UNI-T UTS1000 Series Operating Manual page 68

1. Connect equipment
Connect spectrum analyzer's RF input with two signals
through combiner. Set one source's frequency as 1800MHz
and amplitude as -10dBm; set the other source's frequency
as 1800.05MHz and signal output amplitude as -50dBm.
Open RF output of two signal source.
2. Set parameters
- Press FREQ key;
- Press [Center frequency] key, and input 1800.025MHz;
- Press SPAN key;
- Press [Span] key, and input 500kHz;
- Press BW/SWP key;
- Press [Resolution bandwidth Auto Manual] key, set
resolution bandwidth in manual mode, and input 30kHz.
3. Measurement results
Rectangle coefficient for resolution bandwidth filter of
UTS1000 Series Spectrum Analyzer is about 5:1. When
resolution bandwidth is 30kHz, 60dB point is 115kHz,
half bandwidth is 57.5kHz, larger than frequency spacing
50kHz. So, two input signals can't be distinguished, as
shown in Figure 4-5:
Figure 4-5: Test Done under 30kHz Resolution Bandwidth
1 Reduce resolution bandwidth, observe flooded small
signal.
- Press BW/SWP key;
- Press [Resolution bandwidth Auto Manual] key, set
resolution bandwidth in manual mode, and input 1kHz, as
shown in Figure 4-6.
2 Measure frequency difference of two signals.
- Press PEAK key, marker is at peak frequency;
- Press MARKER key;
- Press [Difference] key, move marker to secondary
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