Harris Corporation

David George Hoyt

Arecio A Hernandez

Heriberto Jose Delgado

Stuart Pullen

Patrick Anthony Begley

Jeffrey M Strang

The hybrid antenna includes a spiral antenna, e.g. a log spiral antenna, and a patch array layer adjacent to the spiral antenna and including a passive periodic patch array of conductive patch elements. A conductive ground plane may be adjacent to the patch array layer, and a dielectric layer may be between the conductive ground plane and the patch array. The spiral antenna may include an upper antenna arm, a lower antenna arm and a dielectric sheet therebetween. Each of the upper and lower antenna arms may be a printed planar conductive trace that is wider at a distal end thereof with respect to a center of the log spiral antenna. The patch or periodic array layer operates in conjunction with the ground plane to couple energy into the spiral antenna and thereby improve low frequency antenna efficiency while maintaining electrically small dimensions.

Hybrid antenna including spiral antenna and periodic array, and associated methods

A test architecture performs calibration and site verification testing of the effectiveness of a radiation shielding structure within which electronic equipment is housed. An external subsystem is outside a shielding cabinet, and an internal subsystem resides with the electronic equipment within the shielded equipment housing proper. The external subsystem includes a host computer, which controls the operation of transmit and receive subsystems. An external receiver is selectively coupled by the host processor to either an RF receive antenna or to a current sense probe. All control signals from the external subsystem are conveyed into the shielded cabinet by way of fiber optic links, in order to preserve the shielding effectiveness of the cabinet. Having the source of test signals and its associated transmission antenna located within the shielded cabinet serves to minimize the impact of such signals on circuits within the environment outside the cabinet.

Electromagnetic protection test and surveillance system

Pulse width modulated (&ldquo;Class D&rdquo;) amplifiers and controllers switching in the 50 khz to 2 MHz range generate harmonics which interfere with AM radio reception. This has precluded wide spread acceptance of class D amplifiers in products with an AM radio. The amplifiers described here use a modified modulation technique when operating with an AM radio to avoid generating harmonics at the receiver selected frequency or its intermediate (IF) frequency. One embodiment uses a harmonic avoidance modulator. A second embodiment uses two or more oscillators and tests for the least distorted output signal. A third embodiment switches the mode of operation to a class AB amplifier when an AM signal is amplified.

Growing community of inventors

Satellite Beach, FL, United States of America

David George Hoyt