Gain and Pattern Improvements of Array Antenna using MSA with Asymmetric T-shaped Slit Loads

This paper presents a 1×4 array antenna using asymmetric T-shaped slit loaded microstrip antenna (MSA). The antenna consists of four MSAs align vertically on a dielectric substrate and ground plane. This antenna will be utilized in WLAN applications as the commercial panel antenna. A modified array configuration is proposed to further enhance the antenna radiation characteristics and usable bandwidth. The desired patterns of array are improved by adjusting the array element spacing from λ/2 down to λ/3. Moreover, alternating of the slit loads positions on each side of some patches in array can control the directive patterns to be symmetric shapes. The measured results of the radiation pattern, input impedance, return loss, VSWR, directive gain, and are also conducted for verification of the IE3D-based simulated results. With good agreement between the simulated and measured results and accordance of the requirements, therefore, this proposed panel antenna is appropriate for the wireless applications. Key-Words: Array Antenna, Directive Gain, Microstrip Antenna, Radiation Patterns, Slit Load