Design and optimization of a hexagonal-slotted wideband microstrip antenna for 5 G networks RF energy harvesting

This research work presents the design, modeling, and experimental validation of a wideband coplanar waveguide (CPW)-fed circular patch antenna integrated with hexagonal ring slots. Three antenna configurations of the proposed model are analyzed, with the final optimized design (Antenna 3) achieving superior performance. Simulated resonant frequencies are observed at 4.6 GHz, 5.9 GHz, and 7.5 GHz with S₁₁ values of –26 dB, –40 dB, and –27 dB, while measured results show resonances at 4.6 GHz, 5.9 GHz, and 7.4 GHz with S₁₁ values of –27 dB, –35 dB, and –23 dB. The simulated and measured –10 dB bandwidths range from 3.7 GHz to 8.5 GHz (equal to 4.8 GHz) and from 3.9 GHz to 8.0 GHz (equal to 4.9 GHz), respectively, confirming wideband behavior. A parallel RLC equivalent circuit model is developed to analyze the resonant behavior, offering theoretical insights that align well with simulation results. The proposed model is validated through current distribution, VSWR, gain analysis, as well as comparison with prior designs. Simulated and measured H-plane and E-plane radiation patterns further confirm stable omnidirectional and bidirectional characteristics across the frequency range. These attributes demonstrate effective impedance matching, strong radiation efficiency, and suitability for multiband operation. Wide operating bandwidth and reliable RF characteristics make it an excellent choice for RF energy harvesting (RFEH) and wireless energy transmission in emerging 5G communication systems.