Stabilized microwave power amplifier system
AssigneeVarian Associates, Inc.
InventorsLarry E. Siegel, John M. Pavkovich, George E. Jahn
Life of this patent
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Abstract
A power amplifier including a klystron is stabilized against variations in output power with a simplified servo-loop system and cooperating temperature compensation. The system is fully solid-state, digital, and includes an operator-presettable initial power selector, a power output sensor, comparator logic, variable attenuation responsive to error signals indicative of deviation from the preset power, and temperature compensation means, for assured accuracy and stability.
Claims23
A stabilized klystron power amplifier system for use with a regulated voltage supply furnishing a regulated voltage, said system comprising:
- a klystron amplifier tube;
- solid-state preamplifier means for driving said klystron, said preamplifier having a variable gain as a function of temperature;
- means for periodically sampling the actual microwave output power from said klystron;
- means for converting said periodic sample to a digital signal representing said actual output power;
- microprocessor means for comparing said digital signal to digital reference signals representative of a reference output power level and generating digital correction signals;
- first solid-state variable attenuator means in series with said preamplifier means for varying the gain of said preamplifier in response to said correction signals;
- means for furnishing a compensation voltage varying inversely to said variable gain in response to changes in ambient temperature, said means accepting said regulated voltage for reference purposes;
- second solid-state variable attenuator means in series with said preamplifier means and responsive to said compensation voltage for varying the gain of said preamplifier accordingly;
- whereby the magnitude of said output power is stabilized at said reference power level.
A stabilized klystron power amplifier system for use with a regulated voltage supply furnishing a regulated voltage, and with a klystron amplifier tube, said system comprising:
- solid-state preamplifier means for driving said klystron, said preamplifier having a variable gain as a function of temperature;
- means for periodically sampling the actual microwave output power from said klystron;
- means for converting said periodic sample to first digital signals representing said actual output power;
- digital encoder means for providing second digital signals representative of a desired power output level, said means including an operator-controlled indicator for selecting said desired output level;
- solid-state digital attenuator means for adjusting the power output of said preamplifier means upwardly or downwardly in accordance with control signals;
- solid-state control signal generator means including a microprocessor for comparing said first and second digital reference signals, and for sensing ambient temperature, said means furnishing said control signals to said attenuator means to control attenuation of said power output as an inverse function of temperature, and to increase or decrease attenuation in accordance with whether said first digital reference signal is less than or greater than said second digital reference signal;
- whereby the magnitude of said actual output power is stabilized at said operator-preselected desired power output level.
Dependencies are inferred from the claim text.