## 1 Introduction
### The State of the Art and Analyses  
This subsection presents the current state of the art in antenna design and analyses of their performance in CubeSat communications. According to the research in [10], a compact stacked-patch antenna with a wide frequency range was developed for a 3U CubeSat communication system, operating in the S band. The authors improved efficiency by using a special slot couple feed method with a cavity for E-field optimization, which improves the link between the feeding and radiating parts. The antenna achieved a gain increase of 9 dBi, redirecting backward radiation, and demonstrated a broad bandwidth of 32.6%, spanning 0.8 GHz. CubeSat systems operating at S-band frequencies are usually bulky, especially when configured as arrays. To address this issue, the authors in Ref. [11] designed a foldable microstrip patch antenna (MPA) with fractal shapes for 1U CubeSats. They constructed a miniaturized antenna without sacrificing high gains and achieved a smaller S\({}_{11}\) and a broad bandwidth by incorporating a Koch snowflake fractal pattern. Theirdesign also incorporates an uncomplicated deployment technique, operating at 2.3 GHz. The antenna exhibited an impressive reflection coefficient of \(-\)28 dB and a substantial bandwidth of 28.7% while delivering a decent gain of 4.39 dBi. The antenna's compactness (60 \(\times\) 26.3 \(\times\) 0.02 mm\({}^{3}\)) is its primary advantage; however, its omnidirectional radiation pattern resulted in a lower gain, a notable downside. Ref. [12] presented a square-shaped, compact, planar dipole antenna designed for 1U CubeSats, introducing four-element arrays interconnected via a phase-shifting network, and a balun was strategically placed to ensure even power distribution. It offered CP, preserving steady communication despite the CubeSat's orientation shifting with the dimensions of 55 \(\times\) 55 mm\({}^{2}\). It provided bidirectional radiation, a significant 33.46% bandwidth, and a gain of 3.49 dBi, which surpassed the dipole antenna's performance in Ref. [13]. A small-scale X-band antenna, functioning in the 7.89-10.49 GHz band, achieved a remarkable gain of up to 35 dB. Another antenna utilized a split ring resonator (SSR) structure to operate at the X band. It was fabricated using chemical etching, and its performance was evaluated. The possibility of using this antenna as part of an array was investigated to enhance signal transmissions and reception gains [14]. Moreover, a compact, inverted S-shaped patch antenna was designed to operate at three X-band frequencies. It delivered bandwidths of 5.02%, 9.13%, and 3.79% across these respective bands. Its gain was enhanced by incorporating elliptical slots into the ground plane, and strong agreement was shown between the simulated and measured results. It also demonstrated stable gains and omnidirectional radiation, making it highly suitable for X-band applications [15]. An MPA with a rectangular slot and a defected ground structure (DGS) was designed for multi-band functionality, achieving notable gains across the C-, X-, and Ku-bands. It performed reliably at frequencies such as 6.035 GHz (GNSS), 6.795 GHz (satellite TV), 7.46 GHz (long-distance communication), 8.505 GHz (radar), 11.45 GHz (space communication), 13.35 GHz (detector), 15.06 GHz (military), 17.24 GHz (aerospace), and 19.05 GHz (astronomical observation). Cutting slots offered a quad-band resonance without altering the ground or patch. By cutting further and optimizing the slot size, a peak gain of 14.679 dBi was achieved in the upper-frequency band at 16 GHz [16]. A small-scale microstrip antenna was designed for dual-band operation in the S- and X-bands. It delivered bandwidths of 13% in the S band and 6.2% in the X band (reflection coefficient \(<\)\(-\)10 dB), with isolation exceeding 38 dB by employing electromagnetic coupling. It also offered gains of 7.5 dBi for the S band and 10.5 dBi for the X band [17].