A Multiband Reflective Cross Polarization Converter

Here we present the design of a multiband cross polarization converter using a frequency-selective surface (FSS), making it suitable for applications in radar, satellite communications, and 5G systems. The polarization converter operates efficiently across four frequency bands, with resonances observed at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.6,5.2 \text{GHz}, 8.8 \text{GHz}$</tex> and 9.7 GHz. The proposed design features a conjoint loop-based copperpatterned structure on an FR-4 substrate which has been optimized to achieve a maximum polarization conversion efficiency (PCE) of 99% at the resonance frequencies. Numerical simulations have been carried out using CST Microwave Studio software for evaluating the performance of cross-polarization conversion. A prototype has been fabricated and measured. Measured results bear a close resemblance with simulated results.