Abstract: In this study, we propose a microstrip Ultra-Wideband (UWB) Bandstop Filter (BSF) using Dual Interdigital Capacitor Frequency Selective Coupling Structure (DIDC-FSCS). The proposed UWB BSF is designed based on lossless FSCS with transverse wave form. The designed BSF used two λ/4 lengths to make an interdigital capacitor and then make it dual FSCS. And one Shunt Open Circuit Resonator (SOCR) with an additional λ/4 length. The SOCR is composed of meander lines. The input and output ports were terminated to 50 Ω for the system application. The designed BSF was simulated using the Sonnet simulator. The measured center frequency is 6.3 GHz, the BSF 3 dB bandwidth is 4.2 GHz and the maximum transmission coefficient and the reflection coefficient are 35.0 and 0.43 dB, respectively. The actual size of the BSF is 10.0×12.57 mm.
Chang-Soon Kim, Tae Hyeon Lee, Kwang Seob Shin, Seong Jeong, Bhanu Shrestha and Kwang Chul Son, 2018. Wide Bandstop Filter using Interdigital Capacitor and Frequency Selective Coupling Structure. Journal of Engineering and Applied Sciences, 13: 8700-8703.