JPH11220325A - Antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of an antenna system as much as possible. SOLUTION: In this antenna device 11, four layers containing a loop pattern 12 having its circumference length of about one wavelength, the feeding conductor patterns 13 and 14 of two different systems, a ground plane 15 and an RF circuit pattern 16 are laminated together via the insulating layers 17. The patterns 13 and 14 are placed along the loop of the pattern 12, and one of both ends of each of both patterns 13 and 14 that serves as a feeding point is connected to the pattern 16 via each through hole 17a. The power is supplied to the pattern 12 from the patterns 13 or 14 via the electromagnetic coupling, and the feeding switching is performed between both patterns 13 and 14 to transmit and receive the leftward and rightward circular polarized waves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device, and more particularly to a miniaturized antenna device.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG. FIG. 1 shows a loop antenna 1 for linear polarization. Both ends of a rectangular loop element 2 are connected to a balanced line connection terminal of a balanced / unbalanced conversion / impedance conversion circuit 4 through a balanced feed line 3 and the other unbalanced line. A coaxial cable 5 connects the connection terminal and an RF circuit (not shown) for reception or transmission.
Connect by. As shown in the figure, when a feeding point is provided in the horizontal element portion of the loop element 2, the antenna becomes a horizontally polarized antenna. If the feeding point is rotated by 90 ° from the position shown in FIG. It becomes an antenna for vertical polarization.

Although not shown, if a perturbation element is provided in the loop element 2, a circularly polarized loop antenna can be obtained.

[0004]

It is desirable that the antenna device be as small and thin as possible. However, the conventional antenna device has a large number of parts, has a limitation in miniaturization, and requires a large number of assembly steps. Then, a technical problem to be solved arises in order to reduce the size of the antenna device and improve productivity, and an object of the present invention is to solve the above problem.

[0005]

SUMMARY OF THE INVENTION The present invention, which is proposed to achieve the above object, is a multilayer printed wiring board, which insulates a loop pattern, a power supply conductor pattern, a ground plane, and an RF circuit pattern. It is an object of the present invention to provide an antenna device in which the power supply conductor pattern and the RF circuit pattern are connected to each other by a through hole or a conductor, and power is supplied from the power supply conductor pattern to the loop pattern by electromagnetic coupling.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an antenna device 11,
A square loop pattern 12, a power supply conductor pattern 13,
14, a ground plane 15, and an RF circuit pattern 16. The multilayer printed wiring board is formed by laminating four conductor layers with an insulating layer 17 interposed therebetween. The insulating layer 17 is made of an alumina ceramic material, a glass epoxy material, a polyimide material. And other synthetic resins or a composite of these materials.

The loop pattern 12 is a rectangular pattern having a circumference of about one wavelength, and the power supply conductor patterns 13 and 14
One end, which is arranged along the loop of the loop pattern 12 and serves as a feeding point, is connected to the RF circuit pattern 16 through a through hole 17a. Various electronic components (not shown) are mounted on the lower surface of the RF circuit pattern 16 to form an RF circuit, and power is selectively supplied to the power supply conductor patterns 13 and 14 via a switching circuit in the circuit. Loop pattern 12
Is supplied from the power supply conductor pattern 13 or 14 by electromagnetic coupling, and performs reception or transmission of radio frequency via the loop pattern 12.

The loop pattern 12 is provided with perturbation elements 12a and 12b for generating a circularly polarized wave at one corner and at a corner facing the corner. When viewed from the front of the loop pattern 12, the perturbation elements 12a and 12b are located at + 45 ° and −1
It is located at 35 ° and is located at −45 ° and + 135 ° from the feed point of the vertical feed conductor pattern 14.

FIG. 2 shows the spatial positional relationship between the loop pattern 12, the power supply conductor patterns 13 and 14, the ground plane 15, and the RF circuit pattern 16. As an example of the dimensions of each part, the perimeter C of the loop pattern 12, Element length ΔL of perturbation element sections 12a and 12b, ground plane 1
5 as the height h of the loop pattern 12 and the length LV + LH of the feed conductor patterns 13 and 14, C = 1.032.
_{λ 1.472, ΔL = 0.029λ 1.472,} h = 0.049
_1λ1.472 , LV = _0.014λ1.472 , LH = 0.2
36λ _1.472 . Here, λ _1.472 is a free space wavelength at a design frequency of 1.472 GHz.

In the above antenna device 11, if power is supplied from the horizontal power supply conductor pattern 13, the perturbation element portion 12
The right and left-hand circularly polarized waves are radiated from the loop pattern 12 in the + Z direction by a and 12b. When power is supplied from the vertical power supply conductor 17, left-handed circularly polarized waves are emitted from the loop pattern 12 in the + Z direction. Therefore, by switching the horizontal power supply conductor 13 and the vertical power supply conductor 14, left and right circularly polarized waves and right circularly polarized waves can be transmitted and received.

Although not shown, if the perturbation elements 12a and 12b are removed from the loop pattern 12, the loop antenna device for linear polarization can transmit and receive by switching between horizontal polarization and vertical polarization.

As described above, since the loop element, the power supply conductor, the ground plane, and the RF circuit are integrated by the multilayer printed wiring board, the size is extremely reduced, and the connection work of each part is unnecessary.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible within the technical scope of the present invention, and it goes without saying that the present invention extends to those modifications. is there.

[0014]

As described above, the antenna device of the present invention is extremely compact because the loop element, the feed conductor, the ground plane, and the RF circuit are integrated by the multilayer printed wiring board, and the connection work of each part is also easy. It becomes unnecessary and productivity is remarkably improved.

[Brief description of the drawings]

FIG. 1 shows an antenna device of the present invention, wherein (a) is a plan view and (b) is a side view.

FIG. 2 is an explanatory diagram of a pattern arrangement of the antenna device of FIG. 1;

FIG. 3 is a front view of a linearly polarized antenna device showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Antenna device 12 Loop pattern 12a, 12b Perturbation element part 13, 14 Feeding conductor pattern 15 Ground plane 16 RF circuit pattern 17 Insulating layer 17a Through hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01Q 19/17 H01Q 19/17

Claims (3)

[Claims] 1. A multilayer printed wiring board, comprising: a loop pattern, a power supply conductor pattern, a ground plane, and an RF circuit pattern sequentially laminated with an insulating layer interposed therebetween, and the power supply conductor pattern and the RF circuit pattern are connected to each other through holes or conductors. An antenna device that is connected to a power supply conductor pattern to a loop pattern by electromagnetic coupling. 2. The first and second power supply conductor patterns are arranged at positions where the power supply points are at an interval of 90 ° when viewed from the center of the loop of the loop pattern, so that horizontal polarization and vertical polarization can be transmitted and received. The antenna device according to claim 1, wherein: 3. The first and second power supply conductor patterns are arranged at positions where the power supply points are at an interval of 90 ° when viewed from the center of the loop of the loop pattern, and the first and second power supply conductor patterns are arranged in the loop pattern.
2. The antenna device according to claim 1, further comprising a perturbation element portion located at an equal distance from the feeding point of (a) to transmit and receive left-hand circular polarization and right-hand circular polarization.