A Directivity-Band-Dependent Triple-Band and Wideband Dual-Polarized Monopole Antenna Loaded with a Via-Free CRLH Unit Cell

A printed triple-band and wideband dual-polarized meander-line monopole antenna with a single CRLH metamaterial loading is presented. The metamaterial loading improves the impedance matching and causes the proposed antenna to radiate at multiple frequency bands with extended bandwidth. We have designed a via-free version of the CRLH transmission line unit cell which simplifies the fabrication process and decreases the costs. The antenna´s E-field radiation has y-directed polarization at first and third resonance bands and x-directed polarization at second resonance band. In addition, proposed antenna has z-directed, y-directed, and x-directed main radiation directions at first, second, and third resonance bands, respectively. A fabricated prototype has small dimensions of the 30 mm×30 mm×1.6 mm, and exhibits good agreement between the measurements and simulations.