| 摘要 |
FIELD: antenna engineering: space-borne television. ^ SUBSTANCE: novelty is that antenna-feeder assembly incorporating four parabolic antennas disposed in same plane has its matching device built around power splitters. Input and four outputs of matching device are made in the form of sections of double-mode transmission line. Input is connected to four outputs through sections of single-mode transmission line. Power splitters are disposed in same plane. Two lateral sides of each power splitter are connected to adjacent outputs and central ones, to matching device input on four sides. Newly introduced are phase shifters affording phase shift through 180 deg. for two outputs disposed on two opposite sides relative to input. Power splitters can be made in the form of T-joints. Design alternates of phase shifters are given in invention specification. Antenna is characterized in that focus of its parabolic reflector is beyond axis; subreflector has elliptical generatrix whose eccentricity is 0.65 to 0.69, its first focus is disposed beyond axis. Subreflector edge is disposed beyond that of circumference plane area of mirror formed by parabolic surface. Conditions for choosing subreflector edge radius, radii ratio of focal rings of subreflector elliptical surface second focus and mirror parabolic surface focus, ratio of horn radius to wavelength in free space, and full aperture angle of feed conical horn are given in invention specification. ^ EFFECT: reduced longitudinal dimensions at high efficiency and broad bandwidth. ^ 20 cl, 8 dwg, 1 tbl |
