ABSTRACT
This chapter reviews short-range radars which are well suited for indoor monitoring as a result of their lower implementation cost, safe emission levels, resolution, and adaptability to different form factors. It discusses indoor monitoring radars capable of providing the range and/or radial velocity signals needed to monitor human activity indoors. In a single-channel homodyne transceiver, the signal generated by the local oscillator (LO) is transmitted, and the return signal reaching the receiver is directly down-converted to baseband by mixing it with the signal coupled from the same LO used at the transmitter. The waveform of the signal transmitted by a pulsed radar can be defined by the carrier frequency, pulse shape, pulse width, modulation, and pulse repetition frequency. A frequency-modulated continuous wave radar can be seen as an extension to the continuous wave radar and enables measurement of both the range and the Doppler shift.
