Fiber Optic Link For Space Communication Application

Future communication satellites and space stations will carry large switching arrays which will allow rapid interconnectivity between many up-link and down-link channels. Key considerations in any complex space-based system include optimization of the size, weight, bandwidth and crosstalk of the components and sub-systems employed in the design . In satellites signal distribution scheme is often of prime concern. It is here where an optoelectronic system is an alternative to and has potential advantages over competing systems using coaxial cables. The advantages of a fiber optic link include small size and low weight, broad bandwidth and excellent crosstalk isolation. The overall system under consideration for this study is a satellite or space station equipped with a number of microwave receivers and transmitters operating in the microwave frequencies (10 to 40GHz). The task is to design a distribution network which is capable of routing the communication signals between the receivers and transmitters. Present design include down and upconverters at the receivers and tranmitters and an IF fiberoptic link connecting the microwave components. The paper will describe the construction and performance of a 750 MHz bandwith optical IF link. The characterization of the link includes the frequency response, intermodulation distortion, noise and power budget.