MICROMACHINED W-BAND FILTERS

Results are presented for high performance planar W-band filters based on silicon micromachining techniques common in microsensor fabricatio n. Two types of micromachined planar transmission lines are studied: m icroshield line and shielded membrane microstrip (SMM) line, In both o f these structures, the conducting lines are suspended on thin dielect ric membranes, These transmission lines are essentially ''floating'' i n air, possess negligible levels of dielectric loss, and do not suffer from the parasitic effects of radiation and dispersion, A 90 GHz low pass filter and several 95 GHz bandpass filters are tested and display excellent performance which cannot be achieved with traditional subst rate supported circuits in CPW or microstrip configurations, A full-wa ve finite-difference time-domain (FDTD) technique verifies the measure d performance of the W-band circuits and provides a basis for comparis on between the performances of membrane supported circuits and equival ent substrate supported circuits.