Broadband and high-efficiency conversion from guided waves to spoof surface plasmon polaritons

Abstract

The conversion from spatial propagating waves to surface plasmon polaritons (SPPs) has been well studied, and shown to be very efficient by using gradient‐index metasurfaces. However, feeding energies into and extracting signals from functional plasmonic devices or circuits through transmission lines require the efficient conversion between SPPs and guided waves, which has not been reported, to the best of our knowledge. In this paper, a smooth bridge between the conventional coplanar waveguide (CPW) with 50 Ω impedance and plasmonic waveguide (e.g., an ultrathin corrugated metallic strip) has been proposed in the microwave frequency, which converts the guided waves to spoof SPPs with high efficiency in broadband. A matching transition has been proposed and designed, which is constructed by gradient corrugations and flaring ground, to match both the momentum and impedance of CPW and the plasmonic waveguide. Simulated and measured results on the transmission coefficients and near‐filed distributions show excellent transmission efficiency from CPW to a plasmonic waveguide to CPW in a wide frequency band. The high‐efficiency and broadband conversion between SPPs and guided waves opens up a new avenue for advanced conventional plasmonic integrated functional devices and circuits.

Circulator Based on Spoof Surface Plasmon Polaritons

“…J. Pendry et al reported that structured metal surface can support and propagate SSPPs [7]. In order to produce high transmission efficiency between single wire and coplanar waveguide (CPW), many efforts have been made [11][12][13][14]. As we know, SSPPs have good characteristics of high field confinement, planar configuration and deep-subwavelength, so we can take the advantage of the SSPPs to fabrication circulator.…”

Design of a Novel Wideband Low-Scattering Shared Aperture Metasurface

“…On a broad scale, electromagnetic band gap [1] (EBG), high impedance surface (HIS) [2], frequency selective surface (FSS) [3], [4], polarization rotation surface (PRS) [5], [6], artificial magnetic conductor (AMC) [7][8][9][10], perfect absorbing material (PMA) [11][12][13][14] and spoof surface plasmon polaritons (SSPP) [15], [16] could be classified into the category of MS, among which AMC (easy processing and flexible in manipulating the reflection phase) and PMA (extremely low profile) draw increasingly interest of the researchers.…”

A new kind of spoof surface plasmon polaritons structure with periodic loading of T-shape grooves

“…from propagation wave to SSPPs and utilizing these ultra-thin plasmonic metamaterial to design plasmonic devices. [15][16][17][18][19][20] However, the studies on improvement of characteristic and enhancement of confinement capacity of SSPPs, which are highly demanded in design of various miniaturized devices and circuitries, have not been paid much attention on. Compare to traditional structures with rectangular grooves or trapezoidal grooves, this proposed structure shows strong confinement of SPPs which means it has less transmission loss of SSPPs and more propagation length.…”