Lockheed Martin Corporation

Space Systems/loral, LLC

Leah Wang

Vijaya Korwar Gallagher

Ghislain Turgeon

Anthony C Kowalczyk

Described herein are ground based subsystems, and related methods, for use in transmitting an optical feeder uplink beam to a satellite that is configured to receive the optical feeder uplink beam and in dependence thereon produce and transmit a plurality of RF service downlink beams within a specified RF frequency range to service terminals. Certain embodiments are related to a resource allocator for inclusion in a ground based subsystem, and methods for use therewith. Beneficially, the resource allocator, and methods for use therewith, eliminate any need for a satellite to perform any bandwidth allocation for the plurality of service downlink beams produced and transmitted by the satellite, thereby eliminating any need for the satellite to include an on-board channelizer. Such a recourse allocator can include a plurality of channels each of which can include an encoder and modulator, a channel filter, and a frequency up-converter.

Flexible high throughput satellite system using optical gateways

Described herein are ground based subsystems, and related methods, for use in transmitting an optical feeder uplink beam to a satellite that includes a multiple element antenna feed array and that is configured to accept the optical feeder uplink beam and in dependence thereon use the multiple element antenna feed array to produce and transmit a plurality of radio frequency (RF) service downlink beams to service terminals. Certain embodiments are related to a ground based beamformer (GBBF) for inclusion in a ground based subsystem, and methods for use therewith. Beneficially, embodiments described herein allow for flexible antenna beam forming for large signal bandwidth without the limitation associated with the available gateway uplink and downlink spectrum at RF frequencies. Also described herein are space based subsystems for use with such ground based subsystems.

Satellite system using optical gateways and ground based beamforming

Described herein are ground based subsystems, and related methods, for use in transmitting an optical feeder uplink beam to a satellite that is configured to receive the optical feeder uplink beam and in dependence thereon produce and transmit a plurality of RF service downlink beams within a specified RF frequency range to service terminals. Also described herein are space based subsystems of a satellite, and related methods, for use in transmitting a plurality of RF service downlink beams within a specified RF frequency range to service terminals. Beneficially certain embodiments eliminate the need for any frequency down-converters or any other type of frequency conversion equipment in a space segment forward link equipment. Also described herein is space segment return link equipment, and related methods, for use in transmitting an optical feeder downlink beam to a ground based subsystem, as well as ground based return link equipment thereof.

High throughput satellite system with optical feeder uplink beams and RF service downlink beams

Described herein are space based subsystems of a satellite, and related methods, for use in producing an optical feeder downlink beam in dependence on RF service uplink beams received from service terminals within a specified RF frequency range. Beneficially certain embodiments eliminate the need for any type of frequency conversion equipment in the spaced based subsystem that is used to produce the optical feeder downlink beam. Also described herein are ground based subsystems, and related methods, for use in transmitting an optical feeder uplink beam to a satellite configured to receive the optical feeder uplink beam and in dependence thereon produce and transmit a plurality of RF service downlink beams within a specified RF frequency range to service terminals. Also described herein is are space based subsystems of a satellite, and related methods, for use in transmitting a plurality of RF service downlink beams to service terminals.

High throughput satellite system with RF service uplink beams and optical feeder downlink beams

A satellite comprises an antenna system configured to provide a plurality of spot beams including one or more small spot beams illuminating a first region of a coverage area, one or more large spot beams illuminating a second region of the coverage area separate from the first region and one or more intermediate sized spot beams illuminating a transition region of the coverage area that is located between the first region and the second region so that the one or more small spot beams are separated from the one or more large spot beams by the one or more intermediate sized spot beams. The one or more intermediate sized spot beams serve to mitigate C/I for the one or more spot beams.

Satellite with transition beam size

A device for coupling microwave signals with arbitrary phase shifts and power split ratios over broadband may comprise a first branch comprising a cascade of first stripline sections connected to one another. A second branch may comprise a cascade of second stripline sections connected to one another. A single stripline section and a capacitor may be coupled in series to at least one of the branches. The first stripline sections of the first branch and the corresponding second stripline sections of the second branch form broadside coupled stripline sections. Those cascaded coupled stripline sections may be arranged to have a monotonically changing horizontal offsets but at a uniform vertical distance.

Wide-band microwave hybrid coupler with arbitrary phase shifts and power splits

Negative refractive index (NRI) transmission line (TL) metamaterial may be applied to phase shifter devices. In some aspects, a one dimensional NRI TL enabled compact and tunable phase shifter is provided. The phase shifter comprises cascaded sections of NRI metamaterial TL and positive refraction index TL with tailored dispersion characteristics. The phase shifter, for example as compared to common delay line based or ferrite based phase shifters, may be compact in size, may be continuously tunable from negative to positive phases, may have flatter and more linear phase responses over wideband, may have small group delays, and may be compatible to microwave circuits.

Metamaterial enabled compact wideband tunable phase shifters

An optical modulator apparatus and linearization method are disclosed. The optical modulator may include a buffer layer disposed proximate the electro-optical material substrate. The optical modulator may also include physically asymmetric waveguide elements, which may have physically asymmetric waveguide arms or physically asymmetric hot electrodes. The waveguide arms may include first and second waveguide arms having different dimensions, and the hot electrodes may include first and second hot electrodes having different dimensions. Modulator linearization may be achieved by the above-described modulator structure. Modulator linearization may also be achieved by asymmetric external driving of electric fields applied to the waveguide elements, where the waveguide or electrode dimensions may or may not be symmetric.

Apparatus and method of linearization in an optical modulator

Examples of apparatus and methods are provided for controlling a bias in an optical modulator. An exemplary apparatus may comprise an optical modulator operable to modulate an optical signal. The optical modulation apparatus may comprise a photodetector disposed to receive at least a portion of the modulated optical signal. The optical modulation apparatus may comprise a bias controller coupled to both the optical modulator and the photodetector. The bias controller may be configured to receive a dither signal and to produce a bias feedback signal for the optical modulator. The bias feedback signal may be based on a ratio between an odd order harmonic signal of the modulated optical signal and an even order harmonic signal of the modulated optical signal.

Bias control apparatus and method for optical modulator

A tunable optical filter apparatus and method are disclosed. The apparatus may include a filter driver, a filter device, a detector device and a controller device. The filter driver generates a filter driver signal, including a dither signal. The controller device may be coupled to the detector device, the filter device and the filter driver. The controller device may receive the detector output signal and determine a ratio of the odd order harmonic signal to the even order harmonic signal with respect to the dither frequency. The controller device may also compare the ratio to a predetermined setpoint ratio and generate a control feedback signal for generating a new filter driver signal. The control feedback signal may be based on the comparison of the ratio of the odd order harmonic signal to the even order harmonic signal, to the predetermined setpoint ratio that corresponds to a desired filter operating frequency.

Growing community of inventors

Fremont, CA, United States of America

Leah Wang