JP2003347832A - Patch antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily provide a general purpose patch antenna, in response to both leftward circularly polarized wave and rightward circularly polarized wave, as well as reducing the cost of designing. <P>SOLUTION: This invention is to provide a power supply patch 12 on a dielectric substrate 11 and a dielectric 13 for adjustment, arranged on a belt-type portion 12a which includes a center portion of this power supply patch 12, to set to about 90° for the relative phase between a lower drive mode of resonant frequency generated at the belt-type portion 12a, by feeding a high-frequency signal to the power supply patch 12 and a high drive mode of resonant frequency generated in a belt-type area 12b crossing to the belt-type portion 12a, and radiate circularly polarized electric wave having a frequency band between these high and low resonant frequencies. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a patch antenna capable of receiving and transmitting circularly polarized radio waves used for, for example, satellite communication and GPS (Global Positioning System).

[0002]

2. Description of the Related Art FIG. 4 is a plan view of a conventional patch antenna for receiving a circularly polarized radio wave. As shown in FIG. A power supply patch 3 having a substantially square shape in plan view and having a degenerate separation element 3 a is provided, and a high-frequency signal is supplied to the power supply patch 3 via a power supply pin 4. The dielectric substrate 2 is mounted on a circuit board (not shown). A low-noise amplifier circuit (not shown) provided on the lower surface of the circuit board is connected to the power supply patch 3 via the power supply pin 4. I have.

The feeding patch 3 is a radiating element having a microstrip structure, and has a long axis A1 for generating an excitation mode having a long resonance length and a low resonance frequency, and a short axis for generating an excitation mode having a short resonance length and a high resonance frequency. An axis A2 is defined,
The major axis A1 and the minor axis A2 are orthogonal. By exciting at a frequency between these high and low resonance frequencies and generating a phase difference of 90 degrees between the radiated electric fields based on both modes,
The combined radiated electric field can be circularly polarized.

[0004] A substantially circular feeding patch, not a substantially square, is also widely known. Further, the degenerate separation element may be in the form of a protruding piece instead of a notch. In this case, the degeneration separation element is loaded on the long axis A1.

[0005]

In the conventional patch antenna 1 described above, a circularly polarized radio wave is generated by providing a feeding patch 3 having a degenerate separation element 3a such as a notch or a projection. Since the resonance condition cannot be satisfied unless the ratio of the area of the degenerate separation element 3a to the area of the power supply patch 3 is strictly set, the size of the degeneration separation element 3a must be finely adjusted especially in the design stage. Often must. However, when the degenerate separation element 3a is a notch, it is possible to cut and increase the notch, but fine adjustment for reducing the notch cannot be performed. Although it is possible to reduce the size by shaving the piece, fine adjustment to increase the size of the protruding piece cannot be performed. Therefore, the conventional patch antenna 1 is not only complicated in the fine adjustment at the design stage, but also often cannot be adjusted and must be newly prototyped.

Further, when manufacturing two types of patch antennas having different radiating electric field turning directions (left-handed or right-handed circularly polarized waves), the above-described conventional structure uses an etching technique or the like to form the left and right shapes. Although two types of symmetric power supply patches must be manufactured, separately manufacturing left and right symmetrical power supply patches is inefficient and increases the processing cost.

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation of the prior art, and its object is to greatly reduce the design cost and to simplify the left-handed circular polarization and the right-handed circular polarization. It is an object of the present invention to provide a highly versatile patch antenna that can cope with the problem.

[0008]

In order to achieve the above-mentioned object, a patch antenna according to the present invention includes a patch antenna on a dielectric substrate.
A power supply patch, which is a radiating element having a microstrip structure, and an adjusting dielectric mounted on a belt-like portion including a center portion of the power supply patch, and a high-frequency signal is supplied to the power supply patch, whereby the power supply patch is provided. The relative phase between the excitation mode having a low resonance frequency generated in the strip portion and the excitation mode having a high resonance frequency generated in a portion of the power supply patch orthogonal to the strip portion is about 90 °. Circularly polarized radio waves in the frequency band between the resonance frequencies are radiated.

In the patch antenna configured as described above, the excitation mode generated in the strip portion of the feeding patch extending along the dielectric for adjustment is greatly affected by the dielectric constant of the dielectric for adjustment. (Resonance length is long). On the other hand, the excitation mode generated in a portion of the power supply patch that is orthogonal to the strip portion has a small contact area with the adjusting dielectric, so that the resonance frequency is relatively unaffected by the dielectric constant and the resonance frequency is relatively small. (Resonance length is short). Therefore, by exciting at a frequency between these high and low resonance frequencies and generating a phase difference of 90 degrees between the radiated electric fields based on both modes, the combined radiated electric field can be circularly polarized.

In the case of this patch antenna, the resonance frequency of the excitation mode generated in the strip can be easily changed by appropriately selecting the size of the adjusting dielectric and the dielectric material thereof. Fine adjustment required to satisfy the resonance condition can be performed very easily. Further, if another band-shaped portion that is symmetrical and orthogonal to the band-shaped portion in the feeding patch is set as the mounting region of the adjusting dielectric, the turning direction of the radiated electric field is reversed left and right, so that the left-handed circularly polarized It is possible to easily cope with any of the circularly polarized waves, and the versatility is improved.

In the above configuration, the feeding patch is preferably a simple symmetrical figure such as a square in a plan view or a circle in a plan view. In this case, reception and transmission of linearly polarized radio waves can be performed unless the dielectric for adjustment is mounted on the power supply patch, so that versatility is further improved.

[0012]

FIG. 1 is a plan view of a patch antenna according to a first embodiment of the present invention, and FIG. 2 is a perspective view of the patch antenna. is there.

In the patch antenna 10 shown in these figures, a feeding patch 12 having a square shape as a radiating element having a microstrip structure and a strip portion including one diagonal line of the feeding patch 12 are provided on the surface of a dielectric substrate 11. 12a
A long and thin adjusting dielectric 13 mounted thereon is provided, and a high-frequency signal is supplied to the power supply patch 12 via the power supply pin 14. The dielectric substrate 11 is mounted on a circuit board (not shown), and a low-noise amplifier circuit (not shown) provided on the lower surface of the circuit board is connected to the power supply patch 12 via the power supply pin 14. I have.

The principle of operation of the patch antenna 10 will be described. When power is supplied to the power supply patch 12, the excitation mode generated in the strip portion 12a is determined by the adjustment dielectric 1
3, the resonance frequency is low (the resonance length is long). In contrast, the power supply patch 12
In the excitation mode generated in the band-shaped region 12b including the other diagonal line, the contact area with the adjustment dielectric 13 is small.
The resonance frequency is relatively high (resonance length is short) relatively unaffected by the dielectric constant. Therefore, by exciting at a frequency between these high and low resonance frequencies and generating a phase difference of 90 degrees between the radiated electric fields based on both modes, the combined radiated electric field can be circularly polarized. In this embodiment, a right-handed circularly polarized antenna is exemplified.

In the above-described patch antenna 10, the resonance frequency of the excitation mode generated in the band portion 12a of the feeding patch 12 can be easily changed by appropriately selecting the size of the adjusting dielectric 13 and the dielectric material thereof. Therefore, in the design stage, fine adjustment necessary for satisfying the resonance condition can be extremely easily performed. In other words, conventionally,
The resonance condition was satisfied by adjusting the size of the degenerate separation element (notch or protruding piece) formed in the power supply patch, so that the adjustment work was complicated and could not be adjusted in many cases. In the case of the embodiment, since the adjustment dielectric 13 mounted on the power supply patch 12 only needs to be changed or processed, a circularly polarized antenna having desired resonance characteristics can be easily realized. As a result, a significant reduction in design costs can be expected.

In this embodiment, the adjusting dielectric 13 is used.
Is mounted on the band-shaped portion 12a of the feeding patch 12, but if the adjusting dielectric 13 is mounted on a band-shaped region 12b which is symmetrical and orthogonal to the band-shaped portion 12a, the turning direction of the radiated electric field can be changed. Can be reversed. That is, in this case, the resonance frequency of the excitation mode generated in the belt-shaped region 12b during power feeding becomes lower, and the resonance frequency of the excitation mode generated in the belt-shaped region 12a becomes relatively higher.
A left-handed circularly polarized antenna. As described above, the patch antenna 10 can easily cope with both left-handed circular polarization and right-handed circular polarization without changing the shape of the feeding patch 12 at all.

Note that the adjusting dielectric 13 is connected to the feeding patch 12
If removed from above, the patch antenna 10 can receive and transmit linearly polarized radio waves. FIG. 3 shows a second embodiment of the present invention.
It is a top view of the patch antenna concerning an example of an embodiment. In the patch antenna 15 shown in the figure, a circular feeding patch 16 is provided on the dielectric substrate 11 in a plan view.
The adjustment dielectric 13 is mounted on the band-like portion 16a including the central portion of the power supply, and a high-frequency signal is supplied to the power supply patch 16 via the power supply pin 14. Therefore, similarly to the above-described first embodiment, the resonance frequency of the excitation mode generated in the band portion 16a of the power supply patch 16 becomes low, and the other band portion including the large-diameter region orthogonal to the band portion 16a is formed. Since the resonance frequency of the generated excitation mode becomes relatively high, a circularly polarized radio wave in a frequency band between these high and low resonance frequencies can be radiated.

[0018]

The present invention is embodied in the form described above and has the following effects.

A patch antenna capable of radiating circularly polarized radio waves by mounting an adjusting dielectric on a belt-like portion including the center of a feeding patch, and appropriately selecting the size of the adjusting dielectric and its dielectric material. By doing so, it is possible to easily change the resonance frequency of the excitation mode generated in the belt-like portion, so that the fine adjustment required to satisfy the resonance condition can be performed very easily, and the design cost can be greatly reduced. Further, if another band-shaped portion that is symmetrical and orthogonal to the band-shaped portion in the feeding patch is set as the mounting region of the adjusting dielectric, the turning direction of the radiated electric field is reversed left and right, so that the left-handed circularly polarized The versatility can be improved by easily coping with any of the circularly polarized waves.

[Brief description of the drawings]

FIG. 1 is a plan view of a patch antenna according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the patch antenna.

FIG. 3 is a plan view of a patch antenna according to a second embodiment of the present invention.

FIG. 4 is a plan view of a patch antenna according to a conventional example.

[Explanation of symbols] 10,15 patch antenna 11 Dielectric substrate 12,16 feeding patch 12a, 16a strip 13 Adjusting dielectric 14 Power supply pin

Claims (3)

[Claims] 1. A power supply patch, which is a radiating element having a microstrip structure, and an adjusting dielectric mounted on a strip including a central portion of the power supply patch are provided on a dielectric substrate, and the power supply patch is provided on the power supply patch. By supplying a high-frequency signal, an excitation mode having a low resonance frequency generated in the band portion of the power supply patch and a high excitation mode having a resonance frequency generated in a portion of the power supply patch orthogonal to the band portion are provided. A patch antenna having a relative phase of about 90 ° and emitting a circularly polarized radio wave in a frequency band between these high and low resonance frequencies. 2. The patch antenna according to claim 1, wherein the feeding patch has a square shape in plan view, and a region including one diagonal line is the band-shaped portion. 3. The patch antenna according to claim 1, wherein the feeding patch has a circular shape in a plan view.