Abstract: A satellite communications system having ground user terminals, hubs, and a geosynchronous satellite. The satellite generates a network of spot beam coverage areas on the earth. A hub and at least one ground terminal are located in each of at least two spot beams. A first user terminal transmits an uplink signal according to a first signal protocol to the hub through the satellite. A second user terminal receives a downlink signal according to a second signal protocol through the downlink spot beam from the hub through the satellite. The hub may be located in the same spot beam coverage area as the first or the second user terminal or may be located in an altogether different spot beam coverage area.

Abstract: A satellite communications system having ground user terminals, hubs, and a geosynchronous satellite. The satellite generates a network of spot beam coverage areas on the earth. A hub and at least one ground terminal are located in each of at least two spot beams. A first user terminal transmits an uplink signal according to a first signal protocol to the hub through the satellite. A second user terminal receives a downlink signal according to a second signal protocol through the downlink spot beam from the hub through the satellite. The hub may be located in the same spot beam coverage area as the first or the second user terminal or may be located in an altogether different spot beam coverage area.

Abstract: A distributed parallel processing architecture for electronically steerable multi-element RF array antennas provides real time rapid array updates with decreased hardware cost and complexity. The array is subdivided into plural sub-arrays (each sub-array has more than one RF radiating element) and a phase shift interface electronics ("PIE") device is provided for each sub-array. Parameters specific to the RF elements within the sub-arrays are preloaded into the corresponding PIE. Pointing angle and rotational orientation parameters are broadcasted to the PIEs, which then calculate, in parallel and in a distributed processing manner, the phase shifts associated with the various elements in their corresponding sub-arrays. Linearization, phase compensation for various factors (e.g., operating frequency, measured characteristics of individual RF elements, feed line delay to individual elements, etc.

Abstract: A processor module is one of several modules mounted in a rack to form a programmable controller. The module has a microprocessor that executes a sequence of machine language instructions to interpret and thereby execute macroinstructions that are part of a control program stored in a read/write volatile main memory. The rate of execution is improved by reducing the instructions in a fetch sequence used in coupling each macroinstruction to its interpreter sequence of machine-language instructions. Hardware assistance is provided to allow expansion of macroinstruction operation codes as they are fetched. The processor module also allows the user to program his own interpreter sequences for specially defined macroinstructions and to load these sequences into a nonvolatile memory that is plugged into the module. An external auxiliary power supply is connected to the processor module to supply the programming voltage required by the nonvolatile memory.