A 24.5pJ/bit OOK/BFSK/QPSK RF Transmitter Employing Injection Locking by MEMS-Based RF Oscillator

An OOK/BFSK/QPSK transmitter employing injection locking by microelectromechanical system (MEMS) resonator-based radio frequency (RF) oscillator is proposed in this paper. Direct OOK/BFSK modulation is implemented based on a switchable and tunable MEMS tank. A loop gain compensation circuit is used in RF oscillator to achieve 10 MHz frequency separation for BFSK modulation. To achieve higher data rate PSK modulation, an injection-locked voltage-controlled oscillator (IL-VCO) and a polarity swap switching circuit cooperate to generate four phases. And the loop gain compensation circuit is reused as the negative resistance for IL-VCO. The transmitter (TX) is designed in 130 nm CMOS SOI process and the active area is 0.4 mm². It delivers an output power of −10 dBm and supports data rates of 10/10/50/100 Mb/s under OOK/BFSK/BPSK/QPSK modulation, respectively. It also achieves 24.5 pJ/bit energy efficiency and 96.1 figure-of-merit (FoM) in QPSK modulation.