High‐gain magnetic‐dipole quasi‐Yagi antenna using higher‐order‐mode dielectric resonator with near‐zero‐index metamaterial

For the first time, the rectangular dielectric resonator (DR) operating in higher‐order TE_3δ1 mode is investigated and used as a magnetic‐dipole driver to design quasi‐Yagi antenna with high gain. For further enhancing the antenna gain, a near‐zero‐index (NZI) metamaterial (NZIM) is proposed instead of the traditional directors and put in the front of DR driver. It is a simple structure and composed of a set of the parallel metallic lines printed on a substrate along the end‐fire direction. Benefiting from the higher‐order mode operation of the DR and NZIM, the realized gain of the proposed antenna can reach 10.3 dBi, including the gain improvement of 2 dBi resulting from the employed NZIM. To verify the design concept, the prototype of quasi‐Yagi DR antenna with NZIM is fabricated and characterized. The measured results agree very well with the simulated results.