Bandpass filter based on low frequency spoof surface plasmon polaritons

Abstract

Based on the mechanism of spoof surface plasmon polaritions (spoof SPPs), a kind of microwave bandpass filter is presented in both theory and experiment, which is realised by a periodic subwavelength metallic Domino array. The transmission bandwidth of spoof SPPs is controllable by designing the geometric parameters of the periodic structure. Simulation and experimental results of the spoof SPPs agree well with each other and verify the feasibility in bandpass filter applications.Introduction: The periodic structure has been utilised in microwave and optical component applications in the past [1], such as the reflection mirror, the DFB laser, the light beam coupler in the optical regime, and the bandstop filter, leaky wave antenna at microwave frequencies [2]. In 2004, Pendry put forward a concept of spoof surface plasmon polaritons (SPPs) in the low frequency band using a subwavelength periodic hole on the surface of the metal to increase penetration depth [3], and the working frequency is controllable by the geometric parameters of the structure. The spoof SPPs in the microwave regime have been verified theoretically and experimentally in [4] and [5], and the mechanism of electromagnetic field confinement of the spoof SPPs is studied in [6].In this Letter, we put forward a new kind of bandpass filter in X-band based on the principle of spoof SPPs constructed by the periodic subwavelength Domino structure. The modal field of the guided mode in the Domino structure is almost constant inside the structure. By adjusting the lattice constant and the height of the Domino, we can control the transmission bandwidth and transmission efficiency. Such a structure can be applied in high power filter components.

An SIW antenna utilizing odd‐mode spoof surface plasmon polaritons for broadside radiation

“…Since these surface waves mimic the properties of SPPs, such as subwavelength localization, near‐field enhancement, and novel dispersion characteristics, they are termed as designed SPPs (DSPPs) or spoof SPPs (SSPPs). Due to these unique advantages, various functional devices based on SSPPs are designed, like filters, power divider, circulator, and antennas …”

A Compact Endfire Radiation Antenna Based on Spoof Surface Plasmon Polaritons in Wide Bandwidth

“…Afterward, SSPPs have inspired intensive interest in microwave community. Extensive applications based on SSPPs waveguide have been reported, including transmission line [28][29][30], filters [31][32][33], and wave splitters [34][35][36].…”

Bandwidth and Gain Enhancement of Endfire Radiating Open-Ended Waveguide Using Thin Surface Plasmon Structure

“…A variety of spoof SPP-based filters and wave splitters have been realized for SSPP communication systems [12][13][14][15]. On the other hand, surface plasmon waveguide based antenna designs, ultra wideband antennas and full-band waveguide differential phase shifters have been proposed recently for microwave applications [16][17][18][19][20][21][22][23][24][25].…”