An Ultra-Wideband MIMO Bowl-Shaped Monopole Antenna with Sturdy and Simple Construction

Anultra-wideband (UWB) bowl-shaped monopole antenna with a sturdy, simple, and lightweight structure is proposed, and then is used to compose the 3 × 3 multiple input multiple output (MIMO) antenna. The wide bandwidth is determined by the outline of the monopole, which has a quarter wavelength and high-order modes. The inner part of the bowl-shaped monopole is removed for a light weight. The simulated and measured results show that an ultra-wide band of 2.3–8.1 GHz (5.8 GHz, 111.5%) and a high isolation of greater than 20 dB between the antenna elements of the MIMO antenna can be achieved.