The WEA615S55S is a wide band fractional – N frequency synthesizer with on Chip doubler implemented in ST BiCMOS55 process. It uses a 100 MHz to 250 MHz Crystal Input and generates a 5.72 GHz to 15.04 GHz frequency range with the integrated VCOs utilizing a 64 band auto-calibration system. It consists of a an Xtal oscillator, a frequency doubler, a Charge Pump, a low noise phase detector with lock detect indication, 5 bank of VCO, a Prescaler and a 16 to 24 bit MASH 1-1-1. The synthesizer is powered by a 1.2 V and 2.5 V supplies.