Design of Planar Resonant Scatterer With Roll-Invariant Cross Polarization

• Published in: IEEE transactions on microwave theory and techniques Vol. 68; no. 10; pp. 4305 - 4313
• Main Authors: Rance, Olivier, Barbot, Nicolas, Perret, Etienne
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE); Institute of Electrical and Electronics Engineers
• Subjects: Calibration; Computer Science; Cross polarization; Dipoles; Ground plane; Invariants; polarimetric scattering; Polarimetry; Radar antennas; Radar polarimetry; Radar scattering; resonator; S matrix theory; Signal and Image Processing; Transmission line matrix methods; Resonator; Polarimetric Scattering; Cross polarization
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2020.3014376

Only a few efforts have been made to design small scatterers with special polarimetric properties. In this article, the possibility of designing a planar single-layer resonant scatterer presenting roll-invariant cross polarization is demonstrated for the first time. The invariance condition for a general scatterer is first derived analytically from the scattering matrix for copolarization and cross polarization. Then, a design method for a resonant scatterer made from two dipoles with unique angular and phase arrangement is presented. The first step of the design is done theoretically using field superposition. The effects of the coupling between the dipoles and the finite ground plane size are taken into account in a second step by simulation. Two scatterers operating at 4.26 and 5.26 GHz have been manufactured and measured providing good performance with a relative variation of their cross polarization component lower than −2 and −2.7 dB, respectively. Finally, the scattering matrix corresponding to the current design is compared with other classical targets.