A Low-Profile Wide-Angle Reconfigurable Transmitarray Antenna Using Phase Transforming Lens With Virtual Focal Source
Min Wang, Shenheng Xu, Nan Hu, Wenqing Xie, Fan Yang, Zhengchuan Chen
Abstract
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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times12$ </tex-math></inline-formula> 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times16$ </tex-math></inline-formula> 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$16\times16$ </tex-math></inline-formula> 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.20\lambda _{\mathbf {0}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.08\lambda _{\mathbf {0}}$ </tex-math></inline-formula> at 12.0 GHz, respectively. Finally, the proposed antenna prototype with an effective aperture of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.68\lambda _{\mathbf {0}} \times 7.68\lambda _{\mathbf {0}}$ </tex-math></inline-formula> (192 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times192$ </tex-math></inline-formula> 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°.