Example 2: Improving Amplitude Measurements With Ampcor - Agilent Technologies 8560E User Manual

Making Measurements

Example 2: Improving Amplitude Measurements with Ampcor

Example 2: Improving Amplitude
Measurements with Ampcor
What Is Ampcor?
The amplitude correction function is used to improve the amplitude
accuracy of your measurement system. System flatness is often
degraded by many things including cable and adapter losses. Additional
systematic amplitude errors such as IF gain uncertainty, resolution
bandwidth switching uncertainty, and attenuator switching
uncertainty can also be corrected. These system effects can be
normalized out of the displayed measurement results using the ampcor
function. Pairs of frequency/amplitude correction points are entered
into the spectrum analyzer. Turning on the ampcor function causes
real-time correction of the measurement data using these points. This
real-time correction is updated as the frequency and amplitude
parameters of the spectrum analyzer are changed.
Spectrum Analyzer Functions Used
This example uses the amplitude correction function, ampcor. It
illustrates the use of some of the ampcor data entry and editing
functions that help with the entry of the frequency-amplitude
correction pairs. Once you have entered a set of correction values, they
can be saved and recalled for later use.
Stepping Through an Ampcor Measurement
The ampcor function will be used to correct for variations in the flatness
of a measurement system. Suppose we want to make measurements on
a personal digital cellular system (PDC). The PDC frequency range is 1
GHz to 1.6 GHz, and in this frequency range the spectrum analyzer
frequency response has a small amount of ripple. The ampcor function
will be used to correct for this and for some cable losses.
Substitute a source and power meter for the PDC signal and set up the
measurement with the system cable. The flatness correction values are
identified, and then entered and saved.
56 Chapter 2