Trw Limited

Northrop Grumman Systems Corporation

Makkalon Em

Charles W Chandler

Gregory P Krishmar-Junker

Louis C Wilson

An antenna system that employs an antenna element for both transmit and receive functions, where a dual band polarizer is used to convert linearly polarized signals to circularly polarized signals and vice versa for two frequency bands. The dual band polarizer includes a waveguide including corrugated structures extending from opposing sidewalls, where ridges in the structures extend perpendicular to the propagation direction of the signal. The height of the ridges taper from a lowest height at the ends of the waveguide to a largest height at the middle of the waveguide. The corrugated structures interact with the field components of the signal in the direction perpendicular to the ridges that cause that component to be delayed relative to the field components parallel to the ridges so that the signal changes accordingly and maintains the same magnitude.

Dual band frequency polarizer using corrugated geometry profile

An antenna system that employs antenna elements for both transmit and receive functions. Signals received by each antenna element are directed to a dual band polarizer that converts the signals to linearly polarized signals, and signals to be transmitted by each antenna element are converted to circularly polarized signals by the polarizer. The orientation of the polarizer and whether the circularly polarized signals are LHCP or RHCP determines whether the linearly polarized signals are vertically or horizontally polarized. A dual-band orthomode transducer is employed to separate the receive and transmit signals into their respective frequency bands based on whether they are vertically or horizontally polarized. The transducer is a waveguide device having only three signal ports. A high pass filter is used to help separate the received signals, and a low pass filter is used to help separate the transmit signals.

Dual frequency single polarization feed network

A horn antenna is provided which is capable of operating at a plurality of separate frequencies while providing substantially equalized E and H-plane patterns for each of the separate frequencies. The antenna includes a coupling portion to permit coupling to a communication device. An inner portion is coupled to the coupling portion, and includes a first choke having a depth which extends substantially parallel to a central longitudinal axis of the antenna and a width which extends in a radial direction of the antenna. The depth and the width of the first choke are set so that the first choke will operate at the first frequency. An outer portion is coupled to the inner portion, wherein the outer portion has a maximum diameter in the radial direction which is greater than the maximum diameter in the radial direction of the inner portion. The outer portion includes a second choke which also has a depth to extend substantially parallel to the central longitudinal axis of the antenna, and a width which extends in the radial direction. The depth and the width of the second choke are greater than the depth and the width of the first choke, and are set so that the second choke will operate at the second frequency. By virtue of the fact that the depths of the chokes extend in a direction substantially parallel to the longitudinal axis of the horn, the maximum electrical aperture of the antenna can be very close in size to the maximum physical diameter.

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Venice, CA, United States of America

Makkalon Em