CN202713231U

CN202713231U - high frequency low phase noise constant temperature crystal oscillation circuit

Info

Publication number: CN202713231U
Application number: CN 201220319559
Authority: CN
Inventors: 梁远勇; 冯培培; 曹海燕
Original assignee: JUST MING ELECTRONIC TECHNOLOGY (SHANGHAI) Co Ltd
Current assignee: Justiming Electronic Technology Shanghai Co ltd
Priority date: 2012-07-04
Filing date: 2012-07-04
Publication date: 2013-01-30
Anticipated expiration: 2022-07-04

Abstract

The utility model relates to a high frequency low phase noise constant temperature crystal oscillation circuit, relates to the technical field of a crystal oscillator and solves technical problems of oscillation starting difficulty and high phase noise existing in the current circuit. The high frequency low phase noise constant temperature crystal oscillation circuit comprises a crystal resonator, a low phase noise triode and an output capacitor, wherein one end of the crystal resonator is connected with a base electrode of the low phase noise triode, the other end of the crystal resonator is connected with externally inputted voltage-controlled voltage and is in grounded connection through a varactor, one end of the output capacitor is connected with a collector electrode of the low phase noise triode, and the other end of the output capacitor forms an output end of the oscillation circuit. The high frequency low phase noise constant temperature crystal oscillation circuit is characterized by further comprising an auxiliary inductor which is connected in parallel with the crystal resonator; an emission electrode of the low phase noise triode is connected with the base electrode of the low phase noise triode through an adjusting capacitor, is in grounded connection through another adjusting capacitor and is in grounded connection through an adjusting inductor and an adjusting resistor in order. The high frequency low phase noise constant temperature crystal oscillation circuit is applicable to a small-volume constant temperature crystal oscillator.

Description

The low constant temperature crystal oscillating circuit of making an uproar mutually of high frequency points

Technical field

The utility model relates to the crystal oscillator technology, particularly relates to the technology of the low constant temperature crystal oscillating circuit of making an uproar mutually of a kind of high frequency points.

Background technology

The high frequency points constant-temperature crystal oscillator is a crucial frequency radix parts in radar communication, measurement field of test instrument, its low phase noise and small size also are the prospects of the market demand, and the equiva lent impedance (ESR) of crystal causes greatly oscillator starting of oscillation difficulty, failure of oscillation but the high frequency points constant-temperature crystal oscillator tends to.

As shown in Figure 2, can consume certain power during traditional crystal oscillation circuit active load, thereby can cause the Q value of crystal resonator Y11 to reduce, so that the stability decreases of crystal resonator Y11, affected by peripheral active block, play pendulum, depressed phenomenon when shaking when occurring, phase noise also has been subject to impact.Take the high-frequency constant temperature crystal oscillator of the 100MHz frequency that adopts traditional oscillator circuit as example, its crystal resonator starting of oscillation difficulty, the noise objective consistency is poor, and be unfavorable for volume production, when output frequency was 1KHz, the phase noise index was generally at-135dBc/Hz, when output frequency is 10KHz, generally at-145dBc/Hz, when output frequency was 100KHz, the phase noise index can reach-150dBc/Hz the phase noise index.

The utility model content

For the defective that exists in the above-mentioned prior art, technical problem to be solved in the utility model provides a kind of easy starting of oscillation, and the low low constant temperature crystal oscillating circuit of making an uproar mutually of high frequency points of phase noise.

In order to solve the problems of the technologies described above, the low constant temperature crystal oscillating circuit of making an uproar mutually of a kind of high frequency points provided by the utility model comprises crystal resonator, low make an uproar mutually triode, output capacitance;

One of described crystal resonator terminates to the base stage of the low triode of making an uproar mutually, the voltage-controlled voltage of the outside input of another termination, and receive ground through a varactor;

The base stage of the described low triode of making an uproar is mutually received ground through a biasing resistor, and connects the supply power voltage of outside input through another biasing resistor, and the collector electrode of the low triode of making an uproar is mutually received the supply power voltage of outside input through a load resistance;

The collector electrode of the low triode of making an uproar mutually of one termination of described output capacitance, the other end consists of output end of oscillating circuit;

It is characterized in that: also comprise an auxiliary induction, described auxiliary induction is in parallel with crystal resonator;

The emitter of the described low triode of making an uproar is mutually received the base stage of the low triode of making an uproar mutually through a control capacittance, receive ground through another control capacittance, and receives ground through an adjusting inductance, a regulating resistance successively.

The low constant temperature crystal oscillating circuit of making an uproar mutually of the high frequency points that the utility model provides, auxiliary induction in parallel between the crystal resonator bipod, eliminated the direct capacitance C0 value of crystal resonator inside from the outside, so that the internal impedance of crystal resonator is compared the conventional crystal oscillating circuit is less, be more prone to starting of oscillation, and by regulating inductance, regulating resistance and two control capacittances can improve the multiplication factor of mutual conductance and the electric current of the low triode Q1 that makes an uproar mutually, make the easier starting of oscillation of circuit, and the Q value of crystal resonator is not a greater impact, noise has also obtained optimization, the noise objective consistency is better, can reach about 95%, is conducive to a large amount of productions.

Description of drawings

Fig. 1 is the circuit diagram of the low constant temperature crystal oscillating circuit of making an uproar mutually of high frequency points of the utility model embodiment;

Fig. 2 is the circuit diagram of traditional crystal oscillation circuit.

Embodiment

Below in conjunction with description of drawings embodiment of the present utility model is described in further detail, but the present embodiment is not limited to the utility model, every employing analog structure of the present utility model and similar variation thereof all should be listed protection range of the present utility model in.

As shown in Figure 1, the low constant temperature crystal oscillating circuit of making an uproar mutually of a kind of high frequency points that the utility model embodiment provides comprises crystal resonator Y1, low make an uproar mutually triode Q1, output capacitance C5;

The end of described crystal resonator Y1 is received the base stage of the low triode Q1 that makes an uproar mutually through a capacitor C 1, the voltage-controlled voltage VC of the outside input of another termination, and receive ground through a varactor CR1;

The base stage of the described low triode Q1 that makes an uproar is mutually received ground through a biasing resistor R2, and meeting the supply power voltage VCC supply of outside input through another biasing resistor R1, the collector electrode of the low triode Q1 that makes an uproar mutually meets the supply power voltage VCC supply of outside input through a load resistance R3;

The collector electrode of the low triode Q1 that makes an uproar mutually of the termination of described output capacitance C5, the other end consists of output end of oscillating circuit;

It is characterized in that: also comprise an auxiliary induction L2, described auxiliary induction L2 is in parallel with crystal resonator Y1;

The emitter of the described low triode Q1 that makes an uproar is mutually received the base stage of the low triode Q1 that makes an uproar mutually through a control capacittance C2, C3 receives ground through another control capacittance, and receives ground through an adjusting inductance L 1, a regulating resistance R4 successively.

Among the utility model embodiment, described crystal resonator Y1 is 5 overtone crystals of 100M AT cut type, and the model of the described low triode Q1 that makes an uproar mutually is BFR92AW, and the model of described varactor CR1 is BB202.

The operation principle of the utility model embodiment is as follows:

The voltage-controlled voltage VC of outside input is input to crystal resonator Y1, under the effect of auxiliary induction L2, eliminated the direct capacitance C0 value of crystal resonator Y1 inside from the outside, so that the internal impedance less of crystal resonator Y1, be more prone to starting of oscillation, the output of crystal resonator Y1 is exported by output capacitance C5 after low make an uproar mutually triode Q1 mutual conductance and amplification;

By the capacitance of suitable adjusting two control capacittance C2, C3, can improve the multiplication factor of mutual conductance and the electric current of the low triode Q1 that makes an uproar mutually, make the easier starting of oscillation of circuit.

The utility model embodiment is applicable to export the constant-temperature crystal oscillator of frequency in the 50-200MHz scope, can be used for the small size constant-temperature crystal oscillator, be easy to starting of oscillation, the noise objective consistency is better, can reach about 95%, be conducive to a large amount of productions, when output frequency is 1KHz, the phase noise index can reach-145dBc/Hz, when output frequency is 10KHz, the phase noise index can reach-158dBc/Hz, and when output frequency was 100KHz, the phase noise index can reach-162dBc/Hz.

Claims

1. the low constant temperature crystal oscillating circuit of making an uproar mutually of high frequency points comprises crystal resonator, low make an uproar mutually triode, output capacitance;