Passive-Circuit-Based Nonreciprocal Metamaterials: Controlling the Phase Gradient of Fields in Resonators and Antennas

In next- and future-generation wireless communication systems, demand for antenna technologies has continued to grow. This demand has fueled the development of design techniques that pursue more desirable configurations with simplification, electrically small size, and low profiles as well as multiple functionalities and higher performance with multiband, broad bandwidth, single/multibeam scanning, polarization control, and dispersionless group delay.