Dispersion engineering of spoof plasmonic metamaterials via interdigital capacitance structures

Area of Science:

• Metamaterials
• Plasmonics
• Microwave Engineering

Background:

• Spoof surface plasmon polaritons (SSPPs) offer unique electromagnetic properties for microwave applications.
• Controlling dispersion and cutoff frequencies in SSPP structures is crucial for device design.
• Existing methods for dispersion engineering often face limitations in compactness and tunability.

Purpose of the Study:

• To present a novel approach for dispersion engineering of spoof plasmonic metamaterials.
• To achieve controllable cutoff frequencies using interdigital capacitance structures.
• To develop a compact SSPP transmission line (TL) with enhanced performance.

Main Methods:

• Utilizing interdigital capacitance structures to construct unit cells for metamaterials.
• Analyzing dispersion properties and the influence of geometrical parameters on cutoff frequencies.
• Designing and simulating a smooth transition for the SSPP TL.
• Validating the proposed strategy through simulation and measurement of transmission characteristics.

Main Results:

• Demonstrated joint tuning of lower and upper cutoff frequencies via interdigital capacitance.
• Achieved a significant reduction in transversal dimension (by a factor of two) compared to substrate-integrated waveguide (SIW) designs.
• Successfully developed and validated an SSPP TL with controllable dispersion.

Conclusions:

• The proposed interdigital capacitance approach provides effective dispersion engineering for spoof plasmonic metamaterials.
• This method enables the creation of highly tunable and compact microwave devices.
• The findings accelerate the development of versatile microwave integrated circuits and systems.