Millimeter-wave ultra-wideband bandpass filter with quarter-wavelength short-stubs and port extensions using 0.18-μm CMOS process

Millimeter-wave ultra-wideband (UWB) bandpass filter implemented in a standard 0.18-μm CMOS process is presented in this paper. Thin film microstrip structure (TFMS) is constructed appropriately on the low-resistivity silicon substrate without any post processing steps. Using the transmission line topology composed of quarter-wavelength short-circuited shunt stubs and port extensions, a wide return loss bandwidth is achieved so as to make up a class of UWB TFMS bandpass filter at 60 GHz. A compact geometry with sinuous shaped lines is designed and fabricated. The predicted and measured results are in good agreement up to 110 GHz.