Browsing by Author "Katko, Alexander R"

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    A microwave metamaterial with integrated power harvesting functionality
    (Applied Physics Letters, 2013-10-14) Hawkes, Allen M; Katko, Alexander R; Cummer, Steven A
    We present the design and experimental implementation of a power harvesting metamaterial. A maximum of 36.8% of the incident power from a 900 MHz signal is experimentally rectified by an array of metamaterial unit cells. We demonstrate that the maximum harvested power occurs for a resistive load close to 70 Ω in both simulation and experiment. The power harvesting metamaterial is an example of a functional metamaterial that may be suitable for a wide variety of applications that require power delivery to any active components integrated into the metamaterial. © 2013 AIP Publishing LLC.
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    Phase conjugation and negative refraction using nonlinear active metamaterials.
    (Phys Rev Lett, 2010-09-17) Katko, Alexander R; Gu, Shi; Barrett, John P; Popa, Bogdan-Ioan; Shvets, Gennady; Cummer, Steven A
    We present an experimental demonstration of phase conjugation using nonlinear metamaterial elements. Active split-ring resonators loaded with varactor diodes are demonstrated theoretically to act as phase-conjugating or time-reversing discrete elements when parametrically pumped and illuminated with appropriate frequencies. The metamaterial elements were fabricated and shown experimentally to produce a time-reversed signal. Measurements confirm that a discrete array of phase-conjugating elements act as a negatively refracting time-reversal rf lens only 0.12λ thick.