SU1510079A1 - Generator synchronizing device - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is the elimination of spurious grips in the event of the loss of an intermediate frequency (IF) signal. The g-ra synchronization device contains a tunable g-r 1, a mixer 2, an amplifier 3 of the frequency converter, frequency dividers 4 and 9, a pulse frequency detector 5, a reversing counter 6, a code-nap converter 7, a reference gr-8, a phase detector 10, switch 11, r-12 pulses, amplitude detector 13 and frequency multiplier 14. If the IF signal does not fall into the passband of amplifier 3, the voltage level at the input and output of the detector 13 decreases dramatically, and Hg 12 is connected to the counting input of counter 6. It changes the content according to the information about the sign of the frequency error at the output of the tuning direction of the detector 5 counter 6 in the direction of decreasing the frequency detuning to establish a synchronous mode of operation. In the absence of a signal at the output of amplifier 3, detector 5 may not store reliable information about the sign of the frequency error. Then, due to Mr 12 and detector 5, Mr 1 will be adjusted in the direction of increasing the frequency error until the IF signal appears at the output of amplifier 3. Next, detector 5 determines the required tuning direction, after which the device will be tuned to reduce frequency detuning. 1 il.

Description

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then you. if the IF signal does not fall into the passband of amplifier 3, the voltage level at the input and output of the detector 13 sharply decreases and rc-12 is connected to the counting input of counter 6. It changes the content according to the information about the sign of the frequency error at the output of the tuning direction of the detector 5 counter 6 in the direction of decreasing the frequency detuning to establish a synchronous mode of operation. In the absence of sig0794

The output of amplifier 3 detector 5 may not store reliable information about the sign of the frequency error. Then, due to Mr. 12 and the detector 5, the adjustment of Mr. 1 will be made in the direction of increasing the frequency error until the IF signal appears at the output of the amplifier Z. Then detector 5 determines the required tuning direction, after which the adjustment to the device This will occur in the direction of decreasing the frequency offset. -1 il.

The invention relates to radio engineering and can be used in wideband communication systems, frequency synthesizers, measuring complexes, including in the UHF band,

The aim of the invention is to eliminate spurious grips in the event of the loss of an intermediate frequency signal,

The drawing shows a structural electrical circuit device,

.The device contains adjustable oscillator 1, mixer 2, intermediate frequency amplifier UPCH 3, first divider 4 frequencies, pulse frequency detector ICD 5, reversible counter 6, converter code - voltage PKN 7, reference oscillator 8, second divider 9 frequencies , phase detector 10, switch 11, pulse generator 12, amplitude detector 13, frequency multiplier 14, voltage accumulator 15, voltage controlled oscillator 16.

The device works as follows.

In synchronous operation mode, the output frequency of the adjustable oscillator 1 fj, for example, is equal to

f, (M + O fg,

where M is the multiplication factor of the frequency multiplier 14; . f is the frequency of the reference generator 8

In this case, the frequencies at the output of the first 4 and second 9 dividers are equal (their division factors are equal) and there is no signal at the output of the difference frequency ICHD 5. The IFC 3 output has an intermediate frequency signal, and therefore the amplitude detector 13 outputs a high-level output signal to the counting input of the reversing counter 6 and a differential frequency output of the IChD 5, the contents of the reversing counter 6 do not change, the control voltage at the PCH output does not change either 7, input to the coarse frequency control input of the voltage controlled oscillator 1. The oscillator of the frequency is automatically controlled by the PLL from the output of the phase detector 10.

When the multiplication factor M is changed in the frequency multiplier 14 (the value of M can be not only integer, but also fractional multiples), frequency detuning appears in the device, and if there is a signal at the output of the PCCH 3, this detuning decreases due to ICT 5 , ICHD 5 determines the sign of the frequency detuning, t, e, the direction of tuning, and at its output of the difference frequency there appear pulses, the repetition period of which corresponds to the frequency difference between the signals compared in ICHD 5. Under the action of the pulses from the output difference The ICP 5 starts to fill the reversing counter 6, because if there is an output of the PFC 3, these pulses through the switch 11 arrive at the counting input of the reversing counter 6, The signal level, in this case, at the output of the amplitude detector 13 is still high. At the UPCH 3 output, tuning to the frequency of the mirror noise in principle is not possible due to the operation of ICHD 5,

However, with a limited UAC 3 bandwidth and a wide tuning band of the adjustable oscillator 1, the intermediate frequency signal from the output of mixer 2 may not fall into the UAC bandwidth. As soon as this happens, the voltage level at the input will sharply decrease and, therefore, at the output of the amplitude detector 13, and a generator 12 will be connected to the counting input of the reversible counter 6, which, in accordance with the information about the sign of the frequency error at the output of the DLI tuning direction 5 will change the contents of the reversing counter 6 in the direction of decreasing frequency detuning before establishing a synchronous mode of operation.

In a number of cases, when there is no signal at the output of the OOFC 3, the RTCHD 5 may not store reliable information about the sign of the frequency error, then, due to the generator 12 and the ICHD 5, the CU-three of the adjustable generator 1 can be produced in the direction of increasing the frequency error. However, such an adjustment will continue only until the intermediate frequency signal appears at the UCHP 3 output. As soon as such a signal occurs, the required restructuring direction (the sign of the frequency error) will be determined in ICHD 5, after which the device will be adjusted in the direction of 3 less frequency detuning. In the future, in the course of adjustment, the disappearance of the signal from the UPCH 3 output does not affect the direction of tuning of the reversible counter 6. By memorizing the sign of the frequency error in ICHD 5, it will always occur in the right direction. Therefore, in these cases, the possibility of capturing at the frequency of the mirror noise is also excluded.

Claims (1)

Invention Formula Generator synchronization device: a motor containing a sequentially adjustable oscillator, a mixer, an intermediate frequency amplifier, the first divider and a pulse frequency detector, a counter and a converter code - voltage, the output of which is connected to the coarse frequency input of the adjustable oscillator, connected in series the reference oscillator and the second frequency divider, the output of which is connected to the second input of the pulse frequency detector, as well as a phase detector, the output of which is connected to the input to fine-tune the frequency of the adjustable oscillator, which is different from the fact that, in order to eliminate spurious captures when the intermediate frequency signal disappears, a switch, a pulse generator, an amplitude detector and a frequency multiplier are introduced into it, while the pulse frequency detector is made with a differential output frequency and the output of the tuning direction, the counter is made reversible, the switch is turned on between the output of the difference frequency of the pulse frequency detector and the counting input of the reversible counter, amplitudes The detector is connected between the output of the intermediate frequency amplifier and the control input of the switch, the frequency multiplier is connected between the output of the reference generator and the second input of the mixer, the output of the pulse generator is connected to the second input of the switch, the first and second inputs of the phase detector are respectively connected to the outputs of the amplifier intermediate frequency and reference oscillator, and the input of the tuning direction of the pulse frequency detector is connected to the control input of the reversible counter.