Highly miniaturised semi‐loop meandered dual‐band MIMO antenna system

A novel dual‐band two‐element directional multiple‐input–multiple‐output (MIMO) antenna system is presented with 68% miniaturisation, which is achieved using a semi‐loop meandered driven element and a small ground plane. The centre frequency of operation is 2 GHz. The antenna system covers two bands: the telemetry L‐band 1.27–1.43 GHz and the global system for mobile communications/long‐term evolution band 1.8–2.133 GHz. The simulation and measurement results are in good agreement. The proposed antenna system mimics the quasi‐Yagi antenna configuration with a measured front‐to‐back ratio of around 15 dB at 1.35 GHz and 17 dB at 2 GHz, which is achieved without using a large ground plane, extra metallic structures, multiple reflector elements, or any complex technique. A gain of more than 5 dBi is measured for the single element with a total radiation efficiency of around 85% in both bands. The measured isolation of the proposed MIMO antenna is more than 15 dB with <0.0785 measured envelope correlation coefficient values in both bands.