A flexible photonic scheme for the generation and modulation of ultrawideband (UWB) based on dual-filter tuning is proposed and experimentally. The UWB polarity-switch monocycle an doublet pulses are obtained in the system. Meanwhile, with a predefined code pattern and control of the optical path difference, the pulse bipolar modulation and pulse shape modulation can be performed. By simulating through the software of Optisystem, the impact of light source power on modulated signal is investigated. In addition, the transmission characteristics of UWB modulated signals are also discussed. It is found out that the input power should between a certain range in order to get optimum UWB signals. Only a laser source introduced in the architecture guarantees the excellent dispersion，which has potential application in UWB impulse radio over optical fiber access networks.

SHAO Jing and ZHANG Kai. Research of UWB multifunctional generation and modulation based on dual-filter tuning.  International Journal of New Developments in Engineering and Society (2017) Vol.1, Num.2: 118-122.

[1] Aiello G R, Rogerson G D. Ultra-wideband wireless systems. Microw . Mag. , IEEE, 2003; 4(2):36—47

[2] Roy S, Foerster J, Somayazulu V, et al. Ultrawideband radio design: the romise of high-speed Short-range Wireless connectivity, Proceedings of IEEE, 2004; 92(2): 295—311
[3] Shao Jing, Liu Shuhui, et al. Photonic generation of filter-free ultrawideband monocycle and doublet signal using single semiconductor optical amplifier in counter-propagation scheme. Optics Engineering, 2016; 55(2):026117-(1~4) (21):3083—3085
[4] YU Xianbin, Gibbon T B, Pawlik M, et al. A photonic ultra-wideband pulse generator based on relaxation oscillations of a semiconductor laser. Optics Express, 2009; 17(12):9680—9687
[5]
Zhao Yu, Liu Yongzhi, Zhao Deshuang. The experiment research of UWB over Fiber indoor wireless transmission. Optoelectronics and Laser, 2009; 20(3): 329—332

[6] Wang Fei. Research on application of semiconductor optical amplifier for several key functions in optical networks. Wuhan: Huazhong University of science and technology

[7] Yin Jie. Study of ultra-wideband radio over fiber system’s design and application. Beijing: Beijing University of Post and Telecommunications, 2010

[8] Yu Yuan, Dong Jianji, Li Xiang, et al. UWB monocycle generation and Bi-phase modulation based on Mach-Zehnder modulator and semiconductor optical amplifier. IEEE Photon. Technol. Lett., 2012; 4(2):327— 339.

[9] Zhang Fangzheng, Wu Jian, Fu Songnian. et al. Simultaneous multi-channel CMW-band and MMW-band UWB monocycle pulse generation using FWM effect in a highly nonlinear photonic crystal fiber. Optics Express, 2010; 18(15): 15870—15875

[10] Zeng Fei, Wang Qing and Yao Jianping. All-optical UWB impulse generation based on cross-phase modulation and frequency discrimination. Electronics Letters, 2007;  43(2): 121—122
[11]
Chen Hongwei, Chen Minghua, Wang Tianliang, et al. Methods for ultra-wideband pulse generation based on optical cross-polarization modulation. Journal of Lightwave Techology, 2008; 26(15): 2492—2499