Making Basic Measurements Using Spectrum Analyzer Mode

Resolving Signals of Equal Amplitude Using the Resolution Bandwidth Function

Example: Resolve two signals of equal amplitude with a frequency separation of 100 kHz.

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CAL OUTINPUT

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LC O U P L E R

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Figure 4-1. Set-Up for Obtaining Two Signals

1.To obtain two signals with a 100 kHz separation, connect the calibration signal and a signal source to the spectrum analyzer input as shown in Figure 4-1. (If available, two sources can be used.)

2.If you are using the 300 MHz calibration signal, set the frequency of the source 100 kHz greater than the calibration signal (that is, 300.1 MHz). The amplitude of both signals should be approximately 29 dBmV.

3.On the spectrum analyzer, press CPRESET]. Set the center frequency to

300 MHz, the span to 2 MHz, and the resolution bandwidth to 300 kHz by pressing CFREQUENCY) 300 INIHz_), m 2 (MHz), then [Bw) 300 IkHz). A single signal peak is visible.

4.Since the resolution bandwidth must be less than or equal to the frequency separation of the two signals, a resolution bandwidth of 100 kHz must be used. Change the resolution bandwidth to 100 kHz by pressing lew] 100 (kHz. Two signals are now visible as in Figure 4-2. Use the knob or step keys to further reduce the resolution bandwidth and better resolve the signals.

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