Quasi-planar high-Q millimeter-wave resonators

Several low-profile 250-/spl mu/m-high Ka-band cavity resonators are demonstrated with resonant frequencies near 26 GHz and unloaded quality (Q) factors greater than 400. The air-filled copper cavity resonators are fabricated on a silicon substrate using a photolithographic process. A microrectangular coaxial transmission-line feed is integrated in the same process. Four resonators with different mechanical support structures are demonstrated. The resonators are designed using the finite-element method and simulation of both the resonant frequency and Q factor agree well with measurements.