A Proximity Coupling RF Sensor for Wrist Pulse Detection Based on Injection-Locked PLL

摘要: In this paper, a proximity coupling RF sensor based on injection-locked phase-locked loop (PLL) for wrist pulse detection is proposed. The composed of two main parts: free-running oscillator and PLL synthesizer containing voltage-controlled oscillator. built with two-port microstrip line resonator (inter-digital electrodes), which acts as part transducer that can transform the expansion or contraction radial artery into an impedance variation. Measurements show variation due to changes in causes frequency change up 0.74 MHz For part, be transformed dc voltage by injection modulated signal from loop-control voltage, one cycle pulse, approximately 10–15 mV peak-to-peak. Our demonstrated effective noncontact noninvasive scheme detection.