JPH0616083B2 - Transponder device - Google Patents

Description

The present invention relates to a DME device and a tacan device, and more particularly to a transponder which is a ground station.

A DME device used as a navigation aid facility gives an aircraft a tilt distance to a ground transponder. The distance measurement randomly emits a coded interrogation pulse from an aircraft transmitter, which the ground transponder recodes after reception and gives a specific delay time (50 μs) for transmission as a response pulse.

Therefore, the aircraft obtains the distance by measuring the time from the interrogation pulse emitted by itself to the response pulse received in synchronization, and correcting the delay time (50 μs) of the ground transponder in advance.

Conventionally, as shown in FIG. 1, a transponder device of this type has a receiver 5, a decoding device 6, and an AGC (Automatic Gain Contr.
The pulse output of the decoder 6 is controlled at a maximum of 2700 pulse pairs / second by the closed loop composed of ol) 10. This 2700
The pulse pair / second is the number of pulses that can give range information to about 100 aircraft. As described above, the transponder receives the interrogation pulse from a large number of aircraft at random, and the pulse output of the interrogator 6 is concentrated due to the fact that the interrogation pulse carrier leakage causes the interrogation pulse to have a higher resolution rate. It happens rarely. However, the AGC10 cannot make a rapid response to this pulse output (if the response is fast, the fluctuation rate of the pulse number becomes large and it becomes unstable).
In addition, the transmitter 9 of the transponder device has an overload condition, which exceeds the allowable duty of the high power amplification transistor and damages it, resulting in a decrease in reliability and an increase in maintenance cost.

The present invention has been made to solve the above-mentioned drawbacks inherent in the prior art. Therefore, an object of the present invention is to add a pulse number control circuit to a transponder device to remove a part of concentrated pulse output. By doing so, it is intended to provide a highly reliable novel transponder device in which the duty of the transmission pulse is averaged and the cause of damage to the high power amplification transistor of the solid-state transmitter is solved.

In order to achieve the above object, according to the present invention, a receiver for receiving an interrogation pulse from an aircraft, a decoder for receiving a receiver output, and a number of output pulses included in the receiver for receiving a decoder output are An AGC unit that controls the receiver so that the maximum number of transmission trigger pulses is a predetermined number per second, an encoder that encodes the trigger pulse of the output of the encoder, a transmitter that transmits the output of the encoder, and an encoder. A pulse number control circuit for limiting the number of transmission pulses in order to prevent the transmission pulses from being instantaneously concentrated and the transmitter from being overloaded. Wherein the pulse number control circuit generates a pulse having a period wider than the average period of the maximum number of transmission trigger pulses per second as a period for measuring the concentration of instantaneous pulses, and for each pulse period from the oscillator. Output pulse from the solver The counting circuit outputs a prohibition signal when it reaches a predetermined number, and the output pulse from the decoder is controlled by the prohibition signal from the counting circuit to limit the maximum number of instantaneous trigger pulses. A transponder device for a DME device or a tacan device, which is characterized by including a gate circuit.

Next, the present invention will be specifically described with reference to the drawings for a preferred embodiment thereof.

2 (A) and 2 (B) are block configuration diagrams showing an embodiment of the present invention. In the figure, reference numeral 11 indicates a pulse number control circuit according to the present invention, and the pulse number control circuit 11 is connected between the delay device 7 and the encoder 8 in this embodiment. The pulse number control circuit 11 is inserted between the delay unit 7 and the encoder 8 shown in FIG. 1 and is a closed loop (receiver 5, interpreter 6, pulse number control circuit 11 and AGC 10). Any of As shown in FIG. 2B, the pulse number control circuit 11 includes an oscillator 12, a counting circuit 13, a gate circuit 14,
It is composed of a monostable multivibrator 15 and an inverter circuit 16. The counting circuit 13 is composed of counters 13 ₁ and 13 ₂ and NOR gates 13 ₃ and 13 ₄ . The outputs A, B, C and D of the counters 13 ₁ and 13 ₂ correspond to 1, 2, 4 and 8, respectively.

FIGS. 3 (A) and 3 (B) are diagrams showing waveforms of respective parts of the pulse number control circuit 11 and time relationships, of which (A) shows a normal case,
(B) shows the case where the pulse outputs are concentrated.

Oscillator 12 is set at about 675 Hz in relation to the transmitted pulses of 2700 pulse pairs / sec, and the output of oscillator 12 is shown at c and d in FIG. The counting circuit 13 controlled by the outputs c and d of the oscillator 12 performs counting when the outputs c and d of the oscillator 12 are at the logic level "Low", and when the outputs c and d of the oscillator 12 are at the logic level "High". The outputs f and g are at the logic level "High".

Therefore, the outputs f and g of the counting circuit 13 are such that the outputs c and d of the oscillator 12 are at the logic level "Low", and the output b of the monostable multivibrator 15 is 4 pulses (set value 4 pulses: number of transmitted pulses 5400). (Corresponding to pulse pairs / second) or more), the logic level becomes “Low”, and the gate circuit 14 operates as an inhibition gate.

Thus, in the normal case (FIG. 3 (A)), the output h of the pulse number control circuit 11 is the same as the input a, but when the pulses are concentrated (FIG. 3 (B)). By inhibiting the input a pulse from the 5th pulse onward, the duty is averaged as shown by h in FIG. 3 (B).

Next, FIG. 4 shows the maximum pulse output as an application example of the present invention.
A circuit for controlling 2700 pulse pairs / second is shown. The configuration is such that a circuit similar to the above circuit is connected to the counting circuit 13a.
The setting value of is 32 pulses, the output frequency of the oscillator 12
The circuit operation is exactly the same as the above-mentioned circuit in that 675 Hz is divided by 1/16 by the frequency divider 17 (about 42 Hz).

Therefore, the output of the gate circuit 14a is controlled to 32 × 2 × 675/16 = 2700 pulses / sec.

As described above, the present invention includes an oscillator, a counting circuit controlled by the oscillator output, and a gate circuit for a concentrated pulse output that occurs infrequently. As a result, the transmitter of the transponder device is protected, the reliability is improved, and the maintenance cost is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a conventional device of this type, and FIG.
(A), (B) is a block diagram showing an embodiment of the present invention,
3 (A) and 3 (B) are timing charts showing waveforms and time relationships of each part of the present invention, and FIG. 4 is a block diagram showing an application example of the present invention. 1 ... Transponder device, 2 ... Antenna, 3 ... Transmission / reception switcher, 4 ... Receiver input circuit, 5 ... Receiver, 6 ...
Decoder, 7 ... Delay device, 8 ... Encoder, 9 ... Transmitter, 10 ... AGC, 11 ... Pulse number control circuit, 12 ... Oscillator, 13, 13a ... Counting circuit, 14 , 14a …… Gate circuit, 1
5, 15a: Monostable multivibrator, 16, 16a: Inverter circuit, 17: Divider

Claims (1)

[Claims] 1. A receiver for receiving an interrogation pulse from an aircraft, a decoder for receiving an output of the receiver, and an output pulse number included in the receiver for receiving an output of the decoder is a predetermined maximum transmission trigger pulse number per second. To control the receiver so that
An encoder that encodes the trigger pulse of the output of the encoder, a transmitter that transmits the output of the encoder, and a transmitter that is inserted between the encoder and the AGC section or between the encoder and the encoder. And a pulse number control circuit for limiting the number of transmission pulses to prevent the transmitter from being overloaded by instantaneously concentrating pulses, the pulse number control circuit, as a period for measuring the instantaneous pulse concentration every second An oscillator that generates a pulse having a period wider than the average period of the maximum number of transmission trigger pulses of, and counts the output pulse from the decoder for each pulse period from the oscillator,
A counting circuit that outputs an inhibit signal when the count value reaches a predetermined number, and a gate circuit that is controlled by the inhibit signal from the counting circuit to inhibit the output pulse from the decoder to limit the maximum number of instantaneous trigger pulses And a transponder device for a DME device or a tacan device.