Stability analysis of non-foster circuit loaded artificial magnetic conductors

Summary form only given. The mushroom-type artificial magnetic conductor (AMC), originally presented by Sievenpiper et al., (IEEE Trans. Microwave Theory Tech., 47, pp. 2059-2074, 1999) has found numerous applications, e.g., underneath horizontally polarized antennas, between planar antennas for reducing the coupling between them, for reducing the E-plane edge diffraction from finite ground planes, and for suppression of noise in multilayer circuits. Recently the AMC loaded with negative-inductor non-Foster circuits (NFCs) was investigated for substantial reduction of the resonant frequency and for increasing its bandwidth (Gregoire et al., IEEE Antennas and Wireless Prop. Lett., 10, pp. 1586-1589, 2011). The objective of this work is to investigate the stability of the active circuit loaded AMC (AAMC).