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US 10,673,388 B2Granted
Bias circuit
AssigneeNXP B.V.
InventorsMark Pieter Van Der Heijden, Gerben Willem De Jong, Xin Yang
Life of this patent
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Abstract
A bias circuit for a bipolar RF amplifier is described. The bias circuit includes a current source coupled to a bias network. The bias network supplies a base current to the transistors in the amplifier circuit of the bipolar RF amplifier. The bias circuit includes a buffer coupled to the bias network and to the bipolar RF amplifier. The buffer provides additional base current to the amplifier circuit of bipolar RF amplifier and sinks avalanche current generated by the amplifier circuit of the bipolar RF amplifier.
Claims20
A bias circuit for an RF bipolar amplifier, the bias circuit comprising:
- a first bias circuit terminal configured to be coupled to the base of a transistor in the RF bipolar amplifier;
- a current source;
- a bias network coupled to the current source and the first bias terminal;
- and
- a buffer amplifier having an input coupled to the current source and an output coupled to the first bias circuit terminal;
- wherein the buffer amplifier is configured to at least partially source current provided to the first bias circuit terminal and to sink current from the first bias circuit terminal;
- and wherein the bias network is configured to provide a current to the first bias circuit terminal, wherein the buffer amplifier comprises:
- a current sourcing transistor having a base coupled to the buffer amplifier input and an emitter coupled to the buffer amplifier output,
- a current sink arranged between the buffer amplifier output and common supply rail.
6 more elements
A bias circuit for an RF bipolar amplifier, the bias circuit comprising:
- a first bias circuit terminal configured to be coupled to the base of a transistor in the RF bipolar amplifier;
- a current source;
- a bias network coupled to the current source and the first bias terminal;
- and
- a buffer amplifier having an input coupled to the current source and an output coupled to the first bias circuit terminal;
- wherein the buffer amplifier is configured to at least partially source current provided to the first bias circuit terminal and to sink current from the first bias circuit terminal;
- and wherein the bias network is configured to provide a current to the first bias circuit terminal;
- a second bias terminal coupled to the bias network, wherein the first bias circuit terminal is configured to be coupled to the base of a common-base transistor of a RF bipolar amplifier and the second bias circuit terminal is configured to be coupled to the base of a common-emitter transistor of the RF bipolar amplifier and wherein the bias network is configured to provide a current to the second bias circuit terminal.
5 more elements
A bias circuit for an RF bipolar amplifier, the bias circuit comprising:
- a first bias circuit terminal configured to be coupled to the base of a transistor in the RF bipolar amplifier;
- a current source;
- a bias network coupled to the current source and the first bias terminal;
- and
- a buffer amplifier having an input coupled to the current source and an output coupled to the first bias circuit terminal;
- wherein the buffer amplifier is configured to at least partially source current provided to the first bias circuit terminal and to sink current from the first bias circuit terminal;
- and wherein the bias network is configured to provide a current to the first bias circuit terminal;
- wherein the bias network comprises a bias transistor having a collector coupled to the current source and the buffer amplifier input, an emitter coupled to the common supply rail, a bias resistor arranged between the bias transistor base and the first bias terminal, and a capacitor arranged between the bias transistor collector and the bias transistor base.
5 more elements
A bias circuit for an RF bipolar amplifier, the bias circuit comprising:
- a first bias circuit terminal configured to be coupled to the base of a transistor in the RF bipolar amplifier;
- a current source;
- a bias network coupled to the current source and the first bias terminal;
- and
- a buffer amplifier having an input coupled to the current source and an output coupled to the first bias circuit terminal;
- wherein the buffer amplifier is configured to at least partially source current provided to the first bias circuit terminal and to sink current from the first bias circuit terminal;
- and wherein the bias network is configured to provide a current to the first bias circuit terminal;
- wherein the buffer amplifier comprises:
- an output stage including a series arrangement of a current sourcing transistor and a current sinking transistor between the bias supply voltage rail and the common supply rail;
- a series arrangement of an input transistor and a level-shift diode between the bias supply voltage rail and the current sink transistor;
- wherein the first bias transistor base is coupled to the current sourcing transistor emitter and the current sinking transistor emitter, and the first bias transistor collector is coupled to the current sourcing transistor base and the input transistor base.
8 more elements
The A bipolar RF amplifier comprising:
- a bias circuit comprising:
- a first bias circuit terminal configured to be coupled to the base of a transistor in the RF bipolar amplifier;
- a current source;
- a bias network coupled to the current source and the first bias terminal;
- and
- a buffer amplifier having an input coupled to the current source and an output coupled to the first bias circuit terminal;
- wherein the buffer amplifier is configured to at least partially source current provided to the first bias circuit terminal and to sink current from the first bias circuit terminal;
- and wherein the bias network is configured to provide a current to the first bias circuit terminal;
- wherein the bias circuit further comprises a second bias terminal coupled to the bias network, wherein the first bias circuit terminal is configured to be coupled to the base of a common-base transistor of a RF bipolar amplifier and the second bias circuit terminal is configured to be coupled to the base of a common-emitter transistor of the RF bipolar amplifier and wherein the bias network is configured to provide a current to the second bias circuit terminal.
6 more elements
Dependencies are inferred from the claim text.