RU2246176C1 - Device for serviceability check of superheterodyne receiver - Google Patents

Abstract

FIELD: radio communications.

SUBSTANCE: pulse noise is detected upon conversion of signal received into intermediate frequency, noise active time is determined, information signal is disconnected from amplifier incorporated in superheterodyne receiver, noise-affected part of information signal is recovered by eliminating simulator signals during extrapolation, and superheterodyne receiver is checked for serviceability at intermediate frequency.

EFFECT: enhanced precision of superheterodyne receiver serviceability check.

1 cl, 1 dwg

Description

The invention relates to radio communications and can be used to monitor the health of superheterodyne radios of moving objects without interruption in the reception of analog signals when exposed to pulsed interference from radio-technical devices for radar and radio navigation.

A device for monitoring the health of a superheterodyne radio receiver is known, which contains a serially connected input signal simulator, a key and a valve, the input of which is connected to the information input of a superheterodyne receiver, a first switching unit and an output amplifier connected in series, a second switching unit and an extrapolator connected in series to a quality assessment unit and an indicator, an OR element (see USSR AS No. 1418920, class H 04 B 3/46, 1984).

The disadvantage of this device is the low accuracy of control. The purpose of the invention is to improve the accuracy of monitoring the performance of a superheterodyne radio receiver.

To achieve this goal, a device for monitoring the health of a superheterodyne radio receiver, which contains a serially connected input signal simulator, a key and a valve, a first switching unit and an output amplifier connected in series, a second switching unit and an extrapolator connected in series, a quality assessment unit and an indicator, an OR element , N pulse impulse noise detection (IP) blocks were additionally introduced, the inputs of which are connected to the intermediate frequency output radio receiver, and the outputs with the inputs of the OR element, a differentiating unit, the input of which is connected to the output of the OR element, and the output is with the control inputs of the key, the first and second switching units, the second output of the second switching unit is connected to the input of the quality assessment unit, the extrapolator output is connected with the input of the first switching unit.

The drawing shows a structural electrical diagram of the proposed device.

The device for monitoring the health of the superheterodyne receiver contains a serially connected input signal simulator 1, a key 2, and a valve 3, the output of which is connected to the information input of the superheterodyne receiver 4, N being monitored, IP detection units 9, each of which consists of a filter 12, connected in series, and an amplitude detector 13 threshold block 14, the pulse shaper 15, and the input of the filter 12 is connected to the output of the intermediate frequency (IF) of the controlled superheterodyne receiver 4, are followed the first switching unit 5 and the output amplifier 6, the output of which is the input of the recipient of information, the second switching unit 7 and the extrapolator 8, the output of which is connected to another information input of the first switching unit 5, are connected in series OR 10, the inputs of which are connected to the outputs of the drivers 15 of the pulses of the blocks 9.1, ..., 9.N detection IP, and a differentiating block 11, the output of which is connected to the control inputs of the first key 2, the first 5 and second blocks 7 switch connected in series to block 16 quality assessment, the input of which is connected to another information output of the second block 7 switching and indicator 17.

The principle of operation of the proposed device is based on the detection of impulse noise at the intermediate frequency output of a superheterodyne controlled radio receiver that occurs as a result of the action of radio-electronic devices for radar and radio navigation, and instead of generating an IP signal, a simulator compatible with the information signal of the controlled receiver. At the same time, the analog outputs (telephone, FM operation mode) of the radio receiver are disconnected from the recipient of information, and the information signal is restored using extrapolation methods.

The principle of compensation for impulse noise using extrapolation, see Analysis and optimization of a method for suppressing impulse noise, ed. Bykhovsky M.A., Terekhov A.S. / Proceedings of NIIR No. 4. - M., Radio and communications. 1986 year

The device operates as follows. The information signal exposed to pulsed noise from the intermediate frequency (IF) output of the monitored receiver is fed to the inputs of the N blocks 9.1-9.N detection IP. The number of blocks 9.1-9.N is selected depending on the accuracy of the detection of the IP. The filter 12 blocks 9.1-9.N of the detection of the IP is tuned to a certain frequency of the spectrum of the information signal that is most exposed to pulsed noise. From the output of the filter 12, a signal of a certain frequency passes through an amplitude detector 13 and a threshold block 14 to the input of the pulse shaper 15. The signal that appears at the output of the threshold block 14 of positive polarity triggers the pulse shaper 15. The pulse duration at the output of the shaper 15 is equal to the duration of the pulse noise and is selected based on a priori information about the sources of SP, see Knyazev A.D. Elements of the theory and practice of providing EMC RES. - M.: Radio and Communications, 1984, 336 p.

If there is an IP, at least one of the blocks 9.1-9.N of detecting an IP, an impulse signal appears at the output of the OR element 10. A positive pulse from the output of the differentiating unit 11 using the first switching unit 5 connects the output of the extrapolator 8 to the input of the output amplifier 6. The extrapolator restores the affected IP portion of the information signal. Using the second switching unit 7, the information output of the monitored receiver 4 is disconnected from the input of the extrapolator 8 (this is necessary to increase the reliability of extrapolation of the extrapolator 8 due to the exclusion of the simulator 1 signals during extrapolation) and is connected to the input of the quality assessment unit 16. This unit is designed to classify the technical condition of the monitored receiver 4. The principle of operation of this unit 16 is based on measuring the signal level of simulator 1 (see Davydov P.S. Technical diagnostics of REU and S. - M .: Radio and communications, 1988. - 256 s. .).

In addition, the signal of the differentiating unit 11 opens the key 2 and the signal of the simulator 1, with a level equal to the sensitivity of the monitored receiver, is input to the receiver. At the end of the IP operation, a negative polarity signal is generated at the output of the differentiating block 11, which closes the key 2, preventing the signal from the simulator 1 from passing to the input of the controlled receiver 4. In addition, this signal connects the information output using the first switching block 5 (telephone output, operating mode FM) of the receiver 4 to the input of the output amplifier bis using the second switching unit 7 connects the information output of the receiver to the input of the extrapolator 8, thereby disconnecting the quality assessment unit 16. The valve 3 is designed to prevent the signal of the simulator 1 from getting into the AFU circuit. The extrapolator 8 and the output amplifier 6. are structurally included in the controlled receiver.

Technical appraisal and economic advantages of the proposed device compared to the prototype device are to improve the accuracy of monitoring the health of the superheterodyne receiver. The use of the proposed device for monitoring the technical condition of VHF FM radio stations of mobile objects will allow to increase the number of rejections by 2 ... 5% compared with the prototype device. In addition, the duration of the health monitoring is reduced 1.1-1.2 times.

Claims (1)

A device for monitoring the health of a superheterodyne radio receiver, comprising a serially connected input signal simulator, a key and a valve, the output of which is connected to the information path of the superheterodyne receiver, a first switching block and an output amplifier, a second switching block and an extrapolator connected in series to the quality assessment unit and indicator, OR element, characterized in that, in order to increase the accuracy of control, N b is additionally introduced impulse noise detection blocks, each of which consists of a series-connected filter, an amplitude detector, a threshold block and a pulse shaper, the inputs of the pulse noise detection blocks are connected to the intermediate frequency output of the superheterodyne radio receiver, the information (telephone) output of which is connected to the inputs of the first and second switching blocks , the outputs of the pulsed noise detection blocks are connected to the inputs of the OR element, the output of which is connected to the input of the differentiating block, the input otorrhea connected to the output of the OR gate, and an output - with a key control inputs and first and second switching units, the second output of the second switching unit is coupled to the input of quality evaluation unit, extrapolator output connected to the input of the first switching unit.