A Compact mm-Wave Bandpass Filter Based on Transversal Signal Interference Concept in IPD Technology

A compact mm-wave bandpass filter (BPF) based on the transversal signal interference concept in integrated passive-device (IPD) technology is proposed and designed in this paper. The proposed structure transmits signals through two paths. In Path 1, a $\pi$-shaped structure consisting of coupled lines, shorted stubs, and a transmission line is achieved. Path 2 is composed of a cascade of coupled lines and transmission lines. By using the IPD technology, the center frequency of the designed BPF is set to 28 GHz. A wideband BPF with multiple transmission poles and transmission zeros is implemented. In the final electromagnetic (EM) simulated results, good performances with the fractional bandwidth of 83.07% of the designed BPF are implemented.