yefj said:
Hello ,reagrding your questions:
1.A ring is good because we can put a diamong on top of it to use it for spectroscopy NV centers,stuff I dont work with and doesnt know more details.
2.It doesnt have to be a ring , any closed loop shape would be great.
Thanks.
You are asking a question with impossible constraints.
Any closed ring, with a circumference that is small in wavelengths, will not be resonant.
A transmission line on a PCB will not work. Any ground plane, or track below a ring, will induce an equal and opposite current, that will cancel the axial B field.
You need an inductor that is resonant with a capacitor. The volume inside the inductor will have a high axial B field. The inductor will need to be wound with a short wire, so will have only a few turns. The current within the inductor should not vary significantly along its length, or it will become a transmission line that cancels its axial field.
The resonant circuit will need to be enclosed by a larger rigid conductive screen, or box, to keep interference out, while keeping the resonant signal in. The screen must provide isolation, so the internal EM environment will not be influenced by the external movement of the operator. The resonant circuit will see itself, like an antenna, reflected from all the internal surfaces of the screen. The cavity inside the screen must be dimensioned to support the resonance.
The sample for analysis will need to be placed in the end of an insulated rod, then introduced into the somehow resonant chamber, by pushing it in along a guide tube.
That system is very different to your imagined resonant ring, etched on a PCB. The scenarios are so different that there can be no transition between them. Your resonant ring cannot be made to work.
