Feeling the heat

The introduction of 4G for higher data rates in mobile communication has created a new need for frequency reconfigurable or tunable antennas. To support 4G, new frequency bands needed to be defined. The bands available varied by region so that in total, 40 different bands have been defined for 4G use across the world. Globetrotters have come to expect to use their mobile phone wherever they go, but the large number of 4G bands makes it difficult for a single phone to use 4G coverage everywhere. An efficient antenna designed to cover all the 4G bands would be larger than most phones itself, thanks to the fundamental relationships between the volume, bandwidth and efficiency of an antenna. To keep the antenna size acceptable for phone manufacturers and maintain good efficiency, we need to reduce the antenna bandwidth. We need to be able to reconfigure the operating bandwidth to different bands. The number of frequency bands is likely to keep increasing, if so, frequency-reconfigurable antennas will be the only way to address future communication standards.