An Active Integrated Ultra-Wideband MIMO Antenna

A radio-frequency (RF) amplifier-integrated ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna system is presented. Instead of designing both the antenna and the amplifier separately based on 50-Ω interfaces, they are codesigned without this impedance requirement so that improved wideband antenna matching and total radiation efficiency are achieved. The design is implemented with a two-element semi-ring UWB MIMO antenna integrated with a commercially available UWB amplifier. The antenna has the size of 0.01λ
₀
²
where λ
₀
is the freespace wavelength at 1.8 GHz. The integrated antenna shows minimum realized gain and efficiency of 14.1 dBi and 60%, respectively, over the 1.8-5.5-GHz band. Diversity parameters of the integrated MIMO antenna are evaluated. Detailed design and measurement procedures are presented with simulation and experimental results.