# The Design and Implementation of a Phased Antenna Array System for LEO Satellite Communications
## 7 Conclusions  
LEO satellite constellations offer a promising solution for enhancing connectivity in remote areas and supporting existing IoT terrestrial communication networks. Traditional antennas used in satellite communications often rely on mechanical systems like rotators to achieve wide coverage in the azimuth plane, leading to maintenance issues and reduced performance in adverse weather. Phased antenna arrays, however, provide electronically controlled directivity without the need for mechanical adjustments, making them suitable candidates for future LEO satellite ground stations. Our research focused on the definition and implementation of a phased antenna system based on an original concept in order to explore its potential to complement LEO satellite reception systems. Our aim was to provide a cost-effective alternative, born from academic research, without competing directly with expensive commercial solutions. The construction details reflect a conceptual approach at the prototype level. The functionality of the concept has been demonstrated and is ready for integration into LEO satellite reception systems. As far as we know, it is the first time that a four-element, three-quarter wavelength phased antenna array system has been successfully realized with the intention of being optimized for this specific field of communications. Using laboratory measurements, we demonstrated precise control of the array's main radiation lobe orientation in the azimuth plane. These results confirmed the presence of a single consistent main lobe and highlighted the system's reliability in covering the directions in the azimuth plane. Previous research on individual antenna elements showed favorable radiation patterns for medium elevation, supporting the \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Antenna System** & **Operating Frequency** & \
\begin{tabular}{c} **\(-\)10 dB** \\ **Bandwidth** \\ **(MHz)** \\ \end{tabular} &
\begin{tabular}{c} **VSWR/** \\ **Return Loss** \\ **(dB)** \\ \end{tabular} \\ \hline \multirow{2}{*}{**Proposed system**} & Three-quarter wavelength & \multirow{2}{*}{\(\approx\)436.5 MHz} & \(\approx\)87 & 1.06/ \\  & antenna array & & (24\(\%\)) & \(-\)30.68 \\ \hline \multirow{2}{*}{[41]} & Coplanar Waveguide (CPW) & \multirow{2}{*}{\(\approx\)10 GHz} & \(\approx\)4400 & 1.13/ \\  & fed quasi-Yagi & & (44\(\%\)) & \(-\)24.24 \\ \hline \multirow{2}{*}{[42]} & Printed quasi-Yagi with & \multirow{2}{*}{\(\approx\)5.6 GHz} & \(\approx\)1848 & 1.49/ \\  & Compact Transition & & (33\(\%\)) & \(-\)14.12 \\ \hline \multirow{2}{*}{[43]} & Printed quasi-Yagi with & \multirow{2}{*}{\(\approx\)1.8 GHz} & \(\approx\)856.8 & 1.29/ \\  & monopole elements & & (47.6\(\%\)) & \(-\)17.94 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Operating Frequency, Bandwidth, VSWR, and Return Loss for various antenna types used for satellite communications. suitability of antenna array systems for LEO IoT satellite communications. The proposed phased antenna array operates in the 435-438 MHz frequency band, utilizing a metallic ground plane to enhance overall performance, including the minimization of common mode currents and environmental influence factors. Simulation results indicated a high gain close to 12 dBi, an azimuthal HPBW of 80\({}^{\circ}\), and a vertical HPBW of about 32\({}^{\circ}\) in the medium elevation range, making the array suitable for LEO satellite reception also, including IoT applications. Measurements in an indoor environment confirmed a consistent single main lobe, highlighting the system's reliable coverage across orientations in the azimuth plane. These results show that the developed array system is suitable for implementation in LEO satellite reception for IoT systems. In the azimuth plane, the F/B values close to 6 dB for 45\({}^{\circ}\), 14.5 dB for 150\({}^{\circ}\), and 3.5 dB for 210\({}^{\circ}\) confirmed the directionality of the array.