Polarizer for two different frequency bands

US6181222A · kind A · utility

Assignee

• ALCATEL · FR

Inventors

• Udo Seewig · Langenhagen, DE
• Reimer Nagel · Feldkirchen-Westerham, DE
• Daniel Wojtkowiak · Neustadt, DE

Key dates

• Filing date: Aug 6, 1998
• Grant date: Jan 30, 2001
• Expiry date: Aug 6, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01P1/2131
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A polarizer for two different frequency bands is described for exciting an antenna with a parabolic reflector. The polarizer has a waveguide section capable of carrying in each frequency band two mutually perpendicularly linearly polarized waves. For each frequency band, two waveguides having a rectangular cross-section are connected to the waveguide section separate from each other and mutually offset in the axial direction of the waveguide section. A respective waveguide is connected directly to the waveguide section for each polarization direction of the lower frequency band, whereas for the upper frequency band--from a connecting point (11, 12) on--each of the two waveguides is subdivided into two branches (18, 19, 20, 21) with each having identical rectangular cross-section. The respective branches terminate on the waveguide section at mutually opposing locations which are circumferentially offset relative to each other by 90.degree. for the two polarization directions. To simplify the portion designated for the upper frequency band, the wider flat sides of the two branches (18, 19, 20, 21) abut each other at each of the connecting points (11, 12) in such a way that the front …