This paper reviews recent developments in the transmitter end of wireless power transfer (WPT) systems, focusing on the limitations of current solutions in addressing variations in the real part of the load resistance. Traditional Class D inverters are limited in high-frequency integrated circuit applications due to issues with parasitic capacitance charging/discharging and dead-time. While Class E inverters are more suitable for highfrequency applications, they are highly sensitive to load variations. To address this challenge, this paper proposes an impedance matching network based on dual-loop negative feedback, which can adjust in real-time according to changes in load resistance, thereby stabilizing output efficiency under varying load conditions. Through circuit design and simulation, the system achieves a maximum output efficiency of 95.16% at 100W output power and can accommodate variations in both the real and imaginary parts of the load, making it suitable for WPT system receivers with variable loads.