A 12GHz lumped-element hybrid fabricated on a micromachined dielectric-air-metal (DAM) cavity

A novel lumped-element hybrid is presented. The hybrid is disposed on a newly developed dielectric-air-metal (DAM) cavity, which consists of an SiN membrane above a metallized 30-um-deep cavity made by a micromachining process. This process enables to make every component be worked from one-side of a silicon (Si) substrate, and to leave back-side as a part of a package. This is indispensable to realize a very thin MEMS-packaged-device consisting of two wafers bonded. Also, patterned metal grounds can provide all kinds of lumped elements. Among those, series inductors are investigated in detail. A hybrid with series inductors and shunt capacitors is fabricated. Good agreement between the measured and simulated results was obtained to validate this structure for fabrication of micro-size microwave components on an Si substrate.