A 2.7 GHz super-regenerative receiver front-end for QPSK modulated signals

In this paper, the operation of super-regenerative (SR) receivers based on super-regenerative oscillators (SRO) is extended to enable the detection of QPSK modulated signals rather than traditional implementation of SR receivers to detect OOK signals. The ability of super-regenerative receivers to properly detect QPSK modulated signals enables using the benefits of such receivers of high gain and low power for current mainstream receivers for wireless sensor networks applications. For this purpose, a low power super-regenerative front end is proposed, it is composed of an LNA and (SRO) merged for current-reuse and operating at 2.7 GHz. The front-end embedded in a downconversion receiver demonstrates that SRO phase preserving property enables proper detection of QPSK modulated signal while consuming an average power of 0.54 mW from a 0.65 V supply at a bit rate of 4 Mbps equivalent to 135 pj/bit.