An Ultra-Narrow-Width Single-Beam High-Gain Microstrip Leaky-Wave Antenna

This paper introduces a recently proposed single-beam microstrip leaky-wave antenna (LWA) with ultra-narrow width, which can be less than 0.2 guided wavelength. The LWA contains two individual microstrip lines with differential excitation, where several horizontal stubs are employed to connect two lines in period. Due to the shunt inductive effects of stubs loaded in each period element, the fast wave region can be generated on the fundamental mode of the differential microstrip line. Based on this loading strategy, the designed LWA shows high-gain, low cross polarization, and ultra-narrow width performances. The matched performances between simulation and measurement prove that the provided LWA is suitable for the situation with limited cross section.