A Triple Inverted U-Slot Single Notch Antenna for Sub-6 GHz Applications

This paper discusses the geometric simple design of an inverted triple U-shaped slotted notch antenna optimized for sub-6 GHz 5G applications. To achieve a size reduction compared to the traditional printed microstrip patch antenna, the antenna incorporates a few key modifications. One of the primary modifications is a partial ground plane with a protruding rectangular structure. Additionally, slots are introduced in the patch itself, which help to miniaturize the antenna while maintaining its efficiency and bandwidth. A single-notch band with dual operating bands are achieved by having triple inverted U-slots in the patch structure. The effect of slots in the design is discussed in detail. The antenna design features a triple inverted U-slot configuration that effectively covers a wide frequency range from 2.85 GHz to 3.7 GHz. Also, the design incorporates a notch characteristic that specifically attenuates signals between 3.2 GHz and 3.39 GHz. This configuration results in a peak gain of 2.15 dBi at 3 GHz and 2.37 dBi at 3.5 GHz. Furthermore, the antenna demonstrates a radiation efficiency of over 80% in the operating bands, while the efficiency drops to below 40% within the notch band.