A 3-D-Printed Wideband Circularly Polarized Dielectric Reflectarray of Cross-Shaped Element

A novel wideband circularly polarized (CP) dielectric reflectarray operating at
K_a
-band is proposed. Each element consists of a cross-shaped dielectric block and a metal ground. The two arms of the cross element are arranged along the diagonal of the square metal floor. For ease of the design, the dimensional scaling factor is used to obtain the reflection phase. The dielectric reflectarray of the size 15 × 15 and dielectric constant 9.8 is designed. Genetic algorithm (GA) is applied to optimize the element size. It is found that the maximum gain is 24.2 dBi, and 1 dB gain bandwidth is 10.7%, respectively. A broad 3 dB axial ratio (AR) bandwidth of 19.3% can also be obtained. The proposed CP antenna is fabricated using the high-precision 3-D printing technology. Relatively good agreement between the simulated and measured results is achieved.