A novel quad-port configuration CPW-fed MIMO antenna design with triangular PBG structures for 6G communications in the sub-terahertz band

The race toward 6G networks necessitates innovative antenna designs to exploit the sub-terahertz (sub-THz) band’s extensive bandwidth. However, conventional antenna designs usually suffer from poor bandwidth, low gain, and insufficient power efficiency, which are required for emerging 6G applications needing ultra-high data rates, low latency, and massive connectivity. To address this problem in this paper, a compact coplanar waveguide (CPW) MIMO antenna with periodic PBG structures is proposed. Our approach incorporates a rectangular patch radiator that has been strategically modified with diagonal and U-shaped slots, further enhanced by triangular air holes in the polyimide substrate to achieve optimal impedance characteristics. The resulting quad-port configuration (2000 μm × 2000 μm × 75 μm) demonstrates exceptional performance across 0.1–1 THz. Its 776.73 GHz bandwidth qualifies its wideband capability to support ultra-fast 6G data rates, while an ECC of less than 0.006 and diversity gain approaching 10 dB ensure robust MIMO performance. With a peak gain of 9.04 dBi and 97 % radiation efficiency, the design supports efficient sub-THz operation, making it a strong candidate for 6G wireless communications, and advanced security sensing applications.