## 1 Introduction
[8] focused on bandwidth enhancement by using U-shaped slots in the patch, achieving an impedance bandwidth of nearly 3 GHz, which is valuable for wideband 5G channels. Beam-steering capabilities are key for targeting specific users in mm-wave communications. [PERSON] et al. [9] designed a beam-steerable phased array at 28 GHz for base stations. Their linear polarized structure achieves \(\pm\)60\({}^{\circ}\) beam steering with high realized gain, highlighting its suitability for microcellular 5G. [PERSON] et al. [10] developed a 4 \(\times\) 4 phased array with hybrid feeding for 28 GHz, achieving 360\({}^{\circ}\) scanning and >12 dBi gain, making it ideal for smart antennas and MIMO applications. Polarization diversity enhances robustness in fading environments. [PERSON] et al. [11] introduced a circularly polarized patch antenna for 28 GHz, achieving a 3 dB AR bandwidth \(>\) 1 GHz with stable gain, contributing to polarization diversity in mobile applications. [PERSON] et al. [12] improved bandwidth using parasitic coupling techniques, enhancing the radiation efficiency and extending the operational bandwidth to 30%, similar to the design performance proposed in this paper. Similarly, the paper proposed in [13] uses a dual-functional structure with endfire elements and complex loading configurations to achieve hybrid radiation modes, which increases design complexity. However, the MPA array proposed in this paper is a single-layer series-fed microstrip patch array, offering simplified geometry, fewer components, and lower fabrication cost, ideal for mass production. The design in [14], involving gap waveguide structures, is not inherently compatible with planar RF components (e.g., filters, amplifiers), whereas the 1 \(\times\) 6 design is easily integrated with standard planar microwave circuits, enabling direct embedding into 5G RF front ends and compact systems. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Author(s)** & **Design Type** & **Substrate** & **Gain (dBi)** & **Dimension (mm)** & **Bandwidth (\%)** & **Side Lobe Level (db)** & **Special Features** \\ \hline
[5] & 4 \(\times\) 4 Phased & Not & 12.0 & 70 \(\times\) 63 & Wideband & **–10** & 360\({}^{\circ}\) beam scanning, hybrid feeding network \\
[6] & Low-Profile & Not & 11.0 & 30 \(\times\) 30 & \(\sim\)10\% & **–13** & ECC \(<\) 0.005, compact and isolated array \\
[7] & Wide-Beam & Not & 10.0 & 37.4 \(\times\) 14.6 & Moderate & **–15** & \(\pm\)40\({}^{\circ}\) scanning, compact design \\
[8] & 2 \(\times\) 2 Patch & High- & frequency & 10.0 & 12 \(\times\) 32 & Approx. 10\% & **–10** & High isolation, compact design \\  & Array & substrate & & & 10\% & **–10** & compact design \\  & Patch with & & & & & & \\
[9] & Parasitic & Not & 10.0 & 33 \(\times\) 27 & 30\% & Not & coupling for bandwidth improvement \\  & Elements & & & & & & \\
[10] & Slot-Loaded & Not & 9.0 & 20 \(\times\) 30 & \(\sim\)12\% & **–8** & Slot-based bandwidth enhancement \\  & Patch & specified & & & & **(E-Plane)** & bandwidth enhancement \\ \hline \multirow{2}{*}{_This Work_} & **1 \(\times\) 6 Linear** & **Rogers 3003** & **9.91–**11.5** & **50 \(\times\) 80** & **30.21\%** & **–12** & **–12** & **-12** \\  & **Patch Array** & & **11.5** & & & **(E-Plane)** & **polarization**, integrated power** \\ \hline
[11] & Circular & Not & 9.0 & Not & Approx. 3.5\% (AR) & **–9** & Circular \\  & Patch & specified & & specified & 3.5\% (AR) & **–(E-Plane)** & polarization \\
[12] & MIMO with & High- & & & & & \\  & EBG & frequency & & & & & \\  & substrate & & & & & \\
[13] & 1 \(\times\) 8 Patch & & & & & & \\  & Array & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparative analysis of 28 GHz mm-wave antenna designs (including proposed work). Despite these advancements, there is still a trade-off between antenna gain, compactness, bandwidth, and ease of fabrication. The need for a simple, low-cost design that maintains high gain and a wide bandwidth across the 28 GHz band is critical.