Modeling and Analysis of Class-E Amplifier With a Shunt Inductor at Sub-Nominal Operation for Any Duty Ratio (original) (raw)
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Variable-Voltage Class-E Power Amplifiers
IEEE Journal of Solid-state Circuits, 2007
The Class-E power amplifier is widely used due to its high efficiency, resulting from switching at zero voltage and zero slope of the switch voltage. In this paper, we extend general analytical solutions for the Class-E power amplifier to the ideal single-ended Variable-Voltage Class-E (Class-Evv) power amplifier that switches at zero slope but not necessarily at zero voltage.
IEEE Transactions on Power Electronics, 2015
This paper presents analytical expressions for the Class-E/F 3 power amplifier with a nonlinear shunt capacitor for satisfying the nonoptimum condition at 50% duty ratio. The design parameters for achieving the nonoptimum condition are expressed as a function of the phase shift and dc supply voltage. The Class-E/F 3 amplifier with nonoptimum condition increases one design degree of freedom compared with the optimum conditions. Because of the increase in the design degree of freedom, one more relationship can be specified as a design specification. The following parameters series reactance, peak switch voltage, output power capability, and maximum operating frequency are presented. Based on analytical results, an example of the Class E/F 3 at operating frequency of 4 MHz is analyzed. The PSpice simulation and measured results agree with the analytical expressions, which show the validity of our analytical expressions at zero-voltage switching. Index Terms-Mixed mode, nonlinear capacitance, nonoptimum operation and zero-voltage switching (ZVS), power amplifier. I. INTRODUCTION T HE nonoptimum operation of the amplifier occurs when the zero-voltage switching (ZVS) condition is satisfied, but the zero-voltage-derivative switching (ZDS) is not equal to zero at the switch turns ON instant. The concept of nonoptimum operation of the Class-E amplifier was defined in the beginning of the Class-E history [1]-[4]. The first research on nonoptimum operation has been done by Raab [1]. In this paper, the degree of freedom for the design amplifier was increased, and the ZDS condition was removed. The mixed-mode power amplifiers are the good choice for obtaining high-power and high conversion efficiency. The optimum conditions of the mixed-mode power amplifier families with a shunt capacitor have been presented in [5]-[7]. But the exact analysis on switch mode PAs are not presented. However, all of the Class-E/F amplifier analyses focus on how to achieve the optimum operation. Many power electronic devices only need to ZVS or zero-current switching (ZCS) condition [8]-[20].
Switching Behavior of Class-E Power Amplifier and Its Operation Above Maximum Frequency
IEEE Transactions on Microwave Theory and Techniques, 2012
The switching behavior of Class-E power amplifiers (PAs) is described. Although the zero voltage switching can be performed properly, the charging process at the switch-off transition cannot be abrupt and the waveform deviates from the ideal shape, degrading the efficiency. For the operation above maximum frequency, the charging process should be even faster but it cannot follow. Moreover, the discharging process is not sufficiently fast and further degrades the efficiency. The discharging process is assisted by the bifurcated current at saturation. The performance of the Class-E PA above the maximum frequency is enhanced by the nonlinear , which helps to shape the voltage waveform. The bifurcated current itself cannot generate enough of a second-harmonic voltage component to shape the required voltage waveform. The performance of the Class-E PA can be further improved by a second-harmonic tuning and a conjugate matched output load, leading to the saturated PA. Compared with the Class-E PA, the saturated amplifier delivers higher output power and efficiency. A highly efficient saturated amplifier is designed using a Cree GaN HEMT CGH40010 device at 3.5 GHz. It provides a drain efficiency of 75.8% at a saturated power of 40.2 dBm (10.5 W).
Design of Class E Power Amplifier with New Structure and Flat Top Switch Voltage Waveform
IEEE Transactions on Power Electronics, 2018
In this paper, a new topology of the class E power amplifier (PA) is proposed. The output circuit in the proposed power amplifier is different from that in the conventional class E PA. The conventional output circuit of class E power amplifier consists of shunt capacitor, resonant capacitor, resonant inductor, and shifting inductor. An additional shunt capacitance is added between the resonant capacitance and the shifting inductor to shape the reduced switch voltage. The peak switch voltage of the proposed class E PA is approximately 78% of that of the conventional one, which shows a reduction in peak switch voltage. The lower peak switch voltage reduces the breakdown voltage of the active device. Also, the proposed structure can introduce a new family of switching power amplifiers with interesting specifications. Several values of switch voltage reduction and output power capability could be achieved by varying the circuit elements. Zero voltage and zero derivative switching (ZVS and ZDS) conditions are achieved in the switch voltage of the designed circuit. The simulation of the proposed circuit is performed using PSpice software. For verification, the presented PA is fabricated and measured.
IET Circuits, Devices & Systems, 2016
In this study, design theory and analysis for the class E power amplifier (PA), considering the metal oxide semiconductor field effect transistor (MOSFET) parasitic input and output capacitances, are proposed. The input resistance and capacitances cause non-ideal input voltage at gate terminal, which affect the specifications of the class E PA. In the proposed study, non-linear drain-to-source, linear gate-to-drain and linear gate-to-source MOSFET parasitic capacitances are considered, while zero voltage and zero derivative switching conditions are achieved. Moreover, the input resistance and the value of the input voltage are taken into account in the design theory. According to the obtained results, the duty cycle of the MOSFET depends on the MOSFET threshold voltage, input voltage, input series resistance, and some other parameters, which will be explained in this study. A design example is finally given to describe the design procedure at 1 MHz operating frequency along with the experimental result. The circuit simulation is also performed using PSpice software. The measured results showed quantitative agreements with simulation and theory results.
Analytical Design Equations for Class-E Power Amplifiers
IEEE Transactions on Circuits and Systems I-regular Papers, 2007
Many critical design trade-offs of the Class-E power amplifier (e.g power efficiency) are influenced by the switch onresistance and the value of dc-feed drain inductance. In literature, the time-domain mathematical analyses of the Class-E power amplifier with finite dc-feed inductance assume zero switch onresistance in order to alleviate the mathematical difficulties; resulting in non-optimum designs.
Generalized Class-E Power Amplifier With Shunt Capacitance and Shunt Filter
IEEE Transactions on Microwave Theory and Techniques, 2019
This paper presents a generalized analysis of the Class-E power amplifier (PA) with a shunt capacitance and a shunt filter, leading to a revelation of a unique design flexibility that can be exploited either to extend the maximum operating frequency of the PA or to allow the use of larger active devices with higher power handling capability. The proposed PA fulfills zero voltage switching (ZVS) and zero voltage derivative switching (ZVDS) conditions, resulting in a theoretical dc-to-RF efficiency of 100%. Explicit design equations for the load-network parameters are derived, and the analytical results are confirmed by harmonic-balance simulations. Two PA prototypes were constructed with one designed at low frequency and the other at high frequency. The first PA, which employs a MOSFET and a lumped-element load-network, delivered a peak drain efficiency (DE) of 93.3% and a peak output power of 37 dBm at 1 MHz. The second PA, which employs a GaN HEMT and a transmissionline (TL) load-network to provide the drain of the transistor with the required load impedances at the fundamental frequency as well as even and odd harmonic frequencies, delivered a peak DE of 90.2% and a peak output power of 39.8 dBm at 1.37 GHz.
An-Analysis-Of-Comparative-Class---E-Power-Amplifier.pdf
High power wideband amplifiers are demanded in many application areas, such as software defined radio, electronic warfare (EM), instrumentation systems, etc. The quality of the wireless communication system requires demand for compact, low-cost, and low power transportable transceivers has augmented dramatically. Among the transceiver’s building blocks is that the power electronic equipment. Thus, there's a desire for low-priced power electronic equipment. It’s necessary to think about the MOSFET gate-to-drain capacitance for achieving the class-E Zero Voltage Switching conditions. As a result, the ability output capability and therefore the power conversion potency are full of the MOSFET gate-to-drain capacitance. The waveform obtained from Analog to Digital simulations and circuit experiments showed the quantitative agreements with the theoretical predictions.