ACS-fed UWB-MIMO Antenna with Shared Radiator

A novel asymmetric coplanar strip (ACS)-fed multiple-input–multiple-output (MIMO) antenna working in the ultra-wideband (UWB) frequency band with a shared radiator is discussed. The proposed antenna is composed of a radiator which is shared by two antenna elements in order to achieve a very compact size of 26 × 26 mm2. By etching an I-shaped slot in the radiator and attaching a rectangular patch on the back, the operating bandwidth is broadened and a high isolation between the two antenna elements is realised. The stub from the ground also has a great effect on the return loss and isolation. The measured results show that the working frequency band of the MIMO antenna covers 3.1–10.6 GHz with an isolation of more than 15 dB. Furthermore, the simple feeding structure and compact size could enable the proposed antenna to be used in portable devices.