Ultrawideband Millimeterwave Robotic Antenna Measurements Enabled by Fmcw Radar Sensors

In this paper ultrawideband frequency modulated continuous wave (FMCW) radar sensors in D-band are used to provide a coherent (magnitude and phase) measurement of an antenna pattern. The antenna under test (AUT) is mounted on the radar sensor using a standard waveguide flange. Due to the compactness of the sensor and its integrated signal source, it is easily moveable by a robotic plattform. Only an ethernet connection to a host PC is required, strongly simplifying cable handling on the robot. The coherent pattern measurement is enabled by performing radar echo measurements (in reflection) onto a probe antenna. A switchable load at the probe antenna feed is utilized to improve the dynamic range and to remove undesired environmental reflections by performing a differential measurement.