Leaky-wave antenna based on non-foster metamaterial - Is stable operation feasible?

A beam-squint-free leaky-wave antenna is one of potentially important applications of non-Foster metamaterials. However, several recent studies pointed out inherent stability problem of non-Foster elements, indicating that practical realization of leaky-wave antenna may be very challenging, if not entirely impossible. Here, we analyze the origin of stability issue and propose the design methodology that assures stable operation.