R&S ESU
Measuring Harmonics with Frequency Sweeps
5.24
Quick Start Guide 1302.6163.62 - 04
4. Switch off trace averaging.
➢
Press the
CLEAR/WRITE
softkey.
5. Reduce the noise by reducing the measurement bandwidth.
The noise is reduced in proportion to the bandwidth by reducing the resolution bandwidth,
i.e. reducing the resolution bandwidth by a factor of 10 also reduces the noise by a factor
of 10 (which corresponds to 10 dB). The amplitude of sinusoidal signals is not affected by
reducing the resolution bandwidth.
6. Set the resolution bandwidth to 10 kHz.
➢
Press the
BW
key.
➢
Press the
RES BW MANUAL
softkey and enter
10 kHz
.
The noise decreases by approx. 25 dB with respect to the previous setting. Since the
video bandwidth is coupled to the resolution bandwidth, it is reduced to 1 kHz in
proportion to the resolution bandwidth. This causes the sweep time to increase to 60
seconds.
7. Reset the resolution bandwidth (couple it to the span)
➢
Press the
RES BW AUTO
softkey.
5.5 Measuring Harmonics with Frequency Sweeps
There are advantages in performing harmonic measurements with a single frequency sweep,
provided that the harmonic distance is in a way that a resolution bandwidth can be selected
which is wide enough to give an acceptably short sweep time.
5.5.1 High-Sensitivity Harmonics Measurements
If harmonics have very small levels, the resolution bandwidth required to measure them must
be reduced considerably. The sweep time is, therefore, also increased considerably. In this
case, the measurement of individual harmonics is carried out with the R&S ESU set to a small
span. Only the frequency range around the harmonics will then be measured with a small
resolution bandwidth.
1. Reset the instrument.
➢
Press the
PRESET
key.
The R&S ESU is now in the default state.
➢
Press the
SPECTRUM
hotkey.
2. Switch on the internal reference generator.
➢
Press the
SETUP
key.
➢
Press the softkeys
SERVICE - INPUT CAL
.
The internal 128 MHz reference generator is now on. The R&S ESU RF input is switched
off.
Summary of Contents for esu
Page 26: ...R S ESU Contents 6 Quick Start Guide 1302 6163 62 04 ...
Page 28: ......
Page 32: ...R S ESU 0 4 Quick Start Guide 1302 6163 62 04 ...
Page 88: ...R S ESU Preparing for Use Operating System Properties 2 38 Quick Start Guide 1302 6163 62 04 ...
Page 104: ...R S ESU Basic Operation Setting Parameters 4 12 Quick Start Guide 1302 6163 62 04 ...
Page 201: ...Quick Start Guide 1302 6163 62 04 R S ESU Appendix Appendix ...
Page 202: ...Quick Start Guide 1302 6163 62 04 R S ESU Appendix ...