## 3 Design and Methodology of the Power Divider  
To feed the antenna array uniformly, a two-way Wilkinson-like microstrip power divider was designed and integrated, as illustrated in Figure 2b. The power divider ensures equal power distribution and impedance matching across antenna elements. The divider is designed using quarter-wave transformers, each with an impedance of approximately 70.7 \(\Omega\) calculated using (9), where Z\({}_{0}\) = 50 \(\Omega\). Along with the quarter-wavelength at the operating frequency of 28 GHz, the guided wavelength \(\lambda\) is calculated using Equations (10) and (11).  
\[z=z_{0}\sqrt{2} \tag{9}\]  
\[\lambda=\frac{c}{f}=0.017\;\mathrm{m} \tag{10}\]  
\[\frac{\lambda}{4}=2.675\;\mathrm{mm} \tag{11}\]  
Similarly, the antenna and the power divider are fabricated on Rogers 3003, with copper layers on both sides. The overall layout covers an area of 50 mm \(\times\) 80 mm. The input and output lines are matched to 50 \(\Omega\) using appropriate transformer sections to minimize reflection.  
A two-element microstrip patch antenna array is integrated with a symmetric two-way microstrip power divider, as shown in Figure 3. This configuration is capable of supporting passive beam steering through phase manipulation via feedline geometry and mutual coupling effects. The use of a Wilkinson-like power divider, integrated on the same substrate, ensures equal power splitting and impedance matching, minimizing reflection loss. The symmetric layout and 0.5\(\lambda\) inter-element spacing facilitate balanced excitation across the patches. The surface current distribution plots confirm uniform excitation across all patch elements, indicating effective power delivery through the feed network. This uniform current distribution contributes to the directive E-plane radiation pattern, which exhibits a well-defined main lobe and minimal back radiation clear evidence of constructive interference along the broadside direction. While the current design employs uniform feeding for simplicity, resulting in a measured side lobe level of approximately 12 dB, further improvement is possible. Future iterations could incorporate side lobe suppression techniques such as amplitude tapering, element shaping, or non-uniform element spacing to reduce side lobe levels below \(-\)15 dB, enhancing pattern cleanliness and beam selectivity. The consistent gain of 9.91-11.5 dBi supports this conclusion, proving that the antenna efficiently radiates energy in the desired direction. Figure 3 illustrates the dimension and layout design of the symmetric two-way microstrip power divider.  
Even without active components like phase shifters, a careful layout of the feed network and spacing of elements makes it possible to tilt the main beam away from the broadside, especially in the E-plane (x-direction). The design uses a spacing of \(\sim\)0.5\(\lambda\), which is optimal for avoiding grating lobes, enhancing constructive interference, and allowing beam steering without compromising gain. At 28 GHz, 0.5\(\lambda\)\(\approx\) 5.35 mm in free space; in the substrate, it is \(\sim\)3.25 mm. This spacing allows the two radiated fields to combine constructively in off-broadside directions. Table 2 illustrates the dimensions of the \(1\times\) 6 linear antenna array.