Gu Rong, Pan Shilong, Chen Xiangfei, Pan Minghai, Ben De
College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China.
Opt Express. 2011 Jul 4;19(14):13686-91. doi: 10.1364/OE.19.013686.
Various schemes based on electro-optic modulators have been reported to generate ultra-wideband (UWB) signals in the optical domain, but the availability of these methods always relies on small signal modulation. In this paper, the influence of large signal modulation on two typical schemes, representing two major categories of external-modulator-based photonic UWB generation schemes, is analytically and numerically studied. While the quasi single-sideband UWB (QSSB-UWB) pulse can maintain its shape, the Gaussian UWB (GUWB) generation scheme suffers serious modulation distortion when the phase modulation index is greater than π/6. The modulation distortion would have negative impact on the receiver sensitivity when the signal is sent to a correlation receiver.
据报道，基于电光调制器的各种方案已在光域中用于生成超宽带（UWB）信号，但这些方法的可用性始终依赖于小信号调制。本文对大信号调制对两种典型方案（代表基于外调制器的光子UWB生成方案的两大主要类别）的影响进行了分析和数值研究。当相位调制指数大于π/6时，准单边带UWB（QSSB-UWB）脉冲虽能保持其形状，但高斯UWB（GUWB）生成方案会遭受严重的调制失真。当信号发送到相关接收器时，调制失真会对接收器灵敏度产生负面影响。
