frequency modulation multisim

[tacx2x2]

Where can I find examples on basic FM circuits. Specifically, interpeting the spectrum analyzer given a set of input values.  

[Andy_Hinde]

Hi Tacx2x2,
Can you elaborate on what you are looking for? I don't understand exactly what you are asking.

Regards,
Andy Hinde
RF Staff PSE
National Instruments

[tacx2x2]

Hi Andy,

     thanks for the response. The trouble I'm having is givena circuit with conditions I have to input, I set the spectrum anaylzer to the values that are given and run the simulation and it produces an output of a spectral plot. When i measure the values of the spectral plot, they do not match up to the Bessel table with a given modulation index of 5.  here is the a list of what goes into the diagram

Spectrum analyzer

o-scope

FM generator

for the O-scope settings, Time base scale =20us/Div

                                         Xpos = 0

                                         Y/T

             Ch A     scale =1v/Div Ypos=0, DC,  Trigger (Pos Edge, level=0)

 Spectrum Analyzer        Freq (Center=100kHz,  span=200kHz)

                                   Amplitude (lin, range =0.1 V/Div),

                                    Resolution = 400Hz 

  Is there a certian way to read the ouput plot on the Spectrum analyzer?

Tim

[rftek]

 Hi Tim,

 Could you please elaborate a bit more on how your system is setup there:

   1. Do you have NI hardware in this system?
   2. Are you using any NI software (LabVIEW, LabWindows, etc)?
   3. Is the system you've described entirely simulated?
   4. Could you take a screenshot of your system and post it here?

 If you have a specific multisim question then you can search for it here.

 In answer your original question, where are RF resources?
 I would like to point you to this DevZone article, RF and Communications Fundamentals.

 I hope this helps,

 Have a great afternoon.

 Best regards,

 MatthewW
 Applications Engineer
 National Instruments


 
 

[tacx2x2]

Using Multisim.Not sure if you read what I wrote previously to Andy but it has all the system parameters

tim

[Fernando_D]

Hi tacx2x2:

This document might help you: Understanding RF with NI Multisim

If you have Multisim specific questions, please post your message here:

Fernando D.

NI