DAVID R. RIVERA, M.D.
Medical Practice at Wells St, Westerly, RI

5488336, Jan 30, 1996

Aug 8, 1994

8/287026

David F. Rivera - Westerly RI
Thomas R. Floyd - Waterford CT
Michael J. Josypenko - Norwich CT

The United States of America as represented by the Secretary of the Navy - Washington DC

H01P 108

333252

A broad passband pressure barrier arrangement is provided for insertion in circular waveguide between a source and a receiver of radio frequency (RF) energy with a spatially circumferential electric field characteristic of the TE. sub. 01 mode. At least two cylindrical barrier regions are coaxially aligned and arranged symmetrically in mirror image fashion about a radial plane of the circular waveguide. The cylindrical barrier regions include at least one solid cylindrical plug region sealed in a cross-section of the circular waveguide and having a longitudinal thickness sufficient to withstand a predetermined pressure load. Each of the cylindrical barrier regions are defined by a characteristic impedance at opposing end faces thereof and a by characteristic impedance between the opposing end faces. A region-by-region impedance analysis process begins with an end face of the arrangement that is furthest from the source and is completed with an end face of the arrangement that is nearest the source. The permittivities of the barrier regions and the longitudinal thicknesses of barrier regions are optimized across the passband of interest.

5471182, Nov 28, 1995

Aug 8, 1994

8/287023

David F. Rivera - Westerly RI
Thomas R. Floyd - Waterford CT
Michael J. Josypenko - Norwich CT

The United States of America as represented by the Secretary of the Navy - Washington DC

H01P 108

333252

A broad passband pressure barrier arrangement is provided for insertion in circular waveguide between a source and a receiver of radio frequency (RF) energy with a spatially circumferential electric field characteristic of the TE. sub. 01 mode. At least three abutting cylindrical barrier regions are coaxially aligned a arranged symmetrically in mirror image fashion about a radial plane of the circular waveguide. The cylindrical barrier regions include: at least one solid cylindrical plug region sealed in a cross-section of the circular waveguide and having a longitudinal thickness sufficient to withstand a predetermined pressure load, and at least one solid cylindrical tuning region having a radius less than that of the circular waveguide and further having a longitudinal thickness. Each of the cylindrical barrier regions are defined by a characteristic impedance at opposing end faces thereof and a by characteristic impedance between the opposing end faces. A region-by-region impedance analysis process begins with an end face of the arrangement that is furthest from the source and is completed with an end face of the arrangement that is nearest the source.

8228243, Jul 24, 2012

Sep 30, 2009

12/587328

David F. Rivera - Westerly RI, US

The United States of America as represented by the Secretary of the Navy - Washington DC

H01Q 1/24, H01Q 1/48

343702, 343846

The invention as disclosed is a parallel plate antenna having a number of stacked horizontal plates and two vertical plates. Alternating ones of the horizontal plates are electrically coupled to one vertical plate such that the horizontal plates coupled to one vertical plate are interleaved with the horizontal plates coupled to the other vertical plate. The assembled antenna is mounted on a planar mounting flange. The height/width of the antenna is approximately 1/30of a wavelength at the frequency of operation.

6999043, Feb 14, 2006

Oct 8, 2004

10/963002

David F. Rivera - Westerly RI, US

The United States of America as represented by the Secretary of the Navy - Washington DC

H01Q 1/36

343895

An amphibious antenna for providing Near Vertical Incidence Skywave (NVIS) communication when grounded to a conductive fluid. The amphibious antenna has a support member for supporting a helix. The helix includes a first helical arm that is not insulated and grounded, when in use, through a conductive fluid into which the antenna is placed, and a second helical arm that is insulated from the conductive fluid.

6950075, Sep 27, 2005

Dec 8, 2003

10/730185

David F. Rivera - Westerly RI, US

The United States of America as represented by the Secretary of the Navy - Washington DC

H01Q003/00

343762, 343709

An apparatus including a gimbal and an antenna with a hollowed frustum having a closed end and an open end. The antenna includes a feed stem at the closed end extending as an internal rod into the hollowed frustum. The opposite end of the rod connects to a receiver section extending from an edge of the open end beyond a longitudinal axis of the antenna. The antenna is supported by the gimbal attachable to a container suitable for towing. A pivot at the open end in relation to the center-of-gravity of the frustum allows a swinging arc in relation to the attached gimbal in that the frustum moves by gravity toward the axes of the gimbal such that the receiver section maintains a facing position to the force of gravity.

6870508, Mar 22, 2005

Jun 16, 2003

10/463907

David F. Rivera - Westerly RI, US

The United States of America as represented by the Secretary of the Navy - Washington DC

H01Q001/34, H01Q013/10

343709, 343767

A slotted antenna comprises a plurality of loop structures and interconnecting conductors that define a slot. The antennas can operate in a single band or over multiple bands. Flexible or inflatable substrates enable easy storage aboard an underwater craft and facilitate deployment and towing behind an underwater craft with minimal chances of detection.

6859180, Feb 22, 2005

Sep 15, 2003

10/663059

David F. Rivera - Westerly RI, US

The United States of America as represented by the Secretary of the Navy - Washington DC

H01Q001/34, H01Q001/04

343709, 343719

An antenna including a feed tube with radial fins and circular plates at the ends of the tube and fins thereby forming a boundary for a plurality of resonant cavities. Curved plates, connected to the tube by switches of a switching system, partially encompass and subtend to the length of the tube. Interior to the tube, a transmission line from an end plate terminus conducts radio-frequency energy from the terminus to a hub and onto a switch of the switching system in which the switch is mechanically reactive to and actuated by a righting action of the curved plates when the curved plates encounter a sea state. When actuated, energy from the switch distributes to a proximate resonant cavity and curved plate to form a radiation pattern based on the difference in phase of the resonant cavity and curved plate.