A Wideband High-Gain Transmitarray Based on Quasi-Yagi Antenna Element

A wideband high-gain transmitarray (TA) at X-band is presented in this paper. The proposed design is based on two ‘back-to-back’ wideband quasi-Yagi antennas as the unit cell, which can achieve a good transmission efficiency at a broadband frequency. A full 360° phase range is obtained by simply changing the length of transmission lines with little influences on the transmission coefficient. The method for forming a high-gain pencil beam is analyzed. To verify this concept, a transmitarray consisting of $16^{\ast}26$ unit cells is designed and simulated. The numerical results show that this proposed transmitarray can achieve a maximum gain of 23.1 dBi with 1-dB gain bandwidth of 14.51 % and 3-dB gain bandwidth of 24.65%, respectively.