SU1401550A1 - Variable quartz oscillator - Google Patents

Abstract

This invention relates to a nickname. The purpose of the invention is to radio-techentiation of the level of phase fluctuations of the output signal while extending the interval of workers tp. Hr contains transistors (T) 1 and 2, U-shaped LC-circuit 3, condensate 4. Quartz resonator 5, inductance 6 katun1ki and 9, el-7 frequency control, resistors (P) 8, 12 and 13, the RC filter 10 parallel to RC Tset 11, choke 14. Circuit 3 is tuned to the frequency of one of the higher harmonics of the resonator 5. Buffer level is realized on T 2, the gain of the generated signal is attenuated, and the load is attenuated by grs mode P 13 serves to attenuate the effect of the output on the dynamic. R.I.T.P1 mode. P12 is the buffer load .1I. In addition, P 12 together with P 8 and P value 11 provides deep otg. direct current feedback T i and 2, which results in high stability of their modes. 1 il. Qfn SS cl Cv / move 4 ate about

Description

The invention relates to radio engineering and can be used in low noise sources of electrical oscillations.

The purpose of the invention is to reduce the level of phase fluctuations of the output signal while expanding the range of operating temperatures.

The drawing shows a structural electrical circuit of a controlled quartz oscillator.

The controlled crystal oscillator contains the first transistor 1, the second transistor 2, the U-shaped LC circuit 3, the capacitor 4, the crystal resonator 5, the first inductor 6, the frequency control element 7, the first resistor 8, the second inductor 9, RC filter 10, a parallel RC circuit 11, a second resistor 12, a third resistor 13, a choke 14.

The controlled quartz oscillator operates as follows.

The control voltage supplied to the control input of the element 7 through the RC filter 10 changes, within the tuning band, the frequency of the series resonance of the resonant system formed by the quartz resonator 5, the first 6 and the second 9 coils and the element m 7 which is at serial resonance has a minimum active resistance. The P-shaped LC circuit 3 is tuned to the frequency of one of the highest harmonics of the 1 CRC of the crystal resonator 5. The voltage allocated by the U-shaped LC circuit 3 is fed through the capacitor 4 to the base of the first ranzistora 1. The second transistor 2 is implemented buffer amplifier providing amplification of the signal generated and weakening the effect of the load on the controlled crystal oscillator mode. The third resistor 13 serves to attenuate the effect of the output signal on the dynamic mode of operation of the first transistor 1. The second resistor 12 is the load of the buffer amplifier made on the second transistor 2. In addition, the second resistor 12 is combined with the first resistor 8 and the parallel RC resistor 11 provides deep negative feedback of the first 1 and second 2 transistors on the direct current, thus achieving high stability of their modes.

When increasing (decreasing) the collector current of the first transistor 1, caused by a temperature change or supply voltage, the voltage drop across the first resistor 8 applied to the base of the second transistor 2 increases (decreases). The voltage increase (decrease) at the base of the second transistor 2 leads - leads to an increase (decrease) of the collector current of the second transistor 2, which in

the turn entails an increase (decrease) in the voltage across the second resistor 12 and the resistor of the parallel RC circuit 11 and a decrease (increase) in the voltages applied to the bases of the first 1 and second 2 transistors and, as a result, decrease (increase) collector currents of the first i and the second 2 transistors.

Claims (1)

Invention Formula five A controlled crystal oscillator containing the first transistor, between the collector and base of which are connected in series U-shaped LC circuit and capacitor, in series connected crystal oscillator, the first inductor and the frequency control element connected between the emitter of the first transistor and the common bus , the second transistor, the emitter of which Q through a parallel RC circuit is connected to the common bus, the first resistor, which is switched between the emitter of the first transistor and the common bus, the second inductance, which is connected parallel to the quartz resonator, RC filter, output 5 which is connected to a control m input of a frequency control element, and whose input is a control signal input, characterized in that, in order to reduce the level of phase fluctuations of the output signal when the interval is extended 0 operating temperatures, a second resistor is inserted, which is connected between the supply bus and the collector of the second transistor, a third resistor, which is connected between the base of the first transistor and the collector of the second A transistor, a choke, which is connected between the power line and the collector of the first transistor, while the base of the second transistor is connected to the emitter of the first transistor.