Date of Award

1992

Degree Name

M.S. in Electrical Engineering

Abstract

In conventional electromagnetic theory, the fields of an antenna are computed from the magnitude and phase of currents flowing in a particular geometry where the geometry is defined by some conducting structure. The only effect of the conducting structure is to define the geometry of the system. In the rarified environment of space, it is possible to form current structures without conducting surfaces. The currents are formed from a flow of charged particles (principally electrons) called beams. The shape of the beams can be controlled by using various combinations of electric and magnetic fields. This report examines the antenna properties of an electron beam launched orthogonal to the geomagnetic field. The Lorentz force causes such an electron beam to form a loop of current in space that can be used in either a transmit or a receive mode. The differential equations governing the motion of the electrons in the presence of a time varying, propagating electromagnetic field are developed, and the effects of a low density, magnetized plasma environment are considered. This report shows that velocity modulation by the E xB and polarization drift velocities can be used for the receive mode, and density modulation can be used for the transmit mode of a low frequency electron beam loop antenna. This report also examines previous theoretical and experimental work which supports the thesis that an electron beam can function as an antenna, and makes suggestions for the direction of future work in high frequency electron beam antennas

Keywords

Antennas (Electronics), Astronautics Communication systems

Rights Statement

Copyright © 1992, author

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