A Wideband Noise-Isolation Bandstop Power Distribution Network Using Quarter-Wavelength Line-Based Structure

This paper presents the design of wideband bandstop power distribution network using the quarter-wavelength (λ/4) line-based bandstop structure. A simple synthesis method starting from the specification on stopband bandwidth is also proposed with detailed design flow and equations. The synthesized λ/4-line bandstop structure has been implemented and verified with circuit simulation, electromagnetic simulation, and measurement. The test board is fabricated using the standard printed circuit board process, and the results show an extremely wide stopband from 1 GHz to more than 20 GHz with 70-dB isolation.