SU993145A1 - Signal delay group time non-uniformity meter - Google Patents

Description

The invention relates to measuring technique and can be used to measure the unevenness of the group delay time of signals in communication communication channels.

A known meter of group time unevenness of signals in communication channels, comprising a variable frequency generator, constant and modulating frequency generators, frequency converters, damping store, adder, phase shifter, detector and phase indicator tl.

The disadvantage of the meter is the low measurement accuracy and the availability of auxiliary power. .

Also known is a non-uniformity gauge for a group of signal delay times, which contains a sawtooth generator, an output connected to a generator of quality frequency, an output connected to one of the modulator inputs, a second input connected to the output of the reference generator through a frequency divider, the output of the modulator and the reference generator through Usedlitel connected to the input of the communication channel, the output connected simultaneously to the inputs of a schlituddogo detector and narrowband filter, the output amplitude force detector through spruce limiter is connected to one input of a phase detector, and the output of the notch filter through a frequency divider and phase shifter coupled to a second input of a single detector, the output of which is connected to pod10 C2l indicator.

A disadvantage of the known meter is the low measurement accuracy (due to the abrupt change in the frequency of the reference signal at the output of the frequency divider in the receiving part). .

The purpose of the invention is to increase the measurement accuracy.

This goal is achieved by

20 that a non-uniformity meter for the group delay of signals, comprising a reference voltage generator, the output of which is connected to one through a frequency divider

25 of the modulator inputs, a sawtooth generator, connected via a sweep frequency generator to another input of the modulator connected by the output to one of the inputs

The amplifier 30, the output of which is connected via a communication channel to the input of a narrowband filter and simultaneously through a sequentially connected amplitude detector and amplifier-limiter with one input of the first phase detector connected to the indicator, is supplied with a phase manipulator, a pulse shaper manipulator a coincidence circuit, a coherent heteroynum, a second phase detector and a control unit, the input of which is connected to the output of the amplitude detector, the first output to one input of the coincidence circuit, the second output to the first coherent heterodyne input, the last input of the latter is connected to the output of the coincidence circuit, and the output of the narrowband filter is connected to another input of the matching circuit and one input of the second phase detector, the other input of which is connected to the output of the coherent heterodyne, the output of the second phase detector with the input of the phase shifter, while the output of the frequency divider is connected to the first input of the phase manipulator connected by the output with another amplifier input through the shaper of the manipulation pulses, and the output is generated The reference frequency ora is connected to the second input of the phase shift key. The drawing shows a structural diagram of the meter for unevenness of the group time of the signal lag, the meter contains a sawtooth generator 1, an output connected to the oscillating frequency generator 2, an output connected to one of the modulator inputs 3, a second input connected to the generator 4 of the reference voltage through the frequency divider 5, the output of which is also connected to the input of the impulse manipulator shaper b, the output connected to one and the inputs of the phase manipulator, 7, the second in turn It is connected to the output of the generator 4, the output of the modulator and the phase manipulator 7 is connected via the amplifier 8 to the input of the communication channel 9, the output of which is connected simultaneously with the input of the amplitude detector 10 and the input of the narrowband filter 11, the output of the amplitude detector 10 is connected simultaneously with the input the amplifier limiter 12 and the input of the control unit 13, one of the inputs of which is connected to one of the inputs of the matching circuit 19, the third input connected and the output of the narrowband filter the output of the matching circuit 14 is connected to the first input to of the primary heterodyne 15, the second input of the control unit 13 connected to the second output, the output of the coherent local oscillator 15 co is connected to one of the inputs of the second phase detector 16, the second input / connected to the output of the narrowband filter 11, the output of the second phase detector 16 is connected through the phase shifter 17 to the first input of the first phase detector 18, the second INPUT of the amplifier-limiter 12 connected to the output, and the output of the first phase detector 18 is connected to the input of the indicator 19. The meter works as follows. The sawtooth voltage from the output of generator 1 is fed to the input of generator 2. The high-frequency oscillations transmitted at the output of generator 2 are fed to the input of modulator 3, where they are modulated in amplitude by low-frequency oscillations coming from the output of generator 4 through divider S, In addition, the signal from the output of divider 5 is fed to the input of the imager 6, from the output of which the generated pulses are fed to the input of the phase manipulator 7, to the second input of which the signal from the output of the generator 4 arrives, the frequency of the latter is chosen passing frequency communication channel bandwidth. The output signal of the modulator 3 together with the dressings coming from the output of the phase manipulator 7 is fed through the amplifier 8 to the input of the channel 9 of communication. At the output of the communication channel 9, the modulated signal under study together with the signals of the phase-shift keyed signal simultaneously arrive at the input of the amplitude detector 10 and the narrow-band filter 11. Since the amplitude decelerator 10 does not respond to the phase-shift keyed signal, only the envelope is detected at its output after detection the investigated modulated signal, the phase difference of which at the output and the input of the communication channel 9 is proportional to the non-uniformity of the group delay time. Phase-manipulated signal through a narrow-band filter 11 is fed to one of the matching inputs 14, and the output signal of the amplitude detector 10 is fed to the input of the control unit 13, at the first output of which a signal with duration tfto is formed. where TO is the duration of the elementary parcel arriving at the second input of the J4 coincidence circuit. The output of the coincidence circuit produces a signal that triggers a coherent local oscillator 15, the output of which has the form of a signal with an initial phase and a frequency equal to the initial phase and the frequency of the phase-shift keyed signal. After graduation

Claims (1)

Claim An instrument for the non-uniformity of group delay of signals, 45 containing a reference voltage generator, the output of which is connected through a frequency divider to one of the inputs