YesReconfigurable antennas play important roles in smart and
adaptive systems and are the subject of many research studies. They
offer several advantages such as multifunctional capabilities, minimized volume requirements, low front-end processing efforts with
no need for a filtering element, good isolation, and sufficient out-ofband rejection; these make them well suited for use in wireless applications such as fourth generation (4G) and fifth generation (5G)
mobile terminals. With the use of active materials such as microelectromechanical systems (MEMS), varactor or p-i-n (PIN) diodes, an
antenna’s characteristics can be changed through altering the current
flow on the antenna structure. If an antenna is to be reconfigurable
into many different states, it needs to have an adequate number of
active elements. However, a large number of high-quality active elements increases cost, and necessitates complex biasing networks and
control circuitry.
We review some recently proposed reconfigurable antenna designs suitable for use in wireless communications such as cognitiveratio (CR), multiple-input multiple-output (MIMO), ultra-wideband
(UWB), and 4G/5G mobile terminals. Several examples of antennas
with different reconfigurability functions are analyzed and their performances are compared. Characteristics and fundamental properties
of reconfigurable antennas with single and multiple reconfigurability
modes are investigated.European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424
