JPH11205036A - Bidirectional polarization antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna system which is bidirectional and can be installed at a wall surface, a ceiling, etc., using horizontal polarization. SOLUTION: A bidirectional antenna 2 for horizontal polarization which is nearly into the shape of X is arranged on a ground panel 3. The antenna 2 is excited by one-point power feeding by a power feeding wire 2b connected to a rear surface. As currents flowing radially (in the state of X) through an antenna element 2a cancels each other, a radio wave is not radiated to the front surface of the antenna. However, all the directions of radio waves flowing through four vertically lowered wire parts 2c of the element 2a are equal and the respective parts of the parts 2c radiate radio waves by characteristic, like a mono-pole antenna. In addition, the radio waves are not radiated in a vertical direction as the directions of the phases are opposite depending on upward/ downward. On the other hand, the radiation of the radio waves in right/left directions is synthesized well by adjusting an interval d2 to radiate horizontal polarization of bi-directional radiating characteristic in the shape of 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bidirectional polarized antenna apparatus suitable as a wall-mounted bidirectional polarized diversity antenna for mobile communication such as a PHS (Personal Handyphone System). About.

[0002]

2. Description of the Related Art A conventional bidirectional antenna is disclosed, for example, in Japanese Patent Application Laid-Open No. 7-245525. This antenna is obtained by improving the unidirectional Yagi antenna to be bidirectional, but only for horizontal polarization. Another conventional bidirectional antenna is disclosed in, for example, JP-A-8-307142. This antenna is composed of a vertical radiating element and an arc-shaped radiating element parallel to the vertical radiating element. However, this antenna also only obtains horizontal bidirectionality.

[0003]

In a bidirectional polarization diversity antenna used for mobile communication such as PHS, it is not clear at what angle the user uses the portable terminal. However, the transmission / reception efficiency is poor and inadequate if only the horizontal polarization is used. An object of the present invention is to enable use of both vertical and horizontal polarization so that transmission and reception efficiency is good, and when a wall is installed, a bidirectional beam is vertically polarized so that radio waves propagate along a road. An object of the present invention is to provide a bidirectional polarized antenna for horizontal polarization that can be used in combination with or independently of a wave antenna.

[0004]

In order to achieve the above object, a bidirectional polarized antenna device according to the first aspect of the present invention supplies a linear or planar impedance matching element with one point feed from the back. A bidirectional antenna for horizontal polarization having a plurality of linear radiating element portions provided to perform excitation, and provided vertically to the matching element portion and grounded at the end, and a ground plate, The gist is that the bidirectional antenna for horizontal polarization is arranged on the ground plate.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. FIG. 1 is an exploded view of a wall-mounted bidirectional polarized wave antenna according to an embodiment of the present invention. In the drawing, reference numeral 2 denotes a bidirectional antenna for horizontal polarization, which uses an antenna element 2a having a substantially X-shape, and excites at a single point by a feed line 2b connected to the back surface.

In the antenna 2, currents flowing radially (X-shape) through the antenna element 2a cancel each other, and no radio wave is emitted to the front surface of the antenna. However, the directions of the currents flowing through the wire portions 2c are the same at the portions where the four wire portions 2c vertically descending of the antenna element 2a contribute to the radiation, and the respective portions of the wire portions are similar to those of a monopole antenna. Emit radio waves with characteristics. Note that radio waves are not radiated in the up and down directions because their phases are opposite in the up and down directions. On the other hand, the radiation of the radio waves in the left and right directions is successfully synthesized by adjusting the interval d ₂ , and radiates a horizontally polarized wave having a figure-eight bidirectional radiation characteristic. In addition,
In the antenna 2, the X-shaped portion is used for impedance matching, and a patch 2d shown in FIG. 9 is attached, and adjustment is made by the size and shape of the patch 2d. The power supply line 2 b is connected through a hole provided in the ground plate 3. The four wire portions 2 c have their tips grounded to the ground plate 3.

Further, since the antenna device of the present invention is bidirectional and uses horizontal polarization, it can be used by being installed on a wall or the like.

Although the antenna apparatus of the present invention theoretically forms a bidirectional beam, the beam actually leaks also in the front direction. Beams can be formed that cover the area along. The horizontal polarization bidirectional antenna 2 can be modified, for example, to have an hourglass shape as shown in FIG.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a bidirectional antenna 2 for horizontal polarization and another bidirectional antenna 1 for vertical polarization of the present invention having the following specifications are superposed and arranged as shown in FIG. We have fabricated a wall-mounted bidirectional polarization diversity antenna. Size: 10 × 10 × 3 (cm) Frequency: 1.9 GHz PHS band Gain: 0 dB (peak gain), bidirectional (vertical, horizontal) Output: 2 ports, horizontal and vertical

An outline of the configuration of the antenna is as follows. (1) Vertically Polarized Bidirectional Antenna The anti-phase excitation type two-notch antenna element 1a shown in FIG. 2 is used. Examples of dimension design are a = 70, b = 20, c = 2
5, d = 10. The antenna 1 uses a dielectric substrate and has an antenna element 1a interposed in an intermediate layer thereof, and a substantially S-shaped feed portion 1b is interposed between two notches above the antenna element 1a via a dielectric layer. Then, the bottom surface of the dielectric substrate is placed on the ground plate 3 (see FIG. 8). FIG.
As shown in (1), the power supply line 1e is connected to the intermediate point of the power supply section 1b through a hole in the ground plate 3. (2) Bidirectional Antenna for Horizontal Polarization The loop antenna shown in FIG. 3 is used as a bidirectional antenna element 2 for horizontal polarization, which is installed on the ground plate 3, and the impedance characteristics at that time are shown in FIG. 4. Show. FIG. 5 shows the return loss characteristics of the antenna 2, and it can be seen that the return loss is obtained in the 1.5 GHz band. FIG. 6 shows the directivity, and it can be seen that no radio wave is emitted in the Z-axis direction. In the diversity antenna with the overlapping arrangement shown in FIG. 8, the antenna element 1a of the antenna 1 described above (1) is used for grounding the antenna 2, and the tips of the four wire portions 2c are connected to the antenna element 1a. In this case, the antenna 2 is mounted on the dielectric substrate forming the antenna 1,
The wire portion 2c is stabbed to the intermediate layer of the dielectric substrate on which the antenna element 1a is provided. The feed line 2b feeds power from the back of the antenna element 2a through the ground plate 3, the hole provided in the antenna element 1a, and the dielectric substrate.

[0011]

As described above, according to the present invention, a bi-directional, small-sized and inexpensive type using horizontal polarization, especially a wall-mounted type bi-directional type used in combination with another vertical polarization antenna. An antenna device suitable as a diversity antenna can be provided. Moreover, it can be installed not only on the wall but also on the ceiling, and it is not limited to diversity. Although a bidirectional beam is formed, the beam actually leaks in the front direction, so that a beam covering an area along a road can be formed, which is suitable for PHS and the like.

[Brief description of the drawings]

FIG. 1 is an exploded view of an embodiment of the antenna device of the present invention.

FIG. 2 shows a negative-phase excitation type 2 used in combination with the antenna device of the present invention.
It is a figure showing an example of a notch antenna element.

FIG. 3 is a diagram showing one embodiment of a bidirectional antenna for horizontal polarization of the present invention.

FIG. 4 is a diagram illustrating impedance characteristics of the antenna element of FIG. 3;

FIG. 5 is a diagram illustrating return loss characteristics of the antenna element of FIG. 3;

FIG. 6 is a diagram showing the directivity of the antenna element of FIG. 3;

FIG. 7 is a diagram showing another embodiment of the gate antenna of the present invention.

FIG. 8 is a diagram showing an example of use of the antenna device of the present invention.

FIG. 9 is a diagram showing another embodiment of the bidirectional antenna for horizontal polarization of the present invention.

[Explanation of symbols]

 Reference Signs List 1 bidirectional antenna for vertical polarization 2 bidirectional antenna for horizontal polarization 3 ground plane

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Teruaki Honma 6-27-8 Jingumae, Shibuya-ku, Tokyo Inside Kyocera D.I.

Claims (1)

[Claims] A plurality of linear or planar impedance matching element sections are excited at a single point from the back thereof, and are provided perpendicularly to the matching element section so that the ends thereof are grounded. A bidirectional antenna for horizontal polarization having a linear radiating element, and a ground plate, wherein the bidirectional antenna for horizontal polarization is arranged on the ground plate. Wave antenna device.