Microstrip-Fed 3D-Printed H-Sectorial Horn Phased Array

A 3D-printed phased array consisting of four H-Sectorial horn antennas of 200 g weight with an ultra-wideband rectangular-waveguide-to-microstrip-line transition operating over the whole LMDS and K bands (24.25-29.5 GHz) is presented. The transition is based on exciting three overlapped transversal patches that radiate into the waveguide. The transition provides very low insertion losses, ranging from 0.30 dB to 0.67 dB over the whole band of operation (23.5-30.4 GHz). The measured fractional bandwidth of the phased array including the transition was 20.8% (24.75-30.3 GHz). The antenna was measured for six different scanning angles corresponding to six different progressive phases alpha, ranging from 0 degrees to 140 degrees at the central frequency band of operation of 26.5 GHz. The maximum gain was found in the broadside direction alpha = 0 degrees, with 15.2 dB and efficiency eta = 78.5%, while the minimum was found for alpha = 140 degrees, with 13.7 dB and eta = 91.2%.