Scott Kee

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− − − − The first switching amplifier in the new E/F 2,odd class belonging to the new E/F x family of switching power amplifiers has been successfully demonstrated. This push/pull amplifier exhibits 1.1kW, 85% drain efficiency and 17dB gain at 7MHz. The amplifier uses low cost switching MOSFETs and fits in a small volume of only 900cm 3 including an(More)
—A new family of switching amplifiers, each member having some of the features of both class E and inverse F, is introduced. These class-E/F amplifiers have class-E features such as incorporation of the transistor parasitic capacitance into the circuit , exact truly switching time-domain solutions, and allowance for zero-voltage-switching operation.(More)
—A novel on-chip impedance matching and power-combining method, the distributed active transformer is presented. It combines several low-voltage push–pull amplifiers efficiently with their outputs in series to produce a larger output power while maintaining a 50-match. It also uses virtual ac grounds and magnetic couplings extensively to eliminate the need(More)
—In this paper, we compare the performance of the newly introduced distributed active transformer (DAT) structure to that of conventional on-chip impedance-transformations methods. Their fundamental power-efficiency limitations in the design of high-power fully integrated amplifiers in standard silicon process technologies are analyzed. The DAT is(More)
—Concentric distributed active transformers (DAT) are used to implement a fully-integrated quad-band power amplifier (PA) in a standard 130 nm CMOS process. The DAT enables the power amplifier to integrate the input and output matching networks on the same silicon die. The PA integrates on-chip closed-loop power control and operates under supply voltages(More)
A 2.4-GHz, 2.2-W, 2-V fully integrated circular geometry power amplifier with 50 Ω Ω Ω Ω input and output matching is fabricated using 2.5V, 0.35 µ µ µ µm CMOS transistors. It can also produce 450mW using a 1V supply. Harmonic suppression is 64dB or better. An on-chip circular-geometry active-transformer is used to combine several push-pull low-voltage(More)
—A novel structure distributed active transformer (DAT), which significantly reduces the coupling from the DAT to the feed line is demonstrated. A grounded guard line is implemented to isolate the feed line from the magnetic field of the DAT. The measured result of the DAT on a GaAs substrate shows a 10.5-dB reduction in the coupling. To reduce DAT loss, an(More)
Acknowledgement I would like to express my deep and sincere gratitude to all who made this work possible. I am especially grateful to Professor Ali Hajimiri for his constant support and guidance throughout my Ph.D. studies. His broad vision, together with his remarkable knowledge of our field of research, has proved to be invaluable in defining my research(More)