# How to determine Solution Frequency?

#### aabdullah

##### Newbie
As part of my final year project, I'm trying to use HFSS to simulate (and eventually build something similar to) the novel WPT antenna found in this paper: https://livrepository.liverpool.ac.uk/3020240/1/Final Version.pdf

I basically know almost nothing about antennas so it's very difficult and I need help. When I go to build the radiation box, I read something the box's faces requirement of being a quarter-wavelength away from the antenna's radiating surface. How would I go about determining the quarter wavelength of this antenna (Either the one in Figure 6 or Figure 8)? Is it tied to the "solution frequency"? If so, how would I determine this frequency when the paper shows that this antenna has multiple resonant frequencies...?

Thank you.

Solution
The quarter-wavelength criterion is from an analysis of overly-simplistic radiation boundary conditions. Modern versions of HFSS use modern boundary conditions that don't have such a limitation.

That being said, if you still wanted to enforce the condition, you would use one-quarter wavelength (of a plane wave in free space) at your lowest solution frequency.

#### PlanarMetamaterials

The quarter-wavelength criterion is from an analysis of overly-simplistic radiation boundary conditions. Modern versions of HFSS use modern boundary conditions that don't have such a limitation.

That being said, if you still wanted to enforce the condition, you would use one-quarter wavelength (of a plane wave in free space) at your lowest solution frequency.