DUAL-BAND CIRCULAR-POLARIZATION FEED Russian patent published in 2007 - IPC H01Q13/02 

FIELD: antenna engineering; reflector-antenna feeds for miscellaneous radio stations including radio-relay and space stations.

SUBSTANCE: proposed dual-band circular-polarization feed has series-connected horn, first section of low-frequency round waveguide with polarizer, rectangular waveguide disposed perpendicular to round-waveguide first-section axis and coupled with its interior by means of longitudinal slit, second section of high-frequency round waveguide with polarizer and rectangular feeding waveguide; first and second sections of round waveguide are series-connected by means of stepless transition and rectangular feeding waveguide is coaxially connected to second section of round waveguide by means of stepless transition; second-section polarizer of low-frequency round waveguide, as well as that of high-frequency round waveguide, is made in the form of two identical metal plates , each being 0.09λ_m ≤ S ≤ 1.1λ_m thick, where λ_m is mean wavelength of respective operating band of isosceles trapezium shape whose lower base length is 2.6λ_m ≤ l_l ≤ 2.8λ_m and upper base length is 0.4λ_m ≤ l_u ≤ 0.6λ_m with lower bases disposed on inner walls of respective round-waveguide section symmetrically to its axes, height h_l of polarizer trapeziums in first section of low-frequency round waveguide h_l being 1.185λ_m and height h_h of polarizer trapeziums in second section of high-frequency round waveguide, (0.16 - 0.17)λ_m; profile of lateral sides of polarizer trapezium in first section of low-frequency round waveguide obeys law, where x and y are abscissa and ordinate of rectangular coordinate system XOY, respectively, whose origin coincides with that of lower base; positive axis OX coincides with lower base of trapezium and positive axis OY is directed toward upper base.

EFFECT: ability of receiving polarization multiplexed signals due to enhancing isolation between orthogonal channels.

1 cl, 2 dwg