
Optimizing Measurements
Reducing Trace Noise
By reducing the system bandwidth you reduce the noise that is measured
during thesweep. However, the decreased bandwidth may slow down the
sweep. While averaging requires multiple sweeps to reduce noise, narrowing
the system bandwidth reduces the noise on each sweep. See the previous
section for a more detailed explanation of system bandwidth.
Narrower system bandwidths cause longer sweep times. When in auto sweep
time mode, the analyzer uses the fastest sweep time possible for any selected
system bandwidth. Auto sweep time mode is the default analyzer setting.
Spurious responses are undesirable signals that result from various internal
mixing products.
The analyzer has two features to eliminate spurious responses. Both features
shift the frequency of the spur without changing the RF output frequency.
They shift the spur by changing frequencies internal to the analyzer that mix
to produce the RF frequency. The features are:
l
dither
l
spur avoid
Dither is usually most effective for narrow frequency span measurements
(generally 15 MHz) as explained below. If dither does not eliminate visible
spurs, use spur avoid instead.
5-14
Summary of Contents for 8712C
Page 1: ...I I User s Guide HP 8712C and HP 8714C RF Network Analyzers I ...
Page 17: ...I 1 Installing the Analyzer ...
Page 35: ...I 2 Getting Started ...
Page 54: ...I 3 Making Measurements ...
Page 81: ......
Page 119: ...4 Using Instrument Functions ...
Page 182: ...Using Instrument Functions Customizing the Display Figure 4 24 Expanded Display 4 64 ...
Page 223: ...5 Optimizing Measurements ...
Page 244: ...6 Calibrating for Increased Measurement Accuracy ...
Page 280: ...7 Automating Measurements ...
Page 298: ......
Page 362: ...8 Front Rear Panel ...
Page 373: ......
Page 381: ......
Page 386: ... 9 w I Suftkey Reference ...
Page 477: ...I 10 Specifications and Characteristics ...
Page 501: ...11 Safety and Regulatory Information ...
Page 508: ...I 12 preset State and Memory Allocation ...
Page 527: ...Index ...
Page 559: ...Y X 9 91 YYW m m IiH rn 9 91 Z zeroing detectors 6 15 Index 33 ...