SU859958A2 - Quartz resonator parameter measuring device - Google Patents

Description

(54) DEVICE FOR MEASUREMENT

PARAMETERS OF QUARTZ RESONATORS

The invention relates to a radio measuring technique and can be used to measure the parameters of quartz crystals. According to the main author. St. No. 437979 discloses a device for measuring parameters of quartz resonators, comprising a high frequency generator, a low frequency modulation generator, a measuring quadrupole, an automatic frequency tuning unit for a high frequency generator consisting of a high frequency amplifier, a high frequency detector, a phase detector, an integrator and an automatic depth setting unit. deviation consisting of a selective amplifier, a low-frequency detector, an electronically controlled attenuator Щ. The disadvantage of this arrangement It comprises the CTBA in measurement accuracy depending on the nominal frequency on ratios hour period to period svilirovani reference frequency, as well as resistance loss and Q of quartz rezoyatorov. The purpose of the invention is to improve the accuracy of frequency measurement while expanding the range of the modified loss resistance and the quality factor of quartz resonators. This goal is achieved in that a device comprising a high frequency generator, a modulation low frequency generator, an automatic frequency tuning unit of a high frequency generator consisting of high frequency amplifiers, a high frequency detector, a phase detector, an integrator and a block; An automatic tuning of the deviation depth, consisting of a selective amplifier, a low frequency detector and an electronically controlled attenuator, was additionally introduced a frequency divider whose input is connected to the output of the frequency meter, and the output to the synchronization input of the low frequency modulation generator, and a high frequency phase detector whose saddle input is connected to the output of a high-frequency generator, a signal input from the output of a high-frequency amplifier, and an output connected to the input of a selective low-frequency amplifier and a signal input of a low-frequency phase detector.

The drawing shows a block diagram of the proposed embgs device.

The device contains a high-frequency gene {Itor 1, a measuring quadrupole 2 with the quartz resonator under study. With quadripole. 2, the signal is fed to an automatic frequency control unit, consisting of a series-connected high-frequency amplifier 3, a high-frequency phase detector 4, a low-speed phase detector 5 and an integrator 6, to the output of the high-frequency phase detector 4 a circuit for automatically adjusting the deviation depth consisting of series-connected selective frequency amplifier 7, frequency detector 8 low frequency, electronically controlled attenuator 9, which also contains a low-frequency modulation generator 10 toty, frequency meter 11, divider 12 frequency.

The device works as follows.

In the vicinity of the excitation frequency of the quartz resonator, an even1.150 pole Ts1k2 with a quartz resonator represents a phase-shifting circuit with a large slope of the frequency – frequency characteristic. When passing through such a quadrupole, the frequency-modulated high-frequency signal has a delay relative to the input signal, which varies in accordance with the modulating signal and phase-response characteristic of the quadrupole 2. The output of the high-frequency phase detector 4- separates the signal of the modulating frequency, the amplitude and phase of which characterize the properties. four hpus The frequency of the first harmonic of the modulating signal and the maximum amplitude of the second are observed at the frequency of the consecutive resoisis. Phase detector 5 is tuned to the first harmonic of the envelope, so that the automatic frequency control unit holds the oscillator of the high-frequency generator 1 near the frequency of the series resonance of the quartz resonator. The selective amplifier 7 is tuned to the second harmonic of the envelope and, through the low-frequency detector 8, controls the attenuator 9, which is used to automatically adjust the amplitude of 5,99584

d) modulating voltage depending on the quality factor and loss resistance of the quartz resonator. When selecting the gain of the selective amplifier and the range

5, the attenuator adjustments 9 take into account the dynamic range of the parameters of the quartz resonators under investigation.

Due to the fact that the frequency of the modeling low-frequency generator 10 is synchronized with the reference frequency of frequency meter 11, the start and end time of the counting coincides with an integer period of the modulating frequency, frequency meter 11 shows the average frequency, which increases the repeatability and accuracy of measurements. The high-frequency phase detector 4 is more protected from amplitude noise compared to the amplitude detector, has a shorter delay time and a higher conversion coefficient, which allows measuring 20 wider loss resistance range and Q-factor of the resonators.

Claims (1)

Invention Formula A device for measuring the parameters of quartz resonators auth. St. N ° 437979, differing from the fact that, in order to improve the frequency measurement accuracy with the frequency range of the resistance, loss and quality factor of quartz resonators, a frequency divider is added to it, the input of which is connected to the output of the frequency meter, and the output to the synchronization input of the module low frequency generator, and a high frequency phase detector, the reference input of which is connected to the output of the high frequency generator, the signal input is connected to the output of the high frequency amplifier, and the output is connected to the input selectively a low frequency amplifier and a low-frequency signal input of the phase detector. , Sources of information taken into account during the examination 1. USSR author's certificate D 437979 ,. cl. G 01 R 27/00, 1971.