[信息与通信]RFandMicrowaveFiber-OpticDesignGuide.pdf

Application Note April 2001 RF and Microwave Fiber-Optic Design Guide Introduction allowing for high signal rates without investing in expensive architectural supports. The placement of Agere Systems Inc., through its predecessors, began fiber cable is further simplified by the natural immu- developing and producing lasers and detectors for lin- nity of optical fiber to electromagnetic interference ear fiber-optic links nearly two decades ago. Over time, (EMI). Not only can large numbers of fibers be tightly these optoelectronic components have been continu- bundled with power cables, they also provide a ally refined for integration into a variety of systems that uniquely secure and electrically isolated transmis- require high fidelity, high frequency, or long-distance sion path. transportation of analog and digital signals. As a result The general advantages of fiber-optics first led to of this widespread use and development, by the late their widespread use in long-haul digital telecommu- 1980s, these link products were routinely being treated nications. In the most basic form of fiber-optic com- as standard RF and microwave components in many munications, light from a semiconductor laser or different applications. LED is switched on and off to send digitally coded There are several notable advantages of fiber optics information through a fiber to a photodiode receiver. that have led to its increasing use. The most immediate By comparison, in linear fiber-optic syst