Comparison of Small Wideband Magnetic Loops

Chavdar Levkov (LZ1AQ) experimentally compared the performance of small wideband magnetic loops, focusing on their sensitivity and the “loop factor” M (A/L), analogous to the effective height in dipoles. By increasing loop area and reducing inductance—using parallel or coplanar crossed (CC) configurations—sensitivity improved significantly. Measurements at 1.8, 3.5, 7, and 10 MHz showed CC loops yielding up to 9 dB higher current than single loops of equal area. Numerical simulations confirmed M as a reliable predictor of loop sensitivity, with CC loops offering the best performance for a given area, while parallel loops minimized volume. Practical recommendations and design tools were provided for optimizing loop configurations in real-world applications.