Loop-Antenna Coupling-Transformer Design

The low-impedance loop coupling-transformer circuit is analyzed, expressing the transformer parameters in terms of the circuit and transformer coupling coefficients. Equations are developed which yield optimum design values for the transformer. It is shown that an ideal transformer-coupled loop has 38.4 per cent of the gain realizable from a direct-connected loop of the same area, assuming the same Q in the transformer secondary as in the direct-connected loop.