Frequency and Polarization Transformer: Longitudinal Modes

A frequency transformer that converts an elliptically polarized standing wave into frequency-shifted circularly polarized standing waves is considered. The transformer is a one-dimensional cavity in which a magnetoplasma, that supports longitudinal modes, is created. Theoretical derivation for the case of sudden and uniform creation of the magnetoplasma is given. Finite-Difference Time-Domain (FDTD) technique is developed to numerically simulate the problem. The simulation is used to verify the results of the theory as well as obtain results for the cases of creation of a lossy magnetoplasma with arbitrary space and time profile of the electron density. A few instructive results are presented as graphs to illustrate the effects of source parameters and system parameters.