Raytheon Company

Wilbur H Thies

Donald H Archer

Kim Mcinturff

Alfred I Mintzer

An amplitude monopulse direction finding system is disclosed. The system is built around a circular array with a circular lens in which the antenna elements and array ports are larger than in conventional systems. The oversized antenna elements and array ports provide a wide range of operating frequencies for the direction finding system. Additionally, the direction finding system contains an omni-directional probe at the center of the lens to detect the presence of signals. In an alternative embodiment, each array port is split into two halves which can be combined in different ways to produce different beam patterns, allowing the beam pattern providing the best signal to noise ratio to be selected. Also, built-in-test circuitry is described.

Broadband direction finding system

A radio frequency antenna system comprising a plurality of antenna elements arranged in an array, such array comprising a pair of subarrays of antenna elements coupled to a pair of electromagnetic lenses. Each lens includes a plurality of array ports, the plurality of array ports of the first lens being coupled to the antenna elements of a first one of the pair of subarrays, and the plurality of array ports of the second lens being coupled to the antenna elements of a second one of the pair of subarrays. The first lens further comprises a first set of beam ports, and the second lens further comprises a second set of beam ports, the first and second sets of beam ports being arranged to form corresponding first and second sets of interleaved beams of radio frequency energy. The antenna array combines the interleaved first and second sets of beams to form a plurality of beams of radio frequency energy, each one of the plurality of beams being a composite beam of adjacent beams of the interleaved first and second sets of beams. With such arrangement, a set of 2N-1 composite beams may be formed with only N beam ports on each lens. Further, the high-frequency crossovers between adjacent composite beams may be maintained substantially at -3 dB, thereby providing substantially uniform coverage over the scan sector of the antenna system. Also, since 2N-1 composite beams are formed from lenses having only N beam ports, the switching complexity between a transmitter or receiver and each lens is reduced.

Modular multibeam radio frequency array antenna system

Radio frequency array antenna structures and methods for fabricating such structures are disclosed wherein a plurality of radio frequency circuits forming the radiating face of an array antenna and a corporate feed are formed on one or more relatively flexible dielectric sheets and then bonded to a suitable core material to form a complete array structure which is light weight, inexpensive and structurally sound.

Growing community of inventors

Santa Barbara, CA, United States of America

Wilbur H Thies