Phase-nonreciprocal ε-negative and CRLH metamaterials are analyzed using a new approach in which field analysis and transmission line model are combined. The examined one-dimensional nonreciprocal metamaterials are composed of a ferrite-embedded microstrip line periodically loaded with shunt stubs. In the present approach, the phase constant nonreciprocity is analytically estimated and formulated under the assumption of operating frequency far above the ferromagnetic resonant frequency. The present approach gives a good explanation to the phenomenon in terms of ferromagnetic properties of the ferrite and asymmetric geometry of the metamaterial structure, showing a good agreement with numerical simulations and experiment.

A novel two-dimensional (2D) beam scanning antenna array using composite right/left-handed (CRLH) leaky-wave antennas (LWAs) is proposed. The antenna array consists of a set of CRLH LWAs and a Butler matrix (BM) feeding network. The direction of the beam can be scanned two-dimensionally in one plane by changing frequency and in the other plane by switching the input ports of the BM. A four-element antenna array in the microstrip line configuration operating at 10.5 GHz is designed with the assistance of full-wave simulations based on the method of moment (MoM) and the finite-element method (FEM). The antenna array is fabricated and radiation characteristics are measured. The wide range 2D beam scanning operation with the angle from -30 deg to +25 deg in one plane by sweeping frequency from 10.25 GHz to 10.7 GHz and with four discrete angles of -46 deg, -15 deg, +10 deg, and +35 deg in the other plane by switching the input port is achieved.