Time-stretched analog-to-digital conversion (TSADC)

Summary form only given. The ability to perform ultrafast A/D and D/A conversion is critical for high performance communication and radar systems. Challenges with traditional approaches have led us to propose the concept of time-stretch preprocessing as a possible solution to the ultrafast A/D conversion. In Nyquist type A/D converters (ADCs) time stretching increases the effective input bandwidth and sampling rate of the ADC. In /spl Sigma/-/spl Delta/ type converters, it has the additional benefit of reducing the quantization noise within the signal bandwidth. In this paper, we will present the experimental data and theoretical analysis for time-manipulation of electrical signal using optoelectronic techniques. We also introduce a new discrete-time rendition of this technique with near transform-limited temporal resolution. Analytical and numerical calculation of the fundamental limits of this approach will be presented. We will conclude by presenting an overview of the COAST (Consortium for Optical A/D System Technology), a new DARPA funded UCLA-lead consortium consisting of 8 Universities, industry and national laboratories dedicated to research in optically assisted A/D conversion.