Multi-Band Miniaturized Antenna Loaded by ZOR and CSRR Metamaterial Structures With Monopolar Radiation Pattern

Miniaturized low-profile monopole antennas loaded by metamaterial (MTM) structures are presented. The antenna is loaded by zeroth-order resonator (ZOR) and complimentary split-ring resonator (CSSR) units, resonating over three frequency bands so that they can be tuned by changing the geometrical parameters of the MTM structures. Surface current distribution and equivalent circuit models are provided to describe the principle of operation. The experimental results are presented to validate the numerical results. Showing the monopole-shape radiation pattern characteristics at all resonant frequencies, the proposed MTM antennas are suitable for vehicular wireless applications.