Investigation of Parallel and Orthogonal MIMO Antennas with Two-Notched Structures for Ultra-Wideband Application

Ultra-wideband (UWB) technology is widely used in many communication scenarios. However, narrowband systems can easily interfere with the UWB system, which generates multipath fading. In order to solve these interferences and meet design requirements of high isolation multiple-input multiple-output (MIMO) antennas, two MIMO antennas double-notch structures are designed. Firstly, U-shaped slots etched on radiating patch feeder achieve notch characteristics WiMAX ITU bands. Using this antenna element, a two-element put symmetrically parallel, rectangular branches loaded improve isolation. The size 0.57λ × 0.32λ 0.013λ (at 2.5 GHz). Then, four-element designed for another application; here, each element placed orthogonally other, improved through loading cross-shaped branch middle elements. 0.013λ. Both samples tested verify design. Measurement results show that working bandwidth 2.45–14.88 GHz 2.14–14.95 GHz, greater than 17 20 dB, peak gain 5.7 5.9 dBi two- antenna, respectively. Compared references, have wider higher radiation efficiency. They well-suited diverse wireless applications.