This section provides an example on how to configure the instrument for generating of an amplitude modulated signal and of a frequency modulated signal with noise.
To generate a simple AM-modulated signal, proceed as follow:
Activate default (preset) state
Press the PRESET key to set a defined instrument state.
Select and activate AM modulation
Turn the rotary knob and select the "Mod" block.
Press the rotary knob to open the dialog where the modulation can be selected (different modulation modes are available depending on the options installed).
The "Amplitude Mod..." menu is the first menu and is highlighted per default.
Turn the rotary knob and highlight "Amplitude Mod...".
Press the rotary knob to open the "Amplitude Modulation" dialog.
Turn the rotary knob to select parameter "AM Depth", press the rotary knob to allow editing and enter the preffered AM depth with the aid of the numeric keypad and the unit keys.
Finally, select "State" and press the rotary knob to switch on the AM modulation.
Press the DIAGRAM key to display the complete block diagram.
To indicate the active state, the "Mod" block is displayed in blue. The "RF" is not yet active, which means that no RF signal is output.
Set frequency and level and activate RF signal
Press the FREQ key to activate the editing mode for frequency entry. The "Frequency" entry field in the header section of the display is highlighted.
Enter the frequency using the numeric keypad and terminate the entry by pressing a unit key.
Press the LEVEL key and enter the level settings in the same way.
Press the DIAGRAM key to display the complete block diagram.
Turn the rotary knob to select the "RF" block.
Press the RF ON/OFF key to activate the "RF" block.
The AM modulation signal is now present at the RF output.
To generate a simple FM-modulated with noise signal, proceed as follow:
![]() | This setting requires option Multifunction Generator, R&S SMA-K24. |
Activate default (preset) state
Press the PRESET key to set a defined instrument state.
Select and activate FM modulation with internal noise signal and a deviation of 500 kHz
Turn the rotary knob and select the "Mod" block.
Press the rotary knob to open the dialog where the modulation can be selected (different modulation modes are available depending on the options installed).
Turn the rotary knob and highlight "Frequency Mod...".
Press the rotary knob to open the "Frequency Modulation" dialog.
The internal source is the LF generator 1 by default. This setting is not changed.
Turn the rotary knob to select parameter "FM Internal Source", press the rotary knob to open the selection list and select "Noise".
Gauss distribution and full bandwidth (10 MHz) are the default settings for the noise signal. These settings are not changed.
Turn the rotary knob to select parameter "FM Int Deviation", press the rotary knob to allow editing and enter the preffered deviation with the aid of the numeric keypad and the unit keys.
Finally, select "State" and press the rotary knob to switch on the FM modulation.
Press the DIAGRAM key to display the complete block diagram.
To indicate the active state, the "Mod" block is displayed in blue. The "RF" is not yet active, which means that no RF signal is output.
Set frequency and level and activate RF signal
Press the FREQ key to activate the editing mode for frequency entry. The "Frequency" entry field in the header section of the display is highlighted.
Enter the frequency using the numeric keypad and terminate the entry by pressing a unit key.
Press the LEVEL key and enter the level settings in the same way.
The noise now modulates the RF carrier.
Press the DIAGRAM key to display the complete block diagram.
Turn the rotary knob to select the "RF" block.
Press the RF ON/OFF key to activate the "RF" block.
The FM modulation signal is now present at the RF output. The LF output is not yet activated, i.e, the modulation signal is not output there.
The graph below shows the FM modulated signal with noise (upper blue trace) and the unmodulated signal (lower greentrace).
Imprint | Statement of Privacy | Terms & Conditions | © 2016 ROHDE & SCHWARZ |