Ultra-Wideband Waveguide Bends Using Continuously Varying Dielectric (CVD) Materials

Bends in waveguides are a problem for high-voltage Ultra-Wideband (UWB) systems. The difficulty arises because only a straight section of standard transmission line can support a pure TEM mode. And a pure TEM mode is necessary to preserve the risetime of the transmitted impulse. When there is a bend in the waveguide, the transmitted signal is a broader impulse than the incident signal. This can severely limit the bandwidth of a UWB system.A new technology has recently appeared which addresses this problem. One can build a waveguide bend in Continuously Varying Dielectric (CVD) materials, which have been shown to support true TEM waves. Because these materials support true TEM waves, a bend can be implemented with no dispersion, or impulse spreading, even though it is electrically large.The purpose of this project will be to design and build nondispersive waveguide bends using CVD materials. The characteristic impedance of various structures will be determined using numerical methods. A scale model of a candidate structure will be built and tested during Phase I.