ABSTRACT
This work presents a novel non-Foster matching circuit to improve the radiation of small loop antennas. The designed non-Foster circuit is achieved using grounded Negative Impedance Converters (NICs), which are based on the operational amplifier (op-amp). A passive matching network is added to offset the input’s negative inductance and negative resistance of the proposed non-Foster circuit. The extracted S1P data file of the loaded small loop antenna is used to instead of the equivalent circuit of an antenna in a traditional integrated design. With the novel designed non-Foster circuit, the loop antenna matched well at 10 MHz–60 MHz frequency band and its reflection coefficient was less than −20 dB. The good agreements between simulated and measured results validate the design concept.
