Radio Frequency Energy Harvesting Receiving Antenna for sub-6 GHz Bluetooth and Wi-Fi Application Bands of 5G Technology

Radio frequency (RF) energy harvesting finds application in wireless sensors, RF codes, smart switches, IoT device applications, etc. Contrary to batteries, RF energy harvesting is open to electromagnetic waves coming from different sources and there is no limitation on the dimension and duration of application. A RF energy harvester captures electromagnetic energy from the source to which it is exposed and convert this energy into usable DC voltage. In this paper we propose the fundamental unit of RF harvester, the microstrip patch antenna. Microstrip patch antenna comes with a host of qualities like small size, low price, simple design, less weight, easy fabrication and many more. The proposed microstrip patch RF energy harvest antenna is developed using FR4 substrate with dielectric constant 4.4 and loss tangent 0.009. The substrate comes in between the ground and copper metal patch. Selected target frequency of operations is 2.4 GHz and 5 GHz, which lie in the Wi-Fi band. A microstrip line of width 1.1 mm for 50 impedance load matching is used. The antenna is inset-fed. The design and simulation are carried out using High-Frequency Structure Simulator (HFSS) software and the antenna dimensions are due to standard antenna equations. Simulation results achieved gain of 7 dBi at 2.4 GHz with low return loss (S11 parameter). The return loss stands near – 13 dB. The gain of the RF harvester at 5 GHz frequency operation is obtained to be 6 dBi with a remarkable low return loss of – 28 dB. With the given results and stable omnidirectional radiation pattern, the proposed antenna design is suitable for energy harvesting application for mm wave application viz. Bluetooth, Wi-Fi, and WiMAX applications, as an alternate energy source meeting the global energy requirement due to increase in demand of power.