Novel Reflectarray for CubeSat Applications

Abstract

CubeSats have recently attracted considerable attention as an alternative to traditional satellites for space initiatives. This is because they are inexpensive to deploy and can be constructed with commercially available components. In addition, CubeSats are able to connect with one another in orbit and with ground stations to perform a variety of missions, including remote sensing and deep space communications. As the number of space missions employing small satellites increases, researchers are actively investigating the viability of missions employing active instrumentation on small spacecraft. Particularly intriguing are synthetic aperture radars (SAR), which have shown to be vital tools for Earth observation. One of the key components of spaceborne SAR systems is the antenna. Due to the confined space of nanosatellites and the restricted weight of the payloads, it is very challenging to have an antenna that meets the requirements of SAR missions or deep space communications. The current state-of-the-art in SAR missions for small satellites deployed in space indicate that their payloads typically have a mass of approximately 100 kg. These missions employ either phased array antennas or mesh-based reflector antennas. However, phased array antennas require substantial power from the payload and need a transmit-receive module, which is highly costly. Conversely, mesh-based reflector antennas involve complex deployment mechanisms and may experience performance degradation due to surface wrinkling. This research proposes a novel reflectarray antenna for high-gain CubeSat missions, specifically targeting SAR applications in Low Earth Orbit (LEO). The proposed reflectarray design offers the significant advantage of enabling high-gain, focused radiation with polarization diversity, achieved using a passive, planar, thin, and lightweight structure. These characteristics make the design particularly suitable for CubeSat applications. The study focuses on developing low-cost, low-complexity, compact microstrip reflectarray with circular polarization capability, operating in the X-band frequency range. The reflectarray design is implemented as single-layer structures to reduce design complexity and fabrication costs. Simulation and experimental results demonstrate excellent agreement, validating the design methodology and confirming the feasibility of the proposed configurations. Furthermore, the research explores the development of a deployable reflectarray antenna for 6U CubeSat SAR missions and addresses its performance prediction in LEO.

Date of Award	15 May 2025
Original language	American English
Supervisor	Mohammed Abou Khousa (Supervisor)