Selected problems in the theory of electromagnetic radiation
Abstract
Electromagnetic interactions in spacetime dependent media are investigated with applications to sinusoidal periodic dielectrics and plasmas and with the display of numerous radiation patterns. The coupled wave and Floquet approaches to periodic waveguides are compared and applied to distributed feedback lasers. Transient radiation problems are solved for a variety of systems  e.g. the cylindrical monopole by the WienerHopf technique, infinitely long and finite cylindrical antennas, loop antennas by varied heuristic procedures; strong electromagnetic pulses at the boundary of a nonlinear plasma; and radiation of electromagnetic waves from oscillating sources in a suddenly created plasma. Models for transition radiation are investigated. New methods are developed for electromagnetic field calculations  the nonuniform lossless transmission line is treated by introducing a nonorthogonal warped coordinate system; a differential geometry scaling method is devised and applied to coaxial waveguide structures; and a shielding theory is constructed for metallic enclosures with apertures. The inverse scattering algorithm is derived and applied to calculating the electron density profile of the ionospheric plasma.
 Publication:

California Instute of Technology Technical Report
 Pub Date:
 October 1975
 Bibcode:
 1975cit..rept.....P
 Keywords:

 Antenna Radiation Patterns;
 PlasmaElectromagnetic Interaction;
 Reports;
 Research Projects;
 Waveguides;
 Algorithms;
 Distributed Feedback Lasers;
 Electron Density Profiles;
 Heuristic Methods;
 Ionospheric Electron Density;
 Laser Applications;
 Loop Antennas;
 Monopole Antennas;
 Communications and Radar