(Revised 12/11/2015)
Small Transmitting Loops (STL) are loops with approximately uniform current around the loop.
(King 1969) gives us expressions for an equivalent circuit of the ‘loop mode’ and ‘dipole mode’, it consists of parallel branches for each mode of series R and X:
- R0: radiation resistance of loop mode;
- X0: reactance of loop mode;
- R1: radiation resistance of dipole mode; and
- X1: reactance of loop mode.
Plotting these and the combined total Rt and Zt for a 1m diameter (perimeter p=3.14m) lossless circular loop of 20mm diameter conductor from 2-30MHz in free space gives an insight into their relative magnitudes at different frequencies. Continue reading Dipole mode of Small Transmitting Loop per King