SU1121627A1 - Lengthy four-terminal network phase fluctuation meter - Google Patents

Abstract

PHASE FLUCTUATION METHOD OF EXTENDED FOUR-POLES, containing a serially connected crystal oscillator and a frequency synthesizer on the transmitting side, the output of which is connected to the input terminals of the quadrupole under study, and the first crystal oscillator, the first mixer, phase-self tuning synthesizer, synthesizer, synthesizer, synthesizer, synthesizer, synthesizer, synthesizer, synthesizer, synthesizer, synthesizer. signals, the signal input of the mixer is connected to the output terminals of the studied quadrupole, characterized in that, in order to increase T In particular, a second crystal oscillator, a second mixer, and a phase detector are introduced into the receiver, the output of the first crystal oscillator is connected to the heterodyne inputs of the first and second mixers and the first input of the phase-locked loop, the output of which is connected to the input of the second crystal oscillator, output connected to the second input an automatic frequency control unit and to the input of the syn- i / frequency tester ;, output connected to the second mixer signal input, the output of which is under- j / connected to the first input a phase detector, a second input coupled to an output, the first mixer and an output connected to block entry by treatment information. / 7reminn Yu yes to

Description

The invention relates to phase measurements and can be used in radio engineering and communications for monitoring phase fluctuations of a four-pole circuit, especially with geographically dispersed input and output. A phase fluctuation meter of extended three-pole circuits is known, comprising a test signal generator, a quadrupole under study and a phase detector connected in series, a low-pass filter and a reference signal generator ij. The disadvantage of the meter is that at high frequencies the measurement error significantly increases due to an increase in the intrinsic fluctuations of high-frequency quartz oscillators used as generators of the reference and test signals, as well as the difficulties of implementing highly stable quartz oscillators in the frequency range above 10 MHz, In addition, the device does not allow measurement of fluctuations at the ends of a predetermined time interval and the automation of the measurement process is difficult. The closest to the technical essence of the invention is a phase fluctuation meter for extended quadrupoles containing a researched quadrupole, quartz oscillators of measuring and angular signals — a frequency synthesizer, a mixer, a phase automatic frequency control unit (PLL), as well as an auxiliary communication line and information processing unit A quartz oscillator is connected to the input of a frequency synthesizer, the first output of which is connected to the input terminals of the studied four-pole, and the other output via the auxiliary communication line — to the first input of the PLL unit. The output terminals of the quadrupole under study are connected to the signal input of the mixer, the heterodyne input of which is connected to the first output of the frequency synthesizer, and the output is connected to the first input of the information processing unit, the second input of which is combined with the second output of the frequency synthesizer. The output of the PLL is connected to the input of a crystal oscillator, the output of which is connected to the input of the C23 synthesizer. However, the known meter is characterized by an insufficient accuracy of measuring phase fluctuations, due to the need to use an auxiliary link, whose natural phase fluctuations are directly included in the measurement result. As a result, strict quality requirements are imposed on the auxiliary line: its own phase fluctuations should be approximately an order of magnitude less than the phase fluctuations of the quadrupole under study. The purpose of the invention is to improve the accuracy of measuring phase fluctuations of extended quadrupoles. This goal is achieved by the fact that the phase fluctuation meter of extended quadrupoles contains a series-connected quartz oscillator and a frequency synthesizer on the transmitting side, the output of which is connected to the input quadrupole terminals and the first quartz oscillator, the first mixer, on the receive side a phase locked loop, a frequency synthesizer, and a signal processing unit; the signal input of the mixer is connected to the output terminals of the two-port network under study. The receiver additionally introduced a second crystal oscillator, a second mixer and a phase detector, with the output of the first crystal oscillator connected to the heterodyne inputs of the first and second mixers and the first input of the phase-locked loop unit, the output of which is connected to the input of the second crystal oscillator, the output connected to the second input of the unit phase-locked loop and to the input of the frequency synthesizer, the output connected to the signal input of the second mixer, the output of which is connected to the first input phase detector, the second input of which is connected to the output of the first mixer, and the output is connected to the input of the signal processing unit. The drawing shows a structural diagram of a phase fluctuation meter for extended quadrupoles. The phase fluctuation meter of the extended quadrupoles contains the quadrupole 1 under study, which is connected to the output terminals of the transmitter and to the input terminals / 1m of the receiver. The transmitter consists of a series-connected crystal oscillator 2 and a frequency synthesizer 3, the output of which is the transmitter output. The receiver contains the first crystal oscillator 4 (identical to generator 2), frequency synthesizer 5 (identical to synthesizer 3), first mixer 6, phase locked loop (PLL) 7, signal processing unit 8, phase detector 9, second crystal oscillator 10, second mixer 11. Moreover, the signal input of the first mixer 6 is the input of the receiver, the heterodyne inputs of the mixers b and 11, and the first input of the PLL unit 7 are combined and connected to the output of the first crystal oscillator 4. The output of the first mixer 6. is connected to the first input detector 9, the second input of which is connected to the output of the second mixer 11, and the output is connected to the input of the signal processing unit 8. The input of the second mixer I is connected to the output of a 5-frequency synthesizer, the input of which is combined with the second input of the PLL unit 7 and connected to the output of the second crystal oscillator 10, whose input is connected to the output of the PLL unit 7. The signal processing unit 8 of the phase fluctuation meter of the extended quadrupoles can be made of a series-connected digital phase meter, a digital delay unit, a subtraction unit, a computing unit, issuing, for example, the rms value of the measured phase signals. The meter works as follows. The reference quartz oscillators 2 and 10 produce oscillations by acting on the synthesizers 3 and 5 frequencies, where the test and reference frequencies are generated. The phase difference between the oscillations produced by the quartz oscillators 4 and 10 is kept constant by means of the PLL block 7, the quartz oscillator 4 being the reference signal source. At the input of the quadrupole from the frequency synthesizer 3, the measuring signal U is applied; (, l.mg (t) si.u ,,, (i) -. (11 where p (), (t) are amplitude and phase fluctuations introduced by kvar. The target generator 2} Wjj is the circular frequency of the signal of the synthesis of the torus 3. Frequency of the studied quadrupole (line) provides the signal u; (t) K, u, where l t is the transfer coefficient of the studied quadrupole (J amplitude and phase fluctuations introduced investigated quadrupole 1. At the heterodyne input of the first dimmer 6, a signal is received from the first vartsev generator 4 and D - -e2 -02 G2 0 N de g2 (amplitude and phase fluctuations of the signal of the first crystal oscillator 4. When the output of the first mixer 6, a signal of different frequencies,., (t)) tV (t) -, J (, (, „ Jt). (4) de p ot intermediate frequency; mixer transfer coefficient 6; see phase fluctuations introduced by mixer 6. Since quartz oscillators 2 and 0, synthesizers 3 and 5 are identical, it is possible to assume that the signal at the output of the injector 5 is similar expression 1) and is distinguished by the parameters encircled by the wave. So at the output of the simulator 11 J) (tl - /. Ctk cm1. (T, (51 de phase fluctuations introduced by the second mixer 11. The signal at the output of the phase detector 9 is determined by the expression u, (, K, t) -v, Kt ), - (s de Fd transfer coefficient of the phase detector; (d) instantaneous phase shifts of the signals U (t) and U (i) frequencies az „, applied to the inputs of the phase detector 9. .K.) rW-r2W-V, ( i) -V ,, (t) (T).) 1 (- Г2 - см1г (("1 With equal phase fluctuations of inthesators 3 and 5 and mixers 6 and 1, the output signal of phase detection 9, according to expressions (6) - (8) Uran, (t |. (9)

51121627b

From the expression (9) it follows that due to the calculation algorithm

the measurement signal contains only a standard deviation of the phase fluctuations of the studied four fluctuations or short-term

rehpoljusnika. As shown by the analogous frequency instability, potent. analysis performed for prop ° p ° s f. a positive effect is proposed by the expression "the meter is achieved by

y (b) cd ,. RN W + (iH, () of the fact that new functional units are introduced to the receiver of the meter 7 AL X DAS J: phase phase fluctuations for the c, in-Q detector, second quartz

the auxiliary line, the generator and the second mixer, which significantly increase in order to eliminate the auxiliary

measurement error, the line of communication, the effect of its own

For further processing of signal phase fluctuations on the result of 4x (t), measurement processing unit 8 is used and, thus, to increase signal signals, the unit can be completed measurement.

Claims (1)

EXTENDED FOUR-POLE PHASE FLOW METER; containing on its transmitting side a quartz oscillator and frequency synthesizer, the output of which is connected to the input terminals of the studied four-pole, and on the receiving side the first quartz oscillator, first mixer, phase-locked loop, frequency synthesizer and frequency synthesizer moreover, the signal input of the mixer is connected to the output terminals of the studied four-terminal network, characterized in that, in order to improve accuracy, a second quartz oscillator, a second mixer and a phase detector are introduced into the receiver, the output of the first quartz oscillator being connected to the heterodyne inputs of the first and second mixers and the first input of the phase locked loop, the output of which is connected to the input of the second quartz oscillator connected to the second input of the auto tuning block frequency and to the input of the syn-ν frequency generator, output connected to the signal input of the second mixer, the output of which is connected to the first input of the phase detector, in the second input of which is connected to the output of the first mixer, the output is connected to the input of the information processing unit> 21GOS