Charging Effects on Dielectric Resonator Antenna Due to Multienergentic E-Beam Irradiation

Dielectric antenna with a smaller size and numerous advantage is hardly applied in spacecraft due to complicated charging effects under electrons irradiation in space. And it is also difficult for researchers to obtain radiation properties of dielectric antenna under electron beam irradiation in experiment. In this paper, we investigate dielectric properties and characteristics of radiation and transmission under charging effects due to electrons irradiation via a numerical simulation. For simulating electrons irradiation in space more realistically, the primary electron (PE) energy is set to be multienergentic basing on the Geostationary Earth Orbit. The scattering process between PE and material atom includes elastic and inelastic scattering, while the transport process of internal charges consists of drift, diffusion, trapping, and neutralization. Performing less power loss and higher radiant efficiency, dielectric resonator antenna (DRA) is selected as the applied research object under E-beam irradiation induced charging effects. It is found that the evolution of internal charges is dominated with accumulation first, and then act in a main form of transporting toward depth with an invariant peak. The dielectric constant increases under the force of internal built E-field in ranges of internal charges. Under the continuous E-beam irradiation, the S(1, 1) curve of DRA shifts toward low frequency, and its bandwidth becomes wider. The numerical simulation method and presented results in this paper can offer a comprehensive insight into researches and developments on dielectric antenna in space.