Questions about the design of a 13.56 MHz magnetic loop antenna

Hi everybody.

I have a few questions about the design of a 13.56 MHz magnetic loop antenna (to listen, not emit).

wavelenght is 300/13.56 = 22.12 m

With this value, how should I define antenna diameter ? Should I use ? wavelenght, ? wavelenght or something else ?

And what about number of turns ? Is it possible to reduce antenna diameter using more turns ?

Finaly, how should I design the tuning capacitor ?

Thanx a lot.

The best performance is from a full wavelength, but half wave will work. The meterial you use will have an effect on the size, 300/13.56 is wavelength in free space. I recomend a search on google for some better information..... As for designing the tuning capacitor, you dont, the veriable capacitor is a component you buy........ Hope this helps

Try to use a ferrite rod antenna similar to the one that used in tradiation AM radio except for different operating frequency. The size is much smaller. I have built a transmitter that operating at 27Mhz in the past using similar method, the rod length was around 60mm.