W-Band Orthomode Transducer for Dense Focal-Plane Clusters

A W-band orthomode transducer has been designed for polarimeter clusters in dense focal planes. Its compact geometry, with aligned output ports, allows for a closely-spaced triangular-lattice arrangement. At these high frequencies, the platelet manufacturing strategy has been applied and verified experimentally on seven prototypes, showing reflection coefficients lower than -20 dB, insertion loss of about 0.25 dB and cross-coupling and isolation levels of -42 dB and 45 dB, respectively, in a 30% bandwidth.