To enhance continuous availability of 5G/6G user equipment and without having to occasionally recharge the battery using the conventional method of connection to power source using a physical cable, energy harvesting technique is a feasible option being explored. This paper briefly presents the concept of energy harvesting and with a particular focus on the design considerations for Harvesting RF Energy uses 5G/6G user equipment. The design presented on this paper, which was done with the Keysight Advanced Design System (ADS) software, provides a positive correlation between RF input power and both output voltage and power, with significant increases observed when the RF input exceeds −5 dB for voltage and 5 dB for power. The rectifier-based design achieved a maximum output voltage of 1.7 V and an output power of 15 mW at 20 dB. This establishes the fact that the higher the RF input power, the higher the energy that can be harvested from it. A typical mobile phone uses about 15 mW when on standby and 1.5 W while being used.