Physiological information sensing device and method

A physiological information sensing device includes: a signal generator, an emitting antenna, a first receiving antenna, a second receiving antenna, a signal processing circuit and a computing element. The signal processing circuit includes a mixer, a first band pass filter and a second band pass filter. The signal generator generates a microwave signal. The emitting antenna emits the microwave signal. The first receiving antenna receives a first reflected signal, and the second receiving antenna receives a second reflected signal. The mixer mixes the first reflected signal and the second reflected signal, and performs demodulation with the microwave signal to generate a demodulated signal. The first band pass filter filters the demodulated signal based on a first frequency domain to generate a first filtered signal, and the first second pass filter filters the demodulated signal based on a second frequency domain to generate a second filtered signal. The computing element outputs a heart rate and a respirati