Traveling Wave Spatial Quantized Analog-to-digital Conversion

An analog-to-digital converter (ADC) architecture that extracts the required quantization energy directly from the input analog signal and sampling clock through a spatial quantization scheme is presented. We experimentally demonstrate 8-level quantization consuming only 7.2 pJ per quantization operation with 18 GHz bandwidth. Measured 8 ps full-width half-maximum photodetector output voltages, promises the potential of realizing a 3 bit 125 GS/s ADC through this system.