Keysight x-series Measurement Guide

84
Measuring Noise
Measuring Signal-to-Noise of a Modulated Carrier
5 Tune to the W-CDMA
signal.
• Press FREQ Channel, Auto Tune.
6 Enable the Band Power
Marker function.
• Press Marker Function,
Band/Interval Power.
This measures the total
power of the 4 carrier
W-CDMA signal.
7 Center the frequency of the
Band Power marker on the
signal.
• Press Select Marker 1, 1.96, GHz
8 Adjust the width (or span)
of the Band Power marker.
• Press Marker Function, Band
Adjust, Band/Interval Span, 20,
MHz.
This encompasses the entire
4 carrier W-CDMA signal.
Figure 7-7 4 Carrier W-CDMA Signal Power using Band Power Marker
Note the green vertical lines of Marker 1 representing the span of signals included in the Band Power
measurement and the carrier power indicated in Markers Result Block.
9 Enable the Noise Marker
using marker 2.
• Press Marker Function, Select
Marker, Marker 2, Marker Noise.
This measures the system
noise power.
10Move the Noise Marker 2
to the system noise
frequency of interest.
• Press Select Marker 2, 1.979, GHz. This encompasses the
desired noise power.
11 Adjust the width of the
noise marker region.
• Press Marker Function, Select
Marker, Marker 2, Band Adjust,
Band/Interval, 5, MHz.
See Figure 7-8.
Step Action Notes

Keysight x-series Specifications

General

Analysis Bandwidth	Up to 1 GHz (depending on model)
Real-Time Bandwidth	Up to 1 GHz (depending on model)
Form Factor	Benchtop
Connectivity	LAN, USB, GPIB
Resolution Bandwidth	1 Hz to 10 MHz (depending on model)