一种超宽带光电混合结构A/D转换器

An UWB Photoelectric Hybrid A/D Converter

现代宽带数字接收机对高性能模数转换器(ADC)的需求逐渐增大,而电子学ADC因载流子迁移速率限制无法实现超宽带直接数字采样。基于光子技术超宽带、超高速的特性,文章提出了一种光电混合结构的ADC技术。通过采用基于超短光脉冲的光学采样代替基于电子学半导体技术的采样/保持(S/H)电路来大幅提高采样带宽。采用时分复用及多通道电学ADC量化技术实现信号数字编码。最后通过数字域均衡与线性化处理提高系统性能,实现了对频率大于24 GHz的微波信号的直接采样,采样信噪比大于40 dB,为超宽带微波信号高精度直接数字化提供了有效途径。

The needs of modern wideband digital receivers for high performance analog-to-digital converters(ADCs) are increasing gradually, but the electronic ADCs cannot realize UWB direct digital sampling due to carrier migration rate limit. Based on the characteristics of ultra-wideband and ultra-high speed of photonic technology, an ADC technology with optoelectronic hybrid structure was proposed in this paper. Optical sampling based on ultrashort optical pulse was used to replace the sample/hold(S/H) circuit used in electronic semiconductor technology to greatly improve the sampling bandwidth, and time division multiplexing and multichannel ADC quantization technology were used to realize digital coding. Finally, the system performance was improved by digital domain equalization and linearization. The direct sampling of microwave signals with frequency greater than 24 GHz, and the sampling signal-to-noise ratio greater than 40 dB were realized, which provided an effective way for UWB microwave signals to be directly digitized with high precision.