Distributed Active Radiator arrays for efficient doubling, filtering, and beam-forming

Distributed Active Radiator (DAR) arrays are demonstrated as novel ways of harmonic generation, radiation, and filtration to generate power at frequencies above the cut-off frequency of a technology. As proofs-of-concept, 2×1 and 2× 2 arrays of DAR with beam-forming are implemented on PCB, which are designed to oscillate at the fundamental frequency of 1.25GHz, while radiating (circularly-polarized) at the doubling frequency of 2.5GHz. The measured EIRP of 2× 1 and 2× 2 arrays are 7.46dBm and 12.96dBm, respectively, at 2.5GHz with a DC-to-radiated 2
^nd
harmonic conversion of 0.8%. Almost 40° of beam-steering at 2.5GHz was measured in 2D space for the 2×2 array and more than 15dB suppression of the first and third harmonic compared to the desired second harmonic was measured in the radiated far-field.