Empowering Spiral Antennas with Metamaterials: A High-Efficiency Solution for C-Band Systems

This study introduces a novel spiral antenna performance improvement technique using metamaterials for use within systems in the $\mathbf{C}$-band frequency range. The authors designed a unit cell of four copper spirals supported by a doubly negative Rogers RT/duroid 5880 substrate for an operating frequency range of $\mathbf{6 - 9. 8 ~ G H z}$. The unit cell was incorporated into a slotted circular patch to create a fully formed antenna structure. The spiral metamaterial antenna maintains improved characteristics, including a minimum reflection of -21.18 dB at a frequency of 6.353 GHz, impedance match, a gain of 5.05 dB, and a maximum efficiency of $86 \%$ at a resonant frequency of 6.535 GHz. The proposed design is a high-efficiency, compact design for use within the communication equipment of the C band that eliminates the conventional shortcomings of spiral antennas, such as large physical size, impedance mismatch, moderate gain, and uncontrollable radiation patterns.