Process and device for compensation of phase instabilities of the wave amplified by a microwave tube
AssigneeThomson-CSF
InventorGilles Cote
Life of this patent
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Abstract
The voltage variation between the electrodes of the tube of a microwave amplifier (1) causing a phase Shift of the output wave from the microwave amplifier (1), the process according to the invention consists of creating a phase shift of the wave entering the tube of the microwave amplifier (1) that is substantially proportional to the voltage variation and in the direction opposite the phase shift of the output wave caused by this voltage variation.
Claims7
A process for compensating voltage variation between the electrodes of a microwave amplifier tube, the voltage variation (.DELTA.V) causing a phase shift (.DELTA..psi.) of the output wave of the microwave amplifier, the phase shift governed by the equation
- .DELTA..psi.=.lambda..DELTA.V
- wherein .lambda., is a coefficient of proportionality of the microwave amplifier tube, and is a positive real number, the process comprising the steps:
- biasing a positive input of a separate amplifier with a voltage nominally equal to the normal operating voltage of the microwave amplifier tube;
- driving a negative input of the separate amplifier with a signal corresponding to .DELTA.V, thereby creating a separate amplifier output proportional to the voltage difference between the positive and negative inputs;
- creating a linear phase shift in response to the separate amplifier output, and expressed as
- .DELTA..psi.'=kG.DELTA.V
- wherein k is the transfer function of a phase shifter, and G is the gain of the separate amplifier, the phase shift being substantially proportional to .DELTA.V and in a direction opposite a phase shift of the output wave from the microwave amplifier tube;
- and
- inputting a wave undergoing the created linear phase shift to an input of the microwave amplifier tube.
A circuit for compensating voltage variation between the electrodes of a microwave amplifier tube, the voltage variation (.DELTA.V) causing a phase shift (.DELTA..psi.) of the output wave of the microwave amplifier, the phase shift governed by the equation
- .DELTA..psi.=.lambda..DELTA.V
- wherein .lambda. is a coefficient of proportionality of the microwave amplifier tube, and is a positive real number, the circuit comprising:
- a separate amplifier having a positive input biased with a reference voltage nominally equal to the normal operating voltage of the microwave amplifier tube;
- a negative input of the separate amplifier driven with a signal corresponding to .DELTA.V, thereby creating a separate amplifier output proportional to the voltage difference between the positive and negative inputs;
- a phase shifter having a first input carrying the wave to be amplified;
- a second input thereof connected to the separate amplifier output for creating a linear phase shift, by the shifter, in response to the separate amplifier output, and expressed as
- .DELTA..psi.'=kG.DELTA.V
- wherein k is the transfer function of the phase shifter, and G is the gain of the separate amplifier, the phase shift being substantially proportional to .DELTA.V and in a direction opposite the phase shift of the output wave from the microwave amplifier tube;
- and
- an output of the phase shifter being connected to an input of the microwave amplifier tube.
Dependencies are inferred from the claim text.