JP2955381B2 - Radar equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

 [Object of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar device capable of accurately determining a cause of deterioration of a reception function.

[0002]

2. Description of the Related Art A conventional radar apparatus is configured as shown in FIG. That is, a transmission / reception switch 3 comprising a radar transmission unit 1, a circulator for receiving a transmission radar signal from the radar transmission unit 1 and supplying it to an antenna 2, and a transmission / reception switch 3
And an amplitude limiter 4 for introducing a reflected signal from a target received via the antenna,
And a radar receiving unit 5 connected to the.

[0003] The amplitude limiter 4 is formed by combining a microwave limiter diode such as a pin diode in parallel with a gas-filled discharge tube.
To prevent the high-power transmitting radar signal leaking through the receiver unit 5 from entering the receiving unit 5 and burning out the amplifying element of the high-frequency amplifying stage.
Has the role of protection. Such an amplitude limiter 4 is widely used because it has been made smaller and longer in life by utilizing the amplitude limiting function of the diode.

[0004] However, in a radar receiving system in which the amplitude limiter 4 is incorporated in the first stage of the signal introducing section, a problem often arises that the reception sensitivity is reduced. Is this due to deterioration of the diode forming the amplitude limiter 4? Or a failure or malfunction of the receiver 5 could not be determined accurately and promptly. Until the amplitude limiter 4 was adopted, a transmission / reception switching discharge tube (TR tube) was used here. The structure of the TR tube is such that conical electrodes are arranged facing each other, a discharge gap is formed, a keep-alive electrode is inserted so that the start of discharge is not delayed, and a constant discharge state is set to enable quick transmission / reception switching. It is a thing. Although the deterioration of the function of the TR tube can be determined by monitoring the value of the keep-alive current, the amplitude limiter 4 composed of a diode has a configuration for checking the function, such as the keep-alive current in the switching discharge tube. Therefore, for example, even if the receiving sensitivity of the apparatus is reduced, there is no means for accurately and quickly determining whether the function of the amplitude limiter 4 is reduced or whether there is a defect in another receiving unit. This is a factor that significantly lowers the maintenance and inspection efficiency, and has been demanded for improvement.

[0005]

In a conventional radar apparatus, an amplitude limiter is connected to a preceding stage for protection of a receiving unit or the like. However, a means for quickly and accurately detecting functional deterioration of the amplitude limiter itself is provided. For example, even if the receiving sensitivity is reduced, it is not possible to quickly determine whether the function is due to the function reduction of the amplitude limiter or the function of another receiving unit, and the radar device cannot be operated efficiently. There were drawbacks.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a radar apparatus which solves the above-mentioned conventional drawbacks and which can determine the function of the amplitude limiter itself accurately and promptly.

[Structure of the Invention]

[0008]

According to a first aspect of the present invention, there is provided a radar transmitting unit, a transmission / reception switch for receiving a transmission radar signal from the radar transmission unit and supplying it to an antenna, and connected to the transmission / reception switching unit via the antenna. And a signal generator for supplying a test signal to the amplitude limiter in a radar device including an amplitude limiter for introducing a reflected signal from a target received by the receiver and a radar receiver connected to the amplitude limiter. A signal detection unit that receives a test signal derived through the amplitude limiter, and a determination unit that determines the amount of transmission loss that the test signal derived through the signal detection unit receives at the amplitude limiter. It is characterized by having.

A second invention is directed to a waveguide switch connected to an antenna, a pair of transmission / reception switches connected to the waveguide switch, and a radar connected to the pair of transmission / reception switches, respectively. A transmitter, a pair of amplitude limiters connected to the pair of duplexers for introducing a reflected signal from a target received via the antenna, and a radar receiver respectively connected to the pair of amplitude limiters; A signal generator that supplies a test signal to each of the pair of amplitude limiters; a signal detection unit that receives a test signal derived through the pair of amplitude limiters; A determination unit that determines the amount of transmission loss that the test signal derived through the unit receives at the amplitude limiter, and a switching controller that switches the waveguide switch by introducing the determination result of the determination unit. To have And butterflies.

[0010]

The radar apparatus according to the present invention has a determination unit for supplying a test signal to the amplitude limiter, detecting the test signal derived through the amplitude limiter, and determining a signal transmission amount in the amplitude limiter. The quality of the amplitude limit function of the amplitude limiter alone can be checked in a timely manner.

Also, in a radar device in which an antenna is commonly used by a waveguide switch and, for example, two working / standby radar systems are simultaneously connected, the waveguide switch is determined by the pass / fail judgment of the amplitude limiter. Timely switching control
Switching operation can be made more efficient.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a radar apparatus according to the present invention will be described below with reference to FIGS. The same components as those of the conventional radar device shown in FIG. 5 are denoted by the same reference numerals, and detailed description is omitted.

FIG. 1 is a configuration diagram showing a first embodiment of a radar apparatus according to the present invention. That is, the transmission radar signal from the radar transmission unit 1 is transmitted to the antenna 2 via the transmission / reception switch 3.
, And a reflected signal from the target received via the antenna is supplied to the amplitude limiter 4 via a signal insertion unit 6 including a transmission / reception switch 4 and a directional coupler.

The reflected signal that has passed through the amplitude limiter 4 is supplied to a radar receiving unit 5 via a signal detecting unit 7 also composed of a directional coupler or the like, and a target image is projected on an indicator (not shown). It is configured as follows. The amplitude limiter 4 is constituted by a pin diode or the like, as in the related art, and functions to suppress a transmission radar signal leaking from the transmission / reception switch 3 at the time of radar transmission, thereby preventing burning of the reception amplification element and the like. A signal generating unit 8 is connected to the signal inserting unit 6, and a pulsed high-frequency test signal a from the signal generating unit 8 uses a radar transmission suspension period t of, for example, about 80 μS as shown in FIG. The signal is supplied to the signal insertion unit 6, passed through the amplitude limiter 4 and taken out from the signal detection unit 7 as a test signal a ′, and
Supplied to In FIG. 2, b is a transmission trigger signal having a repetition period T generated in the transmission unit 1, c is a radar pulse signal activated and transmitted by the transmission trigger signal b,
d is a target reflected signal received via the antenna 2.

The judging unit 9 also receives the supply of the test signal a from the signal generating unit 8 and compares the test signal a ′ supplied through the signal detecting unit 7 with the power or voltage level. To determine whether the amount of transmission loss, that is, the amount of insertion loss due to the test signal passing through the amplitude limiter 4 is normal. The test signal a passed through the amplitude limiter 4
Also passes through the signal insertion unit 6 and the signal detection unit 7 and includes the power or voltage loss when passing through these circuits. However, the amount of transmission loss in these circuits can be ignored or Since it is set and known, the judging unit 9 can detect and judge the abnormality of the transmission loss amount in the amplitude limiter 4 by comparing the two test signals a and a '.

The function of the diode constituting the amplitude limiter 4 often deteriorates due to long-term use or use environment, which causes an increase in signal transmission loss and a decrease in reception sensitivity. 9, the degree of the function deterioration is instantaneously determined, and when the function falls below a preset range, the alarm signal e
And the alarm 91 can be activated.

Therefore, according to the present invention, the test signal a is transmitted through the amplitude limiter 4 using the radar transmission suspension period t, and the transmission loss received there is measured and detected. It is possible to easily determine whether the decrease in sensitivity is due to the decrease in the function of the amplitude limiter 4 or the decrease in the function of the radar receiver 5, and the maintenance and inspection efficiency of the apparatus can be significantly improved. Note that the judgment unit 9
By incorporating a storage circuit into the memory, it is possible to store the history of the characteristics and use it for elucidating the cause of the characteristic deterioration.

The judgment signal e when the insertion loss of the amplitude limiter 4 is increased and the signal transmission amount is increased and the normal operation cannot be obtained can be obtained only by operating the alarm 91 as described above. In other words, even when a radar system is configured in a dual system and operated, for example, as an active / standby system, the switching of the waveguide switch is controlled using the determination signal e, and the amplitude limiter operates normally. Automatically switch to the radar transmission / reception system to use.

FIG. 3 is a block diagram showing a second embodiment of the radar apparatus according to the present invention. In FIG. 3, since the main components of the duplex system have the same configuration, a and b are added to the numbers, and the detailed description is omitted. That is, since each of the transmission / reception switching units 3a and 3b is commonly connected to the antenna 2 via the waveguide switching unit 10, the waveguide switching unit 10a
Thus, one of the radar systems is operated in a state of being connected to the antenna 2. In this state, the judgment units 9a and 9b
Always monitors the insertion loss of the amplitude limiters 4a and 4b, and when the function is deteriorated, the alarm (91)
And is supplied to the switching controller 12 immediately. The switching controller 12 identifies the current switching status of the waveguide switching device 10 and the determination signal from which of the determination units 9a and 9b, and connects the radar system of the amplitude limiter that normally operates to the antenna 2 to the antenna 2. The waveguide switch 10 is controlled so as to be connected, thereby preventing system down and improving reliability. Note that reference numeral 11 denotes a load resistance. FIG. 3 shows a case in which one of the dual systems is used for switching. However, depending on the application, simultaneous transmission is performed by simultaneously operating two radar systems having different radar transmission frequencies. May be used. In that case, switching is not used, so the same usage as shown in FIG.
That is, it is possible to configure so that maintenance can be performed promptly by simply issuing an alarm.

Although the decrease in the receiving sensitivity due to the characteristic deterioration of the amplitude limiter 4 has been described as being caused by the increase in the insertion loss, another cause is, for example, that the transmission pulse signal cannot be blocked sufficiently and a considerable amount of power is consumed. Is leaking,
Alternatively, the receiving sensitivity immediately after the transmission pulse decreases for a moment and then recovers immediately after a slight time lag (recovery).
If the function is deteriorated, the recovery time is delayed, so that it is possible to identify whether the function of the amplitude limiter 4 is deteriorated or abnormal based on the recovery time. FIG. 4 shows the configuration shown in FIG. 1 and FIG. 3, in which an abnormality detection of the leakage power is connected in parallel to the abnormality detection of the amplitude limiter 4 and synchronized with the transmission timing from the transmission unit 1. By operating the system in this manner, a system for discriminating a double function deterioration is configured, and the abnormality detection capability is enhanced.

As described above, according to the present invention, it is possible to realize a radar device which can quickly and surely detect the function of the amplitude limiter, which always plays an important role in a radar receiving system, and improve the operation efficiency. .

[0022]

The radar apparatus according to the present invention can accurately and instantaneously judge the deterioration of the function of the amplitude limiter itself with a simple configuration, and is particularly remarkable for improving operation efficiency when applied to an air traffic control radar or the like. The effect is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a radar apparatus according to the present invention.

FIG. 2 is a signal waveform diagram of the device shown in FIG.

FIG. 3 is a configuration diagram showing a second embodiment of the radar apparatus according to the present invention.

FIG. 4 is another circuit diagram illustrating a configuration of a determination unit applied to FIGS. 1 and 3;

FIG. 5 is a configuration diagram showing a conventional radar device.

[Explanation of symbols]

 1, 1a, 1b: transmission unit 2: antenna 3, 3a, 3b: transmission / reception switch 4, 4a, 4b: amplitude limiter 5, 5a, 5b: reception unit 6, 6a, 6b: signal insertion unit 7, 7a, 7b: Signal detection unit 8, 8a, 8b: Signal generation unit 9, 9a, 9b: Judgment unit 10: Waveguide switch 12: Switching controller 13: Measurement detection unit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01S 7/00-7/42 G01S 13/00-13/95

Claims (2)

(57) [Claims] 1. A radar transmitting section, a transmission / reception switch for receiving a transmission radar signal from the radar transmission section and supplying the signal to an antenna, and a reflection signal from a target connected to the transmission / reception switching section and received via the antenna. An amplitude limiter to be introduced,
In a radar apparatus having a radar receiving unit connected to the amplitude limiter, a signal generator for supplying a test signal to the amplitude limiter, and a signal detection receiving a test signal derived through the amplitude limiter And a determination unit for determining a transmission loss received by the amplitude limiter for the test signal derived via the signal detection unit. 2. A waveguide switch connected to an antenna,
A pair of transmission / reception switches connected to the waveguide switching device, a radar transmission unit connected to the pair of transmission / reception switching devices,
A pair of amplitude limiters connected to the pair of duplexers for introducing a reflected signal from a target received via the antenna, and a radar receiver connected to the pair of amplitude limiters, respectively. In the radar device, a signal generator that supplies a test signal to each of the pair of amplitude limiters, a signal detection unit that receives a test signal derived through the pair of amplitude limiters, and a signal detection unit that receives the test signal. A determination unit for determining the amount of transmission loss that the derived test signal receives at the amplitude limiter, and a switching controller for introducing the determination result of the determination unit and controlling switching of the waveguide switch. A radar device characterized by the following.