JPH0918226A - Microstrip antenna - Google Patents

Abstract

PURPOSE: To receive the frequency of a fundamental mode and also another different fundamental frequency by preparing a conductor pin which pierces through a ground conductor with no contact with it at a prescribed position set on a radiation conductor of a microstrip antenna. CONSTITUTION: A dielectric substrate 101 uses the synthetic resin PFA that has dielectric constant ε (= 2.2), and the core wire 105a of a coaxial probe 105 is connected to a feeding point 106 that is apart from two sides of a batch 102 by distances C and D respectively. A coating wire 105b is grounded at the grounds 103 and 104. A matching pin 1 pierces through the substrate 101 in almost vertical direction and one of both ends of the pin 1 is connected to a contact 2 that is set at a position apart from two sides of the batch 102 by distances E and F respectively. The other end of the pin 1 is located at a position near a point crossing a horizontal plane formed by the ground 103. The ground 103 has an oblong hole 3 which has a prescribed size from the axis of the pin 1 and has no contact with the ground 103. In such a constitution, both a fundamental wave of frequency of 1.575GHz and another fundamental mode frequency of 2.5GHz can be received at a time.

Description

Detailed Description of the Invention

[0001]

[0001]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency antenna used for mobile communication and portable radio.

[0003]

[0002]

[0004]

2. Description of the Related Art There is a microstrip antenna shown in FIG. 3 as a high frequency antenna conventionally used for mobile communication and portable radio.

FIG. 3 is a schematic sectional view of a conventional microstrip antenna.

In FIG. 3, a conventional microstrip antenna has a dielectric substrate 101 in which a patch 102 made of a thin metal conductor plate and a ground 103 have a constant dielectric constant.
The coaxial probe 105 is arranged on the side of the ground 103 by being adhered to both surfaces thereof. The ground 103 is electrically connected to the covered wire 105b of the coaxial probe 105, and the covered wire 105b is grounded to the earth 104.
Further, the core wire 105a of the coaxial probe 105 is the dielectric substrate 1
It is electrically connected to the patch 102 at a feeding point 106 which is a predetermined position of the patch 102 by penetrating 01.

[0007]

Since the conventional microstrip antenna is constructed as described above, when a linearly polarized wave arrives at the microstrip antenna, a domain wall is formed between the end portion of the patch 102 and the ground 103 to act as a resonator. In the dielectric substrate 101, the eigenmode is excited and supplied to a receiver (not shown) connected to the coaxial probe 105.
Further, the eigenmode consists of the fundamental mode and its higher-order modes, and the frequency of the fundamental mode is adjusted by adjusting the permittivity (ε) of the dielectric substrate 101 and the length (d) of the patch 102 in the linear polarization receiving direction. Decided. Therefore, the receiver selects the fundamental mode from the eigenmodes supplied from the microstrip antenna and performs signal processing.

[0008]

FIG. 4 is a VSWR (voltage standing wave ratio) characteristic of the microstrip antenna shown in FIG. In the figure, 110 is a basic mode with a frequency of 1.575 GHz, and 111 is a secondary mode. The secondary mode is a mode that resonates at a frequency about twice that of the fundamental mode. Two fundamental peaks of the fundamental mode 110 and the secondary mode 111 are seen because the antenna is tuned for circular polarization.

[0009]

Further, in the conventional microstrip antenna, the frequency of the fundamental mode can be adjusted by additionally forming a shorting pin. FIG. 5 is a schematic cross-sectional view of a conventional microstrip antenna using a short-circuit pin.

In FIG. 5, the short-circuit pin 1 made of a metal conductor
07 is penetrated into the dielectric substrate 101, one end of which is electrically connected to a contact 108 provided at a predetermined position of the patch 102, and the other end of which is provided on the ground 103.
09 electrically connected to patch 102 and ground 1
03 is short-circuited. Thus, when the short-circuit pin 107 is used, the frequency of the basic mode can be set lower than that in FIG. Therefore, the higher mode also changes according to the frequency of the fundamental mode.

The conventional microstrip antenna is configured as described above and the fundamental mode for reception is adjusted.

[0012]

With the recent diversification of information, GPS (Global) using sanitary radio waves is used as a communication means for automobiles.
In addition to Positioning System)
ICS (Vehicle Information a)
nd Communication System) is being prepared. VICS is a road traffic information communication system, and radio beacons, optical beacons, FM multiplex broadcasting, and the like are considered as information media. The radio wave beacon and the light beacon receive information when the vehicle passes directly under the beacon and is directly installed on the road, and the receiving range is local (about 30 m before and after). Also, FM multiplex broadcasting is intended to send road traffic information and the like over the existing regular broadcasting of FM broadcasting stations, and is considered as a medium for covering a wide area.

[0013]

[0007]

[0014]

However, even if the frequency of the fundamental mode is adjusted by the above-mentioned conventional means, since one antenna has only one fundamental mode obtained from one eigenmode, one antenna has a plurality of bands. It was not possible to receive the signal of at the same time.

The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a microstrip antenna capable of simultaneously receiving different fundamental frequencies in addition to the conventional fundamental mode frequency with one antenna. And

[0016]

[0008]

[0017]

According to the first aspect of the present invention,
In a microstrip antenna in which a flat plate-shaped dielectric is sandwiched between a radiation conductor and a ground conductor, and a feeding line that supplies power to the feeding point on the radiation conductor is attached, the ground conductor is not in contact at a predetermined position on the radiation conductor. The microstrip antenna is characterized in that a conductor pin that penetrates is formed.

[0018]

[0009]

[0019]

The present invention is constructed as described above.
According to the invention described above, a matching pin electrically connected to the patch is provided at a predetermined position of the patch of the microstrip antenna, and the matching pin is arranged so as to pass through the ground in a non-contact manner. It is possible to shift the frequency of the higher mode without changing the frequency of the fundamental mode.

[0020]

[0010]

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The same parts as those of the conventional device described with reference to FIG. 3 are designated by the same reference numerals.

FIG. 1 is a schematic view of a microstrip antenna according to an embodiment of the present invention, in which (a) is a sectional view and (b) is a bottom view. In FIG. 1, the patch 102
Is the length of each side A and B is A = 60 mm and B = 6, respectively.
It is formed of a rectangular copper foil having a thickness of 2.8 mm and a thickness of 35 μm. The dielectric substrate 101 is a synthetic resin PFA (perfluoroalkoxy resin) manufactured by Daikin Industries, Ltd., and has a dielectric constant ε = 2.2 (Daikin Industries, Ltd.).
Model number AP-210) and is formed with a thickness of 4.5 mm. Also, the core wire 105 of the coaxial probe 105
A is connected to the feeding point 106 where the distances C and D from the two sides of the patch 102 are 24 mm, as shown in FIG. In addition, the covered wire 105b is the ground 103
Is electrically connected to and is grounded together with the ground 104.

[0023]

Reference numeral 1 in the figure is a matching pin made of a metal conductor, and penetrates the dielectric substrate 101 substantially vertically as shown in (b) of the drawing, and one end thereof is a distance E from two sides of the patch 102. , F are electrically connected to the contacts 2 provided at positions of E = 30 mm and F = 22 mm, respectively. The other end of the matching pin 1 is located near the intersection with the horizontal plane formed by the ground 103, but the ground 103 is provided with a rectangular hole 3 of a predetermined size with the matching pin 1 as an axis. 1 is arranged so as to be electrically non-contact with the ground 103.

[0024]

Next, the VSWR (voltage standing wave ratio) characteristic of the microstrip antenna of the present invention is shown in FIG.
Here, the VSWR of the conventional microstrip antenna is used.
(Voltage standing wave ratio) It received using the same circular polarization as the characteristic (FIG. 4). In FIG. 2, reference numeral 4 is a basic mode with a frequency of 1.575 GHz, which is received at the same frequency as the basic mode obtained in FIG. 4. However, by providing the matching pin 1, the resonance secondary mode 111 of the related art in FIG. It can be seen that the frequency has moved from 3.15 GHz, which is about double, to 2.5 GHz, and mode 5 has been received.

[0025]

Therefore, the microstrip antenna of FIG. 1 according to the present invention can simultaneously receive other fundamental modes of 2.5 GHz in addition to the fundamental mode of frequency 1.575 GHz. Therefore, by using the microstrip antenna of FIG. 1 according to the present invention as a receiving antenna of an automobile, for example, a GPS reception frequency of 1.57542G
Hz and VICS radio beacon frequency 2.5 GHz can be received at the same time.

[0026]

In this embodiment, the dielectric substrate 101 is a synthetic resin PFA (perfluoroalkoxy resin) manufactured by Daikin Industries, Ltd., and has a dielectric constant ε = 2.
2 (Daikin Industry Co., Ltd. model number AP-210) and formed with a thickness of 4.5 mm, synthetic resin FEP (tetrafluoroethylene / hexafluoropropylene copolymer) manufactured by Daikin Industries, Ltd. Polymerized resin) and permittivity ε = 2.2
(Daikin Industries, Ltd. model number NP-20), 4.5
The same effect can be obtained even if it is formed with a thickness of mm.

The cross-sectional shape of the alignment pin 1 is not limited to a circular shape, and may be irregular. Further, a plurality of matching pins may be provided at predetermined positions on the patch to adjust the mode frequency.

Further, in this embodiment, the rectangular hole 3 is provided in the ground 103 to keep the matching pin 1 and the ground 103 out of electrical contact, but the shape of 3 may be circular or other irregular shape and the matching pin 1 and the ground 103 may be formed. Similar effects can be obtained if the two are close to each other and are electrically non-contact with each other.

In the present embodiment, the case of reception has been described, but the present invention may be used in the case of transmission.

[0030]

[0015]

[0031]

Since the present invention is configured as described above, according to the invention of claim 1, a matching pin electrically connected to the patch is provided at a predetermined position of the patch of the microstrip antenna. By arranging so as to pass through the ground in a non-contact manner, the frequency of the higher mode can be shifted without changing the frequency of the fundamental mode of the eigenmode to be received. In addition, different fundamental frequencies can be received simultaneously.

Therefore, when receiving different basic modes, it is not necessary to use two kinds of antennas as in the conventional case, and the receiving apparatus can be made small and simple, and can be made inexpensive.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a microstrip antenna according to an embodiment of the present invention.

FIG. 2 is a VSWR (voltage standing wave ratio) characteristic of the microstrip antenna according to the present invention.

FIG. 3 is a schematic sectional view of a conventional microstrip antenna.

4 is a VSWR (voltage standing wave ratio) characteristic of the conventional microstrip antenna in FIG.

FIG. 5 is a schematic sectional view of a conventional microstrip antenna using a short-circuit pin.

[Explanation of symbols]

 101 ... Dielectric substrate 102 ... Patch 103 ... Ground 104 ... Ground 105 ... Coaxial probe 105a ... Core wire 105b ... Covered wire 106 ... Feed point 107 ... Short-circuit pin 108 ... Contact 109 ... Contact 110 ... Basic mode 111 ... Secondary mode 1 ... Alignment pin 2 ... Contact 3 ... Rectangular hole 4 ...・ Basic mode 5 ... mode

Claims (1)

[Claims] 1. A microstrip antenna in which a flat dielectric is sandwiched between a radiation conductor and a grounding conductor, and a feeding line for supplying electric power to a feeding point on the radiation conductor is attached, at a predetermined position on the radiation conductor. A microstrip antenna characterized in that a conductor pin is formed so as to penetrate the ground conductor in a non-contact manner.