Patent ID: 8198956

Claim:
A compact planar microwave blocking filter with a predetermined shunt capacitance, comprising: a plurality of a set of filter unit elements disposed on a substrate, the substrate being one of a degeneratively doped semiconductor substrate, and a dielectric substrate, the plurality of said set of filter unit elements being interconnected in a symmetrical series cascade with filter unit elements being organized in the series based on physical size; wherein, a first filter unit subset element of the plurality of said set of filter unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the filter; the plurality of said set of filter unit elements further including: a quarter-wavelength stub for suppressing spurious responses at approximately 45.5 GHz, with multiple sections of said first filter subset element combined in series, said first filter unit subset element split into multiple sections with equivalent minimized parasitic shunt capacitance; each first filter subset element including split-end transmission unit elements to provide limited suppression bandwidth.