title: A Hybrid Circuit for Spoof Surface Plasmons and Spatial Waveguide Modes to Reach Controllable Band-Pass Filters.
abstract: We propose a hybrid circuit for spoof surface plasmon polaritons (SPPs) and spatial waveguide modes to develop new microwave devices. The hybrid circuit includes a spoof SPP waveguide made of two anti-symmetric corrugated metallic strips and a traditional substrate integrated waveguide (SIW). From dispersion relations, we show that the electromagnetic waves only can propagate through the hybrid circuit when the operating frequency is less than the cut-off frequency of the SPP waveguide and greater than the cut-off frequency of SIW, generating efficient band-pass filters. We demonstrate that the pass band is controllable in a large range by designing the geometrical parameters of SPP waveguide and SIW. Full-wave simulations are provided to show the large adjustability of filters, including ultra wideband and narrowband filters. We fabricate a sample of the new hybrid device in the microwave frequencies, and measurement results have excellent agreements to numerical simulations, demonstrating excellent filtering characteristics such as low loss, high efficiency, and good square ratio. The proposed hybrid circuit gives important potential to accelerate the development of plasmonic integrated functional devices and circuits in both microwave and terahertz frequencies.
authors.affiliation: State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China.|Synergetic Innovation Center of Wireless Communication Technology, Southeast University, Nanjing 210096, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China.|Synergetic Innovation Center of Wireless Communication Technology, Southeast University, Nanjing 210096, China.
authors.forename: Hao Chi
authors.initials: HC
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China.
authors.forename: Han
authors.initials: H
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China.|Cooperative Innovation Centre of Terahertz Science, No. 4, Section 2, North Jianshe Road, Chengdu 610054, China.
authors.forename: Tie Jun
authors.initials: TJ
authors.lastname: Cui