The performance characteristics of an electrooptic SNS analog to digital converter

Abstract

High speed data conversion is required to conduct digital signal processing on wideband analog waveform. This thesis explores the performance characteristics of a high speed optical analog to digital technique. This technique extends the resolution of an integrated optical multi-interferometer analog to digital converter (ADC) by using a symmetrical number system (SNS) encoding. The optical SNS ADC can directly digitize wideband signals with a minimum amount of circuit complexity. Using an 8 bit SNS ADC, the results are significantly improved with a modification which incorporates a panty circuit, and a pulse timing circuit. The parity circuit decimates the possible encoding errors that can result when the samples lie at one of the code transition points. The results of this decimation process, and the timing of the corresponding signals are also discussed. Other areas such as the integration of the timing processor and folding circuit, are identified as those in which further design is required. (AN)