The Inductively tuned magnetic loop antenna (ITML) antenna is a series-resonant magnetic loop antenna entirely made of coaxial cable. What makes the ITML antenna unusual is that the same coaxial cable simultaneously provides both reactive components - inductance and capacitance. Since both components rely heavily on the type and lenght of the used coaxial cable, some more complex calculations are necessary.
In order to do this, I built the DJ5SE-ITML-Antenna-Calculator
Geometry dimensioning is an iterative process: for a given cable type and target frequency, the calculator sweeps loop diameters, checks whether the target frequency falls within the achievable tuning range, and uses a Brent root-finding algorithm to solve for the exact turn spacing that yields resonance.
Differences from a classic single-turn magnetic loop
- Two turns instead of one
- Fixed capacitance
- Tuning via turn spacing
- Smaller diameter
This is theoretical concept work so far. The calculations have to be verified by empirical studies. Also mechanical viability has not been proven, yet. If you want to build one for yourself, I would be happy if you would share your construction, results and experiences.
73 de DJ5SE