Sudhakar M Rao, 69Fulton, MD

6937203, Aug 30, 2005

Nov 14, 2003

10/714421

Sudhakar K. Rao - Yardley PA, US
James Wang - Yardley PA, US
Joel A. Fink - Torrence CA, US

The Boeing Company - Chicago IL

H01Q013/00

343786, 343772, 333 21 A, 333125

An antenna comprising a reflector having a reflector surface profile for reflecting a plurality of signals comprising a plurality of communication bands; a multi-depth corrugated horn assembly for receiving the signal comprising the plurality of communication bands; a stepped waveguide coupled to the corrugated horn; a first polarizer coupled to the stepped waveguide for separating a first communication band from the plurality of communication bands; a second polarizer coupled to the stepped waveguide for separating a second communication band from the plurality of communication bands; and a third polarizer coupled to the stepped waveguide for separating a third communication band from the plurality of communication bands. The antenna can simultaneously operate in the K, Ka and EHF frequency bands. Extension of this antenna to include five separate frequency bands is demonstrated.

7382743, Jun 3, 2008

Jan 6, 2005

11/029364

Sudhakar Rao - Churchville PA, US
Mysore Sheshadri - Princeton Junction NJ, US
Jim Wang - Yardley PA, US

Lockheed Martin Corporation - Bethesda MD

H04B 7/185
H04Q 7/00

370316, 370334

Antenna system and methodology for producing multiple interleaved beams using a hybrid frequency-reuse scheme. In particular, depending on the traffic demand in specific coverage areas, some beams are assigned with frequency channels in accordance with a 4-cell frequency-reuse scheme, and the other beams are assigned with frequency channels in accordance with a 7-cell frequency-reuse scheme. The antenna system has multiple feeds divided into clusters, and a number of reflectors fed by respective feed clusters and configured to form one beam for each of the feeds.

7463207, Dec 9, 2008

Nov 8, 2006

11/594157

Sudhakar Rao - Churchville PA, US
Mihn Tang - Yardley PA, US

Lockheed Martin Corporation - Bethesda MD

H01Q 13/00

343786, 343783, 343779

A multiple-beam antenna system includes at least one reflector and a cluster of horns for feeding the reflector. A horn of the cluster of horns is configured for providing transmission and reception of signals over respective transmission and reception frequency bands. The horn includes a substantially conical wall having an internal surface with a variable slope. The internal surface of the substantially conical wall includes slope discontinuities. At least one of the slope discontinuities has a diameter greater than 1. 7 times the wavelength of the lowest frequency of the transmission frequency band. The diameter is also greater than 1. 7 times the wavelength of the highest frequency of the transmission frequency band. In addition, the diameter is greater than 1. 7 times the wavelength of the lowest frequency of the reception frequency band, and the diameter is greater than 1.

7598919, Oct 6, 2009

Jun 6, 2006

11/446974

Sudhakar K. Rao - Churchville PA, US
Clency Lee-Yow - Longmont CO, US
Philip Venezia - Longmont CO, US
Rodolfo Lozano, Jr. - San Diego CA, US
David V. Gardner - Newtown PA, US
Joseph T. Durcanin - Newtown PA, US

Lockheed Martin Corporation - Bethesda MD

H01Q 13/02

343786, 343703

A pick-up horn for absorbing radiation emitted by a transmit antenna is provided. The pick-up horn includes at least one outer metal wall forming a metal body and at least one interior surface disposed in the metal body, forming at least one chamber in the metal body. The pick-up horn further includes a front metal surface disposed at a front end of the metal body, having at least one opening corresponding to the at least one chamber, and at least one high-power absorbing load disposed within the at least one chamber and in contact with the at least one interior surface. The pick-up horn may further include a serpentine coolant path disposed within the metal body between an outer surface of the at least one outer metal wall and the at least one high-power absorbing load.

7692593, Apr 6, 2010

Apr 18, 2008

12/106222

Sudhakar K. Rao - Churchville PA, US
Clency Lee-Yow - Longmont CO, US
Philip Venezia - Longmont CO, US
Mark W. MacGregor - Wyndmoor NJ, US

Lockheed Martin Corporation - Bethesda MD

H01Q 13/02

343703, 343786

Methods, systems, and apparatus are disclosed for high power thermal vacuum testing of satellite payloads using pick-up horns. Such pick-up horns can include at least one outer metal wall forming a metal body and at least one interior surface disposed in the metal body, forming at least one chamber in the metal body. The pick-up horn further includes a front metal surface disposed at a front end of the metal body, having at least one opening corresponding to the at least one chamber, and at least one high-power absorbing load disposed within the at least one chamber and in contact with the at least one interior surface. A pick-up horn may further include a serpentine coolant path disposed within the metal body between an outer surface of the at least one outer metal wall and the at least one high-power absorbing load. Related systems and methods are described.

7710340, May 4, 2010

Jul 5, 2006

11/480497

Sudhakar K. Rao - Churchville PA, US
Stephen R. Peck - Yardley PA, US
Minh Tang - Yardley PA, US
Jim Wang - Churchville PA, US
David M. Brown - Upper Makefield PA, US

Lockheed Martin Corporation - Bethesda MD

H01Q 13/00

343781R, 343778, 343779

An antenna system for generating and configuring at least one defocused beam is provided. The antenna system includes a reflector having a focal plane and a non-parabolic curvature for forming the at least one defocused beam, and a plurality of feed antennas that illuminate the reflector. Each feed antenna is disposed in the focal plane of the reflector. The antenna system further includes at least one incoming signal dividing network that divides at least one incoming signal into a plurality of sub-signals, each corresponding to one of the feed antennas, a plurality of variable phase shifters, each receiving one of the sub-signals from the incoming signal dividing network and phase shifting the sub-signal to generate a corresponding phase-shifted sub-signal, and a plurality of fixed-amplitude amplifiers, at least one corresponding to each of the feed antennas. The at least one amplifier for each feed antenna amplifies the corresponding phase-shifted sub-signal to generate an amplified phase-shifted sub-signal which is provided to the corresponding feed antenna.

7737903, Jun 15, 2010

Mar 2, 2006

11/365487

Sudhakar K. Rao - Churchville PA, US
Minh Tang - Yardley PA, US

Lockheed Martin Corporation - Bethesda MD

H01Q 13/00

343786, 343753, 343840, 343909

A stepped reflector for being illuminated by at least one multiple-band feed is provided. The reflector includes a central region and a first annular region with an annular width of w. The first annular region is axially stepped a height h above the central region, where h is approximately equal toThe central region and the annular region of the reflector may be parabolically curved or may alternately be shaped. The reflector may be fed by one or more multiple-band horn antennas.

7737904, Jun 15, 2010

Jun 11, 2008

12/137472

Sudhakar K. Rao - Churchville PA, US
Chris G. Baran - Hamilton NJ, US
Chih-Chien Hsu - Cherry Hill NJ, US
Surjit S. Dhillon - Robbinsville NJ, US

Lockheed Martin Corporation - Bethesda MD

H01Q 13/00

343786, 343772, 343779

An antenna system for transmitting and/or receiving radio frequency (RF) signals in multiple frequency bands includes a horn antenna and a feed network. The horn antenna may transmit and/or receive RF signals in multiple frequency bands that are spread over more than an octave bandwidth with at least a 2. 44-to-1 bandwidth ratio. The horn antenna includes a throat, an aperture, and an interior surface. The feed network includes a first waveguide section, a first junction, one or more first filters, and a first step-down waveguide section. The first waveguide section can provide a matching network and transmit and/or receive the RF signals in the multiple frequency bands. The first junction can transmit and/or receive the RF signals in first selected band(s) of the multiple frequency bands. The first step-down waveguide section may transmit and/or receive the RF signals in second selected band(s) of the multiple frequency bands.