Design Of Fast Frequency Hopping Synthesizers Based On PLL

In the modern radio field, frequency source is a difficulty but very advancedcommunication technology. With the continuous optimization of various precision deviceperformance indicators, performance of frequency source is also needed to be improved. PLLis the radio emission which to make the output frequency more stability. The phase-lockedloop technology is mainly the following three aspects: First, signal modulation anddemodulation. Second, signal frequency modulation and demodulation. Third, signalfrequency synthesis circuit. The frequency hopping technology is to make the frequencysource from a stable working state to another stable working state of technology.This research aims to design and complete a fast hopping frequency synthesizer based onphase locked loop. The paper first introduces the development of frequency source, and phaselocked loop of the basic application and its working principle. Then, according to the actualsituation of this subject gives the design scheme of frequency sources, Use of frequencyhopping technology combining CY7C68013and fast locking. The CY7C68013receives thefrequency hopping instruction PC, through the USB interface to the ADF4350configuration,the ADF4350loop is out of lock. And then realize the function of frequency hopping.Frequency hopping function realization, enable fast lock mode the loop locked state from theback. This paper also probes influence of each device on the phase noise of frequency source.Finally, the debugging of the frequency source, optimize various performance indicators, toreach the index requirement.Using ADF4350and the design of the two order passive low pass filter combination,according to the requirements given in scheme design and performance index, select thedevice and finished drawing the actual circuit design and the specific PCB. Finally, test theresults, make the frequency source meet the requirements.