Nidhi Pandit

Design, Analysis, and Characterization of Designer Surface Plasmon Polariton-Based Dual-Band Antenna

This paper reports development, design, and analysis of designer (or spoof) surface plasmon polariton-based feeding configuration to excite a dual-band antenna. As an example, a planar transverse electric and magnetic horn antenna is designed and fed by the proposed transition structure. Designer surface plasmon polariton modes are supported by a metal surface at microwave frequency when it is corrugated with periodical grooves. An efficient transition for converting quasi-transverse electric and magnetic waves of microstrip line into spoof surface plasmon polariton (SSPP) waves has been designed in microwave frequency range using periodically corrugated metal strip. SSPP wave is confined at the teeth part of the corrugation. Simulated and measured reflection and transmission characteristics are in good agreement. The spoof SPP-fed dual-band antenna is designed, fabricated, and characterized in microwave anechoic chamber and measured results are coincident with simulated results.

Multiband Multimode Filter for Wireless Applications

This paper reports, design, analysis, and characterization of multimode resonator based multiband band pass filter. In support to the actual response, principle of resonating structure is explained with related mathematical explanations. For validating the concept, a quad-band BPF have been implemented on Neltec substrate and characterized through Keysight vector network analyzer N9918A. All the measured and simulated results are in good agreement with each other.

Design of Spoof Surface Plasmon Polaritons Based Transmission Line at Terahertz Frequency

In this paper, we report a plasmonic metamaterial, i.e., spoof surface plasmon polaritons based back to back broadband transition at terahertz frequency. Also we have designed another structure using a unit cell that is made up of by combining three SSPP strip together. This structure shows a way to realize stopband within the operating frequency of spoof surface plasmon polaritons. Using the new type of unit cell disturbs the surface impedance matching and thus gives band stop in the transmission spectrum of SSPP. The first design of transition has reflection coefficient less than −10 dB and transmission loss is less than 5 dB in 0.1–0.8 THz range of frequency. The second designed structure shows strop band from 0.569 to 0.6124 THz and band pass is maintained from 0.1 to 0.569 THz and from 0.6124 to 0.6516 THz. Reflection coefficients in the band-pass region is less than −10 dB and transmission loss is less than 8 dB while in the band stop region reflection coefficient is −3 dB and transmission coefficient is −24 dB has been obtained. Such type structures will show promising application in plasmonic device and systems.

Spoof Surface Plasmon Polariton-Based Reconfigurable Band-Pass Filter Using Planar Ring Resonator

In this paper, we report the design, analysis, and development of spoof surface plasmon polariton (SSPP)-based reconfigurable band-pass filter using a planar ring resonator. A transition from quasi-transverse electromagnetic (QTEM) mode of microstrip to SSPP mode was implemented which has been subsequently used to develop a reconfigurable band-pass filter. Trapezoidal shape periodically corrugated metallic grooves etched on the planar metallic surface have been used in the implementation of this transition. In the designed transition, impedance and mode matching between QTEM mode and SSPP mode have been achieved using gradient grooves. The developed transition has been used in the characterization of a ring resonator corrugated with the periodical array of the trapezoidal shape grooves. This SSPP ring resonator shows multiple passbands at different frequencies within the specified frequency range. Varactor diodes have been incorporated in the SSPP ring resonator to obtain tunable passband. Three types of varactor-tuned circuits have been experimentally implemented and characterized using SMV2019-079LF diode package. These circuits will pave the path for development of other front-end circuit elements using the concept of spoof SPP.