Beam-scanning traveling-wave-resonator antenna based on nonreciprocal phase-shift CRLH transmission lines

A new type of beam scanning traveling-wave-resonator antenna is proposed and demonstrated numerically. It is composed of a finite-long and straight nonreciprocal transmission-line resonator and the feed line. The resonator section comprises of a nonreciprocal phase-shift composite right/ left handed transmission line with both ends open or shorted. The operational frequency of the antenna is not determined by the total size of the resonator, but by the configuration of the unit cell. The resonator section has field profiles with uniform magnitude and linearly-varying phase distribution along the resonator. Therefore, the gain and directivity of the antenna are enhanced with total length of the resonator section. The slope of the phase distribution on the resonator as well as the radiation angle of the antenna is continuously varied with the nonreciprocal characteristics of the transmission line, for example, by changing the applied dc magnetic field.