ADVANTEST R3131 User Manual

R3131 Spectrum Analyzer Operation Manual
APPENDIX 2 GLOSSARY
A2-1
APPENDIX 2 GLOSSARY
Resolution Bandwidth
The spectrum analyzer uses the bandpass filter (BPF) to analyze the frequency components contained in the
input signal. The 3dB bandwidth of the BPF is called the resolution bandwidth (See Figure A2-1(a) below).
BPF characteristics should be set according to the sweep width and the sweep speed used for the trace. This
spectrum analyzer sets the optimal value for the sweep width. In general, smaller bandwidths improve
resolution so the resolution of the spectrum analyzer should be expressed using the narrowest resolution
bandwidth (See Figure A2-1(b) below).
Figure A2-1 Resolution Bandwidth
Reference Level Display Accuracy
When reading the absolute level of an input signal on the spectrum analyzer, the level is determined by the
distance in dB from the uppermost scale on the screen. The level set for this uppermost scale is called the
reference level.
The reference level is modified by the IF GAIN key and the input attenuator, and is displayed in dBm or dBµ.
The absolute accuracy of this display is the reference level accuracy.
Figure A2-2 Reference Level
þ¨ðÚ«¾¬”×Ë…
″
(a)
þ¨ðÚ«¾
(b)
Signal spacing
RBW
≤
Signal spacing
RBW = resolution bandwidth
Resolution bandwidth
(a)
Resolution
(b)
Dec 1/97

ADVANTEST R3131 Specifications

General

Brand	ADVANTEST
Model	R3131
Category	Measuring Instruments
Language	English