Average Backscatter Clutter Power for RF Sensing Applications in Indoor Environments

A simple model for average backscatter power from clutter is developed for indoor RF sensing applications and verified through measurements. A narrowband 28 GHz sounder used a quasi-monostatic radar arrangement with an omnidirectional transmit antenna illuminating an indoor scene and a spinning horn receive antenna less than 1 m away collecting backscattered power as a function of azimuth. Median average backscatter power was found to vary over a 12 dB range, with average power generally decreasing with increasing room size. A deterministic model of average backscattered power dependent on distance to nearest wall and clutter reflection coefficient reproduces observations with 4.0 dB RMS error.