Communications and microwave technology: Optical fibers compete with premium coax; digital radio reaches cost effectiveness

The “glamour” of communications research and development efforts continues to involve fiber optics. Laboratories in Europe, Japan, and the U.S. report considerable progress in reducing fiber costs, while increasing the data rates that optical transmitter/receiver links can handle. The ultimate goal, of course, is a low-cost glass-fiber replacement for copper conductors. Standard-grade bare fiber (10-dB loss at 200 MHz over 1 km) presently sells for 90€/meter, and costs are dropping fast.