A Quadriphase Fin-Line Modulator

A hybrid-coupled quadriphase rnodulator which has been realized in fin-line technique is described. It operates over a 15-percent frequency band around 15 GHz with an insertion loss of 1.7 dB. The circuit has been scaled to twice the operating frequency. The insertion loss then amounts to 2.2 dB. Furthermore, it is shown experimentally that the performance of the modulator does not degrade if the dimensions of the waveguide housing are altered to amounts of up to 10 percent.