Design of High-Power, Wideband Baluns

Many high-power ultra-wideband (UWB) sources produce a single-ended signal that is fed into a transmission line. Normally, one would like to radiate this signal with an antenna, however, many antennas require a differential mode input. A balun is therefore required to convert the source output into a form acceptable to the antenna. The challenges in designing such a balun lie in the need to avoid voltage breakdown and the need to preserve the risetime of the signal. Conventional balun designs fail to meet these requirements, so new designs are required. The objective of this research is to design a balun to convert single-ended high-power UWB signals to balanced signals. Tradeoffs between voltage, bandwidth, and transition length will be evaluated. We will work toward a design in Phase II that maintain an 80 ps pulse with less than 15% risetime degradation or energy loss. The design goal will be to approach 1 MV peak voltage and 100 GW peak power. During Phase I we will develop a design for a balun that appears likely to reach these objectives. We will provide both analysis and, if necessary, simple experiments to support our design.