CN203039670U

CN203039670U - 1222MHz frequency synthesis unit

Info

Publication number: CN203039670U
Application number: CN 201220718916
Authority: CN
Inventors: 王运宏
Original assignee: Tianjin 764 Communication and Navigation Technology Corp
Current assignee: Tianjin 764 Communication and Navigation Technology Corp
Priority date: 2012-12-24
Filing date: 2012-12-24
Publication date: 2013-07-03
Anticipated expiration: 2022-12-24

Abstract

The utility model relates to an 1222MHz frequency synthesis unit which is used by a local oscillator signal of a Beidou navigation anti-jamming system. The unit circuit is composed of an AVR single chip microcomputer, an integrated PLL frequency synthesizer, a binary power divider, a triple power divider I, a triple power divider II, amplifiers and a crystal oscillator circuit. The integrated PLL frequency synthesizer is respectively connected with the crystal oscillator circuit, the AVR single chip microcomputer and the binary power divider. One way of output of the binary power divider is connected with the three amplifiers through the triple power divider I. The other way of output of the binary power divider is connected with the three amplifiers through the triple power divider II. The 1222MHz frequency synthesis unit provided by the utility model is characterized in that the frequency stability is controlled at 1222MHz +/- 0.01MHz; phase noise is no more than -90dBc 10KHz; clutter suppression degree is no more than -60dBc; and the volume of the circuit is reduced more than 50%.

Description

1222MHz frequency synthesis unit

Technical field

The utility model relates to the 1222MHz frequency synthesis unit that a kind of Big Dipper navigation jamproof system local oscillation signal uses.

Background technology

Need to carry out to received signal down-conversion and upconversion process in the Big Dipper navigation jamproof system, for the 1222MHz local oscillation signal require the stability height, make an uproar low, clutter suppresses high, strict to the frequency synthesis unit volume simultaneously mutually; Existing frequency synthesizer circuit adopts discrete components and parts such as frequency divider, phase discriminator, low pass filter, VCO to combine, and stability is poor, noise jamming is more, and volume is bigger.

Summary of the invention

In view of the deficiency that prior art exists, the utility model provides a kind of 1222MHz frequency synthesis unit, and this element circuit design makes the frequency stability height, make an uproar low, clutter suppresses high mutually, and the circuit volume dwindles greatly.

The utility model for achieving the above object, the technical scheme of taking is: a kind of 1222MHz frequency synthesis unit, it is characterized in that: described frequency synthesis element circuit comprises AVR single-chip microcomputer, integrated PLL frequency synthesizer, two power splitters, three power splitter I, three power splitter II, amplifier, crystal oscillating circuit, described integrated PLL frequency synthesizer is connected with crystal oscillating circuit, AVR single-chip microcomputer, two power splitters respectively, one tunnel output of described two power splitters connects three amplifiers by three power splitter I, and another road output of two power splitters connects three amplifiers by three power splitter II.

Characteristics of the present utility model are: frequency stability is controlled at 1222MHz ± 0.01MHz, make an uproar mutually≤-90dBc@10KHz, clutter inhibition degree≤-60dBc, the circuit volume-diminished is more than 50%.

Description of drawings

Fig. 1 is that circuit of the present utility model connects block diagram.

Embodiment

As shown in Figure 1, a kind of 1222MHz frequency synthesis unit, its element circuit comprises AVR single-chip microcomputer, integrated PLL frequency synthesizer, two power splitters, three power splitter I, three power splitter II, amplifier, crystal oscillating circuit, the integrated PLL frequency synthesizer is connected with crystal oscillating circuit, AVR single-chip microcomputer, two power splitters respectively, one tunnel output of two power splitters connects three amplifiers by three power splitter I, and another road output of two power splitters connects three amplifiers by three power splitter II.

Crystal oscillating circuit: by the Voltage-Controlled Temperature Compensated Crystal Oscillator CFPT-126 of rakon company and the reference frequency 10MHz of peripheral circuit generation high stability;

Single-chip microcomputer: adopt 8 AVR single-chip microcomputers of ATTINY13A-10SSU type, write control program;

Integrated PLL frequency synthesizer: the LMX2531LQ2570E integrated chip that adopts state half, the low-power consumption of 3V power supply 41mA left and right sides electric current, complete integrated frequency divider, phase discriminator, VCO etc., low noise, high-precision low-dropout regulator LDO that while is inner integrated, the system that makes has higher noise suppressed performance and stability.When being used with reference to crystal oscillator with high-quality, can produce highly stable, low noise local oscillated signal;

Power splitter: adopt the MINI SCN-2-15 of company, SCN-3-16 Surface Mount micro module;

Amplifier: adopt the upc2709TB-3 of NEC Corporation wide-band amplifier, low in energy consumption, gain is up to 23dB, and the Surface Mount micro module dwindles the circuit volume greatly.

Use radio frequency simulation software that circuit is carried out the emulation of parameters in advance, with reference to simulation result design circuit figure and pcb board figure.

Operation principle: crystal oscillating circuit provides 10MHz reference frequency, the C programmer of being write by PC injects the AVR single-chip microcomputer, can control the PLL frequency synthesizer after powering up, change its internal storage parameter, carry out frequency division, the processing of phase demodulation frequency discrimination, control inner VCO output 1222MHz signal, again through two power splitters, three power splitter I, three power splitter II and 6 amplifiers, the final output local oscillation signal that totally 6 tunnel frequencies are identical, power equates is used for the frequency-conversion processing that other unit carry out Big Dipper satellite signal.

Claims

1. 1222MHz frequency synthesis unit, it is characterized in that: described frequency synthesis element circuit comprises AVR single-chip microcomputer, integrated PLL frequency synthesizer, two power splitters, three power splitter I, three power splitter II, amplifier, crystal oscillating circuit, described integrated PLL frequency synthesizer is connected with crystal oscillating circuit, AVR single-chip microcomputer, two power splitters respectively, one tunnel output of described two power splitters connects three amplifiers by three power splitter I, and another road output of two power splitters connects three amplifiers by three power splitter II.