The System of Electromagnetic Quantities at Frequencies Above 1 GHz

The system of electromagnetic quantities at frequencies above 1 GHz (109 cycles per second) is briefly described, giving emphasis to those techniques and standards which have been most thoroughly evaluated and tested. The quantities included are power, noise temperature, reflection coefficient and impedance, phase shift, attenuation, and field strength. The measurement of frequency and wavelength, and of the microwave properties of materials is not within the scope of this paper. In addition to a brief review, some of the problems involved in obtaining a higher order of accuracy are discussed. Comparisons of standards of different nations are mentioned and the benefits to be derived from such comparisons are described. Areas needing further research, as well as those which would benefit from international cooperation, are designated. Although a highly detailed and technical presentation is avoided, numerous references are given. In addition, a selected list of definitions is appended.