## 3 Results and Discussion  
### Simulation and Measured Evaluations in Free Space  
This section details the simulation and measurement outcomes for the proposed antenna, both standalone and integrated with a CubeSat. Figure 8 illustrates the experimental setup for testing the antenna in free space alongside the constructed antenna prototype used  
Figure 7: The absorption coefficient of the proposed antenna. to verify theoretical and simulated findings. The antenna's S-parameters were evaluated using a Keysight (formerly HP/Agilent) 8722 ES Vector Network Analyzer (VNA), which operates over a frequency range of 50 MHz to 40 GHz. The VNA was configured with a frequency sweep tailored to the antenna's operational bands, featuring 201 data points per sweep and an intermediate frequency (IF) bandwidth of 10 kHz, which balances resolution and noise. Before measurements, a full two-port calibration was performed using a precision SOLT (Short-Open-Load-Thru) calibration kit, with the reference plane established at the end of the coaxial cable, directly at the SMA connector interfacing with the antenna. This ensured accurate de-embedding of cable losses and connector mismatches. High-quality, phase-stable RF cables were used, and ferrite chokes were applied to suppress common-mode currents. The antenna was mounted on a 1U copper CubeSat mock-up platform to simulate realistic in-satellite mounting conditions, accounting for any possible coupling or detuning that may occur due to platform integration. Radiation pattern measurements were conducted in a fully anechoic chamber designed to suppress unwanted reflections and external electromagnetic interference. The antenna under test (AUT) was placed on a motorized turntable mounted on a non-reflective support at a height corresponding to the antenna's phase center. The measurements were performed in the far-field region, with a separation distance of 3 m between the AUT and a dual-polarized standard gain horn antenna, which served as both the transmitter and receiver. The chamber was equipped with RF absorbers rated for operation up to 40 GHz to minimize wall reflections. Patterns were captured in both the E-plane and H-plane, and both co- and cross-polarization components were recorded. The angular resolution of the turntable sweep was set to 5\({}^{\circ}\) increments over the range of 0\({}^{\circ}\) to 360\({}^{\circ}\) in azimuth, with elevation angles adjusted manually as needed. Polarization alignment was carefully verified to ensure accurate measurements of intended field components. All measurements were repeated multiple times to confirm repeatability, and system errors, such as multipath, connector instability, or ambient noise, were monitored and minimized through background measurements and time gating. Figure 9 depicts the simulated and experimental reflection and transmission coefficient results of the proposed antenna, with good agreement and little discrepancy between them. Minor discrepancies occurred, because the conditions and environment considered during the simulation were ideal unlike those during the measurements. For instance, the ports in the simulation were waveguide ports unlike the measurements, which were actual high-frequency SMA ports. In addition, several fabrication tolerances might have occurred, such as minor misalignments between the MTS layer and other layers when gluing them together, which might have changed the thickness and space among them slightly. Additionally, during the measurements, connector losses, soldering imperfections,  
Figure 8: (**a**) Fabricated layers of the antenna and (**b**) testing the designed antennas in open-air and CubeSat environments. and calibration limitations (e.g., probe placement accuracy or port matching) could have contributed to deviations in S21. Moreover, in our setup, the presence of measurement cables and fixtures--which are not included in simulations--can unintentionally couple to the antenna or introduce parasitic effects, especially in compact or high-frequency designs.