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Full-Text Articles in Engineering
Design, Implementation, And Test Of Spacecraft Antennae And A Ground Station For Mesat1, Travis Russell
Design, Implementation, And Test Of Spacecraft Antennae And A Ground Station For Mesat1, Travis Russell
Electronic Theses and Dissertations
MESAT1 is a CubeSat that was proposed by the University of Maine in response to NASA's CubeSat Launch Initiative, and in early 2020 was selected by NASA to be launched into a Low Earth Orbit (LEO) in June of 2022. The satellite will carry four low-cost complementary metal–oxide–semiconductor (CMOS) cameras which serve as sensing instruments for three science missions proposed by K-12 schools in Maine. The cameras will periodically take pictures of Earth to analyze water turbidity, identify urban heat islands, and predict harmful algal blooms. The multi-spectral image data is packed into frames and downlinked as Binary Phase-Shift Keying …
Reduction Of Mutual Coupling In Antenna Technology Using Elliptically Shaped Metasurfaces, Gabriel Moreno
Reduction Of Mutual Coupling In Antenna Technology Using Elliptically Shaped Metasurfaces, Gabriel Moreno
Electronic Theses and Dissertations
This thesis is devoted to the use of metasurfaces for the goals of the reduction of mutual coupling between closely spaced antennas and the increase of antenna bandwidth. This is done first using a graphene monolayer as a cloak to decrease mutual coupling and restore radiation patterns for closely spaced antennas at THz frequencies. The introduction of the graphene monolayer was also extensively studied in regards to the effect on the radiation properties of the antennas. The use of metasurfaces also has other applications, in particular with the bandwidth of antennas, where an anisotropic metasurface can be used to drastically …
Beam-Steerable And Reconfigurable Reflectarray Antennas For High Gain Space Applications, Kalyan Karnati
Beam-Steerable And Reconfigurable Reflectarray Antennas For High Gain Space Applications, Kalyan Karnati
Electronic Theses and Dissertations
Reflectarray antennas uniquely combine the advantages of parabolic reflectors and phased array antennas. Comprised of planar structures similar to phased arrays and utilizing quasi-optical excitation similar to parabolic reflectors, reflectarray antennas provide beam steering without the need of complex and lossy feed networks. Chapter 1 discusses the basic theory of reflectarray and its design. A brief summary of previous work and current research status is also presented. The inherent advantages and drawbacks of the reflectarray are discussed. In chapter 2, a novel theoretical approach to extract the reflection coefficient of reflectarray unit cells is developed. The approach is applied to …
Characteristics Of Different Focusing Antennas In The Near Field Region, Shaya Karimkashi
Characteristics Of Different Focusing Antennas In The Near Field Region, Shaya Karimkashi
Electronic Theses and Dissertations
Focusing antennas are of interest in many application including microwave wireless power transmission, remote (non-contact) sensing, and medical applications. Different kinds of antennas such as array antennas, reflector antennas and Fresnel zone plate (FZP) antennas have been used for these applications. Here, first, a new scheme in designing focused array antennas with desired sidelobe levels (SLLs) in the near field region is presented. The performance of the large focused array antennas is predicted based on the knowledge of the mutual admittances of a smaller array. The effects of various focal distances on the near field pattern of these antennas are …