FAQs from Rohde & Schwarz

How do I calculate the logarithmic frequency steps for the horizontal axis?


I read the measurement result via remote control, but I don't get the corresponding frequency points in log scale. How do I calculate these frequency points when I have a logarithmic sweep and know the center frequency, the span and the number of sweep points?


The formula for calculating the logarithmic sweep points is as follows:
f(x) = 10^((((log(fStart+Span)-log(fStart))/(n-1))*(x-1)) + log(fStart))
x = the number of the sweep point
n = total number of sweep points

x = 132
n = 200
fStart = 1 GHz
Span = 2 GHz
f(x) = 10^((((log(1GHz+2GHz)-log(1GHz))/(200-1))*(132-1)) + log(1GHz)) = 2.061032528 GHz