A new implementation of S-band TT&C transponder for micro-satellites

A new type of TTC(Tracking, Telemetry and control) transponder is designed and implemented for micro-satelllites. This transponder greatly simplifies the structure ,ruduces the weight and needs less power after updating the traditional transponder. This structure can avoid the error-lock and uses charge-pumps PLL for frequency synthesizer. The entire transponder with the power less than 1 watt including receiver and transmitter has achieved on a 9cm×9cm PCB. After testing ,the transponder works well and meet the requirements of satellites with the weight less than 10kg and orbit less than 1000km.