Fig. 1From: A robust multi-feature based method for distinguishing between humans and pets to ensure signal source in vital signs monitoring using UWB radarBlock diagram of the ultra-wideband (UWB) radar. SPI, serial peripheral interface; LNA, low noise amplifier; HPF, high-pass filter; OSC, oscillator; PLL, phase-locked loop; TA, transmitter antenna; RA, receiving antennaBack to article page