Post Your Answer
2 years ago in Electrical Engineering By Rohan
I’m simulating a small loop antenna over a finite ground plane in HFSS and need to accurately capture its 3D far-field pattern. What is the optimal setup for the radiation boundary and far-field monitor?
My antenna is a printed rectangular loop on a small PCB ground (≈ 1λ x 1λ) at 2.4 GHz. I'm unsure about the radiation box setup. How large should the airbox be from the antenna edges? Should it be a perfect E boundary (PEC) or a radiation boundary? For the far-field monitor, is an "infinite sphere" sufficient, and what resolution (theta/phi steps) is needed for an accurate peak gain and pattern reading without excessive simulation time? I want to avoid near-field artifacts in my results.
All Answers (1 Answers In All)
By Kenny Sebastein Answered 1 year ago
For reliable results with a ground-plane loop, follow this setup. Your airbox should have a radiation boundary (not PEC) and be placed at least λ/4 from the antenna's radiating parts, but I prefer λ/2 to λ for pattern accuracy, especially with a finite ground that also radiates. Set the far-field infinite sphere with a resolution of 1° or 2° in theta and phi; this is fine for most applications. The critical step often missed: ensure your ground plane edges do not touch the radiation boundary, as this can create non-physical reflections. For a loop, the radiation is broadside, so verify your mesh is fine enough on the loop conductors and the ground edges. Finally, always run a convergence test by slightly increasing the airbox size—if gain and pattern shape don't change, your setup is valid.
              ÂReply to Kenny Sebastein
Related Questions