Circuit Modeling of 3-D Cells to Design Versatile Full-Metal Polarizers

Carlos Molero (1) , Maria Garcia-Vigueras (1)

1 IETR - Institut d'Électronique et des Technologies du numéRique

An original mechanism is here proposed to achieve polarization convertion from linear to circular with the use of full-metal polarizing screens. Such screens are self-supported and conceived from the periodic arrangement of 3D unit-cells. They are built from sections of rectangular waveguides operating below cutoff frequency and loaded with slotted discontinuities. The polarizer operates in transmission: the discontinuities are responsible for both its high return losses and the conversion of the impinging linear polarization to circular. Two types of 3D-cells are presented, both of them are analyzed and designed through equivalent circuit models. These models have been thoroughly built in order to capture all the phenomena underlying the discontinuities' behavior. The characterization of the first cell is fully done analytically whereas the second cell needs reduced help from a full-wave solver. Furthermore, the circuit models allow simple design guidelines to be identified for this type of polarizer. Two designs are performed operating in Ka-band, proving that an extension of the operation bandwidth (axial ratio and S11) to 11% is possible by employing the second cell.

Mots clés: analytical circuit modelling; 3D-unit cells; metallic polarizer in transmission; circular polarization

Domaines: Micro et nanotechnologies/Microélectronique

Carlos Molero, Maria Garcia-Vigueras. Circuit Modeling of 3-D Cells to Design Versatile Full-Metal Polarizers. IEEE Transactions on Microwave Theory and Techniques, 2019, 67 (4), pp.1357-1369. ⟨10.1109/TMTT.2019.2898828⟩. ⟨hal-01925693v2⟩