Seminar: Microplasmas for Reconfigurable Radio-Frequency Electronics

Dr. Sergey Macheret, Purdue University

All dates for this event occur in the past.

E001 Scott Lab
E001 Scott Lab
201 W. 19th Ave.
Columbus, OH 43210
United States

Abstract:

Microplasmas, i.e. plasmas confined in cavities less than 1 millimeter in size, have unique properties and show promise for a number of applications, from novel light sources to decontamination to medicine. In this talk, we focus on emerging applications of microplasmas to tunable and reconfigurable radio-frequency (RF) electronics, such as antennas, resonators, and filters. First, we discuss antennas where plasmas are used as electrical conductors. Although the antenna gain is generally low, the cross-coupling between elements of an array is also low. We show results of testing simple microplasma-based dipole antennas, and then discuss more sophisticated antennas with microplasma elements imbedded in metamaterial structures. Thermal EM noise is critical to any antenna, and we show that the low-frequency noise in plasma antennas is higher than in metallic devices, but at frequencies higher than the electron collision frequency the plasma noise is suppressed. Since the demand to reduce losses and noise dictates operation of plasmas with collision frequencies much lower than that of the RF, the EM behavior of such plasmas is that of low-loss dielectric whose permittivity can be tuned. We discuss experiments with basic LC circuits, where plasma ignited inside the capacitor changes the resonant frequency. With low pressure (<10 mTorr) required to suppress losses and noise, sustaining a microscale (<100 microns) plasma with a high electron density at low voltage seems impossible. We propose a novel method to generate plasmas employing nanotechnology, without conventional electron impact ionization.

About the Speaker:

Sergey Macheret obtained his M.S. in applied physics from Moscow Institute of Physics and Technology in 1980, and his Ph.D. in plasma physics and plasma chemistry from Kurchatov Institute of Atomic Energy in Moscow, Russia in ’85.

He worked at the Russian Academy of Sciences from ’83 to ’91. After moving to the United States in ’91, he was a research associate and lecturer at The Ohio State University (’91-’94), a principal scientist at CTSA Inc. (’93-’94), and a senior research scientist at Princeton University from ’94 to 2006. From ’06 to ’14 he was a senior staff aeronautical engineer at Lockheed Martin Aeronautics Co.’s Skunk Works where he served as a program manager for plasma-related programs.

His research interests and contributions are primarily in fundamental physics and aerospace applications of weakly ionized plasmas. These range from kinetics of electrons and ions to highly efficient generation of plasmas by ultra-short repetitive pulses, to novel adaptable plasma actuators that use electric and magnetic fields for aerodynamic control, flow reattachment, lift enhancement, laminar-to-turbulent transition delay. His research also explores drag reduction in a wide range of flight altitudes, from sea level to near space, and from very low to hypersonic speed.

His research also includes microcavity plasmas for novel tunable RF antennas and switches, as well as fundamental understanding of atomic, molecular, and radiative processes that affect aerodynamics and heat fluxes in hypersonic (e.g. reentry) flight.

Hosted by Professor Igor Adamovich.