Study Of Microwave Multiband Of High Quality Local Oscillator

With the advent of the era of intelligent communication, no matter in nationaldefense construction or today’s civil communication equipment developmentconstruction, frequency source in each system acts as an important position now, withthe gradual improvement of the communication requirements of frequency sourcerequirements from the low phase noise low spurious has developed to the high qualityrequest, miniaturization, low power consumption, high purity and indicators into thefrequency source design index, based on these new index as the background, this paperputs forward two S-band point frequency source development, two X-band sweepfrequency source development and a Ku-band point frequency source design. S-bandpoint frequency source still use classic ADF4106phase detector, X-band sweepfrequency source and Ku-band point frequency source used recently launchedHMC704LP4E fusion decimal frequency division and integer frequency division of thephase discriminator.This paper first introduced the concept of the frequency synthesizer, basiccharacteristics, introduces the use of the plan behind several basic synthetic way andanalyzes their principle and compare their advantages and disadvantages. Simpleintroduced at home and abroad in recent years, the development of dynamic.Combined with the introduction of theoretical knowledge, of several frequencysynthesizer are put forward at least two kinds of implementation scheme, and solutionof various frequency source from the phase noise, spurious, as well as one by one on thecontrast, and then selected the optimal solution, and CAD layout on the PCB layoutdrawing and cavity of the cavity design. Later in the circuit debugging, in order tosimplify the debugging, using VB language to write the control window procedure isconcise and easy to operate, saves time for late circuit debugging.The final test results can be concluded that the vibration source index to the basicsubject index requirements. S-band the vibration source phase noise is better than-100dBc/Hz@10KHz, And the final circuit dimension is33×22×7mm~3, meet theminiaturization requirement. The phase noise of X-band local oscillator module is better than-98dBc/Hz@10KHz, Phase leakage rejection ratio is more than70dBc The circuitdimension is40×35×7mm~3. A17.5GHz low phase noise, low spurs and single carrierfrequency source using the HMC704LP4E. The test results show that the phase noise ofoutput signal is-98dBc/Hz@1kHz,-105.2dBc/Hz@10kHz and-108.5dBc/Hz@100kHz; Phase leakage rejection ratio is more than82dBc and the harmonic rejectionratio is more than67dBc. The circuit dimension is80×75×22mm~3.