Compact Ultra-Wideband BPF Based on Square Resonator Using Inter-digital coupling

This paper is about a Ultra wideband BPF with inter-digital coupling line. A novel square resonator integrated with inter-digital coupling on both sides plays a key role in this filter design. Design and EM Simulation of the UWB filter's characteristics are discussed in this work. The proposed UWB filter produces tremendous bandwidth ranges from 2.3 GHz to 8 GHz. It also exhibit out band characteristics which meets the FCC's requirement. The simulation study of the projected filter is executed by electromagnetic tool. The filter evaluation parameters like return loss, insertion loss, phase and group delay are obtained and their responses are analyzed. The complete size measurement of the filter is achieved to be 39mmx3.2mmx1.6mm on accounting the above features. The calculated bandwidth ratio with respect to center frequency of the filter is obtained about 115%. The performance parameter results shows the filter's return loss (S-11) and insertion loss (S-21) are -41 dB and -2 dB respectively.