Low-loss micro-machined four-pole linear phase filter in silicon technology

In this paper, a micro-machined linear phase filter for K-band satellite communication is presented. The filter is a four-pole cavity resonator band-pass filter. It is fabricated in silicon using the KOH-wet etching technique, and the filter is assembled by bonding two silicon wafers. The proposed configuration enables the realisation of low-loss and low-cost filters, which are easily integrable, monolithically or in a hybrid fashion, in microwave front-ends. Further, as it is described in the paper, the arrangement proposed for the cavity resonators allows for the realisation of cross-couplings between the cavity resonators, and it makes possible the design of compact linear phase filters. This paper presents the design and the measurement of a single micro-machined cavity resonator, and it describes the design procedure of the four-pole filter. This design of the complete four-pole micro-machined linear phase filter is finally assessed by full-wave simulation.