Four-shaped 2×2 multi-standard compact multiple-input–multiple-output antenna system for long-term evolution mobile handsets

The use of multiple-input–multiple-output (MIMO) antenna systems will be required by next generation wireless systems to achieve their high throughput data transmissions. In this work, the authors present the design and fabrication of a 2 × 2 MIMO antenna system for the 700 MHz band of the long-term evolution (LTE) wireless standard. The MIMO antenna system is based on a novel 4-shaped antenna geometry that is compact in size and covers two bands of operation. The dual-band 2 × 2 MIMO antenna system covers the 734–790 MHz and the 2307–2475 MHz LTE and industrial, scientific and medical (ISM) bands. It occupies an FR-4 material substrate size of 58×110×1.56 mm3. The antenna has frequency tuning capabilities without changing the over all size of the MIMO system substrate. Several isolation enhancements methods were investigated, and the values of the correlation coefficient (|ρ|max) were within the LTE requirements. The maximum obtained gain for a single operating antenna at 770 and 2380 MHz was −5 and 4.5 dBi, respectively.