JP3248277B2 - Planar patch antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar patch antenna used for a moving body such as a ship or an aircraft.

[0002]

2. Description of the Related Art Mobile satellite communication systems for mobile objects such as ships, aircraft, and automobiles have been vigorously researched and developed by various organizations around the world since the mid-1970s. Antenna technology is one of the most important element technologies in a mobile satellite communication system, and among them, miniaturization and thinning of the antenna are essential conditions. A planar patch antenna is known as a method used to reduce the size and thickness of an antenna. Hereinafter, FIGS. 3 (a) and 3 (b)
A conventional planar patch antenna will be described with reference to FIG.

FIGS. 3A and 3B are a perspective view and a sectional view, respectively, of a conventional planar patch antenna. The planar patch antenna uses a dielectric such as resin or ceramic as the antenna substrate 1, and forms a patch electrode 2 for radio wave reception on one surface and a ground electrode 3 on the other surface, and receives the patch electrode 2. Through holes 4 to transmit signals
A conductor 5 is provided on the inner side surface of the.

[0004] The size of the antenna substrate 1 is determined by the size of the patch electrode 2, and the size of the patch electrode 2 is determined by the frequency of the received radio wave and the relative permittivity of the antenna substrate 1. Therefore, the size of the antenna substrate 1 is slightly larger than the area of the patch electrode 2 and the area of the ground electrode 3 is larger than the area of the patch electrode 2 because the size and the thickness of the antenna substrate 1 are aimed at. I just need.

[0005]

However, in the conventional configuration, when the size of the antenna is reduced, the efficiency of the antenna is reduced and the frequency band is usually narrowed.
Therefore, how to increase the frequency bandwidth when the size of the antenna is reduced becomes a problem. Conventionally, as means for solving this problem, methods such as increasing the thickness of the antenna substrate, decreasing the relative permittivity of the antenna, and devising the shape of the antenna element have been taken.
Such a method has a problem that there is a limit to miniaturization of the antenna.

Accordingly, an object of the present invention is to provide a planar patch antenna which can be reduced in size without changing the material and thickness of the antenna substrate.

[0007]

For this purpose, the present invention provides an antenna substrate, a patch electrode provided on one surface of the antenna substrate, and a surface provided on a surface opposite to the surface provided with the patch electrodes. An earth electrode, a circuit board provided facing the surface on which the earth electrode is provided, and the circuit board
And a circuit section provided with mounting components on the
Patch antenna that electrically connects the part and the antenna substrate
Antenna, and the circuit board
Make the relative permittivity of the board equal or smaller, and
Is equal to or equal to the antenna substrate area
Greater than .

[0008]

According to the above configuration, the frequency bandwidth can be widened.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B are a perspective view and a sectional view, respectively, of a planar patch antenna according to an embodiment of the present invention. FIG. 1C is a three-sided view showing the front, side, and back of the antenna substrate of the planar patch antenna according to the embodiment of the present invention. FIG. 1D is a plan view of the planar patch antenna according to the embodiment of the present invention. FIG. 3 is a three-sided view showing the front, side, and back of the circuit board of the antenna. 1 (a), (b) and (c), reference numeral 11 denotes a relative dielectric constant of 6.0 (ε1) and an outer dimension (length / width / thickness) of 50 (A) × 50 (B) × 5. (M
m), an antenna substrate made of forsterite having a diameter φ1.3 (mm) of the through hole 12, a patch electrode 13 formed on the surface of the antenna substrate 11 with a 39 (mm) square,
Reference numeral 14 denotes a ground electrode printed on the entire surface of the rear surface of the antenna substrate 11 except for the periphery of the through-hole portion by screen printing.

In FIGS. 1 (a), 1 (b) and 1 (d), reference numeral 16 denotes a dielectric constant of .epsilon.2 and an outer dimension (length / width / thickness) of 70 (C) .times.50 (D) .times.0. A circuit board made of a material having a diameter of 1.3 mm and a through hole 17 having a diameter of 1.3 mm; and a circuit 18 comprising a circuit pattern and a mounting component for amplifying a received signal on the surface of the circuit board 16. And 19, a ground electrode formed on the entire surface of the rear surface of the circuit board 16 excluding the periphery of the through hole, and 20 is a φ for transmitting a signal received by the antenna substrate 11 to the circuit board 16.
This pin is made of metal beryllium copper having a small specific resistance of 1.2 (mm).

The antenna substrate 11 and the circuit board 16 have the ground electrodes 14 and 19 facing each other, and the pins 20 are inserted into the through holes 12 of the antenna board 11 and the through holes 17 of the circuit board 16, respectively. The solder 10 is formed and electrically connected to the patch electrode 13 and the circuit section 18 of the circuit board 16. By arranging the circuit board 16 facing the ground electrode 14 of the antenna board 11 in this way, the frequency bandwidth of the antenna can be widened.

In particular, the antenna substrate ｛relative permittivity (ε1),
It is preferable that the relative permittivity ε2 and the area S2 of the circuit board 16 facing the ground electrode 14 having the antenna area S1 条件 11 have conditions expressed by the following formula.

Relative permittivity Relative permittivity of circuit board (ε2) ≦ Relative permittivity of antenna board (ε1) Opposing area S1 ≦ S2 In order to confirm that it is not less than, relative permittivity and external dimensions (vertical / horizontal) A circuit board 16 having a different shape was manufactured, and an experiment was performed.

[0015] The frequency bandwidth of the antenna is
Advantest Spectrum Analyzer R3316
The measurement was performed at A. FIG. 2 is a block diagram of an electric circuit for measuring antenna characteristics of a planar patch antenna according to one embodiment of the present invention. A signal of a predetermined frequency is transmitted from the standard signal generator 21 via the transmitting antenna 22 for measurement, and the signal is received by the planar patch antenna with the circuit board which is the test antenna 23, and the signal is transmitted through the variable resistance attenuator 24. The calculation is performed, and the antenna characteristics are displayed on the measuring receiver 25. The standard antenna 26 is a measurement error correction antenna. The antenna installation conditions at the time of measuring the antenna characteristics are such that the heights of the measuring transmitting antenna 22, the test antenna 23 and the standard antenna 26 are 1.5.
(M) The distance between the measurement transmitting antenna 22 and the test antenna 23 or the standard antenna 26 was set to 4 (m). Table 1 shows the results of the measured antenna characteristics and the measured data of the conventional product.
Shown in

The measured data when the relative permittivity (ε2) and the external dimensions (C × D) of the circuit board 16 are changed are shown in (Table 2) and (Table 3).

[0017]

[Table 1]

As can be seen from (Table 1), the antenna substrate 1
By providing the circuit board 16 facing the one ground electrode 14 side, the frequency bandwidth could be widened.

[0019]

[Table 2]

As can be seen from (Table 2), the antenna substrate 1
By making the relative dielectric constant ε2 of the circuit board 16 facing the ground electrode 14 side equal to or smaller than the relative dielectric constant ε1 of the antenna substrate 11, the frequency bandwidth could be widened.

[0021]

[Table 3]

As can be seen from (Table 3), the antenna substrate 1
By setting the area of the circuit board 16 facing the first ground electrode 14 to be << S1≤S2 >>, the frequency bandwidth could be broadened.

[0023]

As described above, according to the present invention, the frequency bandwidth of the planar patch antenna can be broadened with a simple configuration, and the antenna characteristics can be improved without changing the external dimensions of the planar patch antenna. Can be improved.

[Brief description of the drawings]

FIG. 1A is a perspective view of a planar patch antenna according to an embodiment of the present invention; FIG. 1B is a cross-sectional view of the planar patch antenna according to an embodiment of the present invention; (D) is a three-sided view showing the front, side, and back of the circuit board of the planar patch antenna in one embodiment of the present invention.

FIG. 2 is a block diagram of an electric circuit for measuring antenna characteristics of the planar patch antenna according to one embodiment of the present invention.

FIG. 3A is a perspective view of a conventional planar patch antenna. FIG. 3B is a cross-sectional view of the conventional planar patch antenna.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Antenna board 12 Through hole 13 Patch electrode 14 Earth electrode 16 Circuit board 17 Through hole 19 Earth electrode

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masaaki Arita 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-4-247722 (JP, A) JP-A-1- 135107 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01Q 13/08

Claims (1)

(57) [Claims] An antenna substrate, a patch electrode provided on one surface of the antenna substrate, a ground electrode provided on a surface opposite to the surface provided with the patch electrode, and the ground electrode are provided. A circuit board provided facing the surface and a circuit configured by mounting components on the circuit board
Unit, and electrically connects the circuit unit and the antenna substrate to each other.
A planar patch antenna connected to the antenna board
The relative permittivity of the circuit board is equal to or smaller than the relative permittivity of
And the area of the circuit board is
Make sure it is equal to or larger than the board area.
And a planar patch antenna.