Based On Yto Uwb Frequency Synthesis Technology Research

The ultra-wideband frequency synthesis is the core technology of micro wave testsystem, and plays a key role in the areas of communication, radar, electroniccountermeasure, etc. With the development of electronic science and technology, thefrequency range, output power, stability, and switching speed demand more and more. Itis very necessary to design a kind of frequency synthesizer with ultra-wide bandwidth,fine frequency resolution, excellent phase noise and spurs performance, fast frequencyhopping, wide dynamic and accurate power output.This paper introduced the history and present situation of wideband frequencysynthesis technology first. The scheme with DPLL and DDS were chosen andconfirmed by the calculation of output frequency range, frequency resolution, phasenoise and spurs performance, power dynamic and accurate. The YTO driver circuits andALC system were analyzed. The phase noise and out power optimization werediscussed.A500MHz~6GHz ultra-wideband frequency synthesizer has been designed andimplemented. The SSB phase noise at6GHz was-93dBc/Hz@10kHz. The spurs waslower than-50dBc. The output power dynamic was40dB. The synthesizer was dividedinto seven modules such as main-loop, DDS, YTO, frequency extension, ALC, control,and power supply. The system employed tree structure with the modular design concept,and controlled each module behaviorally by SPI bus. The synthesizer had functions askeyboard input and LCD, and also could be operated by PC with USB connection. Thissynthesizer achieved the level of experimental test instrument in the main.