Phase-locked loop based frequency synthesizer with chirp generation for FMCW secondary radar systems

In this paper a novel synthesizer has been shown which is optimized for secondary radar systems. It is based on a fractional-N phase-locked loop. Additional circuitry is necessary to generate the frequency ramp and minimize the associated spurs. The synthesizer has been implemented in a 0.18um SiGe BiCMOS process. Measurement results showed its suitability for high performance local positioning systems.