Compact circular connected monopole antenna arrays for wideband MIMO applications

摘要

In this work, a connected circular monopole antenna array is presented for ultra-compact, wideband, multiple-input multiple-output (MIMO) wireless access point applications. Two configurations of the circular array are considered; one with 4- and another with 8-antenna elements using the same substrate size. The frequency bands covered were from 2.3 to 5.3 GHz (LTE 2.3-3.8 GHz, Bluetooth 2.4 GHz, wireless local area network 2.4, 5.2 GHz and WiMax 2.3 GHz). The obtained measured bandwidth was 3 and 2 GHz for the 4- and 8-element arrays, respectively. The antenna system is fabricated on a commercially available Roger 4350 substrate with ε_requal to 3.5 and height of 1.52 mm. The radius of the array is 32 mm (the most compact with wideband characteristics). The length of a single element is only 15 mm which is λ/8 at the lowest frequency. The design is planar, low profile and very compact. Good MIMO performance is achieved.