Ka-band surface-mountable pseudo-elliptic filter in multilayer micromachined technology for on-board communication systems

This paper presents the design, manufacturing and testing of a new type of compact and low loss Ka-band filter in multilayer micromachined technology. It consists of a 4th order pseudo-elliptic filter realized by stacking six silicon layers for a reduced footprint. The filter is based on λ/2 TEM Si membrane resonators placed inside shielding cavities and short-circuited at both anchored ends. With respect to conventional cavities based on TE101 resonant mode, the footprint of the proposed resonators is reduced by more than 50% at the expenses of a reduced Q factor degradation (<;20%). The measurements of the 4th order filter at Ka-band show insertion loss better than 3dB and Q factor above 500 in Ka-band. The filter robustness to manufacturing and the assembly tolerances has been verified on eight samples, showing good reproducibility of the filter response. Environmental tests are on-going to demonstrate the space compatibility of the filter.