A Precision Wide-Band Transmission Measuring System

The measuremnent of transmission characteristics with high precision is indispensable for testing and developing cables and repeaters in submarine cable systems. The precision wide-band transmission measuring system has been developed in Kokusai Denshin Denwa Company, Ltd., and has successfully been applied in both experimental and manufacturing stages. In this system, the insertion loss or the insertion gain of a test piece is measured automaticaly with an accuracy of 0.001 dB, over the range from 0 to 60 dB, in the frequency range from 0.1 to 100 MHz. In this paper, newly developed precision techniques to attain the aforementioned accuracy are described. In addition, the characteristic features of computer controlled techniques that resulted in measurement flexibility and improved the accuracy of the measurement are also presented.