The operating bandwidth of the PLL must be much lower than the lowest offset frequency of interest because the PLL partially suppresses phase noise in its bandwidth. At this point the loop bandwidth is not a factor of the measured phase noise. Smoothing or averaging is used if the spectrum analyzer is so equipped to avoid measurement variations. The analyzer's manual should be consulted regarding corrections for analyzer noise response. Normalize to 1 Hz bandwidth.
Calculation assumes the noise is flat within the measurement bandwidth.
Video response of swept analyzer to noise signals. Double sideband to single sideband display. Contribution of two oscillators assuming they are of equal noise quality. The most recent change to this page occurred Friday, September 21, 2001.