Design & Implementation of High Switching & Low Phase Noise Frequency Synthesizer

Abstract

This research describes the design & implementation of frequency synthesizer using single loop Phase lock loop with the following specifications: Frequency range (1.5 – 2.75) GHz,Step size (1 MHz), Switching time 36.4 µs, & phase noise @10 kHz = -92dBc & spurious -100 dBc
The development in I.C. technology provide the simplicity in the design of frequency synthesizer because it implements the phase frequency detector(PFD) , prescalar & reference divider in single chip. Therefore our system consists of a single chip contains (low phase noise PFD, charge pump, prescalar & reference divider), voltage controlled oscillator , loop filter & reference oscillator. The single chip is used to provide the following properties :
•Low power consumptionSmall size, light weight.Flexibility in selecting crystal oscillator frequencies to fit into the system frequency planning.
•High reliability.The application of this synthesizer in frequency hopping systems, satellite communications & radar because it has high switching speed ,low phase noise & low spurious level.