Dual-Band EBG Frequency Reconfigurable Antenna for Integrated Communication and Sensing Applications in Mid-Band 5G

This paper presents a dual-band antenna with a single input port, designed for simultaneous communication and sensing applications. The dual functionality is achieved using the shared aperture technique, by integrating a dielectric-covered slot antenna with a planar checkerboard pattern of via and via-less <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2 \times 2$</tex> Electromagnetic Bandgap (EBG) unit cells. The upper resonance frequency is fixed at 3.5 GHz for sensing, while the lower resonance frequency is reconfigurable for communication across mid-band 5 G frequencies (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2.5 \text{GHz}, 2.1 \text{GHz}$</tex>, and 1.7 GHz). Reconfigurability is achieved using varactor diodes placed between the via and via-less EBG unit cell pairs. By varying the varactor capacitance from 0 pF to 3.1 pF, the lower resonance frequency can be tuned from 2.5 GHz to 1.37 GHz. The antenna maintains a gain above 2.5 dBi across the desired operational frequencies. The proposed structure features a simple geometry and can be scaled to larger arrays for a larger effective aperture and hence higher gain. Compared to state-of-the-art designs, the proposed antenna achieves a wide tuning range with minimal number varactor diodes.