Miniaturized spoof SPPs filter based on multiple resonators or 5G applications

Behnam Mazdouri; Mohammad Mahdi Honari; Rashid Mirzavand

doi:10.1038/s41598-021-01944-6

Miniaturized spoof SPPs filter based on multiple resonators or 5G applications

Sci Rep. 2021 Nov 19;11(1):22557. doi: 10.1038/s41598-021-01944-6.

Authors

Behnam Mazdouri¹, Mohammad Mahdi Honari², Rashid Mirzavand³

Affiliations

¹ Intelligent Wireless Technology Laboratory, Electrical and Mechanical Engineering Department, University of Alberta, Edmonton, AB, Canada. mazdouri@ualberta.ca.
² Department of Electrical Engineering, University of Wisconsin-Madison, Madison, WI, USA.
³ Intelligent Wireless Technology Laboratory, Electrical and Mechanical Engineering Department, University of Alberta, Edmonton, AB, Canada.

Abstract

This paper presents a novel and compact band-pass filter based on spoof surface plasmon polaritons (SSPPs) concept for 5G applications. In the first place, an SSPPs unit cell including L-shaped grooves and its equivalent circuit model are introduced. The obtained results from dispersion analysis shows that cut-off frequency of the cell can be considerably decreased thanks to its geometrical configuration. In the second place, a miniaturized SSPP transmission line (TL) consisting of the proposed unit cell with cut-off frequency of 29.5 GHz is designed. Two mode convertors have been employed for efficient connection between coplanar waveguides and SSPP TL. Moreover, a new method based on loading one unit cell of SSPP TL by stub resonators is proposed in order to block a specific frequency band. An equivalent circuit model for the cell with the resonators is proposed to predict rejected frequency range. Thereafter, as an example of our method, a SSPPs filter operating at 26.5-29.5 GHZ is designed by means of connecting stub resonators with different lengths to provide close resonance frequencies. The circuit model, full wave simulation, and measurement results are in a good agreement. The results of proposed groundless SSPP TL and filter structures are promising to make groundless 5G applications possible.