NIC-Based Non-Foster Impedance Matching of a Resistively Loaded Vee Dipole Antenna

Abstract

Negative impedance converter(NIC)-based non-Foster impedance matching is proposed for an electrically small antenna. The antenna considered in this work is a resistively loaded vee dipole(RVD) antenna, which has considerable reflection at the feed point because of its large negative input reactance. The non-Foster matching circuit built near the feed point consists of two-stage NIC circuit and a capacitor connected between the stages. The NIC is realized by using operational amplifiers(op-amps) and resistors. The circuit is designed by considering of the input impedance according to the finite open-loop gain of the practical NICs. The stability test of the impedance-matched RVD antenna is performed. The non-Foster matching circuit is implemented with the RVD antenna. The measured impedance demonstrates that the proposed non-Foster matching circuit effectively reduces the input reactance of the RVD antenna.