JPH05152837A - Phased array antenna - Google Patents

Abstract

PURPOSE:To reduce a pattern loss at scanning with respect to the phased array antenna scanning a radiation beam. CONSTITUTION:The antenna is formed by arranging plural element antennas 4 in which a dipole antenna 2 on a printed circuit board 3 and an element antenna 4 provided with a waveguide 1 in front of the dipole antenna 2. The element antenna 4 consists of the waveguide 1 whose length with respect to the dipole antenna 2 is 0.28 to 0.32 wavelength and whose distance from the dipole antenna 2 is 0.24 to 0.25 wavelength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phased array antenna for reducing pattern loss during beam scanning.

[0002]

2. Description of the Related Art Conventionally, an antenna constructed by using a director has a reflector 6 placed behind a radiator 7 as shown in FIG. 7 and a plurality of waveguides placed in front of the radiator 7 (radiation direction). It is an antenna that radiates or receives a sharp beam by arranging devices 8 and is widely used for VHF and UHF band television receiving antennas and the like because of its simple structure and small size, and high gain can be easily obtained. There is.

[0003]

When radiating elements, that is, element antennas of the same shape are arranged in an array, the radiation patterns of the element antennas are arranged as shown by dotted lines in FIG. 5 by mutually coupling the plurality of element antennas. May be. That is, when a phased array antenna is configured and beam scanning is performed, there is a problem that the gain greatly decreases as the scanning angle increases.

For example, in FIG. 5, when the scanning angle range of the beam is -A ° to + A °, the beam is -A ° or + A °.
When scanned at A °, the gain is reduced by B as compared with scanning at the boresight direction.

Conventionally, in order to compensate for this pattern loss,
This has been extremely disadvantageous in terms of economic efficiency because measures have been taken such as increasing the aperture area of the antenna to increase the gain of the entire antenna or increasing the transmission power.

An object of the present invention is to provide a phased array antenna in which the gain does not decrease significantly even if the scanning angle is increased.

[0007]

According to the present invention, a dipole antenna section and a director having a predetermined length and arranged at a predetermined distance from the dipole antenna section are provided on the same substrate. A phased array antenna configured by arranging a plurality of element antennas provided on the same plane on the same plane is obtained.

The predetermined length of the director is set between 0.28 wavelength and 0.32 wavelength, and the predetermined interval is set between 0.24 wavelength and 0.25 wavelength. A phased array antenna is obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIGS. As shown in FIG. 1, the dipole antenna 2 is arranged on the printed board 3, and the director 1 is arranged in front of the dipole antenna 2 and on the same board. A substrate composed of the dipole antenna 2 and the director 1 is arranged as one antenna element 4 on a plurality of planes as shown in FIG. 2 to form a plane array antenna (phased array antenna 5).

In the radiation pattern of the element antenna 4 with and without the director 1 shown in FIG.
The gain when the director 1 is not provided is 0 when the beam scanning angle is 0.
It can be seen that there is a decrease in the range from ° to A ° (and 0 to −A °).

The radiation pattern of the element antenna 4 alone is shown in FIG.
3, the position of the director 1, which is a constituent element of the element antenna 4, is set so that the radiation pattern of the element antenna 4 becomes the dotted line in FIG. Further, the combined beam obtained by the plurality of element antennas 4 is as shown by the solid line in FIG. 3, and the gain can be improved within the beam scanning angle range of −A ° to + A °.

The improvement of the above-mentioned gain will be described based on a specific example. First, the element antenna 4 configured by setting the length of the director 1 to 0.32 wavelength and the distance between the dipole antenna 2 and the director 1 to 0.24 wavelength is formed into an array as shown in FIG. , And about 4,500 elements are arranged on the same plane.

Table 1 shows the gain in the beam scanning direction with and without the director. The beam scanning direction is horizontal and vertical (12.24
°, 3.84 °) is 12.24 ° horizontally and 3.84 ° vertically
This means that the beam is being scanned. The results of Table 1 are shown in FIG. As can be seen from FIG. 4, by arranging the director 1 set as shown in FIG. 1 in front of the dipole antenna 2, it is possible to reduce the scanning direction (12.24 °, 3.84 °) to 0.
Gain gain of 4 (dB) is obtained.

[0014]

[Table 1]

[0015]

According to the present invention, by disposing the waveguide in front of the dipole antenna and arranging the configured dipole antenna elements in an array, a large gain can be obtained even if the scanning angle is increased. You can prevent the decrease.

When the distance between the dipole antenna and the director is set from 0.24 wavelength to 0.32 wavelength, and the length of the director is set from 0.28 wavelength to 0.32 wavelength, it becomes more remarkable. The gain is improved within the coverage area when beam scanning is performed.

[Brief description of drawings]

FIG. 1 is a front view showing a dipole antenna element with a director.

FIG. 2 is a front view in which the antenna elements shown in FIG. 1 are arrayed in a triangular array.

FIG. 3 is a diagram showing patterns of an element antenna with a director and a combined beam.

FIG. 4 is a pattern diagram showing the gain in the scanning direction based on the numerical values in Table 1.

FIG. 5 is a diagram showing a pattern of an element antenna and a synthetic beam by a conventional dipole antenna.

FIG. 6 is a diagram showing a comparison of element antenna patterns with and without a director.

FIG. 7 is a diagram showing a configuration of an antenna using a conventional director.

[Explanation of symbols]

 1,8 Waveguide 2 Dipole antenna 3 Printed board 4 Element antenna 5 Phased array antenna 6 Reflector

Claims (2)

[Claims] 1. An element antenna in which a dipole antenna section and a director having a predetermined length and arranged at a predetermined distance from the dipole antenna section are provided on the same substrate are arranged on the same plane. A phased array antenna composed of multiple arrays. 2. The phased array antenna according to claim 1, wherein the predetermined length of the director is between 0.28 wavelength and 0.32 wavelength, and the predetermined interval is 0.
A phased array antenna characterized by being set between 24 wavelengths and 0.25 wavelengths.