Lightweight, Solderless, Ultrawideband Transmitarray Antenna With True-Time-Delay Line
Lin Xiao, Shi‐Wei Qu, Wei Tang, Shiwen Yang
Abstract
An ultrawideband (UWB) transmitarray antenna (TA) using receiving–transmitting scheme is presented in this letter. The TA overcomes its narrowband limitations by combining UWB radiators and integrated grounded coplanar transmission polylines. To reduce the manufacturing cost and the assembly complexities, all metallic components of the TA element are printed on a vertically oriented single-layer substrate, leading to a lightweight and solderless slat structure. The proposed TA element achieves true-time-delay phase responses over a fractional bandwidth of 116%, i.e., from 4.2 to 15.8 GHz, with maximum transmission loss of 1.6 dB at normal incidence. The dimensions of the designed 21 × 21 element TA aperture are 189 × 189 × 28 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , corresponding to 10 × 10 × 1.47 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ<sub>h</sub></i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , where <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ<sub>h</sub></i> is the free-space wavelength at the highest operating frequency. A prototype is manufactured and measured to validate the feasibility. The experimental results agree reasonably well with simulations.