multiply two signals at different freque while avoiding imag

[rajasekhar.rk]

Hi,

I have a 4KHz message signal interpolated to 1.28MHz & a carrier signal of 20KHz sampled at 1.28MHz. while multiplying these two signals, images are formed due to aliasing. How to view those images in simulation(modelsim)? If images are found how to remove those images. Let me know the solution. Thanks in advance.

-Raj

 

[keith1200rs]

I don't really understand what you are doing but there are techniques for multiplying two signals and not getting the image. Search for 'image rejection mixers' or something similar.

Keith

 

[vipinlal]

Re: multiply two signals at different freque while avoiding

I dont think you can see the signal waveform in simulation.I suggest you can write the multiplication results to a file and display it using some other software like MATLAB.

The images occur only when the Nyquist Rule of sampling is not followed.So you have to make sure that the sampling frequency is high enough that images doesnt occur.

Also be more clear about your questions.Give more information if you truly want people to answer your question.

--vipin
https://vhdlguru.blogspot.com/