Development and evaluation of a set of group delay standards

Group delay standards of 15,30, and 60 ns have been developed at JPL. Calibration data provided by NBS and others are presented and compared. Calibrations were performed at microwave frequencies of 2113,2295, and 8415 MHz as well as at a baseband modulation frequency of 500 kHz. The uncertainties of the measurement and effects of dispersion and cable reflections are discussed.