The two designs of millimeter-wave deflector based on ferroelectric ceramic namely – periodic and single-layer were considered and compared. The expressions to relate ceramic characteristics on deflector parameters were derived on the base of filter-synthesis theory. The ferroelectric ceramic samples with different permittivity values were fabricated on the base of the solid state of barium-strontium titanate with different concentration of linear dopants. The parameters of ferroelectric samples were characterized by two measurements procedures. Due to the absence of frequency dispersion of ferroelectric permittivity up to 100 GHz, the experimental results for permittivity and tunability factor were obtained at 1 MHz; while the dielectric loss tangent was measured at 60 GHz via a quasi-optical open resonator technique. The obtained experimental results were used for analyzing the influence of ferroelectric material properties on characteristics of deflector structures. This analysis was performed by the full-wave electromagnetic simulation of both deflector designs at 60 GHz. The presented results show that the periodic deflector design demonstrates a higher deflection angle as well as high insertion loss value in the passband, while the single-layer deflector design requires higher tunability factor to provide the beam deflection equal to one beamwidth. The considerations of material applicability in each deflector design were concluded.
Volume 11 | 02-Special Issue
Pages: 425-430