## 1 Introduction
### Paper Contributions  
This review paper makes a distinct and valuable contribution to the field of CubeSat communication by focusing on the advancements in beam-steering antenna systems, addressing critical challenges such as power efficiency, miniaturization, and integration with CubeSat platforms. Our paper delves deeper into the specific context of CubeSat communication in low Earth orbit (LEO). It also adequately addresses dynamic beam-steering technologies' unique demands and opportunities, such as phased array systems, metasurface-based designs, and reconfigurable antennas. By synthesizing recent research, our review paper investigates the critical gap in beam-steering technology for CubeSats, offering a more targeted and up-to-date analysis of beam-steering antennas tailored to CubeSat communication. This includes highlighting innovative approaches that enhance gain, coverage, and adaptability in constrained environments. In terms of the focus of this review paper, other review papers have discussed the types of antennas used for satellite and CubeSat communications. For instance, Reference [1] is primarily a general survey of planar antennas for pico-satellites, emphasizing their fundamental characteristics. It is also essential for understanding planar antenna designs. However, it does not sufficiently explore the specific requirements and potential of dynamic beam-steering technologies, particularly in the context of CubeSat communications, which is the primary focus of our paper. Our paper, therefore, not only builds upon but also surpasses the foundational insights provided in [1], serving as a modern resource for researchers and engineers seeking to advance CubeSat communication through cutting-edge beam-steering antenna technologies. In addition, Reference [2] reviews antennas designed for CubeSats, providing a broad overview of such designs, covering various types and their fundamental characteristics. It also serves as a valuable resource for understanding the general landscape of CubeSat antennas. However, the authors do not focus on an analysis of beam-steering technologies, which are critical for enabling adaptive communication links with improved gain and coverage. Furthermore, they do not extensively explore emerging techniques, such as phased array systems, metasurface-based designs, and reconfigurable antennas, which are at the forefront of recent advancements in CubeSat communication and the focus of our paper. Our paper addresses these gaps by offering a more focused and up-to-date synthesis of the state-of-the-art developments in beam-steering antennas, highlighting their unique demands, opportunities, and potential to overcome LEO communication challenges.  
The structure of this review paper is organized as follows: In-depth explanations of CubeSat communications, applications, challenges, and techniques are provided in Sections 1 and 2. Then, the general aspects of antennas utilized for CubeSats are assessed in Section 3. Next, Section 4 presents in-depth information on antennas used for beam steering, and several industry cases studies are provided in Section 5. Finally, Sections 6 and 7 discuss and conclude the review.