An E-Plane Broadband Bi-Phase Balanced Modulator for Ka-Band

A bi-phase p.s.k. modulator for use in 29 GHz Radio equipment has been developed that gives state of the art performance (3 dB insertion loss across 7% bandwidth and 70/100 Mbit/s data rate using beam lead PIN diodes as the switching elements). The circuit maintains the full instantaneous bandwidth without requiring any tuning or alignment during or after manufacture.