An Electrodynamics Solver for Moving Sources

An Electrodynamics solver for moving sources is introduced. The main challenges and formulation are highlighted. The solver enables the simulation of fields for sources undergoing arbitrary motion. Two examples of uniformly moving current sources are provided to correlate the numerical solver computations with theory, based on the solution of Maxwell's equations and the relativistic transformation of the electromagnetic fields

Maximum-likelihood estimation of specific differential phase and attenuation in rain

Precise estimation of propagation parameters in precipitation media is of interest to improve the performance of communications systems and in remote sensing applications. In this paper, we present maximum-likelihood estimators of specific attenuation and specific differential phase in rain. The model used for obtaining the cited estimators assumes coherent propagation, reflection symmetry of the medium, and Gaussian statistics of the scattering matrix measurements. No assumptions about the microphysical properties of the medium are needed. The performance of the estimators is evaluated through simulated data. Results show negligible estimators bias and variances close to Cramer–Rao bounds

Solar-Panel Integrated Circularly Polarized Meshed Patch for Cubesats and Other Small Satellites

This paper presents the design of a circularly polarized (CP) meshed patch antenna fully integrated within a solar panel for operation on CubeSats and other microsatellites. The structure has been designed to ensure optimal antenna performance at S -band as well as to minimize any shadowing effects that can reduce the received power at the solar cells. To generate CP, the antenna is driven by two orthogonal feed points, penetrating through a transparent borosilicate glass layer, as well as a silicon and PCB substrate. Simulated and measured performances, on both a preliminary FR4 design and a fully integrated prototype, demonstrate a good impedance bandwidth, satisfactorily axial ratio, as well as stable radiation patterns and minimum shadowing levels. The proposed antenna can be useful for communications between satellites as well as with the ground station, and since the structure is compact and completely integrated, the design can be an alternative approach to new-phased arrays on solar panels and other beam-steering systems