A Low-Profile Wide-Angle Reconfigurable Transmitarray Antenna Using Phase Transforming Lens With Virtual Focal Source

A low-profile wide-angle reconfigurable transmitarray antenna (RTA) is proposed in this communication. This RTA consists of a feeding antenna, a phase transforming lens, and a 1 bit phase-reconfigurable transmitting antenna (PRTA). The feeding antenna is composed of a 12 $\times12$ slot array fed by 36-way waveguide power divider, which possesses the characteristics of equal amplitude and in-phase distribution to obtain high efficiency. The desired 1 bit PRTA uses 16 $\times16$ array of C-shaped probe-fed patch elements to achieve flexible wide-angle beam scanning. To eliminate the mirror lobe effects of 1 bit phase quantization, the phase transforming lens with a $16\times16$ array of perforated dielectric element is designed to generate a spherical phase front from virtual focal source. By spatially cascading these three components, a low-profile RTA architecture is constituted, where the two spatial separations between adjacent components are $0.20\lambda _{\mathbf {0}}$ and $0.08\lambda _{\mathbf {0}}$ at 12.0 GHz, respectively. Finally, the proposed antenna prototype with an effective aperture of $7.68\lambda _{\mathbf {0}} \times 7.68\lambda _{\mathbf {0}}$ (192 mm $\times192$ mm) is fabricated and measured. The measured peak gain is 23.5 dBi at 12.0 GHz with aperture efficiency of 30.2% and a 3 dB gain bandwidth of 1.1 GHz. The measured results demonstrate that the proposed design has the 2-D wide-angle beam scanning capability up to 60°.