| The transmission of electromagnetic signals through a cavity is of great interest. Even a very simple cavity can affect a signal as it propagates through the cavity, and, if the cavity is of more modest complexity, the effect of the cavity on the signal becomes difficult to determine. In addition, because antennas are often excited by signals that travel from the source through a cavity to the antenna feed point, it is desirable to know what the signal shape is at the feed of the antenna.; In this dissertation, techniques are developed to determine the field in a cavity comprising a set of axisymmetric cavities joined through apertures. Each cavity section may have a cross-section that varies with axial displacement and also may be filled with a lossy material. A set of coupled integral equations are derived for the electric fields in the apertures joining the sections. Knowledge of the aperture electric fields is sufficient for determining the field anywhere in the cavity. The coupled integral equations are solved in the frequency domain, and simple Fast Fourier Transform analysis is then used to determine the time-domain behavior of signals in the cavity. Furthermore, because the cavity may be terminated by a wire antenna on a conducting body, a technique is presented to analyze an antenna attached to a planar surface of a conducting body. Finally, experimental models were constructed, and measurements were performed to validate the theoretical and computational techniques presented. |
