Raytheon Company

James D Birch

Max C Mohr

Jerome Howard Pozgay

Raymond C Waterman, Jr

Eileen Conaty

Henry M Majchrzak

Daniel L Fontaine

Stephen R Monaghan

An antenna having: a beam forming network; an array of antenna elements; and a parallel plate region coupling the array of antenna elements and the beam forming network formed on a common, folded dielectric substrate. The beam forming network includes strip conductor circuitry separated from a ground plane conductor by a portion of the substrate. The array of antenna elements comprising strip conductor circuitry separate from a ground plane conductor by a second portion of the substrate. The parallel plate region is disposed about a folded region of the substrate and includes a pair of conductive plates separated by the folded region of the substrate. With such arrangement, a compact antenna is provided using the folded substrate. Also, spurious radiation (which has been found to radiate when strip conductor circuitry is disposed about the folded region to couple the array of antenna elements and the beam forming network) is confined by the parallel plate region.

Compact antenna with folded substrate

A compensated phased array antenna is shown wherein the drive to each one of a plurality of phase shifters is changed to compensate for changes in operating conditions.

Compensated phased array antenna

A radio frequency phase shifter suitable for X-band operation is disclosed. Such phase shifter incudes a waveguide structure and a ferrite assembly disposed within such waveguide structure. The ferrite assembly has a conductive material plated on the sides thereof. A pair of such plated sides is in contact with the wide walls of the waveguide structure thereby preventing the generation of longitudinal section modes (i.e. LSE.sub.1,1, LSM.sub.1,1, and LSE.sub.1,2) and another pair of such plated walls is displaced from the narrow walls of such waveguide structure to form a pair of waveguide sections cut off to the dominant mode of the radio frequency energy passing through the ferrite phase shifter thereby inhibiting such energy from coupling to wires passing through such waveguide sections for supplying drive current to the enclosed ferrite assembly. Because the waveguide structure may be flexed and has a width greater than the width of the ferrite assembly, the ferrite assembly may be inserted within the waveguide structure, when flexed, to provide the desired contact between the plated sides of the ferrite assembly and the wide walls of the waveguide structure when the latter returns to its original dimensions.

Ferrite phase shifter having conductive material plated around ferrite

An antenna element for use in a phased array antenna is disclosed. Such antenna element is a reciprocal device adapted selectively to radiate radio frequency energy of either circular or linear polarization. Such antenna element includes waveguide means for passing radio frequency energy and for radiating such energy; and means adapted to transform the polarization of the radio frequency energy as such passes through the waveguide means to radiate such radio frequency energy selectively with either linear or circular polarization. In a preferred embodiment the just-mentioned means includes a first and a second nonreciprocal quarter-wave plate having field orientations effectively 45.degree. with respect to each other. Such nonreciprocal quarter-wave plates flank a third nonreciprocal quarter-wave plate switchable so that its field orientation is either aligned with the field orientation of the first nonreciprocal quarter-wave plate or, while still aligned as before, turned 180.degree.. Further, the third quarter-wave plate may be switched into a nonenergized state. A reciprocal quarter-wave plate is disposed between the radiating end of the waveguide means and the second nonreciprocal quarter-wave plate. A phase shifter section is disposed between the third nonreciprocal quarter-wave plate and the first nonreciprocal quarter-wave plate. When the field orientations of the first and the third quarter-wave plate are aligned, vertically polarized radio frequency energy introduced into the waveguide means is changed to radiate as horizontally polarized radio frequency energy. When the field orientation of the third quarter-wave plate is reversed by 180.degree., vertically polarized radio frequency energy introduced into the waveguide means is radiated as vertically polarized radio frequency energy. When the third quarter-wave plate is unenergized, vertically polarized radio frequency energy introduced into the waveguide means is changed to radiate as circularly polarized radio frequency energy. The phase shifter section, whatever the polarization of the radio frequency energy passing through, is operative to change, in accordance with a beam steering control signal, the phase of such energy.

Growing community of inventors

Townsend, MA, United States of America

James D Birch