A Two-Loop Antenna Array with One Parasitic Element

The investigation of a small loop antenna with a single parasitic loop is considered.The two loops are coaxially arranged so the planes of the loops are parallel. Far field equations for the case where the two loops are loosely coupled are derived, first using relations in circuit theory, and second, using the field concept of vector potential.Computer solutions for these equations are obtained and the radiation patterns are plotted.An experimental study is attempted, and the results are considered. Solutions obtained show that the parasitic loop tends to act as a reflector or as a director depending on its separation from the active loop and on its tuning.This results in bending the two loops of the radiation pattern of the array either toward the active loop or away from it.As the parasitic loop becomes more detuned and more separated from the active loop, the radiation pattern tends to approach that of a single loop antenna.A loss in the signal strength has also resulted. Advisor:Allen R. Ediso