JPH0414305A - Antenna for radio equipment - Google Patents

Abstract

PURPOSE:To improve the radiation characteristic within the horizontal plane of the antenna by providing arranging 2nd and 3rd conductor plates to both sides opposite to each other of a 1st conductor arranged in parallel above a radio equipment case, and providing a short-circuited conductor and a feeding conductor. CONSTITUTION:A radiation conductor plate 2 arranged above a radio equipment case 1 is made by bending a conductor plate in U-shape, the middle part is used as a 1st conductor plate 2a and arranged in parallel with the upper face of the case 1, both sides are folded down in the vertical direction to form 2nd and 3rd conductor plates 2b, 2c. In such a case, the plate 2a is designed to be of the same size as the face of the case 1 opposite to the plate 2a in a way that both sides of the plate 2a are not projected from the case 1, the length of the plates 2a, 2b provided to both sides is varied to adjust the entire length L of the plate 2, thereby setting the resonance frequency. Then a short-circuited conductor 3 projected from the upper face of the case 1 and the feeding conductor 4 are connected to the plate 2a to connect the plate 2 to the radio equipment electrically and supported, and the impedance is adjusted by varying the distance between the conductors 3 and 4. Thus, the radiation characteristic of the antenna within the horizontal plane is improved.

Description

[Detailed description of the invention] [Industrial application field] TECHNICAL FIELD The present invention relates to an antenna used by being attached to a radio device.

[Conventional technology]

BACKGROUND ART Conventionally, in portable radio devices or stationary radio devices, a so-called built-in antenna, in which the antenna is directly attached to the radio device, is sometimes used from the viewpoint of design and portability. As an example, an antenna having the structure shown in FIG. 3 has been proposed.

The antenna shown in the figure is known as a one-side short-circuited microstrip antenna or a plate-shaped inverted F antenna. That is, the upper side of the radio housing 11 is recessed, and the radiation conductor plate 12 is disposed vertically in this recessed portion.

The radiation conductor plate 12 is connected and supported by the short-circuit conductor plate 13 on the negative side of the radio device housing 11, and the power feeding conductor 14 protruding from the recessed portion of the radio device housing 11 is connected to and supported by the short circuit conductor plate 13 on the negative side. It is connected to 12 required locations.

It is known that an antenna with this configuration can provide performance comparable to a half-wavelength sleeve antenna or a half-wavelength whip antenna when mounted on a portable radio device.

[Problem to be solved by the invention]

However, when we compare in detail the radiation patterns of vertically polarized components in the horizontal plane (X7 plane) for the antenna shown in Figure 3 and the half-wavelength whip antenna, we find that in the latter case, Even if it is mounted on the body, it becomes almost omnidirectional, but in the former case, the radiation level in the -Y direction decreases, so omnidirectionality cannot be obtained. That is, in the case of the antenna shown in FIG. 3, the maximum radiation direction in the horizontal plane is near the Y-axis, and the difference between the maximum gain and the minimum gain is about 5 dB or more.

Therefore, this antenna does not cause many problems in an environment where the direction of arrival of radio waves is uniformly distributed, but when used in an environment where the direction of arrival of radio waves is biased in one direction, especially when the direction of arrival of radio waves is There is a problem in that connection quality and connection rate decrease when the gain is the lowest.

An object of the present invention is to provide a radio antenna with improved radiation characteristics in the horizontal plane.

[Means for Solving the Problems] The radio antenna of the present invention includes a first conductor plate disposed on the upper surface of the radio casing in parallel thereto, and a first conductor plate disposed on both opposing sides of the first conductor plate. The first conductor plate and second and third conductor plates disposed perpendicularly constitute a radiation conductor plate, and this radiation conductor plate is used as a short-circuit conductor and a power supply that protrudes from the top surface of the radio device housing. Connected to and supported by a conductor.

In this case, the length of the radiation conductor plate is set so that the first conductor plate does not protrude from the side surface of the radio housing, and The length spanning the second and third conductor plates is set to a length dimension that provides a required resonant frequency.

[Effect]

According to the present invention, it is possible to reduce the gain deviation in the horizontal plane of the antenna and obtain nearly omnidirectional radiation characteristics.

(Example〕 Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the radio antenna of the present invention. 1 is a transmitter, a receiver, or a conductive casing of a radio device consisting of a transceiver, and 2 is a radiation conductor plate disposed on the upper side of the radio casing. This radiating conductor plate 2 is formed by bending a conductive plate into a U-shape, with the central part serving as the first conductor plate 2a and arranged parallel to the upper surface of the radio device housing 1, and both side parts bent vertically downward. second
They are configured as a conductor plate 2b and a third conductor plate 2C.

In this case, the first conductor plate 2a has its both sides connected to the radio device housing 1.
The first and second conductor plates 2a, 2 have the same dimensions as the opposing surface of the radio device housing 10 and are provided on both sides so as not to protrude from the side.
By changing the length b and adjusting the overall length of the radiation conductor plate 2, its resonant frequency is set.

Then, by connecting the shorting conductor 3 and the power supply conductor 4 protruding from the top surface of the radio device casing to the first conductor plate 2a, the radiation conductor plate 2 is electrically connected to the radio device. We are supporting. In this case, the impedance is adjusted by changing the distance between the shorting conductor 3 and the power supply conductor 4.

FIG. 2 shows the measured values of the radiation pattern in the horizontal plane of the antenna constructed in this way. The dimensions of the antenna used for measurement are the width of the radio housing 1! 1. Height I! ,,,depth 1
3, and the height from the top surface of the radio housing 1 to the top surface of the radiating conductor plate 2 is H1, and when the length of the radiating conductor plate 2 is L, then l
+z50trtm, 12: 160mm, 1
It was a 3x20mm Hzl 5mm Lz40 button, and the measurement was performed at about 900MH.

As can be seen from FIG. 2, this antenna has a gain deviation of about 1.5 dB in the horizontal plane, making it extremely nearly omnidirectional. Therefore, the problem of a decrease in connection quality and connection rate that occurred with conventional antennas can be solved. Also,
The average gain in the horizontal plane is about -2 dB, which is comparable to a half-wavelength whip antenna or the like.

[Effects of the Invention] As explained above, the present invention has a first conductor plate disposed parallel to the top surface of the radio housing, and a first conductor plate disposed perpendicularly on opposite sides of the first conductor plate. Since the second and third conductor plates constitute a radiation conductor plate, it is possible to reduce the gain deviation in the horizontal plane of the antenna and obtain nearly omnidirectional radiation characteristics, which reduces connection quality and connection rate. It is effective in preventing

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the radio antenna of the present invention, FIG. 2 is a horizontal radiation pattern diagram of the antenna of FIG. 1, and FIG. 3 is a perspective view of a conventional antenna. 1... Radio device housing, 2... Radiation conductor plate, 2a...
1st conductor plate, 2b... 2nd conductor plate, 2C... 3rd conductor plate, 3... short circuit conductor, 4... power supply conductor, 11.
...Radio device housing, 12... Radiation conductor plate, 13... Short circuit conductor plate, 14... Power supply conductor. (Kai Eve rdE~shipp 3rd

Claims (1)

[Claims] 1. A first conductor plate disposed on the upper surface of the radio device housing in parallel thereto, and a first conductor plate on opposite sides of the first conductor plate, respectively.
The conductor plate and second and third conductor plates disposed perpendicularly constitute a radiation conductor plate, and the radiation conductor plate is connected to and supported by a shorting conductor and a power supply conductor protruding from the upper surface of the radio device housing. An antenna for radio equipment characterized by: 2. The length of the radiation conductor plate is set so that the first conductor plate does not protrude from the side surface of the radio device housing, and
, the antenna for radio equipment according to claim 1, wherein the length extending over the second and third conductive plates is set to a length dimension that provides a required resonant frequency.