Patent ID: 6181222
Filing Date: 2001-01-30
Classification: H01P

Abstract:
Polarizer for both a lower frequency band and an upper frequency band for exciting an antenna with a parabolic reflector, comprising:(a) waveguide section for carrying two mutually perpendicularly linearly polarized waves for each of the upper and lower frequency bands,(b) means for connecting the waveguide section to two waveguides for the lower frequency band, the two lower frequency band waveguides being connected to the waveguide section separate from each other and mutually offset in an axial direction of the waveguide section;(c) means for connecting the waveguide section to two waveguides for the upper frequency band, the two upper frequency band waveguides being connected to the waveguide section separate from each other and mutually offset in the axial direction of the waveguide section, said connecting means for the two upper frequency band waveguides subdividing each of the two upper frequency waveguides into two branches with identical rectangular cross-sections, the respective branches for each of the two upper frequency band waveguides terminating at two diametrically opposing locations on the waveguide section, the respective branches for one of the two upper frequency band waveguides terminate on the waveguide section circumferentially offset by 90.degree. relative to the respective branches of the other of the two upper frequency band waveguides, the respective branches for each of the two upper frequency band waveguides have wider flat sides which abut each other in such a way that front faces of the respective branches which abut are aligned with each other for connection to the respective upper frequency band waveguide, and one of the respective branches for each of the two upper frequency band waveguides is twisted about an angle of 180.degree..