Novel Design Procedure for Class-${\rm E}_{\rm M}$ Power Amplifiers

Closed-Form Design Equations for Class-EM Power Amplifier with Isolation Circuit

“…Crucially, the analysis of the auxiliary circuit was not presented in [2], thus, the ZVS condition was not fulfilled in the auxiliary circuit, resulting in a poor efficiency of 58% for the auxiliary circuit although the main circuit exhibits a high efficiency of 89%. This issue was addressed in [3]- [4] where both the main and auxiliary circuits were analyzed simultaneously, but this results in a large system of nonlinear equations requiring to be solved by numerical methods, thus adding to the complexity in the design of a Class-EM PA. Furthermore, we failed to reproduce the idealized switch voltage and current waveforms using the component values provided in Table IV of [4].…”

“…This issue was addressed in [3]- [4] where both the main and auxiliary circuits were analyzed simultaneously, but this results in a large system of nonlinear equations requiring to be solved by numerical methods, thus adding to the complexity in the design of a Class-EM PA. Furthermore, we failed to reproduce the idealized switch voltage and current waveforms using the component values provided in Table IV of [4]. The simultaneous analysis presented in [5]- [6], takes into account the interaction between the main and the auxiliary circuit at f0, 2f0 and 3f0 resulting in a large system of equations with no explicit design equations provided.…”

Push-Pull Class-${\rm E}_{\rm M}$ Power Amplifier for Low Harmonic-Contents and High Output-Power Applications

“…1(c). Generally, the nonlinear characteristic of the MOSFET drain-to-source capacitance is expressed as [2], [12]- [14] ( 2) where is the built-in potential, which typically ranges from 0.5 to 0.9 V for silicon devices, is the switch voltage, and is the capacitance at . When the MOSFETs are selected, the parasitic capacitance parameters are fixed.…”

“…In particular, this operation is attractive when the transistor has a long turn-off switching time. By allowing the slow switching of the switching devices, the driving power can be reduced and low-cost switching devices can be used for circuit implementations [1], [2]. Therefore, the classpower amplifier achieves high power-conversion efficiency at high frequencies with low cost by adding the auxiliary circuit.…”

“…The former, however, pays high-cost to realize the amplifier. The latter suffers from the power-added-efficiency reduction [2]. Therefore, the slow-switching devices are allowed and the cost reduction is possible compared with the switching devices having jumps of the switch-voltage and switch-current waveforms, which is a feature of the classpower amplifier [1], [2].…”