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D.G.H. Tan

Bio: D.G.H. Tan is an academic researcher. The author has contributed to research in topics: Amplifier & Switching time. The author has an hindex of 1, co-authored 1 publications receiving 5 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, a state-space model is developed to enable a general analysis of the class E amplifier with a power-MOSFET switch under non-optimal and optimal conditions.
Abstract: A state-space model is developed to enable a general analysis of the class E amplifier with a power-MOSFET switch under nonoptimal and optimal conditions. That is, it permits analysis of nonzero voltage switching and nonzero current switching operation, as well as the optimal zero voltage switching (ZVS) and zero current switching (ZCS) condition. This is achieved by improving the representation of the power MOSFET switch by the inclusion of a series inductance, a model for the on-state resistance and switching time, and a model for the anti-parallel body diode. An optimal 100-kHz class E amplifier was designed and constructed, using the model to choose component values. Experimental results show good agreement with the predictions of the state-space model for both optimal and nonoptimal operating conditions.

5 citations


Cited by
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Journal ArticleDOI
TL;DR: A new iteration-free steady-state analysis to the Class-E power amplifier (PA) in frequency-domain is proposed by extending the scope of electrical impedance by expressing the impedances of different circuit components in the classes, including the active switches, in matrix form.
Abstract: This paper proposes a new iteration-free steady-state analysis to the Class-E power amplifier (PA) in frequency-domain by extending the scope of electrical impedance. Owning to this extension, the impedances of different circuit components in the Class-E PA circuits, including the active switches, can be expressed in matrix form. Based on the conventional circuit laws, e.g., the series and parallel laws and the Ohm's law, the steady-state characteristics of a whole Class-E PA circuit can be obtained by vector and matrix manipulation. The number of harmonics involved in the calculation have effects on the computational efficiency and accuracy. The influences of some circuit conditions towards the selection of harmonic number are discussed. The proposed formulation enables fast mapping of some performance indices, e.g., the output power and conversion efficiency, under steady state, so that the changing trends of these indices with respect to the variations of specified circuit parameters can be estimated. This feature can be utilized to carry out offline optimization by tuning some passive components, or online optimization by tuning two in situ adjustable parameters, i.e., the switch driving frequency and duty cycle. The later scheme provides preliminary knowledge on the in situ tuning of Class-E PA in the load varying applications, e.g., electric process heating and wireless power link.

34 citations

Proceedings ArticleDOI
22 May 2016
TL;DR: It is proved that the EIM based optimization of the class-E power amplifier circuit can be efficiently simulated and optimized in the frequency domain much faster than the state-of-the-art numericalclass-E PA optimization.
Abstract: It has been shown in the previous study that the class-E power amplifier (PA) circuit can be efficiently simulated and optimized in the frequency domain by modeling the whole circuit with the extended impedance method (EIM). This paper reports a breakthrough in the EIM based class-E PA design by taking the nonlinear components into consideration. In analysis, the effect of the two state-dependent nonlinear components in a practical MOSFET switch, i.e., the parasitic drain-to-source junction capacitance and the body diode, is turned into the time-dependent characteristics by carrying out the states-to-time mapping. Iterative computation is necessary for obtaining the steady-state waveforms in view of the nonlinear components. Yet, given the high efficiency of EIM, it is proved that the EIM based optimization runs much faster than the state-of-the-art numerical class-E PA optimization.

9 citations

Proceedings ArticleDOI
31 Oct 2005
TL;DR: A circuit model of the amplifier with parasitic or stray components is developed to explain the phenomenon and its underlying cause, which causes the circuit to deviate from the desired class E operation.
Abstract: For class E power amplifier circuits operating at switching frequencies of the MHz range or higher, the parasitic capacitance of the MOS transistor switch becomes a significant part of the circuit adding to the usual intended circuit components. For the class E power amplifier, this is often regarded as an advantage because the parasitic capacitor can be utilized for achieving zero voltage and current switchings, thus reducing the size of an external capacitor which has to be inserted. However, parallel connection of parasitic, stray and external capacitors may give rise to high-frequency ringings of the voltage across the switch, causing the circuit to deviate from the desired class E operation. In this paper, the phenomenon and its underlying cause is studied by simulations and experiments. A circuit model of the amplifier with parasitic or stray components is developed to explain the phenomenon.

4 citations

Proceedings ArticleDOI
14 May 2006
TL;DR: In this article, a photo-switched Class E amplifier was proposed, which uses a photoswitch as active device instead of a transistor and achieves the best simulated efficiency of 62.5%.
Abstract: Class E amplifier theoretical efficiency is 100%, but the practical results at 10 GHz are much lower. In this paper, we propose a Class E amplifier that uses a photoswitch as active device instead of a transistor. The photoswitch opening and closing is controlled by light pulses. We used Silvaco software to do simulations of such an amplifier. Using this design, our best simulated efficiency at 10 GHz is 62.5%.

2 citations