No abstract

No abstract

Cervical intervertebral disc calcification combined with OPLL was rarely observed in children. Conservative management was carried out and the patients had a full recovery. Our experience suggests that the conservative treatment is an acceptable method.

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 subcavity 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 0.58λ 0 × 0.58λ 0 × 0.02λ 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.