Abstract: A system dedicated to dissipating heat produced by amplifier tubes of a spacecraft comprises a radiating panel installed substantially parallel to the amplifier tubes and thermally coupled to them to radiate to the outside a portion of the heat that they produce, a radiating receptacle whose walls define a housing adapted to receive the collectors of the amplifier tubes, and preferably a heat distributor that is preferably interleaved between the collectors and one wall of the receptacle to distribute the heat that the collectors produce between the collectors and the wall.

Abstract: A system dedicated to dissipating heat produced by amplifier tubes of a spacecraft comprises a radiating panel installed substantially parallel to the amplifier tubes and thermally coupled to them to radiate to the outside a portion of the heat that they produce, a radiating receptacle whose walls define a housing adapted to receive the collectors of the amplifier tubes, and preferably a heat distributor that is preferably interleaved between the collectors and one wall of the receptacle to distribute the heat that the collectors produce between the collectors and the wall.

Abstract: A linearization circuit for a non-linear amplifier optimizes the overall efficiency (>50%). To achieve high efficiency the amplifier is operated in class "E" or class "F" and near saturation, causing phase and amplitude non-linearity. Phase non-linearity is corrected conventionally by a phase error signal generated in a feedback loop. Amplitude non-linearity is corrected by operating on the power supply modulator of the non-linear amplifier in an open loop configuration, using the input signal power. Further, more refined correction of amplitude non-linearity can be effected by operating on an automatic gain control amplifier on the input side of the non-linear amplifier, the gain of the automatic gain control amplifier being controlled by an amplitude error signal generated in a feedback loop.

Abstract: A satellite transponder has the local oscillator in the receiver slaved to a quartz crystal oscillator by a narrowband phase-locked loop during a standby period or in the absence of received signal and by a wideband phase-locked loop immediately the signal is received, at which time the narrowband phase-locked loop is switched out automatically.

Abstract: A phase loop demodulator, in particular for space telecommunications, comprises a primary phase loop, a locking detector circuit responsive to acquisition by the primary loop, and a secondary phase loop controlled by said detector circuit.

Abstract: A Costas loop carrier recovery device with particular application to communications with spacecraft includes a voltage-controlled oscillator. Two filters having different characteristics are connected to the oscillator by a loop filter via two circuits:a direct connection, anda parallel circuit including an amplifier in series with a filter.