SU855526A1 - Pseudo-noise signal phase noise meter - Google Patents

Description

(54) PHASE NOISE METER MEASURING PSEEDRONSHINE SIGNALS

The phase noise meter refers to radio measurements and is intended for use in receiving devices of radio engineering systems with phase-shifted signals, in particular in devices for the automatic recovery of the phase of the carrier wave. Phase gauges used in radio engineering systems and instruments for measuring the phase difference between two continuous or pulsed signals of various shapes containing mixers, limiting, differentiating elements, triggers, reference frequency generator, counters and reading device 1 are known. The disadvantage of this meter is the impossibility of measuring phase noise. A phase difference meter for two harmonic oscillations is known, which contains an attenuator, an electronic switch circuit consisting of two gates, a square wave generator and an adder, a frequency converter with a tunable local oscillator, the output of which is connected to three parallel channels of the spectrum harmonic analyzer consisting in its own turn from filters tuned to the appropriate spectral component, detectors, as well as an analyzer of the ratio of harmonic voltage components and a comparison circuit 2. A disadvantage of the known meter is low accuracy. The purpose of the invention is to increase the points. nosti. The goal is achieved by the fact that the phase noise meter of pseudo-noise signals, containing a square wave generator, the output of which is connected to the control inputs of the first and second valves, the outputs of which are connected respectively to the inputs of the first adder, filter harmonics.and the carrier frequency whose output is connected to the first detector, the amplitude equalizer and the second detector, is equipped with a clock pulse generator, a phase shifter, a harmonic equalizer and a second adder, with the phase shifter inputs and the equalizer the amplitude gate is connected and the outputs are connected respectively to the inputs of the first and second valves, the generator output of the Text pulses is connected to the input of the square wave generator, the output of the first adder is connected via serially connected carrier filter and the first detector to the first input of the second adder, the harmonic equalizer and the second detector to its second input.

FIG. 1 is a block diagram of a phase noise meter; in fig. 2 - stress diagrams and their spectra.

Phase noise meter contains phase shifter 1, first valve 2, carrier frequency filters 3, first detector 4, 5 clock pulse generator, square wave generator, first adder 7, second detector 8, second adder 9, equalizer 10 amplitudes, second valve 11, filter 12 side harmonics and equalizer 13 harmonics.

The device works as follows.

The input A is supplied with a measured signal made up of sinusoidal oscillations of the same amplitude and frequency, but which through the phase shifter 1 and the first valve 2 enters the adder 7 of different duration and phase, which also receives the signal through the equalizer 10 amplitudes and the second valve 11 Spectrum Such a signal is represented in FIG. 2. The measured signal arriving at the input A commutes with the clock pulse generator 5 and the square wave generator 6 with the frequency Sl (where f is equal to the duration of the elementary pulse), the square wave voltage (Fig. 2d). At the same time, the output of the adder 7 is The signal shown in FIG. 2e (for clarity, it is manipulated by a meander of 180 °, in the present of the body phase shift will be 90 °). The spectrum of the signal (Fig. 2e is a manipulated meander, is the sum of the harmonic components - the carrier frequency of the SU and the lateral upper and lower components

with

53 Tijjt (2k-1) Sil, and the amplitude of the harfei

monic components depend on the phase difference between adjacent segments of sinusoidal oscillations of the process being measured. The output voltage of the phase noise meter and its sign are proportional to the ratios of the phase

segments of sinusoids of measured signals.

Thus, the proposed device makes it possible to measure the phase ratio of a complex signal consisting of sinusoidal oscillations of the same amplitude and frequency, but with different phases and durations following each other without pauses, which are one continuous signal. By manipulating such a signal in phase by 90 ° according to the law of the meander voltage with a period equal to twice the clock interval (21) of the modulating pseudo-random sequence, it was possible to compress the spectrum (Fig. 2i) to the form (Fig. 2k) and by its harmonic composition measure phase shift.

Claims (2)

1. USSR author's certificate number 331335, cl. G 01 R 25/04, 19,69. 2. USSR author's certificate number 307353, cl. G 01 R 25/00, 1969. cSefmKU 1 m -I .g L S (f) f 1 ff ft f0l.2