JPH095416A - Direction finder - Google Patents

Abstract

PURPOSE: To provide a direction finder determining the direction of the received radio wave with a simple structure. CONSTITUTION: Antennas 1a-1d having directivity in the prescribed directions and delay elements 3a-3d delaying the antenna outputs by the corresponding prescribed periods are paired. This direction finder is provided with multiple pairs set with different directions and different delay periods respectively, a mixer 5 mixing the outputs of the pairs, and a signal processing means 9 detecting the direction from the amplitude difference of the received radio wave of the mixer output.

Description

Detailed Description of the Invention

[0001]

This invention relates to ESM (Electr)
The present invention relates to an azimuth detecting device having improved capability of "onic Support Measure" (radio wave detecting function).

[0002]

2. Description of the Related Art FIG. 8 shows a conventional direction finding device. In the figure, 1a to 1d are directional antennas that receive incoming radio waves and are installed in, for example, north direction, east direction, south direction, and west direction. 2a to 2d are power supply lines for transmitting the electric wave received at 1 (1a to 1d) to the receiver, and 7a to 7d are
Receivers for converting radio waves received in 1 into video, 8a-8
d is a cable for transmitting the video obtained by the receivers 7 (7a to 7d) to the signal processor, and 9 is a signal processor for obtaining the direction of arrival from the video output from each receiver. Also, FIG.
FIG. 3 is a reception succession diagram explaining the operation of the azimuth detecting apparatus having the above configuration.

Next, the operation of the above device will be described. North of multiple directional antennas 1 so that the pointing directions do not overlap.
Place in the east, south, and west directions. FIG. 9 is a diagram showing the receiving sensitivity based on the north-facing antenna at that time. The received power pattern of each directional antenna at this time is 31a, 31b, 3
1c and 31d. When a radio wave arrives from the direction indicated by →, it cannot be received by 31a and 31b, but 31c and 3
In 1d, the power of 32 and 33 can be received, respectively. The radio waves received by the directional antenna 1 are converted from microwaves to video by the receiver 7 corresponding to each directional antenna. Each converted video is input to the signal processor 9 via the cable 8 and the arrival direction is obtained from the amplitude difference of each video. Next, the process of obtaining the arrival direction from the video amplitude difference will be described. The respective video amplitudes are compared and the video (system) with the largest amplitude is obtained. This corresponds to the rough direction of the arrival direction. In the example of FIG. 9, since the antenna reception power in the rough direction of arrival of this radio wave is larger than the antenna reception power of 33, 3
It can be known as the mounting direction of the directional antenna having the 1c pattern, that is, the south direction. Further, the video (system) having the second largest video amplitude is obtained, and the difference between these two videos is obtained. From this video difference, the relative azimuth is obtained from the directional pattern of each directional antenna 1 that has been measured in advance, and the relative azimuth is added to the previous rough azimuth to obtain the precise azimuth of the incoming azimuth (direction with higher accuracy than the rough azimuth). Is required. That is, the precise direction of the arrival direction is obtained from the level difference between 32 and 33. Specifically, the pattern difference between 31 and c and 31d and the relative angle are set in advance, and 32-3
The relative angle corresponding to the level difference of 3 is obtained. Therefore, the arrival azimuth = 31 mounting angle + (32-33) becomes the corresponding relative angle.

[0004]

Since the conventional azimuth detecting device is constructed as described above, since the video difference of each system directly becomes the azimuth error, the directional antenna 1, the feeder line 2, the receiver 3, It is necessary to match the characteristics of the cable 4, and
There was a problem that it was difficult to search for the faulty part when the detection direction error became large.

The present invention has been made to solve the above problems, and an object thereof is to obtain a device capable of reducing the number of circuit components, shortening the test time, and easily searching for a failed portion. In addition, the present invention aims to obtain an inexpensive direction finding device.

[0006]

An azimuth detecting apparatus according to the present invention comprises a set of an antenna having directivity in a predetermined direction and a delay element for delaying the output of the antenna by a predetermined time corresponding thereto. A plurality of groups each having a different direction and a different delay time set for each, a mixer for mixing the outputs of these groups, and a signal processing means for detecting the azimuth from the amplitude difference of the received radio waves of the mixer output are provided. .

Furthermore, the delay amount of each delay element is made variable in the basic configuration.

Furthermore, the delay amount of each delay element is made variable by external control.

Alternatively, an antenna having directivity in a predetermined direction and a delay element that delays the output of the antenna by a predetermined time corresponding thereto are set as a set, and a plurality of sets each having a different direction and a different delay time are set for each set. , A changeover switch for changing over the output of each set with respect to time, and a signal processing means for detecting the azimuth from the amplitude difference of the received radio waves of the changeover switch output.

Further, one receiver for detecting and amplifying the amplitude of the received radio wave and outputting it to the signal processing means is provided.

[0011]

In the azimuth detecting apparatus according to the present invention, the radio waves incident on the antenna having directivity in different directions are sequentially delayed and mixed for different times, and the output of the mixer is the radio waves received from different directions. The azimuth is detected from the amplitude difference between the received radio waves.

Furthermore, the delay amount of each delay element is variably set, and the delay amount is adjusted so that incoming radio waves do not overlap.

Furthermore, the delay amount of each delay element at that time is adjusted by external control so that they do not overlap.

Alternatively, the radio waves incident on the antenna having directivity in different directions are sequentially delayed by different times and switched, and the switched outputs are correspondingly received radio waves from different directions. The azimuth is detected.

Furthermore, the number of receivers is one, and received radio waves from different directions are amplified by one receiver, and the azimuth is detected from the amplitude difference.

[0016]

【Example】

Embodiment 1 FIG. The present invention compares the intensities of received radio waves received by directional antennas (antennas) installed in different azimuths, and obtains the direction of the received radio waves from the amplitude intensity. At this time, the purpose is to simplify the configuration as much as possible. An azimuth detecting apparatus according to an embodiment of the present invention will be described below with reference to FIG. In FIG. 1, 1a to 1d are directional antennas, 2a to 2d are feeder lines, 3a to 3d are delay lines for delaying signals received by the directional antenna 1 (1a, 1b, 1c, 1d), and 3a and 3b. The delay amounts of 3c and 3d are different. 4a to 4d are power supply lines, 5 is a combiner that mixes the outputs of the delay lines, 6 is a power supply line, 7 is a receiver that converts the combiner output to a video signal, 8 is a power supply line, and 9 is a reception line. It is a signal processor that determines the direction of arrival from the video signal output from the machine.

The operation of the azimuth detecting apparatus having the above structure will be described. It is assumed that the antennas 1a to 1d have the same directivity as the conventional one, and the receiving sensitivity together with the receiver is as shown in FIG. Now, in FIG. 9, it is assumed that the arrival direction is the direction of the arrow and the reception level is 32 for the antenna 31c and 33 for the antenna 31d. First, the relative azimuth is obtained from the value of 32-33, that is, the amplitude difference. Amplitude difference (32-33)
The relative azimuth and the relative azimuth are known in advance from the directional characteristics of the antenna as follows, for example. Amplitude difference (dB) Relative azimuth (degrees) −10 −30 −5 −15 0 0 +5 +15 +10 +30 Next, from the characteristic of 32 and the characteristic of 31c, that is, the ratio of the maximum received value of 31c and the value of 32. The declination α is obtained. This way of obtaining itself is the same as before. In this embodiment, the incoming radio waves from each antenna arrive at the compiner with a different delay time. Therefore, the received radio waves of each directional antenna can be arranged in a column. By arranging the received radio waves of a plurality of channels in tandem, they can be merged into one by a combiner, and the subsequent receiver or signal processor can be configured by one processing system. It suffices to simply follow the processing in time.

FIG. 2 is an example of an operation flowchart showing the steps of the direction detection of the signal processing unit 9 in this embodiment. That is, the specifications of the incoming radio wave are determined in step S1. Next, in step S2, the delay amounts of the delay elements 3a to 3d are shifted so that the received radio waves do not overlap on the time axis. Finally, step S
At 3, the arrival direction is obtained by the same detection and calculation as the above-mentioned conventional method. By doing so, in the conventional example, it was necessary to correct for the difference in sensitivity of each receiver including the variation between channels, but in the present embodiment, the correction is unnecessary, the time can be shortened, and the measurement accuracy can be improved. There is also an advantage that Note that one of the delay elements, for example, the delay element on the reference azimuth side is unnecessary, and in that case, the antenna output is directly input to the combiner.

Example 2. In this embodiment, the structure of the delay element is simplified and selection switching is performed. FIG. 3 is a block diagram of the apparatus of this embodiment, in which 41a to 41d are delay lines with taps, and 42a.
42d are tap changers. The other elements are the same as in Example 1. In the above embodiment, the signal received by each antenna is intentionally staggered in the arrival time with the delay amount fixed delay line and merged by the combiner, but in the present embodiment, the delay amount of the delay line is a semi-fixed tap type, The direction is detected by the amplitude comparison using the optimum delay amount for the system. 41 each
For example, the signal processing unit 9 determines which output tap of (41a, 41b, 41c, 41d) is used, and sets the tap changer. The direction detection after the delay amount is determined is the same as that in the first embodiment or the related art, and thus the detailed description will be omitted.

Example 3. Still another direction detecting device having a simple structure will be described. FIG. 4 is a block diagram of the apparatus of this embodiment. In the figure, two types of delay line groups 43a to 43d and 43e to 43h are provided, and a delay line group suitable for the system is selected and used. This is a configuration in which only two types of delay amounts are selected, and the adjustment or determination range is narrowed, but the device is smaller.

Example 4. Calculate the delay amount with an external computer,
The delay amount may be set. FIG. 5 is a block diagram of the apparatus of this embodiment. In the figure, 51a to 51d
Is a delay element that is variable by external setting, and 52 is an external computer. The computer 52 sets the continuously variable delay line 51 (51a ...) so that the delay amount of the delay line becomes a value that matches the pulse width of the signal.
The delay amount of 51d) is optimally set. The operation of detecting the signal and finding the azimuth by comparing the amplitudes is the same as in the other embodiments.

Embodiment 5. Although the example in which the delay line is used as the delay element is shown, a surface acoustic wave element may be used. FIG. 6 is a device configuration diagram of the present embodiment. In FIG.
d is a surface acoustic wave element. By using this element, a small and low-cost device can be obtained.

Example 6. In this embodiment, an example in which a changeover switch is used instead of the combiner will be described. However, the delay amount is obtained in advance so that the received waves from the respective antennas do not overlap, and a fixed delay is set. FIG. 7 is a block diagram of the apparatus of this embodiment. In the figure, reference numeral 55 denotes a changeover switch, which sequentially switches the delayed arriving waves of 4a to 4d during one measurement time and sends them to the receiver 7. The subsequent direction detection operation is the same as that in the first embodiment. As described in the first embodiment, the delay element 3a inserted on the reference azimuth side is not necessary in any of the embodiments.

[0024]

As described above, according to the present invention, a plurality of sets of antennas having directivity in different directions and delay elements having different delay times, a mixer and a signal processing means for direction detection are provided. The effect is that the direction can be detected with a simple configuration.

Furthermore, since the delay amount of each delay element is made variable in the basic configuration, there is an effect that the azimuth can be detected by preventing incoming received radio waves from overlapping.

Furthermore, since the delay amount of each delay element is made variable by the external control, there is an effect that the azimuth can be detected by preventing the incoming radio waves from overlapping.

Alternatively, since a plurality of sets of antennas having directivity in different directions and delay elements having different delay times, a changeover switch and a signal processing means for direction detection are provided, the direction can be detected with a simple structure. There is.

Furthermore, since different reception radio waves are amplified by one reception amplifier and output to the signal processing means, there is an effect that the configuration is further simplified.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a direction finding device according to a first embodiment of the present invention.

FIG. 2 is a flow chart of delay amount setting and azimuth detection operation according to the first and second embodiments of the present invention.

FIG. 3 is a configuration diagram of an azimuth detecting device according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of an azimuth detecting apparatus according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of an azimuth detecting device according to a fourth embodiment of the present invention.

FIG. 6 is a configuration diagram of a direction finding device according to a fifth embodiment of the present invention.

FIG. 7 is a configuration diagram of an azimuth detecting device according to a sixth embodiment of the present invention.

FIG. 8 is a block diagram of a conventional direction finding device.

FIG. 9 is a reception sensitivity diagram for explaining the operation of the azimuth detecting device.

[Explanation of symbols]

1, 1a, 1b, 1c, 1d Directive antenna, 2, 2
a, 2b, 2c, 2d feeder, 3, 3a, 3b, 3c,
3d delay line, 4, 4a, 4b, 4c, 4d feeder line, 5
Combiner, 7 receiver, 9 signal processor, 31a
Received power pattern of directional antenna 1a, 31b Received power pattern of directional antenna 1b, 31c Received power pattern of directional antenna 1c, 31d Received power pattern of directional antenna 1d, 32 Received power received by antenna 1c, 33 antenna Received power received in 1d, 41
a, 41b, 41c, 41d Tap type delay line, 42
a, 42b, 42c, 42d A switch for selectively determining the delay amount in the system, a delay line 43a having a delay amount 1a,
43b Delay line with delay amount 1b, 43c Delay amount 1
c delay line, 43d delay line 1d delay line, 43e delay line 2e delay line, 43f delay line 2f delay line, 43g delay line 2g delay line, 43h delay line Delay line with 2h, 51a Delay line a with variable delay amount, 51b Delay line b with variable delay amount, 51c Delay line c with variable delay amount, 5
1d Delay line d with variable delay amount, 52 External computer, 55 changeover switch, 61a Delay line a, 61b applying surface acoustic wave Delay line b, 6 applying surface acoustic wave
1c Delay line c applying surface acoustic wave, 61d Delay line d applying surface acoustic wave.

Claims (5)

[Claims] 1. An antenna having directivity in a predetermined direction,
A set of delay elements for delaying the antenna output by a corresponding predetermined time is set, and a plurality of sets in which different directions and different delay times are set respectively, a mixer for mixing the outputs of each set, and a mixer output An azimuth detecting device comprising signal processing means for detecting an azimuth from an amplitude difference between received radio waves. 2. The direction finding device according to claim 1, wherein the delay amount of each delay element is variable. 3. The direction finding device according to claim 2, wherein the delay amount of each delay element is variable by external control. 4. An antenna having directivity in a predetermined direction,
A set of delay elements for delaying the antenna output by a corresponding predetermined time, a plurality of sets having different directions and different delay times set, a changeover switch for changing over the output of each set with time, and the changeover switch An azimuth detection device comprising signal processing means for detecting an azimuth from an amplitude difference between output received radio waves. 5. The azimuth detecting apparatus according to claim 1, further comprising one receiver that detects and amplifies the amplitude of the received radio wave and outputs it to the signal processing means.