This paper presents the effect of coupling between the coils on the power amplifier efficiency and comparisons between the class-C and class-D performance for different coupling conditions. In remotely powered systems, the coupling of the coils can influence the reflected load impedance seen by the power amplifier. The appropriate power amplifier needs to be chosen to deliver the power efficiently for different load conditions. The study also discusses the advantages and drawbacks of designing the class-C and class-D amplifiers.