Lockheed Martin Corporation

Hughes Electronics Corporation

Martin Marietta Corporation

Eric L Holzman

Pyong K Park

Richard Joseph Teti

John G Ferrante

Bradley David Dufour

Stephen Charles Miller

Wilbur Lew

Bruce M Cepas

A hermetically sealed housing (10) includes a dielectric end portion (118) which provides a transmission-line feedthrough between a printed-circuit such as HDI and exterior connections. A first transmission line (1) on the PC board (30) transitions to a 3-via transmission line (4), which transitions to a third coplanar, microstrip, or stripline transmission line (3). The third transmission line (3) transitions to a second 3-via transmission line (5), which ends at a coplanar transmission line (2) which is outside the housing.

Hermetic feedthrough using three-via transmission lines

A broadband horn-like, linearly polarized antenna element is driven from a microstrip line and a balun. The horn is skeletonized, and has no sides, and consequently operates in TEM mode for broad frequency bandwidth. In another embodiment, two or more baluns feed the horn-like antenna element, thereby allowing a plurality of amplifiers or other sources to be combined at the antenna, for power summation or for multiplexing. An array of such elements, arranged for both vertical and horizontal polarization, makes a structure which presents mostly metallic surfaces, and is therefore rugged, and overpressure resistant.

Broadband antenna element, and array using such elements

A low profile, compact microstrip-to-waveguide or stripline-to-waveguide transition. The end of the waveguide is terminated in a cavity backed slot defined in a groundplane formed on a dielectric substrate. The slot is excited by a microstrip or stripline conductor defined on the opposite side of the substrate. The conductor is terminated in a T-shaped junction including two opposed arms extending along the slot, each having a length equal to one-quarter wavelength at the center frequency of operation. A cavity covers the substrate on the conductor side, and is sized so that no cavity modes resonate in the frequency band of operation. The transition is matched by appropriate selection of the length of the slot and the length and position of the microstrip.

End launched microstrip or stripline to waveguide transition with cavity

A low profile, compact microstrip-to-waveguide transition which utilizes electromagnetic coupling instead of direct coupling. The end of the waveguide is terminated in a cavity backed slot defined in a groundplane formed on a dielectric substrate. The slot is excited by a microstrip line defined on the opposite side of the substrate, offset from the slot centerline. A cavity covers the substrate on the microstrip side, and is sized so that no cavity modes resonate in the frequency band of operation. The transition is matched by appropriate selection of the length of the slot and the length and position of the microstrip.

A radar system which uses an active phased-array antenna achieves improved clutter improvement factor (CIF) by powering the various transmit-receive (TR) modules of the antenna with direct voltage (DC) derived from a plurality of phases of the power-line alternating current (AC). Each TR module receives power which originates with one phase of the source AC. The phases are selected so that the modulation of the radio-frequency (RF) signals by each TR module tends to cancel in the summed signal from the array antenna.

Growing community of inventors

Medford, NJ, United States of America

Eric L Holzman