Contributions to the Modeling and Design of Reconfigurable Reflecting Cells Embedding Discrete Control Elements

Abstract

Abstract-This paper presents new contributions to the modeling and design of reflecting cells embedding discrete control elements such as microelectromechanical system (MEMS) or diodes. First, a rigorous assessment of the different possibilities to simulate and measure the reconfigurable cell in a periodic environment is proposed. Strategies to efficiently model a cell comprising discrete control elements are then presented and discussed in terms of versatility, required assumptions, and computational effort. The most efficient method allows computing all reconfigurable states cell parameters, including information such as the total and dissipated power in each MEMS or diode, in a few minutes using a commercial full-wave solver and adequate post-processing. Finally, the benefit of such an efficient modeling is illustrated by the optimization of an element phase states distribution using a particle swarm optimizer. The concepts presented are also directly applicable to reconfigurable transmitting cells.

Reconfigurable Reflectarrays and Array Lenses for Dynamic Antenna Beam Control: A Review

“…In particular, the design of a lumped elements based cell can be carried out representing it by a multi-port scattering matrix where the effect of the lumped elements is included via circuitbased post-processing. This not only allows a single full-wave simulation of the cell for obtaining all the different states of the cell [48], but also allows for other interesting analyses such as the average or maximum voltage induced on each element [49] or some computation related to the sensitivity of the cell response to faults in the lumped control devices [50]. However it is worth noting here that accurate results require rigorous correction of parasitics related to the introduction of the lumped port in the full-wave simulator [48] [51].…”

“…This not only allows a single full-wave simulation of the cell for obtaining all the different states of the cell [48], but also allows for other interesting analyses such as the average or maximum voltage induced on each element [49] or some computation related to the sensitivity of the cell response to faults in the lumped control devices [50]. However it is worth noting here that accurate results require rigorous correction of parasitics related to the introduction of the lumped port in the full-wave simulator [48] [51]. Obviously, this separate computation of cell response and control elements is virtually impossible for technologies relying on the distributed control of some material property, which thus require full-wave solutions for each material state and provide fewer possibilities for advanced optimization methods.…”

“…Switches in the form of PIN diodes and micro-electrical-mechanical systems (MEMS) have been integrated with patches to control the current path and corresponding resonator length [40][59] [60]. Such methods depend on modelling techniques that allow for the analysis of the effect of tunable lumped element devices on the large scale electrical scattering characteristics of the device [48] [61]. In addition to using lumped element devices to effect changes in resonator lengths, more exotic techniques have also been contemplated, such as photo-induced plasmas for changing the length of slots coupled to reflectarray elements [32].…”

“…Indeed, while the modelling complexity of both approaches is quite similar (if the approach described in Section IV-A is used when addressing tunable resonator cells), the fact that the antenna and phase shifter can be optimized separately in the guided-wave approach results in simpler design procedure. For instance, in a digital design it is quite straightforward to achieve equi-spaced phase states in the guided-wave phase shifter, whereas doing so with a tunable resonator can require complex optimization which might still lead to sub-optimal phase distributions [48]. Another advantage of this technique is that wideband behavior is more easily obtained since simple guided-wave phase shifters can be designed to provide truetime delay capability.…”

Design of a reflectarray element integrated in a Solar Cell panel

“…Furthermore, the flatness, low-cost, and high-performance of a RA is well adapted for solar cell integration. Though this work focuses on fixed beam RAs, future development could consider the integration of beam scanning RAs [4][5] into solar panels thereby expending potential applications.…”