Multiple pickup operation is a common scenario for IPT applications. In this scenario, constant current output is often required at the transmitter to avoid a complicated control method at the pickups. The LCL-T topology has been widely used to produce a constant output current for variable loads. This paper will present the analysis, simulation and test of a LCL-T resonant converter. The work here considers the load as a variable impedance comprising both a variable resistance and a variable inductance. The trade-off of LCL-T topology is discussed in the frequency domain to solve the off-resonant problem in a large load range. A 100W LCL-T resonant inverter operating at 50kHz is developed and the experimental results verify that the proposed method can reduce the reactive power required at partial load and ensure constant current output and ZVS in the whole load range.