An Ultrathin Single-Layer Polarization Converter With Independently Tunable Transmission and Reflection Operating Frequencies

A single-layer, ultrathin cross-polarization converter with a metal-dielectric-metal structure is proposed and experimentally demonstrated. The proposed converter comprises a 10 × 10 array of unit cells and has overall dimensions of 290 × 290 mm2. The converter uniquely achieves efficient cross-polarization conversion for both transmitted and reflected waves while enabling independent tuning of their respective operating frequencies. By adjusting specific structural parameters, the transmission band can be tuned from 4.06 GHz to 4.46 GHz while the reflection band remains fixed. Conversely, the reflection band can be tuned from 6.04 GHz to 8.31 GHz with the transmission band unaffected. The underlying polarization conversion mechanism is elucidated through analysis of polarization states, surface current distributions, and electric field patterns. The proposed converter exhibits stable, high-efficiency performance for polarization angles ranging from 0 to 90 degrees. A prototype was fabricated and measured, with experimental results showing excellent agreement with simulations.