The Frequency Synthesizer Module is a Low Temperature Co-fired Ceramic (LTCC) RF module consisting of a high performance frequency synthesizer, loop filter, and voltage controlled oscillator (VCO). The frequency synthesizer is fabricated using National's ABiC BiCMOS process (fT = 14 GHz). The loop filter and VCO are fabricated on National's Low Temperature Co-fired Ceramics. The Frequency Synthesizer Module can be used for local oscillator applications. Using a digital phase locked loop technique, the on board frequency synthesizer can generate a very stable, low noise local oscillator. Serial data is transferred into the module using a three wire interface. The loop filter is designed for fast lock times and maximum attenuation of reference spurs.