论文部分内容阅读
实验研究了一种采用马赫-曾德尔电光调制器产生60 GHz光毫米波的方法和相应的光纤无线传输(ROF)系统。在中心站采用单臂的马赫-曾德尔强度调制器(IM)通过光载波抑制(OCS)方式产生光毫米波,光毫米波的频率为2倍射频(RF)信号的频率。然后再利用另一个电光马赫-曾德尔调制器将下行基带数据信号调制到光毫米波上。下行信号经光纤链路传送至基站单元,光毫米波信号经高速光电转换器产生60 GHz的电毫米波,经过放大后,由天线发送出去。在用户单元通过天线接收到的电毫米波信号利用相干解调恢复下行的基带数据信号。实验显示采用频率为29 GHz射频信号产生光毫米波的频率为58 GHz,将下行链路中2.9 Gbit/s的数据在单模光纤中传输距离达20 km,且实现无线传输2.6 m。
A method of generating 60 GHz optical millimeter wave using a Mach-Zehnder electro-optic modulator and a corresponding optical fiber wireless transmission (ROF) system are experimentally studied. A one-armed Mach-Zehnder Intensity Modulator (IM) is used at the central station to generate optical millimeter waves by means of Optical Carrier Suppression (OCS) with a frequency of 2 times the frequency of the radio frequency (RF) signal. Then use another electromagnet Mach-Zehnder modulator to modulate the downlink baseband data signal onto optical millimeter wave. The downstream signal is transmitted to the base station unit through the optical fiber link. The optical millimeter wave signal is generated by the high-speed photoelectric converter at an electric millimeter wave of 60 GHz. After being amplified, the signal is transmitted by the antenna. The millimeter wave signal received by the subscriber unit through the antenna utilizes coherent demodulation to recover the downlink baseband data signal. Experiments show that the frequency of optical millimeter wave is 29 GHz and the frequency of optical millimeter wave is 58 GHz. The data transmission rate of 2.9 Gbit / s in downlink is 20 km in single-mode optical fiber and wireless transmission is 2.6 m.