An ultra low power QPSK receiver based on super-regenerative oscillator with a novel digital phase detection technique

An original proposal of using SRO-based receiver to demodulate QPSK signals is presented. The receiver is composed of an LNA and a super-regenerative oscillator (SRO), both combined in a single stacked configuration for current reuse. The demodulation of received RF signal is performed via a novel digital circuit capable of detecting phase information embedded in the SRO output. The receiver is able to demodulate incoming signal without the need of an LO, PLL or an ADC. The complete receiver was designed using a 0.13 μm technology and pre-layout simulation confirms proper and efficient operation, where the designed receiver operating in the 402–405 MHz MICS band shows 135 μW power consumption, while being able to properly detect and extract sent information of a −80 dBm, 2 Mbps signal.