JPH07142927A - Antenna device - Google Patents

Abstract

PURPOSE:To enlarge connection attenuation quantity between radiation elements with the arrangement size of the radiation element as it is by engaging a rod member to the intermediate position of the radiation elements with a specified condition. CONSTITUTION:The radiation elements 1 and 2, a back reflecting board 3, side reflecting boards 4 and 5, a feeder 6, a hybrid circuit 7, input/output terminals 8 and 9 and the metallic rod member 12 arranged between the radiation elements 1 and 2 are provided. Namely, a conducting bar 12 whose thickness is sufficiently small (0.02lambda for example) compared with the wavelength of a used radio wave and whose length is about 0.5-0.6lambda is arranged in the almost intermediate position between the radiation elements 1 and 2 arranged in front of the reflecting board 3 at the distance of 0.45-0.6lambda from the back reflecting board 3. Thus, connection attenuation quantity between the adjacent radiation elements 1 and 2 can be enlarged by adopting such structure, and therefore the deterioration of the impedance characteristic of the radiation elements 1 and 2 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device used as a base station antenna in a mobile radio communication system such as a car phone or a mobile phone, and more particularly to a beam antenna having directivity in two directions.

[0002]

2. Description of the Related Art It is conventionally known that an antenna device having directivity in two directions can be obtained by combining two antenna elements using a hybrid circuit having a phase difference of 90 °. FIG. 8 shows a configuration diagram of such a conventional antenna device.

This antenna device includes two radiating elements 1 and 1.
2 are arranged side by side in a horizontal direction of 0.3 to 0.4λ, and a back reflector 3 is provided on the back surface thereof. At both ends of the back reflector 3, side reflectors 4 and 5 are provided by bending the back reflector or adhering another metal plate.

The two radiating elements 1 and 2 are connected to a hybrid circuit 7 via a feeder line 6. A hybrid circuit (denoted as HYB in the figure) 7 operates so that the two radiating elements 1 and 2 have an excitation phase difference of 90 °, and forms a main beam in two directions.

The operation of the antenna device shown in FIG. 8 will be described in more detail below with reference to FIG. In the figure, 1 and 2 are radiating elements, 3 is a back reflector, 4 and 5 are side reflectors, 6 is a feeder line, 7 is a hybrid circuit, 8 and 9 are input / output terminals, and 10 and 11 are beams. It represents.

An input signal A having a frequency f1 input from the input / output terminal 8 is fed to the radiating elements 1 and 2 with a phase difference of 90 ° provided by the hybrid circuit 7 to form a beam 11 displaced to the right. To do.

On the other hand, the input signal B of the frequency f2 input from the input / output terminal 9 is 90 ° by the hybrid circuit 7.
Are fed to the radiating elements 1 and 2 to form a beam 10 which is offset to the left.

In the figure, the letter d is the distance between the radiating elements 1 and 2 of about 0.3 to 0.4λ, h is the distance from the radiating element and the back reflector 3, about 0.4 to 0.65λ, W is a width of the back reflector of about 0.7 to 0.8λ, and Wh is a width of the side reflector of about 0.1 to 0.2λ.

[0009]

As described above, the conventional antenna device has a problem that the impedance characteristic of the radiating element is deteriorated because the coupling attenuation amount between the radiating elements 1 and 2 is small.

The coupling attenuation amount between the radiating elements can be increased by increasing the distance between the radiating elements. However, if the distance between the radiating elements is increased in this way, the side lobe level increases. The unfavorable tendency is caused.

The present invention has been made in order to solve the conventional problems as described above. The arrangement dimension of the radiating elements is the same as the conventional one, and the coupling attenuation amount between the radiating elements is large. It is an object of the present invention to provide an antenna device capable of

[0012]

According to the present invention, the above-mentioned problems are solved by the means described in the claims.

That is, according to the invention of claim 1, when the wavelength of the radio wave to be used is λ, at least two radiating elements arranged at a distance of 0.3 to 0.4 λ and provided on the back surface of the radiating element. In the antenna system provided with a reflector and a hybrid circuit that gives a phase difference to the transmission or reception signal of each radiating element to form a beam in two directions, a length at a position intermediate between the two radiating elements is provided. But 0.5 ~
A rod-shaped member made of a conductor with a thickness of about 0.6λ, which is sufficiently smaller than the wavelength λ of the radio wave used, is placed substantially parallel to the radiating element.
In addition, the antenna device is configured so that the distance from the reflector is about 0.45 to 0.6λ.

Further, the invention of claim 2 has at least two radiating elements which are arranged at a distance of 0.3 to 0.4λ in the horizontal direction, where λ is the wavelength of the radio wave to be used. The antenna device is formed by arranging a plurality of sets of the antenna device in the vertical direction and sharing the input / output terminals of each antenna device.

[0015]

As described above, the antenna device of the present invention has a thickness which is sufficiently small as compared with the wavelength of the radio wave used, at a position approximately in the middle between the two radiating elements arranged in front of the reflector. (For example, 0.02λ) and a conductor rod having a length of about 0.5 to 0.6λ is arranged at a distance of 0.45 to 0.6λ from the back reflector.

By adopting such a structure, the antenna device of the present invention can increase the amount of coupling attenuation between adjacent radiating elements, so that the impedance characteristics of the radiating elements do not deteriorate.

[0017]

1 is a diagram showing a first embodiment of the present invention, which is a perspective view of an antenna device.
2 is a radiating element, 3 is a back reflector, 4 and 5 are side reflectors,
Reference numeral 6 is a power supply line, 7 is a hybrid circuit, 8 and 9 are input / output terminals, and 12 is a metal rod-shaped member disposed between the radiating elements 1 and 2.

The distance between the radiating elements 1 and 2 of this embodiment is 0.
The width of the back reflector is set to 0.7 to 0.8λ, and the width of the side reflector is set to 0.1 to 0.2λ. 2 and 3 are views showing a second embodiment of the present invention, FIG. 2 is a perspective view, and FIG. 3 shows the arrangement of each element as seen from the top.

In these figures, 3 to 9 are the same as those in FIG. 1, 13 is a printed circuit board, 14a, 14b,
Denoted at 15a and 15b are radiating elements formed on the printed circuit board 13, and denoted at 16 and 17 are metal rod-shaped members.

In FIG. 3, the cross section of each radiating element is shown as a circle for easy visual recognition. The outer radiating elements 14a and 15a of the present embodiment are in the 800 MHz band,
The radiating elements 14b and 15b on the inner side are in the 1500 MHz band, and this antenna device is configured as a printed dipole antenna for both of these two frequencies.

As in the case of FIG. 1, the dimensions of the respective parts are the distances d1, 14b, 1 between the radiating elements 14a, 15a.
The distance d2 between 5b is 0.3 to 0.4λ, the width W of the back reflector is 0.7 to 0.8λ, and the width Wh of the side reflector is 0.1 to 0.2λ.

The rod-shaped member 16 made of metal is used for the radiating element 14
The rod-shaped member 17 made of metal is arranged in the middle of a and 14b, and in the middle of the radiating elements 15a and 15b, but their distance from the back reflector is set to about 0.45-0.6λ. To be done.

The length of each of the metallic rod-shaped members 16 and 17 or the distance (height) from the back reflector greatly affects the coupling attenuation between the radiating elements. Figure 4
It is a figure which shows the relationship between the metal rod-shaped member (it is set as the metal rod in the figure) and the amount of coupling attenuation between radiating elements in a 800-MHz band, (a) is a back reflector of a metal rod-shaped member. The relationship between the distance (height) and the amount of coupling attenuation is shown, and (b) shows the relationship between the length of the metal rod-shaped member and the amount of coupling attenuation.

FIG. 5 is a diagram showing the relationship between the metal rod-shaped member and the coupling attenuation between the radiating elements in the 1500 MHz band, and FIGS. 5 (a) and 5 (b) are the same as those in FIG. FIG. 6 is a diagram showing a result of measurement of the antenna device of the embodiment shown in FIGS. In the figure, the vertical axis represents the amount of coupling attenuation between the radiating elements, and the horizontal axis represents the frequency.

As can be seen from the figure, in this antenna device, the frequency band 810 MHz allocated to the car telephone is used.
~ 960MHz (indicated by triangles in the figure, numeral symbols 1, 2
Is attached) and 1429 MHz to 1501 MH
z (indicated by triangles in the figure, with numeral symbols 3 and 4)
At, it is understood that a large amount of coupling attenuation is obtained.

FIG. 7 is a diagram showing a third embodiment of the present invention, which corresponds to claim 2, and a plurality of antenna devices of the embodiment shown in FIG. 2 are arranged vertically. It is made up of equipment.

In the figure, numeral symbols 3 to 9, 14a,
Reference numerals 14b, 15a, 15b, 16 and 17 are the same as those in FIG. 2, 18 is a phase shifter, and 19 and 20 are input / output terminals of the antenna device.

In this embodiment, each hybrid circuit (HY
The phase shifter 18 is connected to the input / output terminals 8 and 9 of B), respectively, and is connected in parallel through the phase shifter 18, and the input / output terminals 19 and 20 of the antenna device are connected thereto.

In the present embodiment, a hybrid circuit is provided for each of the plurality of antenna devices. However, one hybrid circuit is provided, a power distributor is provided on the output side of the hybrid circuit, and the output thereof is a phase shifter. It is also possible to adopt a configuration in which each radiating element is led via the above.

[0030]

As described above, according to the present invention,
Even if the layout dimensions of the radiating elements are the same as the conventional one, the amount of coupling attenuation between the radiating elements can be large, so that an antenna device with good radiating element impedance characteristics and a small sidelobe level is realized. There is an advantage that can be done.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing a second embodiment of the present invention.

FIG. 3 is a top view showing a second embodiment of the present invention.

FIG. 4 is a diagram showing the operation of a metal rod-shaped member in the 800 MHz band.

FIG. 5 is a diagram showing an operation of a metal rod-shaped member in a 1500 MHz band.

FIG. 6 is a diagram showing measurement results for a second example of the present invention.

FIG. 7 is a diagram showing a third embodiment of the present invention.

FIG. 8 is a diagram showing an example of a configuration of a conventional antenna device.

FIG. 9 is a diagram illustrating an operation of a conventional antenna device.

[Explanation of symbols]

 1,2,14a, 14b, 15a, 15b Radiating element 3 Back reflector 4,5 Side reflector 6 Feed line 7 Hybrid circuit 8,9 Input / output terminal 10,11 Beam 13 Printed circuit board 12,16,17 Made of metal Rod-shaped member 18 Phaser

Claims (2)

[Claims] 1. When the wavelength of the radio wave used is λ,
At least two radiating elements arranged at a distance of 0.3 to 0.4 λ, a reflector provided on the back surface of the radiating element, and a transmitting or receiving signal of each radiating element for forming a beam in two directions. In a antenna system including a hybrid circuit that gives a phase difference, a length of 0.5 to 0.
A rod-shaped member made of a conductor with a thickness of about 6λ, which is sufficiently smaller than the wavelength λ of the radio wave used, is arranged substantially parallel to the radiating element and at a distance of about 0.45-0.6λ from the reflector. An antenna device characterized by being attached to a. 2. The antenna device according to claim 1, further comprising at least two radiating elements arranged in the horizontal direction at a distance of 0.3 to 0.4λ, where λ is the wavelength of the radio wave to be used. An antenna device in which a plurality of sets are arranged and the input / output terminals of each antenna device are shared.