# Homogeneous magnetic field inside aperture of PCB

I need to create a homogeneous magnetic field of a certain strength across a 10mm diameter opening of a PCB by using a current track on said PCB around the opening. The signal sent through the conductor track is a microwave signal of about 3 GHz with a variable power. How would I go about achieving the strongest and most homogeneous magnetic field across the area of the opening?

My first thought was just routing the conductor track around the opening and use the magnetic field of the current, but that turned out to be quite power hungry. On the interwebs someone recommended a loop gap resonator but I am inexperienced in antenna design and am not sure where to start. I'm starting to learn ANSYS HFSS but can't get a stable footing with it since I'm lacking reproducible examples to learn.

• It always boils down to "using the magnetic field of the current". Things like resonance are just tricks to get higher current. If the current is what's causing the loss then they won't help you. Aug 18 at 13:47
• As others have implied, RF frequencies are not just current, and can't be treated as such. Use a n*(Lambda/4) (probably where n is odd) conductor to induce resonance. You'll have to simulate and impedance match against the amplifier. Aug 20 at 13:26