Measurement of time-evolving electronically steerable radiation patterns at fast timescales by a sampling technique

Modern electrically steerable antennas have the ability to evolve their far-field radiation pattern on nanosecond timescales. The transient radiation that occurs during this evolution cannot be captured by conventional radiation pattern measurements, which take at least several minutes to complete. We present a temporal and spatial sampling method of measuring the rapid temporal evolution of an electronically steerable antenna´s near- and far-field radiation pattern, which allows for time-domain measurement of the radiation pattern of an antenna at relevantly short timescales and over an arbitrarily large solid angle. An experimental validation of the method is reported, in which an azimuth-plane measurement of a phased-array antenna captures the transient far-field radiation pattern as the antenna switches its main-beam scanning angle with 7-nanosecond time resolution.