Design of a common-base Colpitts switched injection-locked oscillator at 2.45 GHz for a FMCW radar system

In this publication, a fully integrated active backscatter transponder for the positioning and fast rescue of passengers from sea in case of a ship sinking emergency is presented. The active reflector tag is applied in a frequency modulated continuous wave (FMCW) radar and to the authors knowledge is for the first time ever reported based on a Colpitts oscillator topology in common-base configuration. The circuit is operated as a switched injection-locked oscillator (SILO). Furthermore, measurements regarding a self-locking phenomenon to the modulation signal are carried out. The presented backscatter tag operates at 2.45 GHz and reaches a steady-state output power of 12.3 dBm for on PCB measurements.