Mu-near-zero propagation in quasi-TEM microstrip circuits

This paper presents the theoretical analysis and experimental demonstration of mu-near-zero (MNZ) propagation in quasi-TEM microstrip circuits achieved by using metamaterials of the resonant type. We show that two frequencies exist which may support MNZ propagation and how the actual operating of MNZ frequency depends on the properties of the host. The phenomena of MNZ propagation is then used to propose an entirely new class of MNZ bandpass filters characterized by significantly reduced variation of group delay in comparison to conventional solutions.