Abstract
This paper proposes an energy-efficient QPSK demodulator for low-power wireless receivers. It leverages the characteristic of phase-to-amplitude conversion possessed by the injection-locking oscillator. Compared to Costas-loop-based and PLL-based demodulators with high circuit complexity, the injection-locking-based D-QPSK demodulator exploits only one oscillator and one envelope discrimination circuit, which significantly reduce the power dissipation and chip area. Simulation results manifest the effectiveness of injection-locking technique for D-QPSK demodulation.