|A Pseudo-Elliptical Response Filter at W-Band Fabricated with Thick SU-8 Photo-Resist Technology
|Year of Publication
|Leal-Sevillano, C. A., J. R. Montejo-Garai, K. Maolong, M.. J. Lancaster, J. A. Ruiz-Cruz, and J. M. Rebollar
|IEEE Microwave and Wireless Components Letters
|The design and experimental validation of a pseudo-elliptical response filter at W-Band is presented. A micromachining technique based on the thick SU-8 photo-resist is used to construct the filter. The optimized structure is specially well-suited for the implementation of filters with transmission zeros by means of micromachining techniques, since the extracted poles are implemented by simple stubs without irises. Furthermore, a novel topology based on the use of only three SU-8 layers is presented. This new topology, which includes a novel optimized input/output routing, can be potentially used for the design of high-performance devices with a fast and low-cost production. A fourth-order filter with two transmission zeros has been fabricated (bandwidth 5%), presenting 1.2 dB of insertion loss. This level of loss is equivalent to the actual state-of-art for micromachined filters at W-band, in spite of the reduced height and the split block in the H-plane used in the presented design.