53
Brief Description
4 Brief Description
The following chapters are intended to introduce you
to the most important functions and settings of your
new R&S®HMS-X spectrum analyzer (in this example
R&S®HMS-X with all available options) in order to enable
you to immediately use it. You find more detailled explana-
tions in the chapters following these ones.
4.1 How to measure a sine wave signal
The fundamental measurement with a spectrum analy-
zer is the measurement of the level and the associated fre-
quency of a sine wave signal. The following measurement
example demonstrates the steps to be taken for the set-
tings which allow to effectively perform this measurement
with the R&S®HMS-X. The signal source is a HF synthe-
sizer, e.g. the Hameg HM8135. Connect the HF output of
the synthesizer to the HF input of the spectrum analyzer.
Settings on the synthesizer:
❙Frequency 100 MHz
❙Level –10 dBm
Press the AUTO TUNE key
18
in order to cause the instru-
ment to scan the whole measuring range in order to find
the highest signal peak and to display it at the screen cen-
ter together with the proper RBW and span settings. This
procedure may take several seconds.
Fig. 4.1: Area A of the control panel
5
4
6
A
8
7
9
11
10
12
14
13
15
17
16
18
Fig. 4.2: Display with the AUTO TUNE function
4.2 Level measurement
In order to now perform the previouly automatically ta-
ken steps manually, press the key PRESET
17
which resets
the instrument to its initial settings. The analyzer displays
the frequency spectrum of its full frequency range from
100 kHz to 1.6 GHz resp. 3 GHz. At 100 MHz the generator
signal will be discernible as a line. Harmonics of the oscil-
lator are also displayed at multiples of 100 MHz (not visible
here). In order to analyze the generator signal further, use
the frequency settings menu (key FREQ
6
) to set the start
frequency to 50 MHz and the stop frequency to 250 MHz.
The spectrum analyzer now displays the signal with a hig-
her resolution. In order to determine the level of the signal,
the R&S®HMS-X offers up to 8 markers. The marker is al-
ways attached to the measuring curve. The instrument in-
dicates the level and the frequency at the relevant position
on the screen.
Press the key MARKER
15
to enter the marker settings
menu. Marker [1] will be activated by the soft key DISPLAY,
it will be automatically positioned to the center frequency of
the actual curve. The marker frequency is indicated by a
cross resp. arrow symbol (next to the activated marker). The
spectrum analyzer displays the level and the frequency of
the marker position numerically at the top of the screen.
Now move the marker [1] to the displayed level at 100 MHz
by pressing the soft key Position and, after selecting the
marker (the marker indication will turn to orange), use the
knob to move it to the left; you may also enter the desired
frequency of 100 MHz directly via the keyboard.
4.3 Measurement of the harmonics of a sine wave
signal
Due to the property of a spectrum analyzer to resolve dif-
ferent signals in the frequency range, it is well suited to
measure harmonics or the distance between harmonics
and the fundamental. The R&S®HMS-X offers extended
marker functions which allow to arrive at a result after just
a few key pressures. Due to the previous settings in chapter
4.2, the first marker is already located on the fundamental
which should stand clearly out of the noise floor in the left-
hand screen area. The marker should also display the selec-
Fig. 4.3: Level measurement with marker
Содержание HMS-X
Страница 82: ...82 Appendix ...
Страница 83: ...83 Appendix ...
