Self equalizing multi-stage radio frequency power amplifier
First Claim
1. In a radio frequency power amplifier circuit having a driver stage coupled to a high power stage, each stage having an input and an output which contains intermodulation distortion output components, the improvement comprising:
- circuit means for internally defining the intermodulation distortion components of the output of the driver stage such that such components are 180°
out of phase with the intermodulation distortion components of the output of the high power stage whereby the intermodulation distortion component outputs of the two stages will subtract from or cancel each other.
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Accused Products
Abstract
Linearity and efficiency of a radio frequency multi-stage power amplification device 10 are increased by employing two tuned circuits 16 and 18 in the driver stage 12 and two tuned circuits 22 and 24 in the high power stage 14. After selecting elements of tuned circuits 22 and 24 in order to optimize the high power stage 14 for efficiency, linearity, and power output, elements are selected for tuned circuits 16 and 18 in order to cause the intermodulation output components associated with the driver state 12 to have a 180° phase angle relative to the intermodulation output components associated with the high power stage 14. This phase angle relationship will cause the intermodulation output component products from the driver 12 and high power stages 14 to cancel.
42 Citations
16 Claims
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1. In a radio frequency power amplifier circuit having a driver stage coupled to a high power stage, each stage having an input and an output which contains intermodulation distortion output components, the improvement comprising:
circuit means for internally defining the intermodulation distortion components of the output of the driver stage such that such components are 180°
out of phase with the intermodulation distortion components of the output of the high power stage whereby the intermodulation distortion component outputs of the two stages will subtract from or cancel each other.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A power amplification circuit comprising:
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(a) a driver stage having an input and output, and including; (1) a transistor having an input and output; (2) an input tuned circuit connected to the input of said transistor; (3) an output tuned circuit connected to said output of said transistor; (4) biasing means connected to said transistor for biasing said transistor; and (5) capacitive circuit means connected to said input and to said output of said driver stage to block direct current; (b) a high power stage, having an input and output, and including; (1) capacitive circuit means connected to the input and to the output of the high power stage to block direct current; (2) a dual transistor push-pull amplifier circuit, having an input and output,; (3) an output tuned circuit having an input and output wherein said input is connected to the output of the push-pull dual transistor amplifier; (4) an input tuned circuit having an input and output wherein said output is connected to the input of the push-pull dual transistor amplifier; (5) biasing means for biasing the transistors in the dual transistor push-pull amplifier circuit; and (6) first hybrid circuit means connected to the input of the input tuned circuit to balance an input signal and second hybrid circuit means connected to the output of the output tuned circuit to convert an output signal from balanced to single ended; (c) a circulator device connecting the output of the driver stage to the input of the high power stage to provide electrical isolation; and (d) said tuned circuits in the driver stage having elemental values chosen to cause the intermodulation distortion components of the output of the driver stage to have a phase angle which is 180°
opposite from the phase angle associated with the intermodulation distortion components of the output of the high power stage. - View Dependent Claims (10, 11)
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12. A method of combining stages of a multi-stage solid state radio frequency power amplifier together in order to eliminate intermodulation components associated therewith, said multi-stage amplifier containing a driver stage and a high power stage each having an input and output, and wherein said intermodulation components are attributable to the output of each of the individual stages, said method comprising:
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(a) tuning the high power stage for efficiency, linearity and power output; and (b) tuning the driver stage such that the intermodulation components which are produced are of alternate phase angle than the intermodulation components produced in the high power stage such that the intermodulation output components of the stages will subtract from each other or cancel. - View Dependent Claims (13, 14, 15, 16)
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Specification