Add random noise to electric field

Dear all,

I am new to noise generation. I would like to add a random noise to my signal but I failed to create the desired signal with noise.

What I did is just adding a random number to my signal but resulting signal seems like different from I want. It appears above of my original signal in magnitude instead of merge into mixed into my original signal.

May I know the correct way to add noise into a signal ?

Hope to get a reply from anyone who expert in it soon.

Thanks in advance.

Best Regards.

Without any information about your frequency and power it is difficult to enter.
Noise can be generated in noise generators and added to a signal using a directional coupler. Noise can be also amplified to desired levels. You can check "www.noise.com" how they do it.

I am doing a simulation involving microwave antennas for image reconstruction. I would like to add white gaussian noise to my image in order to apply analog filter to filter out the noise.

However, I have to no idea on how to add the noise to my image.

Hope to get some ideas from fellow experts.

Thanks in advance.

Best Regards.