Comparison of Screen- and Inkjet-Printed Meshed Wideband Antennas for Conformal IoT Applications

An experimental comparison is presented between screen- and inkjet-printed realizations of a meshed coplanar waveguide (CPW)-fed planar monopole antenna that was proposed in an earlier publication. Several prototypes were manufactured on 125 μm-thick polyethylene terephthalate (PET) foil using silver nanoparticle (AgNP) ink. Additionally, the antenna's flexibility was studied by conducting measurements under cylindrical deformation, with various bending radii imposed under different orientations. It is shown that the geometrical accuracy of the printed mesh pattern and the surface roughness of the deposited ink layer depend on both the ink properties and the printing process, affecting the mesh strategy's effective ink reduction potential. By optimizing the drop-to-drop distance parameters in the inkjet-printed process, ink reduction levels over 90% are achieved. Furthermore, measurements show that all antennas, either manufactured using screen or inkjet printing, exhibit excellent wideband operation, covering the IMT/LTE-1/n1 (1.92–2.17 GHz), LTE-40/n40 (2.30–2.40 GHz), 2.45 GHz industrial, scientific, and medical (ISM) (2.40–2.4835 GHz), IMT-E/LTE-7/n7 (2.50–2.69 GHz), and n78 5G (3.30–3.80 GHz) frequency bands. This performance is preserved both in flat deployment and under cylindrical deformation, demonstrating the antenna's great potential for cost-sensitive conformal Internet of Things (IoT) applications.