High-efficient and low-coupling spoof surface plasmon polaritons enabled by V-shaped microstrips.

Area of Science:

• Electromagnetics and Plasmonics
• Microwave Engineering
• Materials Science

Background:

• Spoof surface plasmon polaritons (SSPPs) are crucial for sub-wavelength waveguiding.
• Conventional SSPP waveguides often require complex mode conversion structures.
• Efficient and compact designs for SSPP propagation are highly sought after.

Purpose of the Study:

• To introduce a novel V-shaped microstrip design for enhanced SSPP propagation.
• To analyze the dispersion characteristics and tunability of the V-shaped microstrip.
• To demonstrate the low-pass filtering and reduced coupling properties for practical applications.

Main Methods:

• Theoretical analysis of dispersion characteristics for V-shaped microstrip units.
• Design and simulation of broadband transitions using tapered microstrips and graded V-shaped units.
• Experimental validation of low-pass filter performance and coupling effects in parallel V-shaped microstrips.

Main Results:

• The V-shaped microstrip enables significantly reduced asymptotic frequency without increasing lateral dimensions.
• Broadband low-pass filter characteristics were achieved with S11 < -10 dB and S21 > -3 dB from 0 to 10.3 GHz.
• Parallel V-shaped microstrips with overlapping exhibited substantially lower coupling effects compared to conventional designs.

Conclusions:

• The proposed V-shaped microstrip is compatible with conventional microstrips, simplifying integration.
• The design offers excellent broadband low-pass filtering and reduced inter-channel coupling.
• This technology holds significant potential for miniaturized, highly integrated microwave plasmonic circuits and systems.