Constant current bias circuit and associated method
AssigneeTriQuint Semiconductor, Inc.
InventorWilliam H. Davenport
Life of this patent
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Abstract
A constant current bias circuit and associated method is disclosed. The constant current bias circuit comprises an output stage for amplifying a radio frequency (RF) signal, wherein the output stage is operably coupled with a voltage. The constant current bias circuit further comprises a bias circuit operably coupled with the output stage for generating a substantially constant current bias to the output stage. The constant current bias circuit still further comprises a plurality of bias transistors operably coupled with the voltage and the output stage.
Claims18
A constant current bias circuit, comprising:
- an output stage operably coupled with a first voltage, for amplifying a radio frequency (RF) signal;
- and
- a bias circuit operably coupled with the output stage, wherein the bias circuit comprises:
- a first bias transistor having a base and a collector, the collector of the first bias transistor operably coupled with a second voltage through a first impedance element;
- a second bias transistor having a base, a collector, and an emitter, the base of the second bias transistor operably coupled with the collector of the first bias transistor, the collector of the second bias transistor operably coupled with the second voltage, and the emitter of the second bias transistor operably coupled with a ground through a second impedance element;
- a third bias transistor having a base and a collector, the base of the third bias transistor operably coupled with the base of the first bias transistor and with the emitter of the second bias transistor;
- and
- a fourth bias transistor having a base, a collector, and an emitter, the base of the fourth bias transistor operably coupled with the collector of the first bias transistor, the collector of the fourth bias transistor operably coupled with the second voltage through a third impedance element, and the emitter of the fourth bias transistor operably coupled with the collector of the third bias transistor.
A wireless device comprising:
- a transmitter for transmitting RF signals, the transmitter comprising:
- an output power amplifier stage;
- and
- a bias circuit operably coupled with the output power amplifier stage, wherein the bias circuit comprises:
- a first bias transistor having a base and a collector, the collector of the first bias transistor operably coupled through a first impedance element to a voltage;
- a second bias transistor having a base, a collector, and an emitter, the base of the second bias transistor operably coupled with the collector of the first bias transistor, the collector of the second bias transistor operably coupled with the voltage, and the emitter of the second bias transistor operably coupled through a second impedance element to a ground;
- a third bias transistor having a base and a collector, the base of the third bias transistor operably coupled with the base of the first bias transistor and to the emitter of the second bias transistor;
- and
- a fourth bias transistor having a base, a collector, and an emitter, the base of the fourth bias transistor operably coupled with the collector of the first bias transistor, the collector of the fourth bias transistor operably coupled through a third impedance element to the voltage, and the emitter of the fourth bias transistor operably coupled with the collector of the third bias transistor;
- and a battery connected to the transmitter of the wireless device.
Dependencies are inferred from the claim text.