Abstract: One embodiment of the present invention relates to a system for correcting spacecraft thermal distortion pointing errors. The system comprises one or more spacecraft sensors located at positions on a spacecraft and which are adapted to measure spacecraft parameters at those positions. The system also includes a spacecraft distortion prediction module, which is adapted to generate expected spacecraft thermal distortion parameter values and expected antenna thermal distortion pointing errors. Further, the system includes a spacecraft parameter processing module adapted to generate measured spacecraft thermal distortion parameter values from the measured spacecraft parameters, and an antenna pointing error calculation module adapted to calculate antenna pointing error correction commands. Finally, the system includes an antenna pointing control module adapted to receive the antenna pointing correction commands and control the adjustment of the antenna pointing using the correction commands.

Abstract: A traveling wave tube (TWT) amplifier includes a beam forming electrode (BFE) and a BFE modulator having a bias-based keyer so that the TWT amplifier signals are keyed off during periods when RF power is not to be amplified. Biasing the beam forming electrode voltage off relative to cathode voltage effectively shuts down the electron beam without shutting down the power supply minimizes power supply stress and significantly improves reliability, so that low-level RF signal input is not amplified, and no significant RF power is output. Likewise, given that no amplification has taken place, no power associated with the TWT amplification function is consumed. Thus, the only power consumed by the TWT amplifier is that associated with the cathode heater and the electronic power conditioner (EPC) used as the electron beam source.

Abstract: A traveling wave tube (TWT) amplifier includes a beam forming electrode (BFE) and a BFE modulator having a bias-based keyer so that the TWT amplifier signals are keyed off during periods when RF power is not to be amplified. Biasing the beam forming electrode voltage off relative to cathode voltage effectively shuts down the electron beam without shutting down the power supply minimizes power supply stress and significantly improves reliability, so that low-level RF signal input is not amplified, and no significant RF power is output. Likewise, given that no amplification has taken place, no power associated with the TWT amplification function is consumed. Thus, the only power consumed by the TWT amplifier is that associated with the cathode heater and the electronic power conditioner (EPC) used as the electron beam source.