We have studied the design of a WPT system to feed multiple loads with high power and high efficiency. But a system based on a 50-ohm power source is of low efficiency, and hence, impracticable. Thus, we must design the system using a constant voltage source or a constant current source. But there is a problem that multiple loads are not fed with high power by the constant voltage source. So we tried to design the system with a constant current source. Also we have introduced to measure the system by a VNA to obtain S-parameters and transform them into Z-parameters to calculate the transmitted power and efficiency under excitation by a constant current source.