Performance improvement of an electrically-small loop antenna matched with non-foster negative inductance

The paper presents results of a comparative study of a loop electrically-small antenna (ESA) matching with non-Foster negative inductances. Two matching networks which differ in connection of the non-Foster element to the antenna are considered. In one case the negative inductance is connected to the antenna input whereas another case corresponds to the antenna with the negative inductance connected in the middle of the loop, symmetrically with respect to antenna arms. Influence of the matching network architecture on the loop ESA performance is investigated. The second approach is shown beneficial with regard to providing of proper feeding of the loop antenna which results in a symmetrical radiation pattern.