## 1 Introduction  
Today's wireless communication systems are pivotal in enabling high-throughput applications including WLANs (Wireless Local Area Networks), HDTV (High-Definition Television), WBANs (Wireless Body Area Networks), and PANs (Personal Area Networks). Ultra-Wideband (UWB) technology is a strong contender for short-range wireless communication, offering the potential for rapid data transfer [1]. The popularity of this technology grew significantly after the Federal Communications Commission (FCC) released its first report in 2002. While UWB technology enables rapid transmission in indoor environments, it faces challenges such as multipath fading, interference, and constrained spectrum availability [2]. The rapid advancement of wireless communication systems emphasizes not only achieving higher data rates but also ensuring strong error performance [3]. Achieving both high data rates and low error rates simultaneously is challenging due to multipathpropagation and fading effects. As a result, a balance must be struck between bandwidth efficiency and power efficiency. While channel modeling can help mitigate signal fading, it often leads to increased complexity in transceiver hardware [4]. An alternative approach to balance transceiver hardware complexity and signal fading is through antenna design innovations [5]. [PERSON] et al. first introduced the concept of UWB-MIMO antennas, which have gained popularity in the past decade for next-generation wireless systems [6]. Designing ultrawideband antennas that function within 3.1-10.6 GHz presents significant challenges due to wide bandwidth requirements [7; 8]. The time-domain performance must remain stable across the entire range, with factors like dispersion and group delay becoming important alongside frequency-domain characteristics [9; 10]. The development of UWB-MIMO antennas also faces challenges such as size, cost, and integration, while the miniaturization of antennas often leads to increased mutual coupling and reduced isolation [11; 12]. Achieving high isolation, robust diversity performance, and ultra-wideband characteristics simultaneously remains a core challenge in UWB-MIMO antenna design [13; 14; 15]. To tackle these challenges, extensive research has been done on dual-port and quad-port MIMO variants employing various decoupling mechanisms and structural modifications. [PERSON] et al. (2021) introduced a 2-port antenna using a stub of 'T' shape to enhance isolation [16]. [PERSON] and [PERSON] (2021) introduced a miniaturized MIMO variant employing a ground perturbation to suppress inter-element coupling [17]. [PERSON] et al. (2019) combined circularly polarized dielectric resonator elements with an electromagnetic bandgap (EBG) surface to achieve excellent diversity performance for 5G applications [18]. [PERSON] et al. (2024) further improved isolation by leveraging hybrid polarization in their MIMO patch antenna using a polarization conversion parasitic structure [19]. In the 4-port domain, [PERSON] et al. (2016) demonstrated a compact 4-port antenna incorporating a common ground and arrow-shaped slot etching aided isolation enhancement [20]. [PERSON] et al. (2020) integrated neutralization lines into their triple-band MIMO antenna design, achieving good isolation and diversity gain [21]. [PERSON] and [PERSON] (2019) presented a 4-port antenna using a shared radiator along with stepped ground for enhanced diversity effects, advancing miniaturization and performance for WLAN applications [22]. [PERSON] and [PERSON] (2021) introduced a fractal-inspired 4-port UWB MIMO antenna integrating coupling resonators as port-isolators to reduce mutual coupling while maintaining Wi-Max rejection and wideband performance [23].