Design And Realization Of Wideband High-speed Hopping Frequency Synthesizer

This thesis mainly studies the frequency synthesizer of XX VHF transceiver. The main technical specifications of frequency synthesizer include:band, bandwidth, conversion time, stability, phase noise, strays, dimensions, cost, etc. There are two requirements to the frequency synthesizer of VHF hopping transceiver, one is the well phase noise, the other is the quick frequency switching to shorten the frequency switch time of channel in the process of high rate hopping and improve the data transmission rate.This frequency synthesizer adopts the combined scheme of inserting PLL into DDS to realize the performances of high frequency resolution, quick switching rate and wide output frequency and adopts quick frequency presetting and bandwidth transform technology to realize the quick frequency switching. The phase noises of the main devices are also strictly designed and controlled to meet the requirements for phase noise of the complete transceiver. DDS adopts the high speed device AD9951and PLL adopts chips ADF4113and ADF4193. In addition, the low noise VCO is adopted, ADIsim PLL simulated software is applied and various quick lock measures are used to meet the requirements for conversion time of the complete transceiver. After the test, specifications of the frequency synthesizer fully meet the requirements for the complete transceiver.Due to the short time of development, the distribution of PCB, selection of devices, producibility and manufacturability should be further improved.