Additively manufactured polyethylene terephthalate-based high-gain multiband-flexible antenna for wireless mobile applications

This paper presents a novel additively manufactured antenna array on a flexible polymeric substrate for conformal mobile applications. The antenna consists of two identical z-shape patch elements integrated with symmetrical arrangements and right-angle ground assemblies to converge the dispersed radiation pattern for gain improvement. For planar feeding and fabrication, the antenna is fed with a coplanar waveguide and, horizontal defected ground structures are used in the patch to achieve multiband characteristics. The prototype antenna, fabricated with silver nanoparticles (AgNPs) using precision piezoelectric inkjet-printing technique, exhibited operation across five different frequency bands: 0.58–0.83 GHz, 1.39–1.58 GHz, 2.40–2.43 GHz, 2.88–3.52 GHz, and 4.93–5.15 GHz, covering mobile radios, GPS, UMTS, Wi-Fi, ISM, Bluetooth, WLAN, WiMAX, and sub-6 GHz 5G applications. Surface morphological studies of deposited conductive pattern of silver nanoparticles are also evaluated to confirm its smooth and uniform deposition. The antenna demonstrates an omnidirectional pattern with a peak gain of 12 dBi at 3.21 GHz and a measured impedance bandwidth of 640 MHz that show a good agreement with the simulation. The prototype antenna is also tested under bent conditions (radius of 3, 4, and 5 cm) and, the measured performance depicts apart from the minor shift in S11, it still performs sufficiently well. Comparison with existing literature reveals a significant improvement in gain, making this antenna superior in performance. The antenna’s robust performance under deformation, combined with its high gain and multiband capabilities, makes it excellent candidate for wearable electronics and conformal wireless mobile communication applications. This work paves the way for future advancements in flexible and high-performance antennas for next-generation wireless technologies.