Developing reliable and high performance antenna for CubeSat that has limited resources

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)

DOI： 10.3390/electronics11071163

DOI： 10.3390/electronics11071163

Other Link： https://www.mdpi.com/2079-9292/11/7/1163

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)

Microstrip patch antennas (MPAs) are widely used in satellite communication due to their low profile, compact size, and ease of fabrication. This paper presents a design of an X-band microstrip patch antenna using an electromagnetic band gap (EBG) structure for CubeSat applications. The X-band is preferred for CubeSat missions in high-speed communication, long distance or deep space because it allows communication at higher data rates, and the antenna is smaller than those used for lower frequency bands. In our study, the EBG elements are analyzed, modified and optimized so that the antenna can fit a 10 cm × 10 cm surface area of a standard 3U CubeSat structure while providing a significant high gain and circular polarization (CP). A noticeable point of this research is that the simplicity of the antenna and the EBG structure are being maintained by just using a simple single-probe feed to achieve a total antenna efficiency exceeding 90%, and the measured gain of around 11.7 dBi at the desired frequency of 8.483 GHz. Furthermore, the measured axial ratio (AR) is around 1.4 dB at 8.483 GHz, which satisfied the lower-than-3 dB requirement for CP antennas in general. The simulation, analysis and measured results are discussed in detail.

DOI： 10.3390/electronics14112216

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)

DOI： 10.3390/aerospace10090807

Kyutacar

Event date： 2025.08.10 - 2025.08.13   Language：English  

As CubeSat missions demand higher data rates, directional patch antennas have increasingly replaced traditional monopole or dipole antennas, and ensuring omnidirectional coverage—especially under tumbling conditions—has become critical. To address this, we developed a three-dimensional radiation pattern measurement system that enables the evaluation of antenna characteristics across all possible CubeSat attitudes. To apply these measurements to practical operations, we introduce the Coverage Ratio of CubeSat Attitude (CRCA), which intuitively represents the percentage of satellite orientations that exceed a given required gain. In this study, we apply this methodology to the S-band downlink antenna system of VERTECS, a 6U CubeSat developed by the Kyushu Institute of Technology in collaboration with other institutions. The measured results show that a gain of –7.0 dBic or higher is achieved in 50% of all possible attitudes, demonstrating sufficient coverage under tumbling conditions. Incorporating this value into the link budget confirms that stable communication can be maintained with a positive link margin even in the worst-case scenario. These findings highlight the importance of three-dimensional antenna characterization and system-level evaluations in ensuring reliable CubeSat communications. Future work includes in-orbit validation of the link budget and estimation of the expected downlink data volume through combined orbital and attitude simulations.

Event date： 2025.06.19 - 2025.06.20   Language：English  

Event date： 2022.08.06 - 2022.08.11   Language：English  

Application no：特願2025-002546  Date applied：2025.01.07

Country：Japan

Country：Japan

VERTECSで培ったCubeSat開発ノウハウをもとにCubeSatの開発を行うベンチャー企業を設立する．

6U (10cm×20cm×30cm) astronomical nano-satellite designed to reveal star formation history by observing visible extragalactic background light.
I was in charge of S-band and X-band communication sub-system.

Development a 6U CubeSat bringing 5m-class camera and 20Mbps-class C-band(5.8Gz) transmitter.
I was in charge of communication sub-system.

Developing Paraguay's first satellite and supporting space activities in Philippines.
It was launched in 2021 with many missions on board. It also carried the hentenna mission, a non-deployable UHF antenna using a 1U CubeSat structural frame.