I have a pulse generator circuit that needs a roughly 350 nH inductor. RMS current will be about 6 amps, and I used four Coilcraft MiniSpring air-coil inductors series-parallel, running about 3 amps RMS each, which should have been conservative. But they get very hot at well below max current, which I'm blaming on skin effect. The waveform is pulses, but rougly equivalent to 30 MHz maybe.
I wound my own single inductor from #22 bus wire, about 0.2" dia x 1" long, and it gets pretty hot too. DC-to-output power efficiency is a little better but not much.
So, for you RF guys,
I used regular tinned #22 bus wire. Would bare copper, or magnet wire, be much better as regards skin effect heating?
Would Litz be much better at this sort of frequency? It would be hard to wind as a self-supporting air core inductor.
Might any core material help? That would trade copper loss for core loss. I might have an old MicroMetals powdered-iron toroid sample kit around here somewhere.
I might try making four air-wound inductors from #20 bus wire, to replace the four separate Coilcrafts. Might help. Probably not much.
Maybe I just need a huge inductor. I'll have to spin the PCB layout for that.