Presentation description

Recent advancements in electromagnetic surface design have demonstrated that pixelated metasurfaces can achieve powerful RF functionalities such as filtering, impedance matching, and power combining, outperforming many classical structures in size and versatility. Building upon prior work in dual-band filters using pixelated surfaces and direct binary search (DBS) optimization, this project researches how material conductivity influences RF performance.

Specifically, we aim to understand how the finite conductivity of materials affects S-parameters and whether materials with tunable conductivity could be utilized as a platform to dynamically reconfigure the response of these structures. An important question, therefore, is what minimum threshold of conductivity is necessary to maintain acceptable transmission and reflection responses across key frequency bands. In contrast to prior work (which focused on binary metal/dielectric configurations using fixed materials like copper and FR4), this project studies intermediate conductivities using materials such as ITO to enable reconfigurable responses. This will help us bridge the gap between ideal metals and real tunable media that operate in mid-conductive conditions (10^5-10^6 S/m)

We generate a variety of pixel layouts (e.g., random, checkerboard, voided edges) in a 50×50 grid and simulate their performance in CST Studio Suite, sweeping conductivity values from 10^5-10^6 S/m. We monitor S₂₁ to analyze passband degradation as conductivity decreases. Preliminary results show a sharp roll-off in transmission efficiency below ~10⁵ S/m for most layouts, with denser central connectivity mitigating loss better than edge-only configurations.

Ultimately, this research aims to potentially inform the development of dynamically reconfigurable metasurfaces by identifying geometry and conductivity-dependent performance thresholds. The long-term goal is to implement such surfaces using tunable materials whose conductivity can be externally modulated, allowing for RF filters that reconfigure in real time.