JP2676936B2 - Orientation detection device - Google Patents

Description

The present invention relates to an azimuth detecting device for detecting the arrival direction of an incoming radio wave.

[Conventional technology]

Figure 4 is a document "Stephen Lipski," Microwave Passive Direction Detection ", published by Willie Interscience Publications John Willie and Sun (STEPHEN E.LIPSKY," Microwave Passive Direction F
inding ", A Wiely Interscience Publication JOHN WILE
FIG. 24 is a block system diagram showing a conventional direction finding device described in “Y & SONS)” on page 24. In the figure, 1 and 2 are arranged side by side and oriented in the same direction, and antennas with the same characteristics,
3 are hybrids, which rotate about a vertical axis. 4a, 4b are rotary joints, 5a, 5b are receivers, 6,
7 is an azimuth calculator, 8 is an angle detector, and 9 is an output terminal for azimuth data.

Next, the operation will be described. Conventional radio wave with two antennas
It captures at 1 and 2 and sends the high-speed wave signal to the hybrid 3. The hybrid 3 creates a sum signal and a difference signal of two high frequency signals, sends the high frequency signals from the rotary side to the fixed side receivers 5a, 5b via the rotary joints 4a, 4b, and receives and demodulates the high frequency signals, respectively. .

The results of demodulating the sum signal and the difference signal are shown in FIGS. 5 (a) and 5 (b), respectively. Both signals are sent to the azimuth calculator 6, the arrival signal is detected by the sum signal, and the arrival azimuth of the incoming radio wave is calculated by the difference signal based on the azimuth direction of the antennas 1 and 2. The calculated signal and the azimuth angles of the antennas 1 and 2 detected by the angle detector 8 are sent to the azimuth calculator 7 to calculate the arrival azimuth of the radio wave.

[Problems to be solved by the invention]

As described above, the conventional azimuth detecting device has two antennas having the same characteristics arranged in the same direction. For example, the incident direction of an incident radio wave incident on each of these antennas is Is deviated from the directing direction of each hollow line, a phase difference occurs in the output of each antenna, and when the outputs from each antenna corresponding to this phase difference are combined, interference occurs. Each of the sum signal and the difference signal of the high frequency signals captured in 1. causes a phenomenon in which the maximum and null (zero) are repeated in the arrival direction of the radio wave as shown in FIG.

Therefore, there is a problem that the arrival direction of the radio wave cannot be uniquely determined from the above two signals, and rough measurement information of the direction by another system is required.

The present invention has been made in view of such a point,
The purpose is to obtain a new azimuth detecting apparatus that enables azimuth detection of incoming radio waves without requiring other system rough measurement direction information.

[Means for solving the problem]

The azimuth detecting device according to the present invention has
Of the high frequency signal from the second antenna and the second and third antennas having the same characteristics, which are arranged side by side in the same direction as the first antenna and have the same characteristics. The hybrid, a rotary joint that transmits the high-frequency signals from the first antenna and the hybrid from the rotating side to the fixed side, two receivers that respectively receive and demodulate the high-frequency signals from the rotary joint, and the two A first azimuth calculator that calculates the arrival azimuth of the radio wave based on the azimuth to which the first, second, and third antennas are facing, based on the received signal output from the receiver;
An angle detector that detects the direction in which the first, second, and third antennas are facing, and a second direction that calculates the arrival direction of the radio wave based on the signals output from the first direction calculator and the angle detector. A calculator is provided, and the opening width of the first antenna in the horizontal plane is made twice the opening width of the second and third antennas in the horizontal plane.

[Action]

In the azimuth detecting apparatus according to the present invention, the difference signal repeats the maximum and the null in accordance with the arrival direction of the radio wave as in the conventional case, but the received signal from the separately provided antenna has the maximum angle only in the direction in which the antenna is oriented. Therefore, the arrival direction of the radio wave can be uniquely determined.

〔Example〕

FIG. 1 is a block system diagram showing an embodiment of the direction finding apparatus according to the present invention. In the figure, the same or corresponding parts as those in FIG. 3 are designated by the same reference numerals, and 10 is a first antenna. Second antenna 1 and third antenna 2
Are arranged side by side and oriented in the same direction as the antenna 10, and the first, second and third antennas 1, 2 and 10 have the same characteristics.

The following operation will be described. Incoming radio wave to the first antenna
It is captured by 10, 2 second and third antennas 1 and 2, and the high frequency signal from the antenna 10 is transmitted from the rotary side to the fixed side via the rotary joint 4a and sent to the receiver 5a.

On the other hand, high-frequency signals from the two antennas 1 and 2 are sent to the hybrid 3, a difference signal between them is created, and sent to the receiver 5b via the rotary joint 4b. The receivers 5a and 5b respectively receive and demodulate the input signal. The relationship between the demodulated signal from the antenna 10 and the arrival direction of the radio wave and the relationship between the demodulated signal of the difference signal from the two antennas 1 and 2 and the arrival direction of the radio wave are shown in FIGS. 2 (a) and (b), respectively. Shown in. These two signals are sent to the first azimuth calculator 6, the presence of an incoming wave is detected by the demodulated signal from the antenna 10, and the antennas 1, 2 are detected by the demodulated signal of the difference signal from the two antennas 1, 2. The arrival direction of the incoming radio wave is calculated with reference to the direction in which 10 and 10 are facing. The calculated signal and the azimuth angle to which the antennas 1, 2, 10 detected by the angle detector 8 are directed are sent to the second azimuth calculator 7 to calculate the arrival azimuth of the radio wave.

By making the space of the antenna 10 approximately equal to the equivalent aperture of the array in which the two antennas 1 and 2 are arranged side by side,
The signal output from the antenna 10 is not only a signal having only one maximum value but also a signal having the same pattern as the conventional sum signal, and the azimuth detecting accuracy and the azimuth detecting sensitivity are almost the same as those of the conventional azimuth detecting device. Can be obtained. This is the third
Shown as a first antenna 10a in the figure. Antennas 1,2,1 in Fig. 1
Since 0 has the same characteristics as each other, the gain of the first antenna 10 is smaller than that of the conventional sum signal. The device shown in FIG. 3 can prevent this.

EFFECTS OF THE INVENTION As described above, according to the present invention, the arrival direction of the radio wave can be uniquely determined by providing the other first antenna in the same direction as the second and third antennas. There is an effect that a small-sized and inexpensive azimuth detecting device can be obtained without requiring another azimuth detecting device for obtaining rough measurement information.

Further, if the opening of the first antenna is made equal to the equivalent opening of the array in which the second and third antennas are arranged side by side, then another coarse direction-finding coarse measurement for coarse orientation is not required and the same as in the conventional case. There is an effect that a direction finding device having a degree of accuracy and sensitivity can be obtained.

[Brief description of the drawings]

FIG. 1 is a block system diagram showing an embodiment of an azimuth detecting apparatus according to the present invention, FIG. 2 is a characteristic diagram showing characteristics of a reception level versus an arrival angle in the apparatus of FIG. 1, and FIG. 4 is a block system diagram showing an embodiment of the present invention, FIG. 4 is a block system diagram showing a conventional azimuth detecting device, and FIG. 5 is a characteristic diagram showing characteristics of a reception level versus an arrival angle in the device of FIG. 1 ... second antenna, 2 ... third antenna, 3 ... hybrid, 4a, 4b ... rotary joint, 5a, 5b ... receiver, 6 ... first bearing calculator, 7 ... Second bearing calculator, 8 ... Angle detector, 9 ... Output terminal, 10 ... First antenna.

Claims (1)

(57) [Claims] 1. A first antenna in the horizontal direction and second and third antennas having the same characteristics, which are arranged side by side in the same direction as the first antenna, and which have the same characteristics. , A hybrid that creates a difference in the high-frequency signals from the third antenna, a rotary joint that transmits the high-frequency signals from the first antenna and the hybrid from the rotating side to the fixed side, and high-frequency waves from the rotary joints. Two receivers for respectively receiving and demodulating signals, and a reception signal output from the two receivers are used to calculate the arrival directions of radio waves with reference to the directions to which the first, second, and third antennas face. A first azimuth calculator,
An angle detector that detects the direction in which the first, second, and third antennas are facing, and a second that calculates the arrival direction of the radio wave based on the signals output from the first direction calculator and the angle detector Azimuth calculator, wherein the opening width in the horizontal plane of the first antenna is set to be twice the opening width in the horizontal plane of the second and third antennas.