A dual-band power divider based on higher-order modes of spoof surface plasmon polaritons

Salma Mirhadi,Nader Komjani

doi:10.1063/5.0048390

Abstract

In this paper, a dual-band power divider is presented based on the propagation of the higher-order modes of spoof surface plasmon polaritons (SSPPs). A hollow rectangular groove is introduced as a unit cell, and its dispersion characteristics for higher modes and the fundamental mode are examined. Compared with the traditional rectangular groove unit cell, the proposed unit cell provides extreme electromagnetic wave confinement for higher-order modes. In addition, the second and fourth modes are even and can be excited by a coplanar waveguide. By utilizing the even modes of the proposed unit cell, a dual-band transmission line and a dual-band power divider are designed so that the operating bands can be controlled by the inner and outer depth of the grooves. The dual-band SSPP transmission line and the dual-band power divider are manufactured and tested to validate the design procedure. Finally, the measurement results show good agreement with the simulations, demonstrating the effectiveness and robustness of the design procedure.

Highlights

Natural surface plasmon polaritons (SPPs), which result from the coupling between the incident electromagnetic (EM) waves and the free electrons in a metal, propagate along the dielectric–metal interface in the optical regime
spoof SPPs (SSPPs) are realized primarily through the conductors textured with periodic holes and grooves6,7 and extended to ultrathin corrugated metallic strips, which are compatible with planar technology and produce conformal surface plasmons on curved surfaces
The transmission lines (TLs) is split into two branches, each including a single side of the hollow rectangular groove (HRG) unit cell

Summary

INTRODUCTION

Natural surface plasmon polaritons (SPPs), which result from the coupling between the incident electromagnetic (EM) waves and the free electrons in a metal, propagate along the dielectric–metal interface in the optical regime. Considering their superior features, such as subwavelength-scale confinement perpendicular to the interface and non-diffraction limit, SPPs offer numerous applications. Natural surface plasmon polaritons (SPPs), which result from the coupling between the incident electromagnetic (EM) waves and the free electrons in a metal, propagate along the dielectric–metal interface in the optical regime.. Natural surface plasmon polaritons (SPPs), which result from the coupling between the incident electromagnetic (EM) waves and the free electrons in a metal, propagate along the dielectric–metal interface in the optical regime.1 Considering their superior features, such as subwavelength-scale confinement perpendicular to the interface and non-diffraction limit, SPPs offer numerous applications. Reference 13 investigated the dispersion and transmission properties of higher-order modes along a conformal surface plasmon structure consisting of a metal strip with periodic grooves. This is the first time a dual-band power divider based on SSPPs has been designed to the best of our knowledge

UNIT CELL DESIGN

A DUAL-BAND SSPP TL WITH A HRG UNIT CELL

DESIGN OF THE DUAL-BAND EQUAL POWER DIVIDER

CONCLUSIONS