Push–Pull Class $\Phi _{\text{2}}$ RF Power Amplifier

Li, Gu; Zulauf, Grayson; Zhang, Zhemin; Chakraborty, Sudipta; Rivas-Davila, Juan

doi:10.1109/tpel.2020.2981312

Cited by 36 publications

(16 citation statements)

References 41 publications

(90 reference statements)

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“…These systems implement state-of-theart megahertz power electronics designs at both ends of the system (e.g. [14]- [20]), allowing high efficiency to be achieved independent of large changes in load and large changes in the induced voltage on the receive coil.…”

Section: Introductionmentioning

confidence: 99%

Load Characterization in High-Frequency IPT Systems Using Class EF Switching Waveforms

Arteaga

Pucci

Lan

et al. 2021

IEEE Trans. Power Electron.

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Large magnetic field volumes associated with coreless high frequency inductive power transfer (HF-IPT) systems allow multiple receivers to be powered from one transmitter, but also provide greater probability for foreign objects to couple to the system. Knowledge of the types of objects (legitimate receivers or otherwise) that are coupled to the transmitter is critical. Such knowledge on the transmit side would allow the system to be deactivated in the presence of foreign objects, and to determine the exact state of tuning of the receivers so that it may adjust itself accordingly to optimise system performance. This paper introduces a technique to calculate the induced voltage generated by coupled receivers and foreign objects on the transmit coil in real-time. Changes in the position or electrical quantities of the receivers, and foreign objects, alter the induced voltage on the transmit coil, and with it the trajectory of the switching waveforms of the inverter driving the transmit coil. From the shape of these waveforms, information on the phase and amplitude of the induced voltage can be extracted, thus enabling the induced voltage on the primary to be estimated with a single, easy to access, voltage measurement, which is easier than estimating the induced voltage from measurements of coil current and total coil voltage. We used a support-vector-machine (SVM) to perform regression analysis on the drain voltage data. The experimental setup uses a 100 W, 13.56 MHz Class EF inverter, and the model was generated from a large number of samples of the drain voltage waveforms operating at different known loads. These were generated from our in-house HF-IPT test load, which uses a Class EF synchronous rectifier. The results allow the induced voltage on the transmit coil to be estimated in real time from the drain voltage waveform alone, with a normalised root mean square error of 1.1 % for the real part (reflected resistance) and 1.2 % for the imaginary part (reflected reactance).This paper is accompanied by a video file demonstrating the experiments.

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Section: Introductionmentioning

confidence: 99%

Load Characterization in High-Frequency IPT Systems Using Class EF Switching Waveforms

Arteaga

Pucci

Lan

et al. 2021

IEEE Trans. Power Electron.

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“…High frequency power converters are used in several applications, e.g., home theater systems (audio) and motor drives. Some of these types of converters are also suitable for CPT, such as: class D, class E, class EF and class φ converters [85][86][87][88][89][90][91][92][93][94]. By using a resonant LC tank, these converters can be designed to operate in zero voltage switching (ZVS) mode at high switching frequencies.…”

Section: Power Amplifier Based Convertermentioning

confidence: 99%

A Review of the Current State of Technology of Capacitive Wireless Power Transfer

2021

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Wireless power transfer allows the transfer of energy from a transmitter to a receiver without electrical connections. Compared to galvanic charging, it displays several advantages, including improved user experience, higher durability and better mobility. As a result, both consumer and industrial markets for wireless charging are growing rapidly. The main market share of wireless power is based on the principle of inductive power transfer, a technology based on coupled coils that transfer energy via varying magnetic fields. However, inductive charging has some disadvantages, such as high cost, heat dissipation, and bulky inductors. A promising alternative is capacitive wireless power transfer that utilizes a varying electric field as medium to transfer energy. Its wireless link consists of conductive plates. The purpose of this paper is to review the state of the art, link the theoretical concepts to practical cases and to indicate where further research is required to take next steps towards a marketable product. First, we describe the capacitive link via a coupling model. Next, we highlight the recent progress in plate topologies. Additionally, the most common compensation networks, necessary for achieving efficient power transfer, are reviewed. Finally, we discuss power electronic converter types to generate the electric field.

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“…T HE research effort regarding dc-dc converters that operate at switching frequencies of several MHz is mainly motivated by increasing the power density [1]- [13] and improving the transient response [8]- [12] of future power electronic systems. Dc-dc converters studied in this context typically base on a radio frequency (RF) power amplifier, frequently realized by the class E inverter [5]- [7], [14] or the class Φ 2 inverter [3], [8], [9], [15]- [17], in connection with a resonant rectifier stage [7]- [13], [18]. Another converter topology also basing on the mentioned combination is the quasi-resonant single-ended primary-inductor converter (SEPIC) [1], [10].…”

Section: Introductionmentioning

confidence: 99%

A Resonant Push–Pull DC–DC Converter With an Intrinsic Current Source Behavior for Radio Frequency Power Conversion

Weitz

Utzelmann

Ditze

et al. 2022

IEEE Trans. Power Electron.

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In this work, a resonant push-pull dc-dc converter suitable for switching frequencies in the MHz-range is investigated. Despite a simple design procedure with no need of multiresonant tuning, the converter topology is capable of providing a constant output current over a wide output voltage range in unregulated operation. Based on an analytical solution of steady-state operation, normalized dependencies of converter behavior are determined and used to formulate generalized design considerations. In order to verify the theoretical analysis, the design procedure of a 300 W prototype operating at a switching frequency of 6.78 MHz is described considering the impact of circuit parasitics on converter operation. The prototype provides a stable operation within the full output voltage range of 0-150 V and reaches a peak efficiency of 93% at the nominal output voltage. A rapid transient response of the converter is demonstrated by applying a closed-loop on/off-control to the prototype.

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Push–Pull Class $\Phi _{\text{2}}$ RF Power Amplifier

Cited by 36 publications

References 41 publications

Load Characterization in High-Frequency IPT Systems Using Class EF Switching Waveforms

Load Characterization in High-Frequency IPT Systems Using Class EF Switching Waveforms

A Review of the Current State of Technology of Capacitive Wireless Power Transfer

A Resonant Push–Pull DC–DC Converter With an Intrinsic Current Source Behavior for Radio Frequency Power Conversion

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