Matching Small Loop Antennas to rfPIC(TM) Devices
In close proximity to the human body, small loop antennas outperform small dipole and monopole antennas . Their size, robustness and low manufacturing cost have made small loops the most popular antenna for use in miniature key fob transmitters. A small loop antenna typically consists of a circular, square or rectangular copper trace on a printed circuit board. In some cases, discrete wires are shaped into loops.
AN831, small loop antennas, rfPIC