves, and a method of designing a dual-frequency resonant planar patch antenna.