Battery-less ASK/O-QPSK transmitter for medical implants

A battery-less ASK/O-QPSK transmitter is presented using 0.18 mu m CMOS technology for medical implants. The 432 MHz transmitter uses an identical signal source of 54 MHz for injection-locked frequency synthesis and RF powering to accomplish battery-less operation. The transmitter exhibits an output power of 215.1 dBm. The phase noises of -112.6 and -116.1 dBc/Hz are achieved at offsets of 100 and 1 MHz from 432 MHz, respectively. The maximum data rates are 50 kbit/s and 2.5 Mbit/s for ASK and O-QPSK modulation schemes, respectively.