Miniaturized Half-Mode T-Septum SIW Bandpass Filter With an Ultrawide Stopband

• Published in: IEEE microwave and wireless components letters Vol. 31; no. 7; pp. 853 - 856
• Main Authors: Chen, Kai Feng, Yang, Xiao, Zhou, Liang, Mao, Jun-Fa
• Format: Journal Article
• Language: English
• Published: IEEE 01.07.2021
• Subjects: Bandpass filter (BPF); benzocyclobutene (BCB); half-mode T-septum substrate integrated waveguide (HMTSIW); Magnetic separation; Microstrip filters; Microwave filters; Resonator filters; Resonators; Substrates; wide stopband; Wireless communication
• DOI: 10.1109/LMWC.2021.3076456
• ISSN: 1531-1309

In this letter, novel miniaturized bandpass filters with wide stopband performance are proposed on the basis of the half-mode T-septum substrate integrated waveguide (HMTSSIW) resonator. The resonant TE n 00 and TE n 0 m modes of the HMTSSIW resonator are analyzed precisely using the Ritz-Galerkin method, and their resonant frequencies can be controlled flexibly by adjusting the sizes of resonator. A three-order HMTSSIW filter is fabricated using MEMS technology on the benzocyclobutene dielectric. Simulated and measured results show the advantages of compact size and wide stopband. Then, an electric coupling structure is introduced, which allows the further suppression of the spurious TE 300 mode by the controllable mixed coupling. Finally, a miniaturized HMTSSIW filter with 20-dB suppression beyond <inline-formula> <tex-math notation="LaTeX">10.37f_{0} </tex-math></inline-formula> is simulated and measured.