Multiport amplifiers in communications satellites
First Claim
1. A method of adjusting the gain and/or phase characteristics of a multiport amplifier of a communications satellite to improve the isolation of signals within the multiport amplifier, the multiport amplifier comprising a plurality of microwave power amplifier units, a plurality of input ports and a plurality of output ports, the input ports being connected to said amplifier units by an input signal dividing network, and the output ports being connected to said amplifier units by an output signal dividing network, so that an input signal at any input port is amplified by all amplifier units, and then recombined into an output signal at an output port, the method comprising:
- providing at least one of said amplifier units with gain adjuster and phase adjuster,providing input signals to at least some of said input ports, and detecting resultant output signals at least some of said output ports,providing detected versions of said output signals to a multiport amplifier emulator, said emulator comprising a model of the multiport amplifier, the model having modifiable characteristics to determine what characteristics of the multiport amplifier would produce the detected versions of the output signals from the input signals so as to enable cross-talk components within said detected versions to be assessed, and, in response thereto,issuing as required adjusting commands to said gain adjuster and/or phase adjuster.
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Accused Products
Abstract
In order to maintain isolation of signals within a multiport amplifier of a communications satellite and to reduce cross-talk components, by monitoring communications signals passing through the multiport amplifier, output signals of the multiport amplifier are sensed and downconverted to baseband, and applied to an emulator mechanism of the multiport amplifier. The emulator mechanism comprises a reverse matrix of the multiport amplifier, which recovers the input signals of the multiport amplifier together with cross-talk components, and a digital signal processor which carries out a frequency analysis of the cross-talk components by means of an FFT, and employs a digital model of the multiport amplifier to determine the state of the multiport amplifier which gives rise to such cross-talk components. The digital signal processor may be located at a ground station to which communication is made via a telemetry link.
15 Citations
20 Claims
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1. A method of adjusting the gain and/or phase characteristics of a multiport amplifier of a communications satellite to improve the isolation of signals within the multiport amplifier, the multiport amplifier comprising a plurality of microwave power amplifier units, a plurality of input ports and a plurality of output ports, the input ports being connected to said amplifier units by an input signal dividing network, and the output ports being connected to said amplifier units by an output signal dividing network, so that an input signal at any input port is amplified by all amplifier units, and then recombined into an output signal at an output port, the method comprising:
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providing at least one of said amplifier units with gain adjuster and phase adjuster, providing input signals to at least some of said input ports, and detecting resultant output signals at least some of said output ports, providing detected versions of said output signals to a multiport amplifier emulator, said emulator comprising a model of the multiport amplifier, the model having modifiable characteristics to determine what characteristics of the multiport amplifier would produce the detected versions of the output signals from the input signals so as to enable cross-talk components within said detected versions to be assessed, and, in response thereto, issuing as required adjusting commands to said gain adjuster and/or phase adjuster. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A multiport amplifier arrangement for a communications satellite, comprising:
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a plurality of microwave power amplifier units; a plurality of input ports and a plurality of output ports, the input ports being connected to said amplifier units by an input signal dividing network, the output ports being connected to said amplifier units by an output signal dividing network, so that an input signal at any input port is amplified, by all amplifier units, and then recombined into an output signal at an output port, and at least one of said amplifier units having gain adjuster and phase adjuster; a detector for detecting output signals at said output ports and for providing detected versions of said detected output signals to a multiport amplifier emulator, said emulator comprising a model of the multiport amplifier, the model having modifiable characteristics to determine what characteristics of the multiport amplifier would produce the detected versions of the output signals from the input signals so as to enable cross-talk components within said detected versions to be assessed, and being arranged to provide adjusting commands to said gain adjuster and/or phase adjuster. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification