A Flexible and Transparent Polyethylene Based Conformal Array Antenna on for Sub-6 GHz 5G Applications

This work proposes an eight-element conformal array antenna design for Sub- 6 GHz 5G applications. The antenna is fabricated using a flexible, transparent polyethylene substrate with a dielectric constant of 2.25. Initially, a singleelement rectangular-shaped antenna is developed for a 3.5 GHz operating frequency, followed by the integration of a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2 \times 4$</tex> element array to form a corporate feeding network. The overall dimensions of the proposed antenna are <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$189.64 ~\text{mm} \times 180.4 ~\text{mm}$</tex>, with a thickness of 1 mm. Both planar and conformal array configurations are fabricated and measured. The planar 8element array antenna demonstrates a return loss of -47.5 dB, while the conformal array antenna shows a return loss of -37.7 dB, indicating a decrease of approximately -10 dB in performance for the conformal design. Despite this reduction in return loss and some degradation in gain, the simulation results suggest that both the planar and conformal array antennas offer enhanced performance. The conformal array antenna, in particular, benefits from a low-profile polyethylene substrate, higher gain, and its potential for integration into diverse applications. It is a promising candidate for use on the skin of vehicles, such as satellites and aircraft, as well as wearable antennas for Sub-6 GHz 5G systems, making it suitable for integration into smart clothing.