SU728091A1 - Qartz resonator parameter heter - Google Patents

Description

one

The invention relates to a radio-measuring technique and can be used in the development and production of quartz resonators.

A device is known comprising an electronically controlled oscillator, a quadrupole, an amcit detector, a threshold device, a trigger and an indicator 1.

The device provides a measurement of the frequency of the extremum of the dynamic branch of the quartz resonator. The frequency of the extremum is less preferable in terms of metrology. In addition, there is little speed of the measuring device, limited by the time constant of the quartz resistor,

The closest technical solution to the invention is a quartz resonator 2 parameter meter containing a cascade-coupled electronic control generator, a four-point array with a measured quartz resonator, an amplitude detector, a low-frequency amplifier, a phase detector and an integrator whose output is connected to the frequency control input generator "In addition, the device includes a low-frequency generator, one output of which is connected to the input of the generator frequency control, and the other to the second input of the phase the detector. The device is based on frequency modulation of the oscillator frequency, its conversion on a quartz resonator into amplitude modulation

0 and the phase indication of the amplitude-modulated signal envelope.

A disadvantage of the known quartz resonator parameter meter is insufficient

5, due to the fact that the circuit provides a measure of the partial frequency of the extremum of the modulus of the impedance of the dynamic branch, while it is necessary to measure the resonant frequency of the dynamic branch, i.e. the frequency at which the impedance of the dynamic branch has zero phase. There is a significant difference between these characteristic 4acTOTauvm (at a clock of about 100 M1c), which determines the measurement error. With an asymmetric modulus curve of the dynamic branch, the measurement result depends on the devi0 value.

Frequencies, which adds an additional norpaiiHocTb s- “5v .-- -“ ° --V In addition, the iOe device is known to have a small 6% loss and stability of the automatic frequency control system. This is due to the fact that the period must be 1Brls ;; the duration of the time of a measurable quartz rebirth, because of which the frequency of the modulated signal cannot exceed 100 Hz. reduces & action and the ability to work out interference. As a rule, such devices for resonators with high Q

 have parasitic excitation at a frequency several times lower than the modulation frequency, as a result of which

; The first automatic frequency tuning system maintains the average frequency of the gönöragor aside from the extremum, which causes additional iibripeiiiHocTb measurements. According to this scheme, the bottom is limited to about 10 MHz.

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

The goal is achieved by the fact that, in the quartz resonator parameter meter, a series-connected electronically controlled harmonic signal generator, a p {5xp1silusnik with a й imM quartz resonator, an amplitude detector, a low-frequency amplifier, a phase detector whose output is connected with the input of the frequency control of the electronically controlled refireiprsfOpa of harmonic signals, as well as moduli, the generator of rectangular signals, the output of which is connected to the input of the phase 3ietek 8jpW7 S% 64IOK electronic Controls of the control panel are equipped with four quadruple plugs, the input of which is connected to the second output of the modulating oscillator and the output to the second input

quadrupole. ;

 The drawing is represented structurally: a circuit for measuring the parameters of quartz resonators containing an electronically controlled oscillator. 1 harmonic signals, signal; 7; 2 of them; Ibstush; e of the GChneta1 Result; Yatnik 2 with the EMERM quartz resonator. From the output of the quadrupole The signal arrives in a cascade-connected amplitude detector 3, a low-frequency amplifier 4 and a phase Sefiiftop 5. At the second input of the phase detector, it acquires a modulating oscillator; signals. With friend-rto; b bda this generator signal is fed to the input of the electronic control unit 7 of the reactive element of the cell 728091

the pole The output of the phase detector through the integrator 8 is connected to the clock control input of a electronically controlled harmonic signal generator.

The device works as follows. . ,,., .. - The input of a quadrupole 2, such as a bridge, receives a signal with a frequency slightly lower than the frequency of the quartz resonator, at which its impedance is the static capacitance of the quartz resonator. The modulating oscillator пр of pr uogral signals receives a signal that changes the reactance of one of the bridge’s shoulders by a certain amount. By balancing the bridge, one can achieve such a position where the voltage at the output of the quadrupole is the same for both half-periods of the modulating oscillator signal. This position corresponds to the state of balance of the bridge. After this frequency tuning of the controlled oscillator of harmonic signals, a part is introduced, and in the resonance curve of the quartz resonator.

If the impedance of the quartz resonator is negative at this frequency, the signal frequency is less than the resonance frequency of the quartz resonator, an increase in reactivity in one of the half-periods leads to an increase in the output level of the bridge compared to the other half-period. If the impedance of the quartz resonator is Positive, that is, the signal frequency is greater than the resonant frequency of the quartz resonator, then the increase in the output level of the bridge compared to the second half-period is due to a decrease in reactivity.

Thus, depending on the sorting frequency of the signal and the resonance frequency of the measured quartz resonator, the phase of the output signal envelope changes. This signal is then fed to a low-frequency amplifier and then to a phase detector, where a direct-current signal is generated with polarity, with a sort of oscillator frequency tuning towards the resonant frequency of the quartz resonator.

Claims (2)

1. Author's certificate of the USSR. № 460510, cl. G 01 P 23/00, 2.VV.V.St.ckeana.Technignee of the the rneaeurment of the COLO-in rogaple Vlarconl ev, etru ", oiV.on,