Transparent Antennas for Solar Cell Integration

Transparent patch antennas are microstrip patch antennas that have a certain level of optical transparency. Highly transparent patch antennas are potentially suitable for integration with solar panels of small satellites, which are becoming increasingly important in space exploration. Traditional patch antennas employed on small satellites compete with solar cells for surface area. However, a transparent patch antenna can be placed directly on top of solar cells and resolve the issue of competing for limited surface real estate. For such an integration, a high optical transparency of the patch antenna is required from the solar cells\u27 point of view. On the other hand, the antenna should possess at least acceptable radiation properties at the same time. This dissertation focuses on some of the most important concerns from the perspective of small satellite applications. For example, an optimization method to simultaneously improve both optical transparency and radiation efficiency of the antenna is studied. Active integrated antenna design method is extended to meshed patch applications in an attempt to improve the overall power efficiency of the front end communication subsystem. As is well known, circular polarization is immune from Faraday rotation effect in the ionosphere and thus can avoid a 3-dB loss in geo-satellite communication. Therefore, this research also aims to present design methods for circularly polarized meshed patch antennas. Moreover, a meshed patch antenna capable of supporting a high communication data rate is investigated. Lastly, other types of transparent patch antennas are also analyzed and compared to meshed patches. In summary, many properties of transparent patch antennas are examined in order to meet different design requirements

Development of Novel Integrated Antennas for CubeSats

The Development of Novel Integrated Antennas for CubeSats project is directed at the development of novel antennas for CubeSats to replace the bulky and obtrusive antennas (e.g., whip antennas) that are typically used. The integrated antennas will not require mechanical deployment and thus will allow future CubeSats to avoid potential mechanical problems and therefore improve mission reliability. Furthermore, the integrated antennas will have improved functionality and performance, such as circular polarization for improved link performance, compared with the conventional antennas currently used on CubeSats

Transparent Solar Panel Antenna Array

This dissertation research presents a comprehensive study to answer the question of “Can it be possible to integrate a high gain optically transparent antenna array directly on top of solar cells?”. The answer to such question is extremely important in space exploration where very small satellites have been extensively employed. Due to their small mass and size, those small satellites create challenges for one to mount the antennas, and the challenge is further increased when a high gain antenna is need for more communication capacity. Based on feasibility studies, the dissertation concludes that it is possible to do such an integration, and then proceeds to present the approaches for design and integration. On the element level, the thesis presents research in assessing the effects between a planar antenna integrated on the solar cell and the photovoltaic cell. A series of experiments were designed to perform assessments for antennas operating from C to X bands. It is concluded that a commercial triple junction space–certified solar cell normally would decrease the gain of the antenna to 2–3 dB and is not affected by the working states of solar cells. The shadow of the antenna casts on solar cells, however, is not significant (less than 2%). The thesis also provides a model of a common space solar cell that helps to explain the gain loss. The model was validated by experimental data, and it was utilized to predict iv a possible custom design of solar cell where with a minimal design modification, it would facilitate less gain loss of the antenna integrated on top. On the array level, the research surveys different high gain antenna array design and then focus on an optimal sub–wavelength reflectarray design. The final antenna array design is a 30 cm by 20 cm, X band (8.475 GHz) reflectarray that shows 94% transparency, 24 dB gain, and higher than 40% aperture efficiency. The design is then prototyped and tested on actual solar panel. The measurement of the reflectarray placed on the solar panel showed a gain of 22.46 dB and an aperture efficiency of 29.3%. While those results are considered excellent, the thesis continues to address the reasons for reduction of the antenna’s performance due to the solar panel, through both theoretical analysis and experiments

Applications of Nano-Satellites and Cube-Satellites in Microwave and RF Domain

This paper presents an overview of microwave technologies for Small Satellites including NanoSats and CubeSats. In addition, examples of space communication technology demonstration projects using CubeSats are presented. Furthermore, examples of miniature instruments for Earth science measurements are discussed

Analysis and Design of Highly Transparent Meshed Patch Antenna Backed by a Solid Ground Plane

This paper analyzes rectangular and circular patch antennas fabricated from meshed conductors and backed with solid ground planes. Because of the meshing, the antennas are rendered optically transparent, where the transparency is determined by the mesh geometry. It is found that although there is a compromise between the antenna\u27s efficiency and the optical transparency of the meshed patch, it is possible to optimize the antenna by refining mesh lines to certain extent. The limiting factors for refining mesh lines include material handling and fabrication process as well as the increased line impedance when being refined, which accordingly causes loss in antenna\u27s efficiency or gain, it is seen that there is a limit for such an optimization method. This limit is closer to the efficiency of a solid patch for a lower transparency, whereas it is lower for increased transparency. Cross polarization level was also examined, and there was no significant effect on such a parameter due to meshing

Antenna Designs for 5G/IoT and Space Applications

This book is intended to shed some light on recent advances in antenna design for these new emerging applications and identify further research areas in this exciting field of communications technologies. Considering the specificity of the operational environment, e.g., huge distance, moving support (satellite), huge temperature drift, small dimension with respect to the distance, etc, antennas, are the fundamental device allowing to maintain a constant interoperability between ground station and satellite, or different satellites. High gain, stable (in temperature, and time) performances, long lifecycle are some of the requirements that necessitates special attention with respect to standard designs. The chapters of this book discuss various aspects of the above-mentioned list presenting the view of the authors. Some of the contributors are working strictly in the field (space), so they have a very targeted view on the subjects, while others with a more academic background, proposes futuristic solutions. We hope that interested reader, will find a fertile source of information, that combined with their interest/background will allow efficiently exploiting the combination of these two perspectives

Applications of Nano-Satellites and Cube-Satellites in Microwave and RF Domain

This paper presents an overview of microwave technologies for Small Satellites including NanoSats and CubeSats. In addition, examples of space communication technology demonstration projects using CubeSats are presented. Furthermore, examples of miniature instruments for Earth science measurements are discussed

Compact and Planar End-fire Antenna for PicoSat and CubeSat Platforms to Support Deployable Systems

A miniaturized planar Yagi-Uda antenna for integration with PicoSats or other SmallSat missions is proposed. Miniaturization techniques, such as meandering and 1-D artificial dielectric concepts to reduce the guided wavelength, are employed to overcome space constraints imposed by the SmallSat footprint while still maintaining good performance for the FR-4 antenna. Simulations and measurements have been carried out on the Unicorn-2 PicoSat chassis from Alba Orbital and are in good agreement. Also, antenna dimensions have been reduced between 15% and 66% when compared to a more conventional planar Yagi-Uda antenna working at the same frequency. This compactness allows for simple integration with the deployable solar panel array of the Unicorn-2 PicoSat spacecraft. Full end-fire radiation is achieved and peak gain values are about 5 dBi for the antenna when fully integrated on the satellite chassis, offering an attractive solution for downlink connectivity. This compact antenna design can also be used within an array for beam steering or integrated within the solar cell modules of other PicoSats, CubeSats and SmallSats. Applications include Earth observation, remote sensing, as well as SmallSat to ground station communications. The planar Yagi-Uda antenna may also be useful wherever end-fire radiation is required from a compact antenna structure

A Curved Microstrip Patch Antenna Designed From Transparent Conductive Films

Transparent microstrip patch antennas suffer from low radiation efficiency and gain when manufactured using transparent conductive films (TCFs), mainly at low frequency (starting from the microwave S band). To address this problem, we propose a curved microstrip patch antenna designed using transparent materials. This new configuration has proven to be a simple and effective solution to improve the radiation efficiency and gain of TCF printed antennas. In fact, when typical values of the TCF surface resistance are considered (between 2 and 10 Ω/sq), the new antenna features a radiation efficiency of up to 72.3% and a realized gain of up to 5.3 dBi at 2.15 GHz, with a significant improvement in comparison with the flat transparent microstrip antenna (up to 17.7% radiation efficiency, and 0.5 dBi realized gain). Good transparency and lightweight is ensured by the deposition of the TCF on a polyethylene terephthalate film, which lies, in turn, on a 3D-printed curved polyethylene terephthalate glycol supporting frame. Simulations using Ansys HFSS are presented to demonstrate the potential of the proposed configuration. Then, a prototype of the transparent curved patch antenna is fabricated and measured to assess the simulated results