A Planar Dual-Band Periodic Leaky-Wave Antenna Based on a Mu-Negative (MNG) Transmission Line

In this study, a planar periodic leaky-wave antenna (LWA) that provides a dual-band full-space scanning property is presented. The LWA is based on a mu-negative (MNG) transmission line that offers a nonlinear dispersion characteristic with a very simple structure. The dualband beam scanning property is achieved by utilizing the n = -1 and n = -2 space harmonics to overcome the limitation of the MNG line that provides forward scanning only in then = 0 space harmonic. Microstrip bends are introduced to achieve proper matching and thereby suppress the open stopband effect at both broadside radiation frequencies, to avoid interference between two space harmonics, and to ensure efficient radiation. The proposed design method is validated by good agreement between the simulated and experimental results for the dual-band LWA that is designed to provide full-space scanning with the first and second broadside radiation frequencies at 4.3 and 8 GHz. The demonstrated total scan angle range of 279° is the widest range reported for the dual-band LWA.