Conception and realization of highly selective bandpass filters in Ka-band built on thin polymer films
Résumé
A novel structure of high performance narrow bandpass filters on thin polymer film is reported in this paper. It’s composed of two microstrip resonators placed between two viafree microstrip–grounded coplanar waveguide transitions. It combines therefore compactness, low-cost, fabrication easiness of microstrip lines and connection facility of coplanar pads. Narrow band-pass filters have been optimized by using HFSS software, realized and characterized, over the range of Ka-band frequencies. With the band-pass filter realized on thin BCB polymer (benzocyclobutene, relative permittivity er = 2.65 and loss tangent tanδ = 0.0025) film of 60 μm thick, the performance obtained for a center frequency optimized at 30.5 GHz is 28.8 for quality factor and -1.4 dB for insertion losses, with very good agreement between simulation and experiment results.