Fractal Modified Reconfigurable Antennas for Modern Wireless Communication Systems: A Review

Today's wireless technology requires a compact and flexible single antenna that can operate as a multifunctional antenna based on the digital switching action of RF switches. Fractal technology transforms a conventional patch antenna into a multi-tuned or multi-band antenna. Therefore, it is essential to combine the properties of a fractal antenna with a reconfigurable antenna. Such reconfigurable fractal antennas integrate fractal geometry with tunable frequency selective surfaces (FSS), metasurfaces, and efficient RF switching technologies, achieving dynamic reconfigurability of frequency, radiation pattern, gain, and polarization with minimal loss. The entire review concluded that PIN diodes, varactor diodes, and RF-MEMS switches are most commonly used for switching with 0-2V external DC power supplies, providing real-time adaptability of the four reconfiguration mechanisms (frequency, pattern, polarization, and gain), gain-reconfigurable antennas are not available in the literature. Tunable FSSs will be used to accomplish this difficult task. Other solutions include multilayer FSSs and dual-feed configurations, which facilitate gain enhancement and linear-to-circular polarization reconfigurability. These antennas are ideal for next-generation wireless communications, satellite, and radar applications.