Circular ring UWB antenna with reconfigurable notch band at WLAN/sub 6 GHz 5G mobile communication

A compact UWB circular ring-shaped monopole antenna with a reconfigurable band-notched characteristic is introduced. The antenna design has a low profile of 10 × 28 mm2 consists of a circular ring radiating element with an inner and outer radius of 3 mm and 4.9 mm successively fed by a microstrip transmission line with a matching line and a partial ground structure with a semi-circle in the middle of it. This antenna’s structure was used to attain the whole UWB spectrum of 3.1–12.3 GHz. In order to achieve reconfigurable characteristics, three shaped slots were engraved on the circular ring radiator with three-pin diodes inserted between the poles of each slot. When the pin diodes are at ON-state, the circular patch behaves skillfully like a circular ring radiator, thereby the antenna operates in the whole UWB frequency. On the other hand, switching on or off the pin diodes enable or disable the bands notched and thus the reconfigurability is introduced; the antenna has two bands-notched covering Sub 6 GHz 5G and a band-notched characteristic that correspond to WLAN operating with frequency ranges of [3.4–3.8] GHz, [3.8–4.9] GHz and [5.1–5.8] GHz respectively. The proposed antenna design was validated by a prototype. Therefore, the proposed antenna excels a straightforward, compact geometry, omnidirectional and bi directional pattern, high efficiency as well as band-notched reconfigurability.