Specifications

Chapter 2 17
Measuring Multiple Signals
Resolving Signals of Equal Amplitude
Measuring Multiple Signals
Resolving Signals of Equal Amplitude
In this procedure a decrease in resolution bandwidth is used in
combination with a decrease in video bandwidth to resolve two signals
of equal amplitude with a frequency separation of 100 kHz. Notice that
the final RBW selection to resolve the signals is the same width as the
signal separation while the VBW is slightly narrower than the RBW.
Step 1. Connect two sources to the analyzer input as shown in Figure 2-6.
Figure 2-6 Setup for Obtaining Two Signals
Step 2. Set one source to 300 MHz. Set the frequency of the other source to
300.1 MHz. Set both source amplitudes to
−20 dBm. The amplitude of
both signals should be approximately
−20 dBm at the output of the
bridge.
Step 3. Setup the analyzer to view the signals:
Press
Preset, Factory Preset (if present).
Press
FREQUENCY Channel, Center Freq, 300, MHz.
Press BW/Avg, Res BW, 300, kHz.
Press
SPAN X Scale, Span, 2, MHz.
A single signal peak is visible. See Figure 2-7 for an ESA example.
NOTE If the signal peak is not present on the display, span out to 20 MHz,
turn signal tracking on, span back to 2 MHz and turn signal tracking
off.:
Press
SPAN, Span, 20, MHz.
Press
Peak Search, FREQUENCY, Signal Track (On).
Press
SPAN, 2, MHz.
Press FREQUENCY, Signal Track (Off)