Microwave Properties of an Inhomogeneous Optically Illuminated Plasma in a Microstrip Gap

Investigation of an optically induced superstrate plasma for tuning microstrip antennas

“…4 shows the plasma applied to a single slot of the antenna. Unlike the case shown in [20], the region of maximum conductivity is now in line with the region of maximum field strength. The E-field in the space between the slot decays rapidly into the depth of the silicon so that the lower layers of plasma interact very little with the E-field.…”

An Optically Tunable Cavity-Backed Slot Antenna

“…Section IV shows the simulated performance using CST Microwave Studio. Section V shows the measured results and Section VI draws conclusions [15] and diffusion length, Ln=120m [15]. It can be seen that the illumination causes a conductivity maximum close to the silicon surface, and the generated charge carriers diffuse exponentially away from the surface.…”

“…It can be seen that the illumination causes a conductivity maximum close to the silicon surface, and the generated charge carriers diffuse exponentially away from the surface. The drop in conductivity at the surface is related to the surface recombination velocity and represents the effects of surface states [15]. (b) Figure 1 also shows how the modelled conductivity profile is converted into nested blocks of differing material properties, which will be subsequently incorporated into the simulation model.…”

Optically induced conductivity in silicon: An active control technique for antennas

“…Reconfigurability typically requires either mechanical movement of elements such as MEMS, switching of parasitic elements using varactors, PIN diodes or transistors, or phase weighting, all of which have certain drawbacks . A potential improvement is to exploit optically controlled semiconductors . By illuminating an area of semiconductor, electrons are excited into the conduction band, generating a plasma of free charge carriers.…”