Ultra-wideband (UWB), as opposed to traditional narrowband radios, is a wireless digital communication system that exchanges data using short duration pulses. The complexity of the analog front-end in UWB is drastically reduced due to its intrinsic baseband transmission. Based on this simplification and the high spreading gain it possesses, UWB promises low-cost implementation with fine time resolution and high throughput at short distances without interfering with other existing wireless communication systems. However, the wideband nature of the front-end architecture leads to a totally different design methodology from traditional narrow-band systems. For example, if one employed the conventional narrow-band design approach, matching between the power amplifier and the antenna would be a big problem owing to the fact that it is extremely difficult to match accurately over a such a wide range of frequencies. In addition, we desire a high degree of integration, which requires an antenna on the order of centimeters in size, but it is hard to attain efficient transmission bandwidth from DC to GHz with such a small antenna.
The focus of this research is to determine the methodology for co-designing an appropriate antenna suitable for efficient pulse transmission/generation and pulse reception with analog circuits that won’t induce signal dispersion (ISI, inter-symbol interference) or further complicate the digital back end. Finite-difference time-domain (FDTD) electromagnetic wave simulation will be used to characterize the antenna. While doing antenna/circuit co-design optimization, the method of combining FDTD and SPICE simulation will also be investigated.