자료유형  

 학위논문

Control Number  

0017161423

International Standard Book Number  

9798382841922

Dewey Decimal Classification Number  

621.3

Main Entry-Personal Name  

Hou, Yuetao.

Publication, Distribution, etc. (Imprint  

[S.l.] : Cornell University., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

154 p.

General Note  

Source: Dissertations Abstracts International, Volume: 85-12, Section: B.

General Note  

Advisor: Afridi, Khurram.

Dissertation Note  

Thesis (Ph.D.)--Cornell University, 2024.

Summary, Etc.  

요약Ion-beam accelerators have been widely used in applications such as medical therapy, ion implantation and nuclear fusion. Compact and low-cost ion-beam accelerator enables wider adoption of these technologies. Multiple-Electrostatic-Quadrupole-Array Linear Accelerator (MEQALAC) has been proposed and has the potential to make a low-cost compact tabletop particle accelerator. Such accelerator needs to be driven by high-frequency power amplifiers that generate high voltages. This thesis provides steady-state modeling, circuit architectures, design methodologies and hardware implementation of an evolution of high-frequency high-efficiency compact switch-mode power amplifiers that generate voltage at kilo-volt scale suitable for MEQALAC. First, a Class-D power amplifier with a novel capacitive shunt branch is proposed and designed which achieves 10 kV output voltage with reduced transistor current. Class-E power amplifiers are then employed for frequencies beyond 27-MHz. A widely applicable steady-state model for Class-E inverter is proposed based on the Laplace-Based Steady-State Modeling (LBSM) approach. The value of this model is demonstrated by using it to design a finite-input-inductor Class-E inverter with constant output voltage in which the input inductance is selected to resonate with the shunt capacitance enabling constant output voltage and Zero-Voltage-Switching (ZVS) for a range of loading conditions. The proposed approach results in an accurate selection of the inductance value of the input inductor. This approach to inductance value selection is much faster than but equally accurate to a simulation-based approach.Moreover, a novel optimization approach is proposed to optimize the dimensions of an aircore toroidal inductor and improve system efficiency. A toroidal inductor with an outer diameter of 8.4 cm and an operating frequency of 50 MHz optimized using this approach achieves a quality-factor of 595. To extend the thermal limit of the power amplifier and improve its reliability and operation time in vacuum, a stacked power amplifier architecture using air-core transformers is proposed to combine multiple inverters. A 27-MHz compact power amplifier is built based on the proposed architecture and design methodology. This power amplifier generates more than 6 kV output voltage from 20 V dc input voltage, featuring a voltage gain of more than 399, while operating at greater than 5% duty ratio in vacuum.Finally, a novel vertically stacked piezoelectric transformer structure with piezoelectric resonator and substrate is proposed. Two generations of prototype piezoelectric transformers are built and tested to verify the proposed structure which achieves 3 - 6 voltage gain at MHz operating frequency with less than 6mmx6mm area and up to 80V voltage rating. The piezoelectric transformers show potential to replace magnetics used in the conventional power amplifiers. Limitations of the prototype piezoelectric transformer voltage rating is discussed which leads to future work. The piezoelectric resonator used in building the piezoelectric transformers is studied in DC-DC power conversion. A merged switched-capacitor piezoelectric-resonator based DC-DC converter is proposed which achieves high efficiency across a wide range of conversion ratio.

Subject Added Entry-Topical Term  

Electrical engineering.

Subject Added Entry-Topical Term  

Applied physics.

Subject Added Entry-Topical Term  

Energy.

Index Term-Uncontrolled  

High voltage

Index Term-Uncontrolled  

Ion accelerators

Index Term-Uncontrolled  

Piezoelectric component

Index Term-Uncontrolled  

Power amplifiers

Index Term-Uncontrolled  

Radio frequency

Added Entry-Corporate Name  

Cornell University Electrical and Computer Engineering

Host Item Entry  

Dissertations Abstracts International. 85-12B.

Electronic Location and Access  

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Control Number  

joongbu:655621