Patent attributes
A non-contact phase-locked and self-injection-locked vital sign sensor includes a self-oscillating voltage-controlled frequency-adjustable radiating element and a phase-locked loop. The self-oscillating voltage-controlled frequency-adjustable radiating element is used for transmitting an oscillation signal to an organism and for receiving a corresponding reflected signal from the organism to be posed at a self-injection-locked state, the oscillation signal being tuned by a vital sign of the organism to form a frequency-tuned signal. The phase-locked loop is used for demodulating the frequency-tuned signal to obtain a corresponding vital signal of the organism. By comparing the oscillation signal frequency-eliminated and outputted from the self-oscillating voltage-controlled frequency-adjustable radiating element with a reference signal, a corresponding comparison result is used to vary a phase of the frequency-divided oscillation signal for maintaining the same phase of the reference signal. Thereupon, the oscillation frequency can be stabilized, and the measurement sensitivity can be enhanced.
