This manuscript focuses on the design of a transparent circularly polarized (CP) antenna subarray integrating with CubeSat’s solar panels. The sub-array antenna employs two techniques including the Fabry_Perot cavity (FPC) and sequential rotation-feeding network. These techniques are used to generate CP along with a high level of directivity over a broad bandwidth. The main aim here is to propose a multi-functional antenna with the high radiation properties as well as the capability of power harvesting, simultaneously. To harvest power using a solar panel the transparency requirement should be satisfied. Hence, the proposed design is sputtered with the thin layer of indium-tin-oxide (ITO) with a thickness of 200nm. However, it seems to be sacrificed a large amount of conductivity at the frequency band of interest (x-band). Correspondingly, the performance of conductivity and transparency both the materials of ITO and copper as coated on the proposed design is determined. Alternatively, as an optically transparent conductor (OTC), a combination of both coating layers, including ITO and copper with thicknesses of 200nm and 5nm, respectively, are applied. In the scattering point of view, the proposed design is also capable of suppressing the radar cross section (RCS) for the space missions with the aim of space-based observations.

The coating layer of an electromagnetic wave scatterer with a thin collisional plasma structure was studied by using low-pressure fluorescent lamp parameters. The physical parameters of the designed plasma were obtained through analytical Microwave Interferometry measurements. Analytical solutions showed that the inventive coating system absorbed almost half of the incident X-frequency band. Accordingly, the radar cross-section of a covered metallic surface in an anechoic chamber was measured and compared at on- and off-plasma states. A significant electromagnetic wave dissipation in the frequency band was observed using a thin low-pressure plasma absorber in this study. Both qualitative tests and quantitative experimentations based on the electromagnetic scattering theory clearly verified the ability of the proposed practical coating structure in radar cross-section reduction. Moreover, a tangible numerical solution was prepared for both normal and varied incident angles. As a final point, the designed structure used in the far-field experiments paves the way for valuable applications, for instance, in reducing the radar cross-section of huge antennas, in plasma frequency-selective surfaces and in target shielding.

This paper presents four different approaches utilized in beam tilting that are based on the phase gradient (phase shifting) surfaces. Each approach is individually analyzed and then compared to other techniques. Beam tilting is obtained through various techniques by transforming the phase distribution of Fabry-Perot cavity antenna (FPCA) in the near-field region by means of inexpensive and passive surfaces including wedge-shaped dielectric lens (WSDL), discrete multilevel grating dielectric (DMGD), printed gradient surface (PGS), and perforated dielectric gradient surface (PDGS). To enhance efficiency in the millimeter-wave (MMW) band, the FPCA is fed through printed ridge gap waveguide. In addition, considerable enhancement in radiation performance of the antenna at 60GHz is acquired by a partially reflective surface (PRS), including a gain enhancement from 6.5 dB to 22 dB. To validate the suggested methodology and performance of the designs, several prototypes are chosen for fabricating. A satisfactory agreement between the numerical results and experimental ones is achieved. The proposed designs are also applicable for millimeter-wave frequencies especially the narrower band communication system.

Advanced! electromagnetic (EM) surfaces, namely meta-surfaces, are designed for multifunctional purposes. A glass material with a chessboard configuration is exploited to realize non-absorbing coating for backscattering reduction. Simultaneously, a solar cell is implemented above the metallic target for light energy harvesting using the transparency feature of the coat. Therefore, two separated aims are obtained in one structure using the plexiglass material and mono solar cell. Initially, EM wave interactions with both materials are determined. Then, by the use of the wave interactions and scattering theory, two different surfaces are investigated analytically with the aim of transparent backscattering reduction cover. Next, an optimization algorithm is employed to achieve the minimum reflection from the adjacent surfaces. To validate the design performance, a prototype is manufactured. The proposed chessboard cover with plexiglass material is numerically and experimentally analyzed and compared together, having an acceptable agreement. The experimental results indicate a 75% bandwidth for backscattering reduction. In addition, the proposed structure can give promising opportunities to enhance the scattering properties with simultaneously power harvesting, which could generate critical advantages for real-world applications.