SU1645912A1 - Interferometer with high frequency paths non-identity correction - Google Patents

Abstract

The invention relates to a technique of radio measurements and can be used in measuring the arrival angles of radio signals. The purpose of the invention is to improve the accuracy of measurement of the phase difference during operation. Interferometer with correction of non-identity high-frequency paths contains the source 1 of the signal under study, the reflector 2, the first and second receiving antennas 3, 5, the transmitting antenna 4, segments 6 and 8 of the high-frequency path, the phase shifter 7, the local oscillator 10. the first and second mixers 9 and 11, the first and the second amplifiers 16 and 18 of the intermediate frequency, the difference unit 17, the first and second phase meters 13 and 19. At the output of the difference unit 17, the magnitude of the phase difference of the calibration signal is subtracted from the value of the phase difference of the path signals, therefore at its output - phase difference mask is free from dynamic error due to non-identical paths. 1 il CO WITH

Description

The invention relates to a technique of radio measurements and can be used in measuring the arrival angles of radio signals.

The purpose of the invention is to improve the accuracy of measurement of the phase difference during operation.

The drawing shows a structural scheme of the interferometer with the correction of non-identity high frequency paths.

Interferometer with correction of non-identical high-frequency paths contains the source 1 of the signal under investigation, the reflector 2, the first receiving antenna 3, the transmitting antenna 4, the second receiving antenna 5, the first segment of the high-frequency path 6, the phase shifter 7, the second segment of the high-frequency path 8, the first

mixer 9, local oscillator 10, second mixer 11, first low frequency amplifier 12, first phase meter 13, second low frequency amplifier 14, low frequency generator 15, first intermediate frequency amplifier 16. differential unit 17, second intermediate frequency amplifier 18, second phase meter 19 Reflector 2 is mounted on the interferometer axis in the direction of receiving the measuring signal.

The interferometer with the correction of non-identity high-frequency paths works as follows.

The radio signal from source 1 through the radio channel, the passage of the route between source 1 and the interferometer, is fed to the inputs of receiving antennas 3, 5 and high

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the frequency path 6, 8, and then to the first inputs of the first and second mixers 9, 11 and the first input of the phase shifter 7. To the second input of the phase shifter 7, a control signal from the low frequency generator 15 is fed. The phase shifter 7 modulates the signal of the local oscillator 10 calibrated in phase varying linearly in a single period of control low-frequency voltage. The modulated signal of the local oscillator 10 is fed to the transmitting antenna 4 and is radiated in the direction of the reflector 2. The radio signal reflected from the reflector 2 is supplied simultaneously with the measured radio signal to the receiving antennas 3 and 5 and further to the mixers 9,11. In mixers 9, 11, the modulated signals of the local oscillator 10 are mixed with the signal of the local oscillator 10 and as a result of mixing the low frequency component is extracted and amplified by low frequency amplifiers 12, 14, from the outputs of which the signals are fed to the second phase meter 13. From the first phase meter 13 the difference phases of low-frequency signals are supplied to the first input of the difference block 17. Simultaneously from the mixers 9, 11, the signals of the intermediate frequencies of the measured radio signal are fed to the first and second amplifiers 16, 18 of the intermediate frequency, and after amplification - to the input first phase meter 13, the output of which the phase difference value applied to a second input of difference unit 17, in which the magnitude of the phase difference measured signal is subtracted the value of the calibration signal phase difference. Since the magnitude of the phase difference of the calibration signal is caused by the nonidentity of the high frequency paths, the output of block 17 separates the magnitude of the phase difference of the measured signal that is free from dynamic error due to the nonidentity paths, and the high frequency path of the antenna-feeder part is corrected.

Claims (1)

Invention Interferometer with correction of non-identity -high-frequency paths, containing series-connected the first receiving antenna, the first segment of the high-frequency path, the first mixer, the first intermediate frequency amplifier and the first phase meter connected in series to the second receiving antenna, the second segment of the high-frequency path, the second mixer and the second intermediate frequency amplifier, the output of which is connected to the second input of the first phase meter, as well as the local oscillator, the output of which is connected with the second inputs of the first and second mixers, characterized in that, in order to improve the accuracy of measuring the phase difference during operation, a reflector located in near the reception area on the axis of the interferometer, which also contains the inserted, transmitting antenna, the input of which is connected through the input of the phase shifter to the output of the local oscillator, the first low-frequency amplifier connected in series, the input of which is connected to the output of the first mixer, the second phase meter and the differential unit, the second input connected to the output of the first phase meter, and the output is interferometer output, as well as the second low-frequency amplifier, connected between the output of the second mixer and the second input of the second phase meter, and a low-frequency generator, the output of which is connected to the control input of the phase shifter. J  9 four A) 7 Sir1 -four SH -four / P I V one H I -4rfi - H / HZ--