A Ka-Band Multilayer Beaming-Scanning Antenna Using Liquid Crystals

Abstract

This letter presents a Ka-band multilayer beaming-scanning antenna based on the electronically controlled liquid crystal (LC) phase shifter and proposes a new integrated and miniaturized LC antenna structure. The antenna is composed of four planar magnetoelectric dipole antenna units, four LC-based reflective phase shifters, and the power divider network, including the bias loading and dc blocking circuits. An external four-channel adjustable power module is designed with the field-programmable gate array (FPGA) to output the independent control and continuous adjustment bias voltage. It has overall dimensions of 35 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\times 50$</tex-math></inline-formula> mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\times 2.5$</tex-math></inline-formula> mm, which operates at 35 GHz. Measured results demonstrate that by adjusting each phase of the LC-based phase shifter through the power module, the structural and functional LC array achieves the one-dimensional (1-D) scanning angle from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$-22^\circ$</tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$+23^\circ$</tex-math></inline-formula> and the main lobe gain is 6.7 dBi.