Design and Simulation of THz Filters Embedded in LTCC Multi-layer Substrate

THz (Terahertz) technology has made great strides; however, publications on millimeter wave and THz passives, such as filters, are somewhat few by now. This paper proposes design of THz filters based on substrate integrated waveguide (SIW) and cavities implemented by micromachining of low-temperature co-fired ceramic (LTCC) multilayer substrate and utilizes SIW rectangular coupling cavity filter and cylindrical cavity coupling filter mechanism. The filters are embedded in a multi-layer LTCC substrate, and are validated with a finite element full-wave simulation tool. With mid-band frequency set to frequencies in THz bands, both filters demonstrate excellent return loss in stopband and insertion loss in passband; furthermore they are shown promising in combining vacuum microelectronics into highly integrated 3D Microsystem-in-packages.