Bandwidth‐enhanced four‐antenna MIMO system based on SIW cavity
Bing‐Jian Niu, Yanjie Cao
Abstract
A bandwidth‐enhanced four‐antenna multiple‐input–multiple‐output (MIMO) system based on a substrate‐integrated‐waveguide (SIW) cavity is proposed. By etching two long rectangular slots on the top plane of the cavity, four quarter‐mode sub‐cavities with the same size are constructed and then individually fed by a coaxial port to form a four‐antenna MIMO system. Suitable port isolation is achieved by optimising the length and width of these slots. To enhance bandwidth, a pair of back‐to‐back L‐shaped slots is cut to split each sub‐cavity into three smaller parts. Three resonant modes are generated in these parts and merged into the operating band. A sample with the overall size of 0.58 λ 0 × 0.58 λ 0 × 0.02 λ 0 has been fabricated. Measured bandwidth is enhanced from 80 to 230 MHz and measured isolation is better than 15.0 dB. Owing to covering the band of 3.40–3.60 GHz, the proposed antenna system has potential applications for fifth‐generation communication.