中英文翻译--RF和微波光纤设计指引.doc

RF and Microwave Fiber-Optic Design Guide Agere Systems Inc., through its predecessors, began developing and producing lasers and detectors for linear fiber-optic links nearly two decades ago. Over time, these optoelectronic components have been continually refined for integration into a variety of systems that require high fidelity, high frequency, or long-distance transportation of analog and digital signals. As a result of this widespread use and development, by the late 1980s, these link products were routinely being treated as standard RF and microwave components in many different applications. There are several notable advantages of fiber optics that have led to its increasing use. The most immediate benefit of fiber optics is its low loss. With less than 0.4 dB/km of optical attenuation, fiber-optic links send signals tens of kilometers and still maintain nearly the original quality of the input. The low fiber loss is also independent of frequency for most practical systems. With laser and detector speeds up to 18 GHz, links can send high-frequency signals in their original form without the need to downconvert or digitize them for the transmission portion of a system. As a result, signal conversion equipment can be placed in convenient locations or even eliminated altogether, which often leads to significant cost and maintenance savings. Savings are also realized due to the mechanical flexibility and lightweight fiber-optic cable, approximately 1/25 the weight of waveguide and 1/10 that of coax. Many transmission lines can be fed through small conduits, allowing for high signal rates without investing in expensive architectural supports. The placement of fiber cable is further simplified by the natural immunity of optical fiber to electromagnetic interference (EMI). Not only can large numbers of fibers be tightly bundled with power cables, they also provide a uniquely secure and electrically isolated transmission path. The general advantages o