Design of loop antennas and matching networks for low-noise RF receivers: analytic formula approach

A comprehensive procedure for designing loop antennas and matching networks for low-noise receivers, by using an analytical formula approach, is presented. The effective length l_effect of an equivalent transmission line, for a single-turn loop antenna, and the effective coupling coefficient ρ, for a multiturn loop antenna, are introduced in the approximate formulas for the impedances of single loop as well as multiturn loop antennas, which are valid up to the first resonant frequency. Hence, an accurate design of loop antennas and matching networks of receiving systems can be achieved by using circuit analysis. The theoretical results are compared with the measured results