11.5 CLASS E WITH FINITE DC-FEED INDUCTANCE
In real practice, it is impossible to realize an RF choke with infinite impedance at the fundamental frequency and its harmonic components. Moreover, using a finite dc-feed inductance has an advantage of minimizing size, cost, and complexity of the overall circuit. The detailed approach to analyze the effect of a finite dc-feed inductance on the idealized Class E mode with shunt capacitance and series filter was firstly described in [48]. It was based on Laplace-transform technique to solve a second-order differential equation describing the behavior of a Class E load network with finite dc-feed inductance. Later this approach was extended to the load network with finite QL-factor of the series filter and finite device saturation resistance [49,50]. However, since the results of excessive analytical and numerical calculations are given only for a few particular cases, it is difficult to figure out the basic behavior of the load network elements and define simple equations for their parameters. Generally, based on the composing of the circuit equations in the form of a system of the first-order differential equations for currents and voltages and setting the design specifications, the optimum Class E load network parameters can be numerically calculated taking into account the finite dc-feed inductance, drain current fall time, finite QL-factor, nonzero device saturation resistance, and nonlinear operation of any passive element simultaneously ...
