SU885920A1 - Radio pulse phase-meter - Google Patents

Description

I

The invention relates to phase metering and MOKet to find application in radio engineering.

Phase meters are known for measuring the instantaneous value of the phase shift of radio pulse signals, which contain reference and test channels, input blocks, a phase shifter and a wideband amplifier G1.

The disadvantages of the known device are long and multi-step measurement procedure and their accuracy is low.

Also known is a radio-pulse phase meter made according to a two-channel symmetric scheme, each channel of which includes a mixer, a phase detector, a storage unit, a tunable generator, which form a tracking phase system with a control element, and also search the reference generator and the measuring pulse shaper with indicator device 12.

The disadvantage of the known phase meter is the presence of an error due to the non-ideality of the storage unit, which increases with an increase in the pause duration, which limits the allowable duty cycle of the input radio pulse sequences.

The purpose of the invention is to increase accuracy.

The goal is achieved by

10 that a radioimpactor phase meter containing first and second input units connected in series, phase detectors, switches and storage units, first and second

"5 tunable generators, the outputs of which are connected respectively to the second inputs of the first and second phase detectors, the first and second mixers, are equipped with the third and fourth phase detectors, integrator, phase shifter, zero indicator, reference generator, local oscillator, and adder, and the output the first memory unit is connected to one of the inputs of the adder, the second input of which is connected to the integrator output, and the output through the first tunable generator to one of the inputs of the first mixer, the second input connected to the output of the local oscillator and the second input of the second mixer, the first input of which is connected to the output of the second tunable generator, the output of the first mixer through the phase shifter, and. The second is directly connected respectively to the first and second inputs of the third phase detector, the output of which is connected to the inputs of the integrator and the null indicator, the output of the second mixer and the reference generator are respectively connected to the first and second inputs of the fourth phase detector, the output of which is connected to the input of the heterodyne. The drawing shows a block diagram of a radio pulse phase meter,. The radio pulse phase meter contains the first input unit 1, the first phase detector 2, the first key 3, the first memory block 4, the adder 5, the first tunable generator 6, the first mixer 7, the phase shifter 8, the third phase detector 9, the integrator 10, the zero indicator 11, the fourth phase detector 12, the second mixer 13, the reference generator 14, the local oscillator 15, the second tunable generator 16, the second memory block 17, the second key 18, the second phase detector 19 and the second input block 20. The device operates as follows. The radio pulse phase meter is made according to a symmetric two-channel scheme. In the first channel, the input unit, the first phase detector 2, the first key 3, the first block 4. memory, the adder 5 and the first tunable generator 6 form a closed tracking phase system. In the second channel, the second input unit 20, the second phase detector 19, the second switch 18, the second storage unit 17, and the second tunable generator 16 also form a loop of the tracking phase system. Loops work during the operation of the radio pulse initial phase difference of the input signal and signals of tunable oscillators 6 and 16, and at the time of its absence, memory blocks 4 and 17 keep the voltage and, therefore, the frequency and phase of tunable oscillators 6 and 16 unchanged. outputs tunable generators 6 and 16 of each channel are fed to the input of the first 7 and second 13 mixers, and the heterodyne inputs of these mixers receive a signal from the common dp of both channels of the local oscillator 15. The intermediate frequency signal from The output of one of the channels enters the phase shifter 8, and from the output of the second mixes the bodies 13 to the first 9 and second 12 phase detectors. The second input of the phase detector 12. Receives the signal of the reference oscillator 14 with a frequency equal to the intermediate, and the signal. with 1 output phase detector 12 enters on. controlling the frequency of the local oscillator 15, the mixer 13, the local oscillator 15, the phase detector 12 and the reference oscillator 14 form a phase locked loop, which reduces the error due to the instability of the frequency of the local oscillator 15. In addition, the signal from the mixer 13 output goes to the input of the phase detector 9. The second input of which receives the intermediate frequency signal from the output of the phase shifter 8. During the first radio pulse, the phase shifter 8 is reset, the signal from the output of the phase detector 9 is proportional to the current Phase of the signals from the output of the mixers of both channels and is not zero. The signal from the output of the phase detector 9 through the integrator U is fed to the adder 5 in the circuit of the tracking phase system of the first channel. Since the integrator time constant is much longer than the radio pulse duration, during its operation from the integrator 10 input 10 the input of the adder 5 does not receive a signal and does not affect the frequency tuning of the tunable generator 6 of the first channel. In the pause, due to the fact that the voltage on the first and second memory blocks 4 and 17, the first and second channels at the start of frequency mismatches other than zero, is not equal to zero, when the memory devices are not ideal, the phase of the PRruneable generators ,, 5UUjy (t ) uUJ ,, r. (t) i,

where u is the change in voltage on the storage device during pauses. This leads to an increase in the synchronization error with an increase in the pause length of 9. ЧЧ (t) Cho + 5U nГьW-Уп rr lt) йi,

where b is the duration of the pause, and limits the accuracy of the measurements and the permissible duty ratio of radio pulses. To reduce this component of error, the additional circuit introduced contains a calibrated phase shifter 8, a phase detector 9, integrates 10, and a tunable one. The generator 6 also forms an auto-trim ring, which is aestatic in phase. Changing the phase of the signal from the output of the mixer 7 of the first channel using a calibrated phase shifter, the frequency of the tunable generator of the first channel is controlled by a signal from the output of phase detector 9, a post. Packing through the integrator 10 to the input of the adder 5 and further to the control element of the tunable generator 6. As soon as the phases of the signals from the output of the phase shifter 8 of the first channel and the mixer 13 of the second channel become equal, the signal from the output of the phase detector 9 will be zero, which is induced by zero The indicator 11 and the phase shifter .8 take readings on the measured phase shift. The signal from the output of the phase detector 9 and integrator 10 is zero, and the phase meter is ready for a new series of measurements.

The use of an adder and a feedback ring from the output of the phase detector makes it possible to reduce the error component due to imperfection, and the memory unit is not less than an order of magnitude. Since the tunable generator 6, the mixer 7, the phase shifter B, the phase detector 9, and the integrator 10 form phase-locked loop systems, which are astatic in phase, there is an error.

introduced by this circuit is determined by the accuracy of the phase shifter 8.

Claims (2)

1. Volkov V.M., Ivanko. Non-stationary processes in the elements of phaseometric. Kiev, Technique, 1977, pp. 22-24. 2. USSR author's certificate Iff 602877, class GOIR .25 / 00, 1977.