A Negative Index Nonagonal CSRR Metamaterial-Based Compact Flexible Planar Monopole Antenna for Ultrawideband...

Area of Science:

• Electromagnetics and Wave Propagation
• Materials Science
• Antenna Engineering

Background:

• Metamaterials offer unique electromagnetic properties not found in natural materials.
• Textile-based antennas are desirable for wearable and flexible electronic applications.
• Ultrawideband (UWB) antennas are crucial for high-data-rate wireless communication.

Purpose of the Study:

• To propose and characterize a compact textile UWB planar monopole antenna.
• To integrate a metamaterial unit cell array (MTMUCA) with epsilon-negative (ENG) and near-zero refractive index (NZRI) properties.
• To demonstrate enhanced bandwidth and gain using the MTMUCA on a textile antenna.

Main Methods:

• Design and fabrication of a MTMUCA using a combination of rectangular and nonagonal unit cells.
• Integration of the MTMUCA with a textile UWB planar monopole antenna.
• Characterization of antenna performance using simulations and experimental measurements.
• Analysis of working principles using an equivalent circuit model.

Main Results:

• The MTMUCA exhibits ENG properties with a bandwidth of 11.68 GHz and NZRI bandwidth of 8.5 GHz.
• The textile UWB antenna achieved a 10 dB impedance fractional bandwidth of 142% (2.55–15 GHz) in simulations and 138.84% (2.63–14.57 GHz) in measurements.
• Peak realized gains of 4.84 dBi (simulated) and 4.4 dBi (measured) were obtained.
• Good agreement was observed between simulated and experimental results.

Conclusions:

• The proposed textile UWB antenna loaded with MTMUCA demonstrates significantly enhanced bandwidth.
• The antenna exhibits favorable gain and performance characteristics.
• The study highlights the potential of negative index metamaterial-based antennas for microwave applications.
• The use of viscose-wool felt offers a practical substrate for wearable antenna fabrication.