A novel low-power transceiver topology for noncontact vital sign detection including the power management technique

摘要

In this paper, power management technique utilized in the direct down-conversion non-quadrature transceiver is presented for the low-power application of vital sign detection. The simultaneous switching noise (SSN) and overshoot and undershoot of the transient waveform distortion resulting from a pulse signal will give rise to interference with a vital sign signal. The pulse width, rise/fall time, and period of pulse bias are analyzed to mitigate the interference in this investigation. Significant issues about direct-current (DC) offset and noise confronted by the presented technique are addressed based on mathematical analysis. In radio-frequency (RF) transceiver architecture including power amplifier (PA), low-noise amplifier (LNA), and mixer, the current-reused (CRU) topology is utilized to achieve low DC power consumption. The post-layout simulation results exhibit that power consumption of the transceiver using the optimized pulse bias is reduced to 40％ of the power consumption for transceiver applying the DC bias. In addition, DC offset and null detection point can be alleviated by tunable phase shifter.