A low cost planar filter for 60 GHz applications

A low cost printed planar filter on alumina ceramic substrate was developed at 60 GHz. This filter is advantageous in cost, size, weight and connectiv ity to MMICs. It is especially suitable for millimeter-wave module integrat ion, where MMICs and filters are all assembled inside one compact package. The filter is based on a new equivalent circuit structure, which has two or four transmission zeros on both sides of the passband. The neu;future of t he structure is a mutual inductive coupling between the input and output po rts. The equivalent circuit simulation exhibits more idealistic rectangle-s haped bandpass performance than a conventional bandpass filter (BPF) with t wo transmission zeros. The equivalent circuit is very simple, anti easily f abricated in various styles, for operation at both millimeter-wave and micr owave frequency ranges.