MMIC circulators covering the frequency range from L- to W-band

A new type of circulators is presented which has been tested using circuits covering the frequency range from L- to W-band. This is, for the first time, a principle suitable for applications at 1.8 GHz as well as 77 GHz. At the lower frequencies ferrite drop-in circulators in microstrip technique have been used in the past, while at the upper frequencies the usage of circulators has not been established yet. The measurement result presented here demonstrate the applicability of the new concept.