SECONDARY STANDARD FOR PM AND AM NOISE AT 5, 10, AND 100 MHZ

This paper describes a practical implementation of a portable secondar y standard for phase modulation (PM) and amplitude modulation (AM) noi se at 5, 10, and 100 MHz. The accuracy of the standard for both PM and AM noise is +0.14 dB, and the temperature coefficient is less than 0. 02 dB/K. The noise floor S(phi)(10 kHz) of the standard for PM noise m easurements is less than -190 dBC relative to 1 rad2/Hz at 5, 10, and 100 MHz. The noise floor for AM measurements depends on the configurat ion. A calibrated level of PM and AM noise of approximately -130 +/- 0 .2 dB relative to 1 rad2/HZ (for Fourier frequencies from approximatel y 1 Hz to 10% of the carrier frequency) is used to evaluate the accura cy versus Fourier frequency. Similar PM/AM noise standards are under t est at 10 GHz. This new standard can also be used as an alternative to the normal method of calibrating the conversion sensitivity of the PM /AM detector for PM/AM measurements. Some types of time-domain measure ment equipment can also be calibrated.