Short term oscillator frequency stability as a function of its phase noise distribution

The rapidly emerging market for microwave communication systems such as wireless applications, forces the use of many limited bandwidth channels. The undesired linkage problem between two adjacent channels is well known. One of the causes of the linkage problem is the frequency instability of the transmitter VCO. Characterization of the short term stability enables one to calculate statistically the system “error”. This paper presents mathematical expressions to calculate the short term VCO stability, by its noise skirt. The VCO noise skirt is caused essentially by a random voltage, the phase noise. Using the expressions we present, one can estimate the linkage period time between two adjacent channels. These mathematical expressions are also used to calculate the frequency stability between two adjacent time periods of a periodic signal (e.g. FMCW)