Propagation issues related to mm-waves can be avoided by selecting a suitable type of antenna for 5G systems. Array antennas are considered decent candidates to compensate for these issues regarding the path loss for short-range communications, and two-dimensional arrays with large electrical apertures can provide narrow beamwidth, which is essential for 5G operations. Large electrical apertures at mm-waves for 5G do not affect the physical profile of the antenna due to the short wavelengths, while massive multiple-input and multiple-output (MIMO) systems have also been suggested for 5G due to their possible integrity with small cells. However, compared to array antennas, massive MIMO systems are unsuitable candidates for 5G systems due to their design complexity and reduced adaptability at shorter wavelengths.

There are many other types of antennas that can be found in the literature for proposed 5G operation. Their main purpose is to achieve wide bandwidth to support the high throughput of 5G systems, and the operation of antenna systems for 5G compatibility largely depends on the enhancement of their bandwidth performance. A massive bandwidth is required in mm-wave range to support high data requirements. Bandwidth of the order of GHz is attainable at mm-wave frequency range, but additional efforts are still required to fully utilize this with other requirements. However, only enhancing the bandwidth of the proposed antenna does not solve all the issues regarding 5G compatibility. Significant improvements in some other parameters, like gain, efficiency, polarisation diversity, and adaptive beam steering, are also urgently needed as the antenna performance for 5G can directly depend on the mode of antenna operation. Antennas used for transmission or reception can significantly affect the required parameters for 5G operation. It is widely believed that the requirement for the improvement of antenna parameters for transmission is higher than the same parameters for reception.

This Special Issue aims to publish comprehensive research work on the design of efficient antennas for 5G communication systems. This Special Issue focuses on the design and performance characterization of such antennas, with scopes revolving around but not limited to the topics given below. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Antennas for 5G communication systems
• Design and measurement techniques for antenna arrays
• Reflectarray antennas
• Phased arrays for future communication systems
• Massive MIMOs
• Reconfigurable antennas
• Antenna measurements for 5G and future systems
• Beam steerable and polarization diverse antennas
• High gain antennas
• Chip antennas for 5G communications
• Wearable and flexible antennas for 5G communications
• Antenna optimization techniques for 5G and future communications