Analysis and design of class E power amplifier considering MOSFET parasitic input and output capacitances (original) (raw)
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Analysis and design of class-E power amplifier considering MOSFET nonlinear capacitance
International Journal of Power Electronics and Drive Systems (IJPEDS), 2021
Class-E power amplifiers are integrated into many applications because their simple design and high performance. The efficiency of the power amplifier is significantly impacted by the nonlinear characteristic of the switching device, which is not analyzed clearly in theory. The nonlinear drain-tosource parasitic capacitance of the power transistor and the linear external capacitance are both contributed to the optimum conditions for obtaining the exact shunt capacitance. In this paper, a high-efficiency class-E power amplifier with shunt capacitance is designed with the consideration of both linear and nonlinear capacitance. Furthermore, a mathematical analysis is derived to calculate the component values in order to design the class-E power amplifier. Consequently, high power-added efficiency of 94.6% is obtained using MRF9030 MOSFET transistor with parameter of 4W output power and 13.56 MHz operating frequency. Finally, the measurement result of a linear class-E power amplifier circuit is obtained to compare and realize the efficiency of the proposed work.
IET Circuits, Devices & Systems, 2016
In this study, the Class-E/F 3 power amplifier with linear gate-to-drain and nonlinear drain-to-source capacitance is proposed. The analysis for the effect of the parasitic capacitance in the mixed mode Class-E/F 3 with square and sinusoidal gate-to-source voltage has been done. Most of the design equations in this study do not have analytical solutions, and the numerical analyses are used. As can be seen, there is little difference between the results related to the sinusoidal and square gate-to-source voltage. So, only the simulation and experimental result for Class E/F 3 with square gate-to-source voltage at operating frequency of 4 MHz has been done. The results in this study indicate that it is important to consider the effect of the MOSFET gate-to-drain capacitance for achieving the ZVS/ZDS conditions in the Class-E/F 3 power amplifier. The PSpice simulation and measured results are agreed with the analytical expressions, which show the validity of the presented analytical expressions. Finally, the waveforms of Class E/F 3 are compared with equivalent waveforms of Class-E power amplifier, in order to indicate its advantages.
IEEE Transactions on Microwave Theory and Techniques, 2017
A single-ended Class-E/F n power amplifier (PA) with linear external and nonlinear drain-to-source (intrinsic) capacitances is designed and analyzed to achieve optimum operation. The effects of nonlinear intrinsic and linear external capacitance at high and low frequencies increase, respectively. The different specifications of the Class-E/F 3 PA are shown versus the external and intrinsic capacitances. A Class-E/F 3 amplifier at 4-MHz frequency, based on the theoretical results, is analyzed, simulated, and fabricated. The efficiency, power gain, and output power versus the input power are presented as well. The measured results are close to the analytical derivations at optimum conditions of zero-voltage switching and zero-voltagederivative switching.
IEEE Transactions on Power Electronics, 2016
This paper presents theory and analysis for class E power amplifier considering MOSFET nonlinear gate-to-drain and nonlinear drain-to-source capacitances at any grading coefficient of the MOSFET body junction diode. The nonlinearity degree of a MOSFET parasitic capacitance is determined by the grading coefficient. When the grading coefficient is not considered in design procedure, the switch voltage waveform of the class E power amplifier does not satisfy the switching conditions, which results in a decrease of the power conversion efficiency. Therefore, the grading coefficient is an important parameter to satisfy the class E zero voltage and zero derivative switching (ZVS and ZDS) conditions. The MOSFET gate-todrain capacitance is highly nonlinear and it is more nonlinear than drain-to-source capacitance for most MOSFETs. In some cases, the change in the gate-to-drain capacitance can be as large as 100 times. The results show that this nonlinearity affects the class E power amplifier properties, such as switch voltage, power output capability, and maximum switch voltage. Therefore, it is necessary to consider the nonlinearity of the gate-to-drain capacitance, along with the drain-to-source capacitance. A design example at 4 MHz operating frequency is also given to describe the design procedure. The ZVS and ZDS conditions are achieved in the obtained switch voltage. The circuit simulation was performed using PSpice software. For verification of the presented theory, a class E power amplifier was fabricated. The measured results were verified with simulation and theory results.
IEEE Transactions on Power Electronics, 2013
TE (AS) mode. Since this frequency is of some importance, it is tabulated in Table 2. When b ϭ 1 the frequency checks the first root of J 1 Ј͑k͒ and when b approaches zero, the value of 2.150 is extrapolated. The TM modes are also important in the vibration of membranes. The lowest TM frequency (fundamental frequency) corresponds to TM (SS) and is tabulated in Table 3. When b ϭ 0 it is the first root of J 0 ͑k͒. When b approaches zero, it is infinite. In fact, the frequencies of all TM modes (and all TE (SA) modes) become infinite when the thickness b approaches zero. It is seen that for b close to one (near circle) numerous modes can be excited. However, as b becomes smaller (narrower shape), the modes become more separated. For an aspect ratio of 2:1 (b ϭ 0.5), there are seven modes for k below 6. The field lines are shown in Figure 2. If the waveguide is made narrower, say b ϭ 0.2 (5:1 ratio), there are only three widely separated modes for k below 6.5 (see Fig. 3). There is no improvement for even narrower waveguides. In conclusion, we find the Ritz method is efficient and accurate for this problem. Our results should be useful in the design of waveguides.
IEEE Transactions on Power Electronics, 2018
In this paper, the effects of the duty ratio variation on the class-E M power amplifier are studied and analyzed, including nonlinear gate-to-drain and drain-to-source parasitic capacitances. The duty ratio is one of the important parameters in class-E M power amplifiers, which has high effects on the switch voltage and current waveforms, output power, efficiency, power loss, and output phase shift. To achieve a better agreement between theoretical and experimental results, the nonlinear gateto-drain and drain-to-source parasitic capacitances are included in theoretical analysis. To demonstrate the validity of the presented analysis, five class-E M power amplifiers are designed, simulated, fabricated, and tested using IRF510 MOSFET with duty ratio equal to 0.5, 0.6 and 0.7 and IRFZ24N MOSFET with duty ratio equal to 0.5 with and without considering MOSFET nonlinear capacitances. It is shown that the amplifier with IRFZ24N MOSFET has higher efficiency than that with IRF510 MOSFET. This is because of the lower drain-to-source on-state resistance of the IRFZ24N MOSFET. The obtained efficiency with IRFZ24N MOSFET considering nonlinear capacitances at the operating frequency of 3.5 MHz was 95.7%. The obtained output power for IRF510 and IRFZ24N MOSFETs at duty ratio equal to 0.5 were 14.41 W and 17.82 W, respectively. Simulation and theoretical results are performed using PSpice and MATLAB, respectively. The theoretical results and PSpice simulations agreed with experimental results.
Design of Class-EM Power Amplifier at any DC voltage source considering nonlinear capacitances
International Journal of Electronics, 2018
In this paper, the effects of the DC input voltage source on the class-E M power amplifier design and specifications at 4 MHz operating frequency are investigated. The most important parameters of the class-E M power amplifier are the output power, output power capability, maximum voltage and current of the MOSFETs and power conversion efficiency which are all dependent on the input DC power supply. In this paper, IRFZ24N and IRF510 transistors have been used for the presented designs. The measured efficiency and output power at DC source voltage of the main circuit equal to 12 V for the proposed class-E M power amplifier with IRFZ24N are 96.2 % and 21.78 W, respectively. The measured results for IRFZ24N are consistent with simulation and analysis results.
A Class e Power Amplifier with Low Voltage Stress
2015
A new output structure for class E power amplifier (PA) is proposed in this paper. A series LC resonator circuit, tuned near the second harmonic of the operating frequency is added to the output circuit. This resonator causes low impedance at the second harmonic. The output circuit is designed to shape the switch voltage of the class E amplifier and lower the voltage stress of the transistor. The maximum switch voltage of the conventional class E PA is 3.56Vdc. However, higher switch voltage of about 4.5VDC may be occurred, by considering nonlinear drain-to-source capacitance in class E PA. The obtained peak switch voltage of the designed class E PA is approximately 75% of the conventional one with the same conditions, which shows a significant reduction in peak switch voltage. MOSFET parasitic nonlinear gate-to-drain and nonlinear drain-to-source capacitances of the MOSFET body junction diode also affect the switch voltage in class E PA, which are considered in this paper. The actu...
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 Power Electronics, 2020
In this study, the design of the class-E M power amplifier is presented. In this design, the effects of on-state resistance and non-linear parasitic capacitances of the transistors are investigated. Two metal oxide semiconductor field-effect transistors (MOSFETs) of IRFZ24N and IRF510 with different drain-source resistances are used in the presented circuits. In the given design, the values of the operational frequency and duty ratio are 3.5 MHz and 0.5, respectively. This study shows the importance of considering non-linear parasitic elements of MOSFET, especially drain-source resistance in the designing of the class-E M power amplifiers. It is shown that the class-E M power amplifier with high MOSFET drain-source resistance needs high DC input voltage for both the primary and auxiliary circuits. In the previous works, non-linear on-state resistance and non-linear drain-source and gate-drain capacitances have not been included at the same time in the analyses. Two class-E M amplifiers contain IRF510 and IRFZ24N are designed, simulated, and measured. The efficiency equal to 96.6% with 11.851 W output power at 3.5 MHz and the efficiency equal to 88.4% with 12.361 W output power are achieved for presented class-E M amplifiers contain IRFZ24N and IRF510, respectively.