JPS6319902A - Antenna system - Google Patents

Abstract

PURPOSE:To shorten the time needed for calculation of the phase setting value by using a memory storing an initialization phase used for execution of the nonlinear optimization method. CONSTITUTION:The radio waves received by element antennas Ea1-EaN are synthesized by phase shifters Ps1-PsH and transmitted to a receiver 2. Each phase shifter is set by a phase shifter controller 3 based on the calculation of a control processor 4. When the undesired wave arriving direction is instructed by an angle instructing circuit 5, an initial value setting memory 6 sets sensitivity of said direction at zero and at the same time gives a phase component PAi of a complex exciting amplitude of each phase shifter that is used to turn a main beam to a desired direction to the proceesor 4 as the initial value. Thus the initialization phase can be set at a level near the optimum value and therefore the calculating time of the nonlinear optimization method can be greatly shortened. Furthermore it is possible to avoid such a case where the result of calculation is converged to the wrong value.

Description

[Detailed Description of the Invention] [Industrial Application] This invention forms a zero point at a desired angle other than the main beam direction of a radiation pattern by controlling a phase shifter connected to each element antenna. The present invention relates to an antenna device.

[Conventional technology]

FIG. 8 is a block diagram showing the configuration of a conventional antenna device disclosed in, for example, Japanese Unexamined Patent Publication No. 57-38003. In FIG. 1, Eal, ga2, . . .

EaN is an element antenna, Psl, Ps2 j-
, PsN is a phase shifter, il+ is a combiner, (2) is a receiver, (3) is a phase shifter control device, (4) is a control processor,
(5) is an angle indicating circuit.

Next, the operation will be explained. Here, the case where this antenna is used as a receiving device will be explained as an example. The radio waves received by the element antennas E'a1, Ea2,..., EaN are transferred to the phase shifters Ps1, Ps2,...
, the phase can be changed by PsN. Next, the output signals of each phase shifter are combined by a combiner +11. This combined signal is transmitted to the receiver (2).2 When performing normal beam scanning, the control processor (4) calculates the setting amount of each phase shifter necessary for beam scanning. According to the calculation results, the phase shifter 17+control device (3) sets each phase shifter to perform beam scanning. The operation described above is that of a normal phased array antenna.

If jamming waves or clutter are present, in addition to the above operations, it is necessary to form a zero point of the radiation pattern in the direction in which the unwanted waves arrive. At this time, a ninth-order operation is performed. First, the angle instruction circuit (5) instructs the control processor (4) about the arrival direction of unwanted waves such as jamming waves and clutter. The control processor (4) includes phase shifters Ps1 and Ps2 for maintaining the level in the main beam direction and forming the zero point of the radiation pattern in the direction in which unwanted waves arrive.

..., Calculate the phase setting amount of PsN. For this calculation method, use steepest descent method, 5equential U
ncon -5trained Minimizati
on Technique (3UMT).

Nonlinear optimization techniques such as the conjugate gradient method are used.

All of the above-mentioned nonlinear optimization methods are methods in which the phase setting amount is changed and calculations are performed repeatedly in order to realize a desired radiation pattern. In the conventional antenna device, the initial value for performing this recalculation is 9, which uses a phase setting amount that does not take into account zero point formation when performing normal beam scanning.

Next, according to the calculation result of the phase setting amount, the phase shifter control device (3) controls the phase shifters Ps1, r'g2, -, P
sN was set, and a zero point was formed in the direction of arrival of unnecessary waves.

[The problem that the invention attempts to solve]

Since the conventional antenna device is configured as described above, the number of return calculations is large, and when the number of element antennas is large, a large amount of calculation time is required to realize the desired radiation pattern. did.

In addition, if the values of the initial set phase amount and the set phase meter for obtaining the desired radiation pattern are significantly different, the solution of the set phase amount may be changed to a local minimum value (Local m
There was a problem in that the radiation converged to a certain value (inimum), making it impossible to obtain a desired radiation pattern.

This invention was made in order to solve the above-mentioned problems, and it is possible to shorten the calculation time to obtain the desired radiation pattern, and also to form a sufficiently low level zero point in the direction of arrival of unnecessary waves of the radiation pattern. The purpose is to obtain an antenna device that can.

[Means for solving problems]

The antenna device according to the present invention is additionally provided with a memory that stores an initial setting phase when executing a nonlinear optimization method in order to form a zero point in the direction in which unnecessary waves arrive.

[For production]

In the antenna device of the present invention, the control processor retrieves the initial setting phase when executing the nonlinear quantity optimization method from the memory storing the initial setting phase, and sets the initial setting phase to a value close to the setting phase for realizing a desired radiation pattern. So,
Since the number of repeated calculations is reduced and the difference between the initial set phase amount and the solution phase amount is still small, there is no risk of convergence to the set phase amount to an incorrect value.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, (6) is an initial setting phase memory, and the other parts are similar to the conventional device described above.

The operation of this initial setting phase calculation device will be explained. Here, the arrival direction of the desired wave is θ. , the arrival direction of unnecessary waves is θ
, θ , ..., θ1. θ. The radiation pattern that formed the main beam in the direction f, Eo(, θ1°...θ, the radiation pattern that formed the main beam in the direction g, (θ),...
The complex excitation amplitude given to the first element to form +En( of , ~() is A, E().

In order to form . Give to the first element to form a zero point: *Primary width A1
is expressed by the +11th equation.

A1- Ao, +α b Ill where M1 Also, α is the solution of the following simultaneous equations.

Eα-e o13) When the above complex excitation amplitude A1 is given to the first element, it has a main beam in the 0o direction as shown in FIG.

A radial turn with zero points in the directions 0, . . . , θ is obtained. Here, when giving the complex excitation amplitude Ai, the excitation loss width and phase must also be changed.

Now, let PAl be the phase component of the complex excitation amplitude A.

The excitation amplitude is fixed and when the excitation phase is set to FA□, the third
As shown in the figure, a complete zero point is not formed in the θ . . . , θ directions, but a radiation pattern in which the electric field level in the θ .

The initial setting phase memory is a memory that stores PAi.

After reading the initialization phase in the first element from the initialization phase memory, the control processor:

Using a nonlinear optimization method, the final setting phase is calculated to make the electric field in the directions 0, .theta., completely zero.

When the excitation amplitude is fixed and the excitation phase is adjusted according to this final setting phase, the angle θ is as shown in Fig. 4.

Zero points of the radiation pattern are formed at θ..., θj.

〔Effect of the invention〕

As described above, according to the present invention, the initial value for calculating the set phase to obtain the desired radiation pattern is read from the initial setting phase memory and given, so the calculation time can be shortened and the calculation result can be incorrect. This has the effect of eliminating the risk of convergence to a certain value. The above effects will be illustrated using figures.

Figure 6 shows a linear array antenna in which 30 element antennas are arranged linearly at half-wavelength intervals and given a -25 dB Taylor distribution, using a single antenna device.
This is a radiation pattern with a zero point at 5°.

Figure 7 shows that the main beam is O@ in the above calculation model.
, 5', 10@, 20', 30'', 4
It is a diagram showing the zero depth in the range of -20° to -5° when scanning G@ and forming zero points at -20'' to -S0. In the figure, the solid line indicates the zero point formed by this antenna device. As a result, the broken line is the result of forming a zero point using a conventional antenna device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure shows a radiation pattern in which a zero point is formed by changing both the excitation vibration phase, Figure 3 shows a radiation pattern when the initial setting phase is given to each phase shifter, and Figure 4 shows a control A diagram showing a radiation pattern when the set phase calculated by the processor is given to each phase shifter, FIG. 5 is a flowchart showing the control operation of this antenna device, and FIG. 6 is a diagram showing the radiation pattern by the antenna device of the present invention. FIG. 1 is a diagram showing a comparison of zero depth with a conventional example, and FIG. 8 is a diagram showing the conventional example. In the figure, 1lal, Ea2, m, and RaN are element antennas. Psl, Ps2, ..., PsN are phase shifters,
(1) is a synthesizer. (2) is a receiver, (3) is a phase shifter control device, (4) is a control processor, (5) is an angle indicating circuit, and (6) is an initial setting phase memory. In addition, in FIG. 9, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A plurality of element antennas, a phase shifter connected to each of the element antennas, a power divider, a phase shifter control device for controlling the phase shifter, and a direction of arrival of a desired signal wave and a plurality of unnecessary signal waves. An antenna comprising an angle indicating circuit for instructing, and a control processor for calculating a set phase to be given to the phase shifter in order to direct the main beam in the direction of arrival of the desired signal wave and form the zero point of the radiation pattern in the direction of arrival of the unwanted signal wave. In the device,
A memory storing an initial setting phase for calculating an initial value of the setting phase at the start of calculation of the control processor from the radiation electric field of each element antenna in the arrival direction of the desired signal wave and the unnecessary signal wave is connected to the angle indicating circuit and the above. An antenna device characterized in that it is provided between a control processor.