High-Efficient Wideband Transmitarray Antenna

A new structure for transmitarray antennas is presented. The proposed semiplanar transmitarray keeps certain geometrical curvature, that the required transmission phase range is reduced significantly from 360°, causing an increase in bandwidth and efficiency. The proposed antenna structure has varied element thickness-the central element being the thinnest and elements growing in thickness as we move toward the edges. To evaluate the new model, an X-band prototype antenna is fabricated with the number of layers for the elements growing from 2 to 5 from center to the edges of the aperture. The required phase range for the elements was reduced from 360° to 51.5°. Measurement results show that proposed antenna with aperture size of 21.8λ02has 22.3 dBi maximum gain at 10.3 GHz. In addition, the proposed design achieves a 24.27% 1 dB gain bandwidth and 62% efficiency.