JP2626574B2 - Radio wave detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave detection device,
In particular, the present invention relates to a radio wave detection device that searches for a reception of a pulse modulated wave emitted from a radar or the like.

[0002]

2. Description of the Related Art As a radio wave detecting device for detecting a pulse modulated wave emitted from a radar or the like, a device shown in FIG. 5 is conventionally known. In FIG. 5, the radio wave detection device includes a monitoring reception system including an omnidirectional antenna 9 and a signal detection circuit 2 and a reception processing circuit 6 connected thereto, and a plurality of reception beams having different directivity directions by a plurality of feeding units. And a direction finding receiving system composed of a direction finding receiving circuit 8 connected thereto, and operates as follows.

When a pulse-modulated wave is received by the omni-directional antenna 9, it is detected by the signal detection circuit 2, and the detection signal is used as a trigger signal for the reception processing circuit 6 and the direction finding reception circuit 8.
Given to.

Each time a trigger signal is input, that is, each time a pulse-modulated wave arrives, the direction-finding receiving circuit 8 measures the reception level of each received beam of the multi-beam antenna 1, and determines the pulse-modulated wave from the reception level difference. The arrival direction is measured, and the measurement result is provided to the reception processing circuit 6.

[0005] Further, each time a trigger signal is input, that is, each time a pulse-modulated wave arrives, the reception processing circuit 6 converts the frequency, pulse width, pulse amplitude, and pulse amplitude of the arriving radio wave from the reception signal of the omnidirectional antenna 9. It measures the radio wave parameters such as arrival time and outputs it and the direction of arrival.

[0006]

The conventional radio wave detection apparatus detects a signal in an omnidirectional antenna, and uses this as a trigger to measure radio wave characteristics and arrivals. There is a problem that the system reception sensitivity including the antenna gain such as the original measurement sensitivity and the signal processing sensitivity is low, and it is difficult to expand the coverage area.

As a measure to solve this problem, it is conceivable to provide a reception processing circuit for each beam of the multi-beam antenna. However, in this case, since the reception processing circuit itself has a large-scale configuration, it is not appropriate to have a plurality of the reception processing circuits because the cost of the system is increased and the scale is increased.

In addition, since the monitoring receiving system and the direction finding receiving system are provided with separate antennas, there is a problem that the installation space becomes large.

An object of the present invention is to provide a single reception processing system,
An object of the present invention is to provide a radio wave detection device capable of improving system reception sensitivity in all directions of reception.

[0010]

Means for Solving the Problems To achieve the above object, the radio wave detecting apparatus of the present invention has the following configuration. That is, the radio wave detecting apparatus of the first invention is provided with a plurality of directional antennas having different directional directions; a plurality of directional antennas provided in one-to-one correspondence, and performing signal detection from reception signals of the corresponding directional antennas. A signal detection circuit and a plurality of signal delay circuits for delaying the reception signals of the corresponding directional antennas; a reception antenna determination circuit for receiving the outputs of the plurality of signal detection circuits and determining a directional antenna that has received a predetermined radio wave; A signal switching circuit for selecting one of the delay outputs of the plurality of signal delay circuits based on the determination result of the reception antenna determination circuit; a reception processing circuit for receiving the output of the signal switching circuit and measuring radio wave specifications;
It is characterized by having.

[0011] The radio wave detecting apparatus according to the second aspect of the present invention includes: a plurality of directional antennas having different directional directions; And a reception processing circuit for measuring radio wave specifications from the input received signal. A radio wave detection apparatus provided with a plurality of directional antennas in one-to-one correspondence, and performs signal detection from the received signals of the corresponding directional antennas. A plurality of signal detection circuits and a plurality of signal delay circuits for delaying reception signals of the corresponding directional antennas; a trigger signal output circuit receiving outputs of the plurality of signal detection circuits and outputting the trigger signal; A signal switching circuit for selecting one of the plurality of signal delay circuits based on the measurement result of the circuit and outputting the delayed output to the reception processing circuit.

More specifically, in the first invention and the second invention, the plurality of directional antennas having different directional directions can be constituted by a multi-beam antenna forming a plurality of reception beams having different directional directions, and a signal delay circuit is provided. Can be constituted by an optical fiber delay circuit or a superconducting delay circuit.

[0013]

Next, the operation of the radio wave detection device of the present invention having the above-described configuration will be described. In the present invention, signal detection is performed from reception signals of a plurality of directional antennas by omitting a conventional omnidirectional antenna, and the detected reception signal is provided to one reception processing circuit to measure radio wave specifications. In the first invention, the radio wave arrival direction is given by the beam direction of the antenna related to the detected received signal, and in the second invention, it is given by the measurement value of the direction finding reception circuit.

Therefore, since the radio wave specifications are measured from the reception signal of the directional antenna, the system reception sensitivity can be increased in all directions to be received, and the monitoring coverage in a distant place can be further extended as compared with the conventional case. In addition, since one reception processing circuit having a large circuit scale is provided and a reception signal of one directional antenna is given to the reception processing circuit, the scale of the apparatus can be reduced by eliminating the omnidirectional antenna. In addition, since a multi-beam antenna can be used as a plurality of directional antennas as in the past, the problem of the installation space of the antenna can be solved,
The size of the apparatus can be further reduced.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a radio wave detection device according to a first embodiment of the present invention. In FIG. 1, in the present embodiment, a multi-beam antenna 1 similar to the related art is used as a plurality of directional antennas having different directing directions from the viewpoint of reducing the size of the apparatus.

The multi-beam antenna 1 has a plurality of feed portions, and forms a plurality of reception beams having a constant beam interval in a horizontal plane from a single antenna opening surface. The incoming pulse-modulated wave is received by a receiving beam having the directivity gain of the multi-beam antenna 1.

The signals received by the plurality of reception beams are provided to a plurality of signal detection circuits (2-1 to 2-4) provided in a one-to-one correspondence with the plurality of reception beams and a plurality of signal delay circuits (3). -1 to 3-4).

A plurality of signal detection circuits (2-1 to 2-4)
Detects the level of the input signal, corresponding respectively
Identifies whether a pulse modulated wave was incident on the receive beam
And a signal indicating the presence or absence, for example, "1" if there is,
If not, the signal of "0" is output to the reception beam discriminating circuit 4.
Output to

The reception beam discriminating circuit 4, receiving beam receives an input signal <br/> pulse modulation wave output signals from the plurality of signal detection circuit (2-1 to 2-4), it is determined either The output of the signal delay circuit corresponding to the received beam determined
Is output to the signal switching circuit 5 and is given to the reception processing circuit 6 as arrival direction information.
The number of the reception beam is determined by a plurality of signal detection circuits (2-1 to 2).
-4).

A plurality of signal delay circuits (3-1 to 3-4)
Is configured, for example, as described later (FIGS. 3 and 4), and holds a reception signal during a period (for example, 0.2 μsec) during which the above-described determination can be performed in the reception beam determination circuit 4.

The signal switching circuit 5 receives the delay outputs of the plurality of signal delay circuits (3-1 to 3-4), and holds a delay signal for holding a reception signal corresponding to the reception beam number designated by the reception beam discriminating circuit 4. And gives it to the reception processing circuit 6.

The reception processing circuit 6 measures the radio wave specifications from the input reception signal in the same manner as in the conventional case (FIG. 5), but every time a pulse modulated wave arrives as described above, the arrival of the pulse modulated wave The output of the reception beam in the direction is always selected, and the reception signal is input to the reception processing circuit 6. The reception processing circuit 6 outputs the reception beam number (arrival direction) from the reception beam discrimination circuit 4 and the measured radio wave data to the outside.

Therefore, in the radio wave detection device, the reception sensitivity is increased by the gain of the multi-beam antenna 1, and the distant coverage area is expanded. Moreover, since there is only one expensive reception processing circuit,
The cost of the apparatus does not increase.

FIG. 2 shows a radio wave detecting apparatus according to a second embodiment of the present invention. In the second embodiment, an OR circuit 7 is used instead of the reception beam discriminating circuit 4 in the first embodiment.
And a direction search receiving circuit 8.

The OR circuit 7 includes a plurality of signal detection circuits (2
The logical sum of the outputs of -1 to 2-4) is obtained, and the result is supplied to the direction receiving circuit 8 as a trigger signal.

In response to the input of the trigger signal, the search signal receiving circuit 8 measures the reception level of each reception beam of the multi-beam antenna 1 in the same manner as in the prior art (FIG. 5), and determines the pulse modulation wave from the reception level difference. The direction of arrival is measured, the number of the received beam corresponding to the direction of arrival is given to the signal switching circuit 5 as a switching control signal, and the measured direction of arrival is given to the reception processing circuit 6 as in the conventional case.

Since the direction of arrival measured by the direction finding receiving circuit 8 is high in accuracy, the receiving beam can be selected more accurately than in the first embodiment.

Next, the signal delay circuits (3-1 to 3-4) will be described. The signal delay circuit needs to have a delay time of about 0.2 μs, but since the signal to be handled is in the microwave band, the method using a coaxial cable of several tens of meters reduces the size, weight and transmission loss. Large inappropriate. Therefore, in this embodiment, the delay circuits shown in FIGS. 3 and 4 are used.

FIG. 3 shows an optical fiber type delay circuit. This delay circuit converts a microwave signal into an optical signal by an E / O converter 10 and passes it through an optical fiber 11 of an appropriate length to delay the optical signal. The signal is converted into a microwave signal and output.
Since the optical fiber 11 is small and lightweight, and has very little transmission loss, a delay line of about 0.2 μsec can be realized in a practical range.

FIG. 4 shows a superconducting delay circuit. This delay circuit uses a superconducting material that forms a stripline type superconducting delay line 13 by a fine processing technique to reduce the size of the delay line and cools a transmission loss, which is a problem in the microwave band, with a cooler 14. Thus, a low-loss microwave delay circuit has been realized.

By using the two new delay circuit technologies described above (optical fiber delay circuit and superconducting delay circuit), the radio wave detection device of the present invention used in the microwave band can be put to practical use.

[0032]

As described above, the radio wave detection device of the present invention directly detects a signal with a plurality of directional antennas and measures the radio wave specification and the radio wave arrival direction based on the signal detection.
The system reception sensitivity can be increased in all directions of reception, and the monitoring coverage in a distant place can be further extended to a farther distance than before. In addition, since one reception processing circuit having a large circuit scale is provided and a reception signal of one directional antenna is given to the reception processing circuit, the scale of the apparatus can be reduced by eliminating the omnidirectional antenna. Since a multi-beam antenna can be used as a plurality of directional antennas in the same manner as in the related art, the problem of the installation space of the antenna can be solved, and the size of the apparatus can be further reduced.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a radio wave detection device according to a first embodiment of the present invention.

FIG. 2 is a configuration block diagram of a radio wave detection device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a signal delay circuit (optical fiber delay circuit) used in the present invention.

FIG. 4 is a configuration diagram of a signal delay circuit (superconducting delay circuit) used in the present invention.

FIG. 5 is a configuration block diagram of a conventional radio wave detection device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 multi-beam antenna 2-1 to 2-4 signal detection circuit 3-1 to 3-4 signal delay circuit 4 reception beam discrimination circuit 5 signal switching circuit 6 reception processing circuit 7 OR circuit 8 direction search reception circuit 10 E / O (Electric / optical) converter 11 Optical fiber 12 O / E (optical / electrical) converter 13 Superconducting delay line 14 Cooler

Claims (5)

(57) [Claims] A plurality of directional antennas having different directional directions; a plurality of signal detection circuits provided in a one-to-one correspondence with the plurality of directional antennas and detecting signals from received signals of the corresponding directional antennas; A plurality of signal delay circuits for delaying a reception signal of a directional antenna to be received; a reception antenna determination circuit for determining a directional antenna that has received predetermined radio waves in response to outputs of the plurality of signal detection circuits; A radio wave detection device, comprising: a signal switching circuit for selecting one of delayed outputs of a plurality of signal delay circuits based on a result of the determination; and a reception processing circuit for receiving the output of the signal switching circuit and measuring radio wave data. apparatus. 2. A plurality of directional antennas having different directional directions; a direction finding receiving circuit for receiving a trigger signal to measure a direction of arrival of a radio wave from reception signals of the plurality of directional antennas; A reception processing circuit for measuring
A plurality of signal detection circuits provided in one-to-one correspondence with a plurality of directional antennas and detecting signals from received signals of the corresponding directional antennas, and delaying reception signals of the corresponding directional antennas; A plurality of signal delay circuits; a trigger signal output circuit that receives the outputs of the plurality of signal detection circuits and outputs the trigger signal; and selects one of the plurality of signal delay circuits based on a measurement result of the direction detection receiving circuit. A signal switching circuit for outputting the delayed output to the reception processing circuit. 3. The radio wave detecting apparatus according to claim 1, wherein the plurality of directional antennas having different directing directions are a multi-beam antenna forming a plurality of reception beams having different directing directions. apparatus. 4. The signal delay circuit according to claim 1, wherein the signal delay circuit is an optical fiber delay circuit.
The radio wave detection device according to 1. 5. A signal delay circuit comprising: a superconducting delay circuit;
The radio wave detection device according to claim 1 or 2, wherein