A miniaturized metamaterial-based tri-band antenna is proposed, which achieves multi-band coverage and performance enhancement through innovative structural design. The compact geometry is realized by integrating short-circuit stubs, significantly reducing the physical footprint. By synergistically combining the reconstruction of the negative first-order resonance mode with an additional resonance point, the operational bandwidth is effectively broadened to fully cover three key communication bands: 2.4–2.6, 3.3–3.8, and 5.2–5.8 GHz. The antenna employs a coplanar waveguide fed structure, incorporating a metamaterial unit cell and a grounded rectangular patch on a monopole configuration. This design improves the front-to-back ratio of the radiation pattern and achieves cross-polarization suppression better than −25 dB. Experimental verification shows that while maintaining a compact size, this antenna has excellent impedance matching characteristics and stable gains in each frequency band. Simulation and measurement results indicate that it meets the performance requirements of modern multi-standard wireless communication systems for compact multi-frequency antennas.
Liu et al. (Sun,) studied this question.