Compact ultrawideband MIMO dielectric resonator antennas with WLAN band rejection

Abstract

A new compact configuration of ultrawideband (UWB) multiple-input-multiple-output (MIMO) dielectric resonator antennas (DRAs) with wireless local area network (WLAN) band rejection is proposed. The antenna arrangement consists of two identical inserted rectangular DRAs excited by two microstrip feeds, with an overall compact size of 29 × 29 × 5 mm³. To enhance isolation and improve impedance bandwidth, a stub connected to the ground is added to the bottom plane of the substrate. Further, to reduce interferences with WLAN systems, two L-shaped parasitic strips connected to the dielectric resonators are added to create a band rejection between 4.98 and 6.08 GHz. The measurement results demonstrate that the proposed DRAs achieve satisfactory MIMO UWB performance, with an impedance bandwidth of around 106% excluding a rejection band for WLAN, low mutual coupling and a low envelope correlation coefficient across the whole desired frequency band.