## 3 Results and Discussion
### Simulation and Measured Evaluations Integrated with CubeSat
The antenna incorporates a flower-shaped MTS with coffee bean-like unit cells, which effectively manipulates surface currents and suppresses unwanted surface wave propagation. The inclusion of a cavity layer, rather than introducing an excessive loss, was optimized to enhance interlayer coupling and maintain impedance matching across the operating bands without degrading efficiency. Low-loss dielectric materials with carefully selected permittivity values were employed to minimize dielectric absorption, and high-conductivity metals were utilized for radiating elements to mitigate ohmic losses. The compact 40 \(\times\) 30 mm\({}^{2}\) footprint further limits propagation losses and supports integration within CubeSat form factors. Full-wave simulations were conducted using realistic models in CST Microwave Studio (or HFSS), \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Ref.** & **Size (mm\({}^{2}\))** & **fr (GHz)** & \begin{tabular}{c} **Gain** \\ **(dBi)** \\ \end{tabular} & **Eff (\%)** & **Polarization** & \begin{tabular}{c} **CubeSat** \\ **Type** \\ \end{tabular} & \begin{tabular}{c} **Beamsteering** \\ **(c)** \\ \end{tabular} & \
\begin{tabular}{c} **Improvement** \\ **Techniques** \\ \end{tabular} &
\begin{tabular}{c} **Printed Area** \\ **(mm\({}^{2}\))** \\ \end{tabular} \\ \hline
[25] & 120 \(\times\) 229 & 9, 10 & \textless{}10 & \textless{}90 & N/A & N/A & \textless{}75\_75 &
\begin{tabular}{c} SIW and Nyquist \\ metasurface \\ \end{tabular} & 27,480 \\ \hline
[26] & \textless{}85 \(\times\) 85 & 36.5–27 & N/A & N/A & Dual & N/A & 15\_45 &
\begin{tabular}{c} IRS and \\ metasurface \\ \end{tabular} & 7225 \\ \hline
[43] & 131 \(\times\) 131 & 5.5 & 10.7 & N/A & N/A & N/A & \textless{}48\_48 &
\begin{tabular}{c} Reconfigurable \\ PSS \\ \end{tabular} & 17,161 \\ \hline
[28] & 80 \(\times\) 80 & 3.6 & 8 & \textless{}80 & N/A & N/A & \textless{}30\_30 &
\begin{tabular}{c} Partially \\ reflecting surface \\ \end{tabular} & 6400 \\ \hline
[44] & 21.3 \(\times\) 21.3 & 8, 11.2 & 6.45, 5.34 & N/A & Dual, CP & 3U & N/A & Slot antenna & 453.69 \\ \hline
[45] & 141 \(\times\) 117 & 5.1 & 5.9 & N/A & CP & 1U & N/A & N/A & 16,497 \\ \hline
[42] & 193 \(\times\) 193 & 5.8 & 6.98 & N/A & CP & 1U & N/A &
\begin{tabular}{c} Transparent and \\ glass antenna \\ \end{tabular} & 37,249 \\ \hline
[41] & \textless{}300 \(\times\) 300 & 10 & 15 & 65 & CP & 1U & N/A &
\begin{tabular}{c} Fabry-Perot \\ cavity \\ \end{tabular} & 90,000 \\ \hline
[39] & 100 \(\times\) 100 & 8.2 & 20 & 97.5 & CP (RHCP) & 1U & N/A &
\begin{tabular}{c} Unequal series \\ with parallel \\ power dividers \\ \end{tabular} & 10,000 \\ \hline
[40] & 100 \(\times\) 200 & 8.425 & 29.2 & 45 & CP (RHCP) & 6U & N/A & \begin{tabular}{c} Offset-fed \\ reflectarray \\ \end{tabular} & 20,000 \\ \hline This work & 40 \(\times\) 30 & \
\begin{tabular}{c} 3.75-5.25, \\ 6.4-15.4, 22.5-30 \\ \end{tabular} & 12.9 & 85 & CP & 1U &
\begin{tabular}{c} Port1: 18\_155 \\ Port2: 206\_341 \\ \end{tabular} & LWA and MTS & 1200 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: A comparison of the proposed antenna and several antennas designed for CubeSat communications. incorporating dielectric loss tangents, conductor surface roughness, and proper meshing to emulate fabrication tolerances. These simulation parameters were chosen to ensure that the reported efficiency closely reflects practical performance. The antenna's high gain (12.5 dBi), wideband response across three frequency bands, and stable circular polarization all support the validity of this high-efficiency result. Collectively, these factors justify the reported 85% radiation efficiency and highlight the effectiveness of the proposed design for high-performance CubeSat communications. The proposed MIMO leaky-wave antenna offers several features that lend themselves to future research. One research direction involves the use of beamsteering techniques such as reconfigurable MTS, which provide dynamic control over the radiation pattern with no mechanical changes.