Predistorter for compensating linearity of an amplifier
AssigneeRichWave Technology Corp.
InventorsChih-Sheng Chen, Pei-Chuan Hsieh
Life of this patent
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Abstract
A predistorter has a first capacitor and an impedance conversion circuit. A first end of the first capacitor is coupled to a first node of the amplifier. The impedance conversion circuit is used to perform an impedance conversion to provide a variable capacitance. The impedance conversion circuit has a first bias input circuit and a bipolar junction transistor (BJT). The first bias input circuit is used to receive a first input bias. A base of the BJT is coupled to an output end of the first bias input circuit and a second end of the first capacitor, a collector of the BJT is floating, and an emitter of the BJT is coupled to a second node of the amplifier.
Claims13
A predistorter for compensating linearity of an amplifier, the predistorter comprising:
- a first capacitor having a first end coupled to a first node of the amplifier;
- a first bias input circuit configured to receive a first bias;
- and
- an impedance conversion circuit configured to perform an impedance conversion to provide a variable capacitance, the impedance conversion circuit comprising:
- a bipolar junction transistor (BJT) having a base coupled to an output end of the first bias input circuit and a second end of the first capacitor, a collector being floating, and an emitter coupled to a second node of the amplifier.
A predistorter for compensating linearity of an amplifier, the predistorter comprising:
- a first capacitor, a first end of the first capacitor being coupled to a first node of the amplifier;
- an impedance conversion circuit configured to perform an impedance conversion to provide a variable capacitance, the impedance conversion circuit comprising:
- a first bias input circuit configured to receive a first bias;
- and
- a diode, an anode of the diode being coupled to an output end of the first bias input circuit and a second end of the first capacitor, and a cathode of the diode being coupled to an input end of a second node of the amplifier;
- and
- a selection circuit configured to select one of a first voltage and a second voltage to be the first bias, wherein the first voltage is a constant voltage, and the second voltage is varied with an input power of the amplifier.
Dependencies are inferred from the claim text.