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1. Warmonger
   

   Member
   Joined: Nov '13
   Posts: 7

   I am trying to simulate phased array. However, I'm getting very firrent beam angles at different grid pitch. Here's the scene with equidistant sensor arch:

   

   256 x 256 grid with 2.5 mm pitch

   

   512 x 512 grid with 1.25 mm pitch (same physical size)

   

   The results are completely different and every beam goes its own direction I don't know why is that. Some things I checked:
   - Max supported frequency is higher than signal frequency (40 kHz)
   - Simulation sampling rate is 5 MHz so it should represent phase precisely

   Posted 9 years ago #

2. Bradley Treeby
   

   Developer
   Joined: Mar '10
   Posts: 1,643

   Hi Warmonger,

   Unfortunately your pictures don't show up. Is it possible to upload them somewhere else?

   Brad.

   Posted 9 years ago #

3. Warmonger
   

   Member
   Joined: Nov '13
   Posts: 7

   Now you tell me...

   Scene
   

   256x256, 2.5 mm pitch
   

   512 x 512, 1.25 mm pitch
   

   Posted 9 years ago #

4. Bradley Treeby
   

   Developer
   Joined: Mar '10
   Posts: 1,643

   Hi Warmonger,

   It's hard to say just looking at the pictures. Are the elements in your phased array spaced by less than wavelength/2? If not, it could be grating lobes. If you are using a linear array, you could also try comparing your code with Steering A Linear Array Example.

   Brad.

   Posted 9 years ago #

5. Warmonger
   

   Member
   Joined: Nov '13
   Posts: 7

   Right, they are spaced by more than half a wavelength. I expected it to have lobes, but the simulation should still show the effect consistently.

   Posted 9 years ago #

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