Half wave metal helix

Hi,

I need help finding papers on half wavelegnth helical resonator design equations. I have found tonnes of materials for quaterwavlength helixes but I have no luck finding anything on half wave helixes. If anyone could lend a hand , that will we great.

cheers.

On which mode you are working?

I'm thinking it will be TEM mode.i.e. the first resonance mode

cheers