Loop antennas aren’t ideal–but neither is any other small antenna. Because the loop is tightly tuned to a particular frequency, it requires retuning for even relatively small frequency changes ...

Magnetic loop antennas are great if you are limited on space since they are just a potentially small loop of wire. The problem is, they are sharply tuned. You normally have an adjustment capacitor ...

Figure 15 shows the equivalent schematic of a small loop antenna. 15. Equivalent Schematics of the Small Loop Antenna in Figure 13. The radiation resistance of loop antennas is small, typically ...