FAQs from Rohde & Schwarz

EMC32-S: Pulse train support in EMC32

Question:

I am using EMC32. How can I configure a test template with the SMB100A (including SMB-K27) or the SMF100A (including SMF-K27) to generate pulse trains for my EMC32 application?

Answer:

The pulse train software option is the SMF/B-K27. It is selected as an AWG in the device list for the pulse modulation setup.The EMC32 software considers the signal generator and pulse train source (AWG) as two separate devices in the device list.

Example:

In the following screenshot, I am using an SMF100A as the signal generator and the SMF-K27 (pulse train) for a radar application.

As already mentioned, it is important to note that the source used to pulse modulate the SMB100A is configured as a separate generator within EMC32. This is the case when using an external function generator like the Agilent 33220A as shown below:

or, in this case, the internal source available with the -K27 pulse train option as shown in the following screenshot:

The modulation setup is done in the test template. The following template shows a scan based on 80% AM with a 1 kHz tone.

To change the test to a radar pulse, simply right click on the signal generator icon (in this case SMF100A), which brings up the following dialog box:

As you can see in the dialog box, the modulation is currently set to 80% AM from the internal source to the SMF100A. Low frequency generator 1 (LFGEN1) is selected and set to generate a 1 kHz sine wave. Any of these fields can be changed in this dialog. To create a radar waveform, simple change the type to pulse modulation (PM) and the source to pulse train generator (PGen Train).

The pulse train parameters are accessed by right clicking on the function generator icon (SMF-K27).

The pulse width, pulse frequency, pulse count and repetition rate can be entered in this dialog box. The settings shown above will result in a pulse-modulated signal with 50 pulses (each 3 us wide) with 3.33 ms off time, the entire sequence repeating once per second. This is how these settings are shown in the test template: