US6731173B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Doherty bias circuit to dynamically compensate for process and environmental variations
Assignee: Skyworks Solutions Inc
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Filing: 2001-09-10
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Granted: 2004-05-04
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Expires: 2021-09-10
Abstract
Abstract The invention includes a Doherty power amplifier system having a Doherty power amplifier electrically connected to a Doherty bias circuit. The Doherty amplifier includes a carrier amplifier and peaking amplifier. The Doherty bias circuit includes a current mirror and a first node that works to maintain a constant current in the current mirror as a function of a base voltage at the first node. The base voltage that results in a constant current is passed from a current mirror circuit to the carrier amplifier. The base voltage is at least one of scaled and shifted to produce a second voltage at a second node by employing a scaling/level shifting circuit. The scaling/level shifting circuit includes an input electronically connected to the current mirror circuit. The second voltage is passed through a voltage buffer to the peaking amplifier. An effect of the invention is to generate bias voltages for a Doherty amplifier that dynamically adjust to compensate for manufacturing process and environmental changes.
Inventors
- 👤 Philip H. Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:37
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/30; H03F1/02; H03F1/0205; H03F1/0288
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
69 words
A bias circuit to bias a Doherty amplifier having a carrier amplifier and peaking amplifier, the bias circuit comprising: a current mirror circuit comprising an output electronically connected to the carrier amplifier; a scaling/level shifting circuit comprising an input electronically connected to the current mirror circuit; and a voltage buffer having an input electrically connected to the scaling/level shifting circuit and an output electrically connected to the peaking amplifier.
Claim 2
Dependent Claim
69 words
A bias circuit to bias a Doherty amplifier having a carrier amplifier and peaking amplifier, the bias circuit comprising: a current mirror circuit comprising an output electronically connected to the carrier amplifier; a scaling/level shifting circuit comprising an input electronically connected to the current mirror circuit; and a voltage buffer having an input electrically connected to the scaling/level shifting circuit and an output electrically connected to the peaking amplifier.
Claim 3
Dependent Claim
29 words
The bias circuit of claim 1 , wherein the current mirror comprises a reference device that is electrically connected to the carrier amplifier to form a control current mirror.
Claim 4
Dependent Claim
33 words
The bias circuit of claim 1 , wherein the current mirror comprises a reference device and a voltage follower having a low output impedance electrically connected to an input of the reference device.
Claim 5
Dependent Claim
24 words
The bias circuit of claim 3 , wherein the reference device is electrically connected to the carrier amplifier to form a control current mirror.
Claim 6
Dependent Claim
30 words
The bias circuit of claim 1 , wherein the current mirror comprises a voltage follower having a low output impedance electrically connected to the input of the scaling/level shifting circuit.
Claim 7
Dependent Claim
30 words
The bias circuit of claim 5 , wherein the current mirror further comprises a reference device having an input electrically connected to the low output impedance of the voltage follower.
Claim 8
Dependent Claim
24 words
The bias circuit of claim 6 , wherein the reference device is electrically connected to the carrier amplifier to form a control current mirror.
Claim 9
Dependent Claim
23 words
The bias circuit of claim 1 , wherein the scaling/level shifting circuit further comprises at least two resistors disposed as a voltage divider.
Claim 10
Dependent Claim
24 words
The bias circuit of claim 1 , wherein the scaling/level shifting circuit further comprises an amplifier having a voltage offset source as an input.
Claim 11
Dependent Claim
71 words
A Doherty power amplifier system comprising: a Doherty amplifier having a carrier amplifier and peaking amplifier; and a bias circuit comprising a current mirror circuit comprising an output electronically connected to the carrier amplifier, a scaling/level shifting circuit comprising an input electronically connected to the current mirror circuit, and a voltage buffer having an input electrically connected to the scaling/level shifting circuit and an output electrically connected to the peaking amplifier.
Claim 12
Dependent Claim
71 words
A Doherty power amplifier system comprising: a Doherty amplifier having a carrier amplifier and peaking amplifier; and a bias circuit comprising a current mirror circuit comprising an output electronically connected to the carrier amplifier, a scaling/level shifting circuit comprising an input electronically connected to the current mirror circuit, and a voltage buffer having an input electrically connected to the scaling/level shifting circuit and an output electrically connected to the peaking amplifier.
Claim 13
Dependent Claim
28 words
The system of claim 10 , wherein the current mirror comprises a reference device that is electrically connected to the carrier amplifier to form a control current mirror.
Claim 14
Dependent Claim
32 words
The system of claim 10 , wherein the current mirror comprises a reference device and a voltage follower having a low output impedance electrically connected to an input of the reference device.
Claim 15
Dependent Claim
23 words
The system of claim 12 , wherein the reference device is electrically connected to the carrier amplifier to form a control current mirror.
Claim 16
Dependent Claim
29 words
The system of claim 10 , wherein the current mirror comprises a voltage follower having a low output impedance electrically connected to the input of the scaling/level shifting circuit.
Claim 17
Dependent Claim
29 words
The system of claim 14 , wherein the current mirror further comprises a reference device having an input electrically connected to the low output impedance of the voltage follower.
Claim 18
Dependent Claim
23 words
The system of claim 15 , wherein the reference device is electrically connected to the carrier amplifier to form a control current mirror.
Claim 19
Dependent Claim
22 words
The system of claim 10 , wherein the scaling/level shifting circuit further comprises at least two resistors disposed as a voltage divider.
Claim 20
Dependent Claim
23 words
The system of claim 10 , wherein the scaling/level shifting circuit further comprises an amplifier having a voltage offset source as an input.
Claim 21
Dependent Claim
97 words
A process to bias a Doherty amplifier having a carrier amplifier and peaking amplifier, the process comprising: maintaining a constant current in a current mirror as a function of a base voltage at a first node; passing the constant current from a current mirror circuit to the carrier amplifier; at least one of scaling and shifting the base voltage to produce a second voltage at a second node by employing a scaling/level shifting circuit comprising an input electronically connected to the current mirror circuit; and passing the second voltage through a voltage buffer to the peaking amplifier.
Claim 22
Dependent Claim
97 words
A process to bias a Doherty amplifier having a carrier amplifier and peaking amplifier, the process comprising: maintaining a constant current in a current mirror as a function of a base voltage at a first node; passing the constant current from a current mirror circuit to the carrier amplifier; at least one of scaling and shifting the base voltage to produce a second voltage at a second node by employing a scaling/level shifting circuit comprising an input electronically connected to the current mirror circuit; and passing the second voltage through a voltage buffer to the peaking amplifier.
Claim 23
Dependent Claim
51 words
The process of claim 19 , wherein passing the constant current from a current mirror circuit to the carrier amplifier includes mirroring the constant current through a control current mirror, wherein the control current mirror comprises a reference device within the current mirror that is electrically connected to the carrier amplifier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-05-04 | 2007-11-03 | 2008-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-05-04 | 2011-11-03 | 2012-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-05-04 | 2015-11-03 | 2016-05-04 | $7700.00 | Window Closed / Lapsed |