Dual band frequency polarizer using corrugated geometry profile

An antenna system comprising:

• a dual frequency antenna element, said antenna element receiving a first signal having a first frequency band and transmitting a second signal having a second frequency band, said first and second frequency bands being different;
• a dual frequency polarizer including a first end and a second end, said polarizer receiving the first signal at the first end and receiving the second signal at the second end, said polarizer converting the first signal from a circularly polarized signal to a linearly polarized signal and converting the second signal from a linearly polarized signal to a circularly polarized signal, the polarizer including a waveguide including two pair of opposing side walls, a first pair of the side walls including corrugated structures, each corrugated structure including a plurality of parallel ribs, said ribs causing an E-field component of the first and second signals to be delayed relative to another E-field component so that the relative phases of the E-field components change as the signals propagate through the waveguide;
• and
• a diplexer receiving the linearly polarized first signal and the linearly polarized second signal, said diplexer directing the first signal to reception circuitry and directing the second signal to the polarizer.

An antenna system comprising:

• a dual frequency antenna element, said antenna element receiving a first signal having a first frequency band and transmitting a second signal having a second frequency band, said first and second frequency bands being different;
• a dual frequency polarizer, said polarizer converting the first signal from a circularly polarized signal to a linearly polarized signal and converting the second signal from a linearly polarized signal to a circularly polarized signal, the polarizer including a waveguide including two pair of opposing side walls, a first pair of the side walls including corrugated structures, each corrugated structure including a plurality of parallel ribs where the height of the ribs from the side walls is tapered in an increasing manner from each end of the waveguide towards the center of the waveguide, said ribs causing an E-field component of the first and second signals to be delayed relative to another E-field component so that the relative phases of the E-field components change as the signals propagate through the waveguide;
• and
• a diplexer receiving the linearly polarized first signal and the linearly polarized second signal, said diplexer directing the first signal to reception circuitry and directing the second signal to the polarizer.

An antenna system on a satellite for receiving satellite uplink signals and transmitting satellite downlink signals, said uplink signal and downlink signal having different frequency bands, said system comprising:

• a dual frequency feed horn, said feed horn receiving the uplink signal and transmitting the downlink signal;
• a dual frequency polarizer, said polarizer convening the uplink signal from a circularly polarized signal to a linearly polarized signal and convening the downlink signal from a linearly polarized signal to a circularly polarized signal, said polarizer including a waveguide having two pair of opposing side walls, a first pair of the side walls including corrugated structures, said corrugated structures including a plurality of parallel ribs, wherein the height of the ribs relative to the side wall is tapered in an increasing manner from each end of the waveguide towards the center of the waveguide, said waveguide receiving the uplink signal from the feed horn at a first end of the waveguide;
• and
• a diplexer receiving the linearly polarized uplink signal and the linearly polarized downlink signal, said diplexer directing the uplink signal to reception circuitry and directing the downlink signal to the waveguide at a second end of the waveguide opposite to the first end.

A dual frequency band polarizer for converting a linearly polarized signal to a circularly polarized signal in two separate frequency bands, said polarizer comprising:

• a rectangular waveguide structure having a first end, a second end, a first pair of opposing side walls and a second pair of opposing side walls;
• a first corrugated structure extending from a side wall of the first pair of side walls, said first corrugated structure including a plurality of parallel ribs extending in a direction transverse to the propagation direction of the signal;
• and
• a second corrugated structure extending from the opposing side wall of the first pair of side walls, said second corrugated structure including a plurality of parallel ribs extending in a direction transverse to the propagation direction of the signal, wherein all of the parallel ribs in the first and second corrugated structures have about the same width, said first and second corrugated structures being symmetrical relative to each other and interacting with an E-field component in the signal to delay the component to ornate the circular polarization for the signals in both frequency bands.

A dual frequency band polarizer for converting a linearly polarized signal to a circularly polarized signal in two separate frequency bands, said polarizer comprising:

• a rectangular waveguide structure having a first end, a second end, a first pair of opposing side walls and a second pair of opposing side walls;
• a first corrugated structure extending from a side wall of the first pair of side walls, said first corrugated structure including a plurality of parallel ribs extending in a direction transverse to the propagation direction of the signal;
• and
• a second corrugated structure extending from the opposing side wall of the first pair of side walls, said second corrugated structure including a plurality of parallel ribs extending in a direction transverse to the propagation direction of the signal, wherein the height of the ribs from the side walls is tapered in an increasing manner from each end of the waveguide towards the center of the waveguide, said first and second corrugated structures being symmetrical relative to each other and interacting with an E-field component in the signal to delay the component to create the circular polarization for the signals in born frequency bands.