JPS5910005A - Antenna device - Google Patents

Abstract

PURPOSE:To improve the S/N of a received signal, by turning a main beam to the arriving direction of a signal wave and forming a zero point of directivity in the arriving direction of a disturbance wave. CONSTITUTION:The arriving directions of both signal wave and disturbance wave are given to an exciting distribution arithmetic circuit 7 by an angle indicating circuit 6. The circuit 7 decides the phase quantity of element antennas 1a-1n respectively and gives the information to an exciting distribution control circuit 8. The circuit 8 controls a driving circuit 9 in accordance with the above- mentioned information and sets phase shifters 3a-2n at desired values respectively to form a zero point of radiation directivity in the direction of a disturbance wave. That is, the beam is turned to the arriving direction of a signal wave with a simple bardware constitution by a simple operation, and a zero point of directivity is formed in the arriving direction of the disturbance wave. Thus the S/N is improved for a received signal.

Description

[Detailed description of the invention] This invention directs the main beam in the direction in which the signal wave arrives.

The present invention relates to an antenna device that forms a directional zero point in the arrival direction of interference waves and improves the S/N ratio of a received signal.

When conventional antenna devices of this kind are constructed using analog circuits, the signal-to-noise ratio is improved by correlating signals using mixers, filters, and the like. However, in this method, when the amplitude 1M1 wave number of the interference wave changes, the convergence time and the level of the zero point change. It has been difficult to realize this as an actual antenna system due to problems such as the complicated configuration of the hardware and the difficulty in removing interference waves that have the same frequency as the signal wave.

In order to eliminate these drawbacks, this invention uses an angle indicating circuit to indicate the directions of signal waves and interference waves, and based on the excitation distribution obtained by superimposing patterns with main beams in each direction. .

This antenna device is characterized by controlling the phase of each element antenna to form a main beam in the direction of the signal wave and a zero point in the direction of the interference wave.The purpose is to eliminate interference waves with a simple hardware configuration. The purpose is to form a perfect zero point in the direction of arrival. The drawings will be explained in detail below.

FIG. 1 shows an embodiment of this invention, (+a),
(1b).

(IC), ..., (+n) is an element antenna, (2)
are element antennas (1a), (1b), (1C),...
, (1n), the play antenna + (
3a) I (3b) l (3C), ・= l (3n
) phase shifter, (4) phase shifter (5a), (5b),
(sc), ・= , (gn) constitutes an excitation distribution adjuster, and (5) is a power divider.

(6) is an angle indication circuit, (71-digit excitation distribution calculation circuit, (
8) excitation distribution control circuit (91 drive circuit). Next, the present invention will be explained in detail. First, the direction of arrival of the signal wave and the direction of arrival of the interference wave are determined by the angle indicating circuit (61) and the excitation distribution calculation circuit. The power can be seen in (7).Excitation distribution calculation circuit (
7) is an element antenna (+a) (+
b), (IC), ・I Determine the phase amount of (1m>) and give that information to the excitation distribution control circuit (8). The excitation distribution control circuit (8) controls the drive circuit (9) according to the above information. and phase shifters (5a), (5b), (5C), -
, (3n) to the required values.

Here, a method for determining the phase amount in the excitation distribution performance circuit 1 (7) will be described. FIG. 2 is a diagram showing a radiation pattern with a main beam in the arrival direction θS of the signal wave.

The electric field at angle θ is represented by Es(θ), and the excitation distribution given to the first element to form this radiation pattern is S1 (includes both amplitude and phase components).

Figure 3 is a diagram showing a radiation pattern with the main beam in the direction of arrival of the interference wave θj. The distribution is assumed to be 61 (including both s-width and 1-phase components). Fig. 4 shows the combination of electric fields E8 (and Ej).

FIG. 7 is a diagram showing a radiation pattern in which a main beam is formed in the direction of arrival of a signal wave θS and a zero point is formed in the direction of arrival of an interfering wave θj.

The excitation distribution a1 given to the first element to form this radiation pattern is shown by equation +11 and equation (2). Mi1
contains both amplitude and phase components.

6 □ = d engineering + α also □ ・・・(
1) The excitation distribution adjuster (4) is a phase shifter (3a
), (3b) +...+ It consists only of (3n)
Therefore, the excitation distribution 1 is directly converted to the element antenna (1
) cannot be given. Therefore, in the next step 11@, the excitation distribution 61 is closest and θ8 is determined by only the phase.
A distribution for forming the main beam in the direction and a zero point in the θ1 direction is realized.

FIG. 5 is a diagram showing the state of the electric field vector of each element at the angle θj when the auxiliary layer distribution ε1 is given. vDa
, vOb, "' * vol, vOm+ ■On is the electric field vector of each element at θj when the excitation distribution a1 is given, and the combined vector is a zero vector.

FIG. 6 is a diagram showing the state of the electric field vector of each element at the angle θj when only the phase is adjusted from the initial state to the phase component δ of 6□. VlEL, Vlb.

``' + ■11+ Vllll, v, n x θj fJ electric field vector of each element The resultant vector is not a zero vector.Here, by shifting the phases of the 1mth and nth elements, the resultant electric field in the θj force direction is set to zero. Fig. 6 is a diagram showing the electric field vector at angle θj when the θj force direction resultant electric field is set to zero by shifting the phase of mth and n#th.

V2m and v2n are m 41st and n at υ by shifting the phases of electric field vectors v, m, and Vln to make the composite electric field zero.
is the electric field vector of the th element. In this case, m-th and n
The phases φm and φn given to the th element are +31. ,
f4+.

(Represented by formula 51.

M=V1a+v1b+ +++ +v11'
−(31·−·(5)) Note that 11 represents the absolute value of the vector, and L represents the phase.

Here, two sets of solutions are obtained, but the one that changes less from & is adopted. From the above, the phase of ui is given to the elements other than the m-th and n-th elements, and the 1m-th element is given.

+41. for the nth element. φm, φ shown in equation (5)
If a phase of n is given, a radiation pattern with a zero point of directivity in the main beam θj force direction in the θ8 direction can be obtained. Although the case where the phases of two elements are shifted has been described here, the distribution is determined in a similar manner when two or more elements are shifted.

FIG. 8 is a block diagram of another embodiment of the present invention.

(1oa), (+ob),..., (1o is a digital phase shifter, (nm).

(++n) is a phase shifter (+Oa), (+ob), ・l
This is a phase shifter with a larger number of bits than (101). In this example, the mth.

By adjusting the viscosity of the phases φm and φn applied to the n-th element, the θj force direction composite electric field can be made zero as shown in Figure 6, so the increase in the level of the zero point due to quantization phase error can be suppressed. becomes possible.

Although the case where the interference waves arrive from one direction has been described above, the present invention is not limited to this, and can also be used when a plurality of interference waves arrive from different directions.

As described above, in the antenna device according to the present invention, the main beam is directed in the direction of arrival of the signal wave by a simple hardware configuration and simple calculation, and the zero point of directivity is formed in the direction of arrival of the interference wave. , a received signal with an improved signal-to-noise ratio can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is a diagram showing a radiation pattern with the main beam directed in the direction of arrival of the signal wave,
Figure 3 shows a radiation pattern with the main beam directed in the direction of arrival of the interference wave, and Figure 4 shows a radiation pattern with the main beam directed in the direction of arrival of the signal wave and a zero point formed in the direction of arrival of the interference wave. Figure 5 is a diagram showing the electric field vector at the coming signal when the amplitude and phase are combined, and Figure 6 is a diagram showing the electric field vector at the arrival angle of the interference wave when only the phase is combined. 1 is a diagram showing an electric field vector when the phases of two elements are shifted to form a zero point at the arrival angle of an interfering wave, and FIG. 8 is a diagram showing another embodiment of the present invention. In the figure (11 is an element antenna, (2) is an array antenna, (3) is a phase shifter, (4) is an excitation distribution adjuster, (5) is a sum circuit. (6) is an angle indicating circuit, and (71) is an array antenna. Excitation distribution calculation circuit, (
8) is an excitation distribution control circuit, (91 is a drive circuit, 01 is a digital phase shifter, (++m) and (11n) are digital phase shifters. In the figure, the same or equivalent parts are given the same symbols. Agent Makoto Kuzuno - Figure 1 Figure 2 Figure 3 Figure 1 Figure 4 of 5 Figure 6 Figure 5

Claims (1)

[Claims] (11) A plurality of element antennas, a phase shifter connected to each of the element antennas, a power divider, a drive circuit that drives the phase shifter, and a drive circuit that controls the drive circuit. In an antenna device comprising a control circuit, an angle indicating circuit for indicating the direction of arrival of a signal wave and a direction of arrival of a disturbance wave, and an excitation distribution calculation circuit for calculating the amplitude and phase to be given to each element antenna, the excitation distribution described above is provided. An arithmetic circuit creates a radiation directivity zero point in the direction of arrival of the interference wave, calculates the optimal amplitude and phase to be given to each element antenna in order to maximize the gain in the direction of arrival of the signal wave, and calculates the optimal amplitude and phase to be given to each element antenna, to give only the phase obtained by the above calculation to each element antenna.Next, the phase shifter connected to at least two of the element antennas is controlled to bring the zero point of the radiation directivity in the direction of the interference wave. (2) A patent claim characterized in that a digital phase shifter is used as the phase shifter, and the phase shifter connected to at least two element antennas is an analog phase shifter. (3) A digital phase shifter is used as the phase shifter, and the number of bits of the phase shifter connected to at least two element antennas is equal to the number of bits of the phase shifter connected to element antennas other than these. The number of bits of the phase shifter is greater than the number of bits of the phase shifter.
1) The antenna device described in item 1).