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Abstract-In this paper, a compact planar quasi-Yagi antenna with enhanced radiation characteristics is presented. The proposed structure is designed by incorporating metamaterial unit cells in place of conventional directors. Here, the technique used for directivity improvement is that the refractive index of the metamaterial is lower than that of the antenna substrate, which acts as a regular lens for beam focusing. Loading the quasi-Yagi antenna with metamaterial results in directivity as well as gain enhancement at the end-fire direction compared to the quasi-Yagi antenna with directors. In addition, reduction in the overall size of the proposed quasi-Yagi antenna by 26.67% is achieved. An enhanced impedance bandwidth has also been noticed. The gain performance of the proposed antenna within the frequency band has been studied.

Abstract-An approach of miniaturizing planar Yagi array using metamaterial is presented in this paper. In this methodology, metamaterial structures are incorporated in the antenna in place of directors. An investigation in reflection and radiation characteristics of the antennas is done, and the findings are presented. The metamaterial loaded antenna shows improved directivity and efficiency of 16.3% and 2.95% with respect to the microstrip Yagi antenna while achieving a noticeable size miniaturization of 33.3%. Also, a better matching, compared to Yagi antenna, is observed in this proposed design. The fabrication and measurement of metamaterial loaded structure have been performed. The measured result shows an acceptable extent of agreement with the simulated ones.