SU1469536A1 - Multifrequency crystal oscillator - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to increase the spectral purity of the output signals. Hr contains an active part 1, a quartz resonator 2 and a positive feedback circuit 3, consisting of each bandpass filter 4, amplifier-limiter 5, phase detector 6, low-pass filter 7 and adjustable g-8. The frequency of the tuned lasers 8 is stabilized by the frequencies of the series resonance of the quartz resonator 2. The independence of the tuned lasers 8 and their correct voltages, as well as the linearity of the active part 1 and the linear operation mode of the quartz resonator 2 allow multi-frequency quartz g-spectral-pure oscillations. -1 il. S cl

Description

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The invention relates to radio engineering and can be used as a source of reference frequencies.

The purpose of the invention is to increase the spectral purity of the output signals.

The drawing shows a structural electrical circuit of a multi-frequency quartz oscillator.

A multi-frequency crystal oscillator contains an active part 1, a crystal oscillator 2, and a positive feedback circuit 3. Circuit 3 includes a band-pass filter 4, a limiting amplifier 5, a phase detector 6, a low-pass filter 7, a tunable oscillator 8.

Multi-frequency quartz generator works as follows.

At the moment of its switching on, an increase (coasting) of frequencies f, ... f ,, of adjustable generators 8 occurs in each circuit 3. At the same time, due to the natural increase of frequencies, ... (, in adjustable generators 8, frequencies coincide with frequencies fiu- -fhV series resonance of the quartz resonator 2. At the output of the quartz resonator 2, a signal appears that is fed through a band-pass filter 4 of each of the circuits 3 and the limiting amplifier 5 to the first input of the phase detector 6, and to the second input - from output adjustable oscillator 8. So m, at the output of the phase detectors 6 of each of the circuits 3, when the frequencies f, ... .f and f, ... .f 1 coincide, control voltages are formed for the adjustable oscillators 8. Thus, when the frequencies f1. .fh are gone, the adjustable oscillators 8 from the frequencies fv, .. .f i. Of the series resonance of the quartz resonator 2, there occurs a corresponding change in the phases of the signals at the output of the quartz resonator 2. A change in the phase difference of the signals at the input of the phase detectors 6 causes a change in the control voltages of the adjustable oscillators 8. control changes The frequency adjusts the frequencies of the adjustable oscillators 8 to match the frequencies f, ..., f ((. Thus, the stabilization (synchronization) of the frequencies ... of adjustable oscillators 8 with the frequencies f, ... fn of the series resonance of the quartz resonator 2,

The output signals from the adjustable oscillators 8 are fed to the corresponding inputs of the active part 1, which in the multi-frequency quartz oscillator serves as an adder. The control voltages at the output of the filters 7 synchronize the respective adjustable oscillators 8, while at the same time stabilizing the frequencies. Since the frequency deviation of the tunable oscillator 8 from the frequency f, the successive resonance of the quartz resonator 2 causes a change in the phase Lf. which is equal to

Cf, () M, g (+) + -3, (+),

where L (, () is the phase increment of the frequency f when the frequency of the frequency f goes away from the frequency f 1 of the series resonance of the quartz resonator 2. The change (f leads to a change in U ,,,. Impact and ,,, on the tunable oscillator 8 causes such changing the frequency f of the tunable oscillator 8, at which the frequency f does not become equal to the frequency f of the series resonance of the quartz resonator 2. Thus, the frequency of the tunable oscillator 8 is stabilized by the quartz resonator 2. Similar frequency stabilization occurs in other stages nx 3 multi-frequency crystal oscillator. The independence of adjustable oscillators 8, control voltages. Uy, linearity of the active part 1, linear operation of the crystal quartz resonator 2 allows to obtain at the output of the multi-frequency crystal oscillator pure spectral oscillations.

Claims (1)

Invention Formula A multi-frequency quartz oscillator containing a series-connected active part and a quartz resonator, n positive feedback circuits, each of which is connected between the second output of the quartz resonator and the corresponding positive input n of the n inputs, while each of the positive feedback n circuits contains a band-pass filter, whose input is the input of a positive feedback circuit, and an amplifier-limiting device, characterized in that, in order to increase the spectral purity, -period signals, Each of the n positive-low-frequency circuits and a geostrate is introduced into the serial link, the output of which is connected to the connected phase detector, the first to the second input of the phase detector and the output of which is connected to the output of the positive output of the circuit do amplifier-limiting, filtering communication.