Design And Analysis Of Frequency Synthesizer For Multiband Radio

There is an obvious trend in recent years in the tactical radios is that it develops from the single-band and single-mission to the multi-band and multi-mission. Widen existing bands and develop multi-band is convenient for communication in harmony and campaign in all band, also it improve communications in equipments' flexibility in campaign. As the core of a radio, frequency synthesizer's capability has the crucial effect on the whole radio. Therefore, the design of multi-band frequency synthesizer is very important in the whole design of multi-band radio.This paper introduces multi-band radio's situation and the developing trend internationally, and frequency synthesizer's major function target; discusses and compares the most frequently used frequency synthesizers' good-comings and short-comings; designs exactly different synthesize and circuit for different bands.The main work and innovations of this paper are presented as follows: presents frequency synthesizers' function target for 1.6～108MHz multi-band radio of XXX factory; lays out a practical scheme based on frequency synthesizers' target; combines software and hardware to realize multi-band synthesizer, also explains designs detailedly for loop filter,low pass filter,switch logic circuit and VCO in the circuit; tests settling time,phase noise,spurs,frequency error and amplitude for synthesizer,and offers the correlative data and graph.