Wideband Microtrip Bandpass Filters for Radio Astronomy Applications

This paper presents wideband bandpass filters with a novel microstrip configuration. Using quarter-wavelength resonators, internal coupling between resonators was realized by interdigital capacitors (IDC) and capacitive open-ended stubs. Impedance steps, was utilized for external couplings. Two wideband filters at L band and C band with a fractional bandwidth (FBW) of 48% and 76%, respectively, were demonstrated as the concept for use in e-MERLIN receivers of radio astronomy applications. The measurement performance agrees well with the simulation