JPH07105656B2 - Antenna device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to radiation pattern formation of an electronic scanning antenna that electronically scans a beam.

[Conventional technology]

A conventional electronic scanning antenna will be described. FIG. 7 shows a conventional electronic scanning antenna, in which a _{1 to} a _n are element antennas, b _{1 to} b _n are modules composed of a phase shifter and a phase shifter control unit, and c is power distribution combining. A circuit, d is a duplexer, e is a transmitter, f is a receiver, and g is a beam controller. FIG. 8 shows the inside of the modules b _{1 to} b _n , (1) is a phase shifter,
(2) is a phase shifter controller, (3a) is a control signal line connected to the beam controller g, and (3b) is a microwave transmission line.
At the time of transmission, this electronic scanning antenna distributes the signal from the transmitter e by the power distribution / combining circuit c, and the modules b ₁ ...
The element antenna is controlled by the phase shifter (1) in b _n
Supply to a _{1 to} a _n . Then, it is radiated into space from the antenna elements a ₁ ~a _n, are beamformed. Signal incident on the element antenna a ₁ ~a _n during reception by phase controlling the phase shifter in the modules b ₁ b _n, enters the receiver f by synthesizing the signals by the power distributing and combining circuit c. Further, this antenna can electronically perform beam scanning by transferring the phase data calculated by the beam controller g to the phase shifter controller (2) of the module.

The beam controller g performs the following calculation for each element.

P _n = P _Bn + P _Fn + P _cn where P _n is the amount of phase shift given to the phase shifter of each module, P _Bn
Is the amount of phase shift required for beam scanning, P _Fn is the amount of phase shift for beam shaping, and P _Cn is the amount of phase shift that compensates for variations in each element.

A method of obtaining the phase shift amount P _Bn required for beam scanning will be described. FIG. 9 is a conceptual diagram showing beam scanning. In the figure, x, y, z are coordinate axes, the x-y axis plane is the antenna aperture plane, θ and φ are beam scanning angles, and x _n , y _n are the coordinates of the element. At this time, the beam scanning phase shift amount given to the element is Is. Where λ is the wavelength.

P _Fn is the amount of phase shift for beam shaping, which is the amount of phase shift given to a beam shape other than the pencil beam.
This is normally held as memory data.

P _Cn is the amount of phase shift that compensates for antenna variations.

This is due to errors in machining, due to frequency characteristics, due to temperature characteristics, due to differences in transmission system and reception system, due to differences in pulse duty, etc., depending on each factor when adjusting the antenna. It is the data that is measured and stored. Therefore, when there are many elements and many factors, the amount is enormous.

These calculations are performed by the beam controller g and set in the phase shifter (1) of each module to form a radiation pattern. Figure 10 shows a pencil beam radiation pattern that is commonly used. In the figure, the horizontal axis is the angle, the vertical axis is the power level, (a) is the pencil beam radiation pattern, and (b) is
Is the null filling setting level.

The null filling setting level (b) is a level at which the radiation power level of the antenna device should be maintained according to the angular range. Below this level, the power level required in that direction decreases, and it becomes impossible to transmit power and information to the target in that angle direction.

As shown in the figure, the pencil beam radiation pattern has side lobes with a notch (null point) between them. As a result, an angle becomes equal to or lower than the null-filling setting level (b), and it becomes impossible to transmit power, information, etc. to the target in that direction.

Fig. 11 shows the change pattern of beam scanning. In the figure, B _{1 to} B _m are patterns that represent changes in beam scanning, and each of B _{1 to} B _m represents beam changes corresponding to changes in beam scanning angle, frequency, beam shape, pulse duty, and the like. P _Bn , P _Fn , and P _Cn change corresponding to this change.

[Problems to be Solved by the Invention]

Since the conventional antenna device is configured as described above, an angle that is less than or equal to the nullfilling set level in (b) of Fig. 10 occurs, so that power and information can be transmitted to the target in that angle direction. There was a problem that disappeared. Also,
Even if the phase of the antenna device is controlled to create a radiation pattern that does not fall below the null filling setting level (b) in the required angular range, the null filling setting level (ro )
There is a problem that it is difficult to obtain a radiation pattern that satisfies

The present invention has been made to solve the above problems, and an object of the present invention is to obtain an antenna device that can easily obtain a radiation pattern satisfying a null filling setting level without increasing hardware. .

[Means for Solving the Problems]

In the antenna device according to the present invention, the amount of phase shift given to each module is changed in a time division manner so that the null filling setting level is satisfied as a time average.

[Action]

The antenna apparatus according to the present invention can satisfy the null-filling setting level as a time average pattern by changing the beam forming phase shift amount in a time division manner.

〔Example〕

 An embodiment of the present invention will be described below.

FIG. 1 shows a pattern of changes in beam scanning and the like according to an embodiment of the present invention. B ₁₁ B ₁₂ … B _1l , B ₂₁ B ₂₂ … B _2l … B _m1 B _m2 … B _ml
It shows changes in beam scanning, etc., B ₁₁ B ₁₂ … B _1l , B _{21
B 22 ... B 2l, ...,} B m1 B m2 ... B ml correspond to each of the conventional _{B 1, B 2 ... B m} . Therefore, it is necessary to change the beam scanning more finely than the conventional beam scanning.

At this time, the phase of each element calculated by the beam controller is _P'nl = _Pn + _Prl (l = 1, 2, ..., L). P _rl is a phase term that changes the conventional data P _n . 1 kind of change is given by what is obtained by adding the change by P _rl to P _n calculated in a certain mode. At this time
The average value of P _r is 0 and the phase is random with dispersion. FIG. 2 shows an example obtained in this way. FIG. 2 is an example in which changes in three cases are overwritten. Thus, the main beam is the same and the side lobe level changes. FIG. 3 shows three pattern peak levels. By changing the random phase in this manner, it is possible to change the radiation pattern in a time division manner and obtain a time average that satisfies the null filling setting level.

Next, the inside of the module of another embodiment is shown in FIG. In the figure, (4) is an adder and (5) is a memory. Here, the P _rl data is transferred and stored in the memory (5). Then, while changing P _rl to the transferred P _n in a time-division manner, it is set in the phase shifter, and by superimposing the time-division radiation patterns, the one satisfying the null-filling setting level can be obtained. The principle is the same as above.

The inside of the beam controller g of another embodiment is shown in FIG. In the figure, (6) is a control unit, (7) is a calculation unit, and (8) is a random phase generation unit. P _n calculated by the beam controller
The random phase generated by the random phase generator is added to and transferred to the module.

In this way, the radiation pattern can be changed in a time division manner by the change due to the random phase, and the null filling setting level can be satisfied as a time average.

The inside of the module of another embodiment is shown in FIG. In the figure, (9) is a random phase generator. This is the fourth
In the figure, P _rl that is fixedly changed is stored in the memory, but in this embodiment, P _rl is generated in the random phase generator and added to the phase transferred from the beam controller. Then, the radiation pattern is changed in a time-sharing manner, and the overlapping is satisfied to satisfy the null-filling setting level.

Although a passive electronic scanning antenna has been described in the above embodiment, an active electronic scanning antenna including an amplifier or the like may be used, and the module may have any configuration. Further, it goes without saying that the configuration of the phase adding circuit, the method of generating the random phase, the number and the type of generation, etc. may be arbitrary.

〔The invention's effect〕

As described above, according to the present invention, by changing the radiation pattern in a time division manner, it is possible to easily obtain a radiation pattern with few side lobe breaks as a time-averaged radiation pattern.

[Brief description of drawings]

FIG. 1 is a diagram showing a variation pattern of beam scanning or the like according to an embodiment of the present invention, FIG. 2 is a diagram in which radiation patterns are overwritten when the beam scanning is varied, and FIG. 3 is a graph showing peak values. FIG. 4 is a pattern diagram drawn, FIG. 4 is a diagram showing the inside of a module of another embodiment, FIG. 5 is a diagram showing the internal structure of a beam controller of another embodiment, and FIG. 6 is a diagram of another embodiment. Fig. 7 shows the inside of the module, Fig. 7 is a block diagram of a conventional electronic scanning antenna, Fig. 8 is a block diagram of the module, Fig. 9 is a conceptual diagram showing beam scanning, Fig. 10 is a diagram showing a radiation pattern, First
FIG. 11 is a diagram showing a conventional beam scanning change pattern. In the figure, (1) is a phase shifter, (2) is a phase shifter controller,
(3a) is a control signal line, (3b) is a microwave transmission line,
(4) is an adder, (5) is a memory, (6) is a control unit,
(7) is a calculation unit, (8) is a memory, (9) is a random phase generation unit, a _{1 to} a _n are element antennas, b _{1 to} b _n are modules, c is a power distribution / combining circuit, d is a duplexer, e is a transmitter, f is a receiver, g is a beam controller, (a) is the pencil beam radiation pattern, (b) is the nullfilling setting level, and (c), (d), and (e) change the random phase. The radiation pattern at the time of making is shown. In the drawings, the same or corresponding parts are designated by the same reference numerals.

Claims (4)

[Claims] 1. A plurality of element antennas, a module corresponding to each of these element antennas and comprising a phase shifter, a phase shifter control unit, etc., a transceiver, and between the module and the transceiver. In an antenna device having a beam controller connected to the phase shifter controller, the beam controller provides a beam scanning phase and a random phase having an average value of 0 and dispersion. , The phase data is transferred to the phase shifter, and the radiation pattern is changed in a time-division manner so that a radiation pattern with few side lobe breaks is formed as a time-averaged radiation pattern. An antenna device characterized by. 2. A plurality of element antennas, a module corresponding to each of these element antennas and comprising a phase shifter, a phase shifter control unit, etc., a transceiver, and the module and the transceiver. In an antenna apparatus having a beam controller connected to the phase shifter control unit, the beam scanning phase is calculated by the beam controller, transferred to the module, and phase-shifted. In the controller control unit, a random phase with an average value of 0 and dispersion is added, and the radiation pattern is changed in a time-division manner, so that a radiation pattern with few side lobe breaks is obtained as a time-averaged radiation pattern. An antenna device characterized by being formed. 3. A plurality of element antennas, a module corresponding to each of these element antennas and comprising a phase shifter, a phase shifter control unit, etc., a transceiver, and between the module and the transceiver. In an antenna device having a beam controller connected to the phase shifter controller, the antenna device has a power distribution / combining circuit interposed in Random phase is added, the phase data is transferred to the phase shifter, and the radiation pattern is changed in a time-division manner, thereby forming a radiation pattern with few side lobe breaks as a time-averaged radiation pattern. An antenna device characterized by the above. 4. A plurality of element antennas, a module corresponding to each of these element antennas and comprising a phase shifter, a phase shifter control unit, etc., a transceiver, and the module and the transceiver. In an antenna apparatus having a beam controller connected to the phase shifter control unit, the beam scanning phase is calculated by the beam controller, transferred to the module, and phase-shifted. By adding random phases with an average value of 0 generated by the controller and having dispersion, and changing the radiation pattern in a time-division manner, there are few side lobe breaks as a time-averaged radiation pattern. An antenna device characterized in that a radiation pattern is formed.