The weasic WEA14S is a complete 24 bits Fractional-N low power microwave synthesizer able to synthesize frequencies from 12 GHz to 14 GHz with the integrated VCO or from 8 GHz to 16 GHz with an external VCO. It consists of a low noise phase detector with lock detect indication, a programmable charge pump, a programmable bandwidth loop filter, a multi modulus prescaler, and a 64 band VCO with auto-calibration circuitry. Implemented in a 45nm CMOS SOI GlobalFoundries process, the WEA14S occupies a silicon area of 3.4 mm2. It exhibits high performance, high integration and flexibility targeting cutting edge applications operating in multi-GHz frequencies.