JPH0770909B2 - Antenna monitor - Google Patents

Description

TECHNICAL FIELD The present invention relates to an array antenna monitoring device, and more particularly to an antenna monitoring device for monitoring the operational limit of a phased array antenna due to a failure of an antenna module or the like.

[Prior Art] In general, an array antenna in which a radiation opening is formed by a plurality of antenna modules has redundancy that the antenna performance does not significantly deteriorate even if a part of the antenna module fails. For example, in an elliptical aperture array antenna with about 2000 elements, if the aperture distribution is designed at -35 dB Taylor, it is reported that the side lobe level rises about 3 dB even if 5% of the antenna modules fail randomly ( Kato et al. "Characteristics of array antenna for broadcasting hygiene" IEICE Transactions Bvol.J70-BN
O.9pp.1071-1081, September 1987).

In the case of a linear array antenna, the allowable value for the ratio of the number of antenna module failures decreases, but the property of having redundancy is similar to that of a planar array antenna.

In order to take advantage of the redundancy of the array antenna in the previous term, conventionally, the method of monitoring the operation status of the antenna module and issuing a warning that the array antenna has failed when the number of allowable failures is reached has been adopted. Note that the allowable number of antenna module failures is set here in the same manner as in the case of the cited document, such as random failure, failure of the central portion of the array antenna, failure of the end portion, etc. The antenna pattern was simulated assuming some failure conditions, and it was decided in consideration of the performance of the radar system including the array antenna.

Next, an example of the prior art will be described with reference to the system diagram of the linear array antenna shown in FIG.

In the example of FIG. 2, antenna elements 1-1 to 1-N (where N is a positive integer), phase shifters 2-1 to 2-N, and phase shifter drive circuits 3-1 to 3-N. Antenna module 4-1 including and
4-N are arranged in a straight line and the transmitter / receiver 6 is connected by the power supply circuit 5.
And the high frequency signals between the antenna modules 4-1 to 4-N are distributed and combined. The beam controller 7 is for controlling the phase shifters 2-1 to 2-N through the phase shifter driving circuits 3-1 to 3-N to perform beam scanning in a predetermined direction.

There are methods to detect the operating status of the antenna module, such as checking the amplitude and / or phase shift of the high frequency signal, and checking the operating current of the phase shifter, but to simplify the monitoring system. The method of checking the operating current of the phase shifter is generally used. In the example of FIG. 2, the phase shifter driving circuits 3-1 to 3-N include a function of checking the operating current of the phase shifter, and a signal indicating the presence or absence of a failure is collected in the antenna monitor circuit 8.

The collected signal of the presence or absence of the antenna module is
It is sent to the failure number judgment circuit 11 and compared with a preset allowable number, and whether or not the array antenna can be continuously operated is displayed on the alarm display 12. In order to determine the allowable number set in the failure number determination circuit 11, it is necessary to perform many combinations of antenna pattern simulations assuming the failure number of the antenna module and the failure site in the array antenna.

[Problems to be Solved by the Invention] In the above-described conventional antenna monitoring method, the operational limit of the array antenna is determined by assuming the number of failures of the antenna module and the failure site in the array aperture plane. However, there is a drawback in that the redundancy of the array antenna cannot be fully utilized because it is necessary to allow an allowance for the number of failures of.

In addition, in order to determine the allowable operation limit of the array antenna, it is necessary to perform a large antenna pattern simulation and then examine a system including the array antenna, which is a disadvantage that requires a lot of labor. It was

[Means for Solving Problems] A phased array antenna according to the present invention controls a plurality of antenna modules each including an antenna element, a phase shifter, and a phase shifter drive circuit, and controls each of the plurality of antenna modules in the previous period. Beam control means for performing beam scanning by means of beam scanning, and antenna monitor means for detecting a failure or malfunction of the antenna module, and an antenna pattern is calculated using the detection result relating to the malfunction or malfunction detected by the antenna monitor means in the previous period. The gist is to have a calculating means and a judging means for judging the characteristics of the antenna based on the antenna pattern determined by the calculating means in the previous period and judging whether or not the operational limit of the phased array antenna has been reached.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a system diagram showing an embodiment of the present invention, in which antenna elements 1-1 to 1-N (where N is a positive integer), phase shifters 2-1 to 2-N, and phase shifters. The antenna modules 4-1 to 4-N including the drive circuits 3-1 to 3-N are arranged in a straight line, and the power feeding circuit 5 causes a high frequency between the transceiver 6 and the antenna modules 4-1 to 4-N. It distributes and combines signals. The beam controller 7 is a phase shifter driving circuit 3-1 to 3-N.
The beam scanning is performed by setting the phase shifters 2-1 to 2-N to a predetermined phase shift delay amount.

The failure detection of the antenna modules 4-1 to 4-N is performed by the phase shifter driving circuits 3-1 to 3-N, and the antenna monitor circuit 8 collects signals indicating the presence or absence of a failure. The antenna monitor circuit 8 stores the number of antenna modules 4-1 to 4-N in association with the signal indicating the presence or absence of a failure,
The number of the failed antenna module is transmitted to the antenna pattern calculator 9. The antenna pattern calculator 9
Aperture distribution of array antenna, amplitude and phase shift error due to manufacturing error of feeding circuit 5, antenna modules 4-1 to 4-
The amplitude of N, the phase shift error, etc. are stored, the number of the failed antenna module is received from the antenna monitor circuit 8, and the antenna pattern is calculated by the array antenna model with corresponding elements thinned out, including the above error. .
The beam pointing accuracy can be checked by inputting the beam pointing data corresponding to the data for controlling the phase shifters 2-1 to 2-N from the beam controller 7 to the antenna pattern calculator 9 in advance. After calculating the antenna pattern, the antenna pattern calculator 9 determines some or all of the characteristics of the array antenna, such as the beam width, gain, side lobe level, and beam pointing accuracy, and the determination result is displayed on the alarm display 10. Is displayed. The criteria for determining the characteristics of the array antenna can be easily set by studying the system performance including the array antenna, such as a radar system, and can be stored in the memory or switch of the antenna pattern calculator 9.

Although the above description has been given for the linear array, the same effect can be obtained for the planar array antenna. Also,
Even in the case of an active array antenna including a low noise amplifier and a power amplifier in the antenna module, the contents to be monitored are different from those in the present embodiment, but the present invention can of course be applied.

EFFECTS OF THE INVENTION As described above, according to the present invention, since the antenna monitor system has the antenna pattern calculation means and the determination means, the antenna pattern corresponding to the failure of the antenna module can be grasped. The antenna operation limit becomes clear, and the redundancy of the array antenna can be fully utilized. That is, the maintenance period of the array antenna can be lengthened, and the continuity of system operation can be improved.

In addition, a large amount of antenna pattern simulation for setting the allowable number of antenna module failures is unnecessary.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, and FIG. 2 is a system diagram showing an example of a conventional technique. 1-1 to 1-N ... Antenna element, 2-1 to 2-N ... Phase shifter, 3-1 to 3-N ... Phase shifter drive circuit, 4-1 to 4-N ... Antenna Module, 5 ... Feeding circuit, 6 ... Transceiver, 7 ... Beam controller, 8 ... Antenna monitor circuit, 9 ... Antenna pattern calculator, 10, 12 ... Alarm display, 11 ... Failure number judgment circuit.

Claims (1)

[Claims] 1. A plurality of antenna modules including an antenna element, a phase shifter, and a phase shifter drive circuit, beam control means for controlling each of the plurality of antenna modules to perform beam scanning, and said antenna module. In a phased array antenna equipped with an antenna monitoring means for detecting a failure or malfunction, a calculating means for calculating an antenna pattern using the detection result regarding the failure or malfunction detected by the antenna monitoring means in the previous term and a calculating means for the previous term are determined. A phased array antenna, comprising: a determination unit that determines the characteristics of the antenna based on the antenna pattern and determines whether or not the operation limit of the phased array antenna has been reached.