Micromachined circuits for Mm-wove applications

A novel transmission line which utilizes micromachining techniques in the development of circuits for millimeter-wave applications is presented. Micromachined circuits incorporate the fabrication of an upper-half shielding environment with the circuit geometry. The circuit development requires the use two silicon wafers where one has cavities that have been etched using anisotropic etching while the other one has the planar circuits which have been printed using standard photolithographic techniques. Afterwards, the two wafers are aligned and secured using bonding techniques to form a circuit that has an upper-half shielded cavity incorporated monolithically. This paper presents a detailed description the fabrication procedure necessary for upper-half shielded (UHS) circuits as well as for completely shielded (CS) circuits. Experimental results of the upper half shielded circuits will be presented as compared to theoretical results and conventional coplanar waveguide circuits of the same type.