JPH0682968B2 - Antenna device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention arranges a plurality of element antennas and controls the phase and amplitude for each element antenna so that a desired radiation pattern can be obtained. The present invention relates to the antenna device.

[Prior Art] Conventionally, in an antenna device configured by arranging a plurality of element antennas uniformly on a straight line or a plane, such as a phased array antenna, a signal phase is changed for each element antenna. A phase shifter for controlling and an amplitude controller for controlling the amplitude level by amplifying or attenuating the amplitude of the signal are connected. The phase shifter controls the phase of a signal transmitted or received by each element antenna to electronically change the directivity direction of the combined radiation pattern by each element antenna, thereby performing beam scanning at high speed. In addition, each amplitude controller has its amplitude level set so that the amplitude distribution of each element antenna corresponds to a predetermined amplitude distribution, such as the Taylor distribution. It has a lobe level. However,
In this way, in addition to those in which each element antenna is arranged on a straight line or a plane, those in which each element antenna is arranged on a curved surface are increasing in demand, and even in such a thing, a radiation pattern having a desired side lobe Need to get

FIG. 4 is, for example, 1986, National Institute of Electronics and Communication Engineers, National Conference on Optical and Radio Waves, 82, "Cylindrical array antenna for SSR mode S", Tokuyo et al. FIG. 3 is a configuration diagram of an antenna device in which element antennas are arranged on a curved surface as shown in FIG. In the figure, 1 is a plurality of element antennas arranged on a cylindrical surface, 2 is a phase shifter that is connected to each element antenna 1 and controls the phase of a received signal from each element antenna 1. It is individually controlled by the control device 3. An amplitude controller 4 is connected to each element antenna 1 through the phase shifter 2 and controls the amplitude level of the received signal from each element antenna 1, and the amplitude level can be set individually. Reference numeral 5 is a power combiner for combining the signals from the respective amplitude controllers 4, and 6 is a receiver for receiving the signals from the power combiner 5. The power combiner 5 can be used for transmission by using the power distributor and the receiver 6 as a transmitter.

In the antenna device configured as described above, beam scanning is performed by changing the phase of each phase shifter 2 by the phase shifter control device 3, and reception or transmission operation is performed.
At this time, in order to obtain a desired side lobe level, it is necessary to appropriately set the amplitude level given to each amplitude controller 4. However, when the element antennas 1 are arranged on the curved surface, the amplitude ai of the element pattern Ei (θ) in the main beam direction is different for each element antenna 1i as shown in FIG. First, it is necessary to calculate the amplitude level given to each amplitude controller 4.

[Problems to be Solved by the Invention] Since the conventional antenna device is configured as described above, in an antenna device having a plurality of element antennas arranged on a curved surface, each amplitude controller is provided for each main beam scanning. Since it is necessary to calculate the amplitude level given to No. 4, a lot of calculation time is required, and there is a problem that the beam scanning cannot be performed at high speed.

The present invention has been made to solve the above problems, and has an antenna device having a plurality of element antennas arranged on a curved surface, which can obtain a desired combined radiation pattern in a short calculation time. The purpose is to

[Means for Solving the Problem] An antenna device according to the present invention includes a plurality of element antennas 1 arranged on a curved surface, and a phase shifter 2 for controlling the phase of a transmission or reception signal of each element antenna 1. A phase shifter control means 3 for individually controlling each of the phase shifters 2, an amplitude controller 4 for controlling the amplitude of a transmission or reception signal of each of the element antennas 1, and a combined radiation by each of the element antennas 1. The calculation means 7 calculates a set value of the amplitude for making the pattern desired, and the amplitude setting means 8 sets the value of the amplitude in each amplitude controller 4 based on the calculation result of the calculation means 7, The phase shifter control means 3 sets the excitation phase in each phase shifter 2 so that the phase of the radio wave in each element antenna 1 becomes a cophase in the beam direction each time the beam scanning angle changes, and the computing means 7 In the phase shifter control means 3 The beam scanning range is divided into a plurality of blocks for each step of the beam scanning angle, and the set value of the excitation amplitude for obtaining the desired combined radiation pattern that is constant over the entire beam scanning range is calculated and changed every time the block changes. This is provided to the setting means 8.

[Operation] In the present invention, the phase shifter control means 3 sets an optimum excitation phase in each phase shifter 2 every time the beam scanning angle changes, and the computing means 7 causes the phase shifter control means to operate. The entire beam scanning range is divided into a plurality of blocks for each step of the beam scanning angle in 3, and the set value of the excitation amplitude for obtaining a desired combined radiation pattern that is constant over the entire beam scanning range is calculated every time the block changes. Since each amplitude controller 4 is set via the amplitude setting means 8, it is not necessary to set the amplitude for each beam scanning angle, and a desired combined radiation pattern can be realized in a short calculation time.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the antenna device of the present invention.
6 are the same as those of the conventional example. In the figure, 7
Is an excitation amplitude calculator for calculating the set value of the excitation amplitude given to each amplitude controller 4, and 8 is an amplitude setter for setting the amplitude level to be given to each amplitude controller 4 based on the calculation result of this calculator 7. , These are realized by a microcomputer or the like.

In the antenna device thus configured, beam scanning is performed by changing the phase of each phase shifter 2 by the phase shifter control device 3 as in the conventional case. That is, each time the scanning angle of the main beam changes, the excitation phase is set in each phase shifter 2 so that the phase of the radio wave in each element antenna 1 becomes co-phase in the main beam direction. Further, at this time, in order to obtain a desired combined radiation pattern, it is necessary to set the amplitude level of each amplitude controller 4 to an appropriate value, and the procedure is shown in the flowchart of FIG. In the above flow chart, each phase shifter 2
By controlling the set phase shift amount of, at Φ = 90 °, θ = 90 ° ～
The main beam shall be aimed at -90 ° (θ is in 1 ° steps). First, in step 10, θ = 90 ° is set, and in step 11, the angle θ when the excitation amplitude is calculated and set is input to the excitation amplitude calculation device 7. For example, here, θ = 90 ° ~
Amplitude is calculated under the condition that θ is an angle that is a multiple of 10 within -90 °. That is, the entire main beam scanning range is divided into 18 blocks. Next, in step 12, the excitation phase for directing the main beam in the θ direction is calculated and set in each phase shifter 2. Further, in step 13, it is determined whether or not θ is the angle input in step 11. θ = 90 ° above
Since the condition of being a multiple of 10 is satisfied, the routine proceeds to step 14, where the excitation amplitude for obtaining the desired combined radiation pattern having the main beam in the θ direction is calculated, and each amplitude controller 4 is operated via the amplitude setter 8. Set to. After setting the excitation phase and amplitude in steps 12 and 14, it is judged in step 15 whether θ is −90 °, and if not, in step 16, θ = θ−1
Return to step 12 as °. Since θ = 89 ° now,
In step 12, the excitation phase for directing the main beam to θ = 89 ° is calculated and set. Next, in step 13, θ = 89
Since ° does not satisfy the condition that it is a multiple of 10, the process proceeds to step 15 without calculating and setting the excitation amplitude in step 14. The combined radiation pattern at this time is θ as the excitation phase.
The phase for directing the main beam at = 89 ° and the amplitude for obtaining the desired combined radiation pattern having the main beam at θ = 90 ° as the excitation amplitude are given. By forming the beam by giving the excitation phase and amplitude in the above procedure, the desired combined radiation pattern can be achieved in a shorter calculation time than the conventional method of calculating and setting the excitation amplitude for each main beam scan. it can.

FIG. 3 is a characteristic diagram showing the radiation pattern obtained by the present application, in which the excitation phase is the phase for directing the main beam to θ = 10 °, while the excitation amplitude is in the θ = 0 ° direction. With the main beam, the amplitude was given to obtain a radiation pattern with a cylobe of -25 dB. As is clear from this figure, if the excitation phase is set every time the beam scanning angle changes, even if the excitation amplitude is calculated and set for each block in units of 10 °, a virtually desired combined radiation pattern can be obtained. I understand.

[Effects of the Invention] As described above, according to the present invention, the excitation phase is applied to each phase shifter so that the radio wave phase in each element antenna becomes a co-phase in the beam direction every time the beam scanning angle changes. On the other hand, the excitation amplitude is set to the excitation amplitude setting value for dividing the beam scanning range into a plurality of blocks for each step of the beam scanning angle and obtaining a desired combined radiation pattern that is constant over the entire beam scanning range. Since the calculation is performed each time the block changes and is given to each amplitude controller, it is not necessary to calculate and set the amplitude for each beam scanning angle, and the desired combined radiation pattern can be realized in a short calculation time. Can be done.

[Brief description of drawings]

FIG. 1 is a block diagram showing an antenna device according to an embodiment of the present invention, FIG. 2 is a flow chart showing the operation of the embodiment,
FIG. 3 is a characteristic diagram of a radiation pattern obtained by the antenna device of the present invention, FIG. 4 is a configuration diagram showing a conventional antenna device, and FIG. 5 is a diagram showing a radiation pattern of an element antenna on a curved surface. 1 is an element antenna, 2 is a phase shifter, 3 is a phase shifter control device (phase shifter control means), 4 is an amplitude controller, 7 is an excitation amplitude calculation device (calculation means), 8 is an amplitude setting device (amplitude). Setting means).

Claims (1)

[Claims] 1. A plurality of element antennas arranged on a curved surface, a phase shifter for controlling the phase of a transmission or reception signal of each element antenna, and a phase shifter for individually controlling each phase shifter. Control means, an amplitude controller that controls the amplitude of the transmission or reception signal of each element antenna, and an operation means that calculates the set value of the amplitude for making the combined radiation pattern by each element antenna a desired one, Amplitude setting means for setting the amplitude value to each amplitude controller based on the calculation result of this calculation means is provided, and the phase shifter control means changes the beam direction of the radio wave in each element antenna each time the beam scanning angle changes. The excitation phase is set in each phase shifter so that the phases become co-phase, and the arithmetic means divides the beam scanning range into a plurality of blocks for each step of the beam scanning angle in the phase shifter control means, and the total beam Scanning range The set value of the excitation amplitude to obtain a constant desired composite radiation pattern by calculating for each block is changed over antenna apparatus characterized by that to give the amplitude setting means.