Abstract: Broadband satellite communications systems using optical feeder links are disclosed. Various optical modulation schemes are disclosed that can provide improved capacity for fixed spot beam, on board beamforming, and ground-based beamforming broadband satellite systems.

Abstract: Systems and methods are described for paired-beam satellite communications in a flexible satellite architecture. Embodiments include one or more “bent pipe” satellites having multiple transponders for servicing a number of spot beams. Implementations include novel types of paired-beam transponders that communicatively couple gateway terminals and user terminals in different spot beams. Some implementations also include loopback transponders that communicatively couple gateway terminals and user terminals in the same spot beam. The transponders can use similar components, can provide for flexible forward-link and return-link spectrum allocation, and/or can provide other features. Certain embodiments further include support for utility gateway terminal service and/or redundancy (e.g., active spares) for one or more active components.

Abstract: Systems and methods are described for paired-beam satellite communications in a flexible satellite architecture. Embodiments include one or more “bent pipe” satellites having multiple transponders for servicing a number of spot beams. Implementations include novel types of paired-beam transponders that communicatively couple gateway terminals and user terminals in different spot beams. Some implementations also include loopback transponders that communicatively couple gateway terminals and user terminals in the same spot beam. The transponders can use similar components, can provide for flexible forward-link and return-link spectrum allocation, and/or can provide other features. Certain embodiments further include support for utility gateway terminal service and/or redundancy (e.g., active spares) for one or more active components.

Abstract: Systems and methods for supporting more flexible coverage areas and spatial capacity assignments using satellite communications systems are disclosed. A hub-spoke, bent-pipe satellite communications system includes: terminals; gateways; a controller for specifying data for controlling satellite operations in accordance with a frame definition including timeslots for a frame and defining an allocation of capacity between forward and return traffic. The satellite communications system may employ a satellite with a feed array assembly and may use on-board beamforming or ground-based beamforming. Beam hopping within timeslots of the frame may be used to provide coverage to different cells in different time periods. The flexible coverage areas may be provided using changes in satellite position, antenna patterns, or beam resource allocations.

Abstract: Systems and methods are described for paired-beam satellite communications in a flexible satellite architecture. Embodiments include one or more “bent pipe” satellites having multiple transponders for servicing a number of spot beams. Implementations include novel types of paired-beam transponders that communicatively couple gateway terminals and user terminals in different spot beams. Some implementations also include loopback transponders that communicatively couple gateway terminals and user terminals in the same spot beam. The transponders can use similar components, can provide for flexible forward-link and return-link spectrum allocation, and/or can provide other features. Certain embodiments further include support for utility gateway terminal service and/or redundancy (e.g., active spares) for one or more active components.

Abstract: Systems and methods are described for paired-beam satellite communications in a flexible satellite architecture. Embodiments include one or more “bent pipe” satellites having multiple transponders for servicing a number of spot beams. Implementations include novel types of paired-beam transponders that communicatively couple gateway terminals and user terminals in different spot beams. Some implementations also include loopback transponders that communicatively couple gateway terminals and user terminals in the same spot beam. The transponders can use similar components, can provide for flexible forward-link and return-link spectrum allocation, and/or can provide other features. Certain embodiments further include support for utility gateway terminal service and/or redundancy (e.g., active spares) for one or more active components.

Abstract: Systems and methods are described for paired-beam satellite communications in a flexible satellite architecture. Embodiments include one or more “bent pipe” satellites having multiple transponders for servicing a number of spot beams. Implementations include novel types of paired-beam transponders that communicatively couple gateway terminals and user terminals in different spot beams. Some implementations also include loopback transponders that communicatively couple gateway terminals and user terminals in the same spot beam. The transponders can use similar components, can provide for flexible forward-link and return-link spectrum allocation, and/or can provide other features. Certain embodiments further include support for utility gateway terminal service and/or redundancy (e.g., active spares) for one or more active components.

Abstract: An improved soft switched AC power distribution system for minimizing electromagnetic interference and AC losses in an AC power distribution system. The improved AC power distribution system comprises a flyback transformer comprising a primary winding and at least one intermediate secondary winding. A synchronization control circuit is connectable to the primary winding while at least one load transformer is connectable to the at least one intermediate secondary winding. The at least one load transformer connectable to the at least one intermediate secondary winding is connectable via an EMI shielded connection with controllable voltage and current rise times.

Abstract: An improved soft switched AC power distribution system for minimizing electromagnetic interference and AC losses in an AC power distribution system. The improved AC power distribution system comprises a flyback transformer comprising a primary winding and at least one intermediate secondary winding. A synchronization control circuit is connectable to the primary winding while at least one load transformer is connectable to the at least one intermediate secondary winding. The at least one load transformer connectable to the at least one intermediate secondary winding is connectable via an EMI shielded connection with controllable voltage and current rise times.

Abstract: Circuit apparatus for controlling a plurality of parallel connected batteries to equally share a common load is shown that includes an n parallel batteries connected to a common load element through a load current monitor that monitors the current through the load element, a battery current monitor for each battery, and a plurality of DC/DC converter circuits having outputs connected in series with each battery respectively. The load current output signal of the load current monitor is scaled down by 1/n, where n is the number of batteries, by a scale down amplifier circuit and distributed as a reference voltage to summing circuits where the scaled down load current is compared to the output of the battery current monitors. The outputs of the summing circuits are respectively connected as control signals to each of the DC/DC converters that are connected to each battery. Each DC/DC converter circuit adjusts it's output voltage to regulate the battery currents to I1 . . .

Abstract: A battery charging system that may advantageously be used to directly charge a battery of a spacecraft, for example. The battery charging system permits charging of the battery without the use of power conditioners or dedicated charging arrays. Primary and secondary solar array strings are coupled by way of a shunt regulator circuit to a power bus, such as a power bus of the spacecraft. A shunt regulator circuit is coupled to the secondary solar array string and to the power bus. Charge control relays are coupled between the secondary solar array string and the battery. A computer is coupled to the shunt regulator circuit and to the charge control relays. Current from the secondary solar array string is used to charge the battery when the charge control relays are closed. If the computer determines that the battery is fully charged, the charge control relays are commanded open and current flows to the power bus unless shunted by the shunt regulator circuit.

Abstract: A system for managing the operation of a battery such as a lithium ion battery having a plurality of serially connected individual cells comprises a bypass module electrically in parallel with each individual cell or, alternatively, with at least one of the cells or alternatively again with an individual cell and its associated grouping of one or more parallel cells. The module includes a sensor for detecting an operating condition of its associated cell and a charger operable for charging the cell. A charge controller is electrically connected with each bypass module and is operable in response to an operating condition of a cell detected by the sensor which is outside a predetermined range of magnitudes to change the bypass module to the conductive mode and thereby shunt current around the battery cell, while leaving unaffected each of the remaining cells.