Ultra low power RF transceiver architecture for in-body communication system

This paper presents a ultra low power RF transceiver architecture for 402-405 MHz medical implant communication system. The differential complementary colpitts super-regenerative oscillator is used in this architecture to achieve low phase noise, high gain and linearity at low power consumption. The external PCB loop antenna is incorporated into the oscillator. This provides a high Q-factor inductive element to achieve high sensitivity and selectivity. The oscillator transmits RF signals in switched OOK mode and receives in super-regenerative mode. The DSSS super-regenerative mode is proposed for multi-user environment. The design concept is simulated in 0.18 um CMOS technology. The exchange rate upto 120 kbps is achieved for detecting -95d Bm signals with the power consumption of 400 uW.