Dual oxide gate device and method for providing the same

• US 6,392,488 B1
• Filed: 09/12/2000
• Issued: 05/21/2002
• Est. Priority Date: 09/12/2000
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Paul, Susanne A., Dupuis, Timothy J.
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Choe, Henry
• Application Number:
  US09/659,636
• Time in Patent Office: 616 Days
• Field of Search: 330/277, 330/307, 330/310, 330/311, 330/305, 257/316, 257/315, 257/321, 257/320, 365/187
• US Class Current: 330/277
• CPC Class Codes: H03F 3/193 with field-effect devices H03F3/195 takes precedence
• CPC Class Codes: H03F 3/195 in integrated circuits

Abstract

An RF power amplifier is provided for use with wireless transmission systems such as cellular phones. An RF power amplifier includes direct drive amplifier circuitry operating in a push-pull scheme. The RF power amplifier includes a pair of switching devices driven by a pair of mutually coupled inductive devices. The inductive devices may be magnetically or capacitively coupled together. The RF power amplifier may be formed on a single integrated circuit and include an on-chip bypass capacitor. The RF power amplifier may utilize a voltage regulator for providing a regulated voltage source. The RF power amplifier may be provided using a dual oxide gate device resulting in an improved amplifier. The RF power amplifier may be packaged using flip chip technology and multi-layer ceramic chip carrier technology.

Claims

1. A dual gate oxide CMOS RF power amplifier for a wireless transmission system comprising:

an input stage having pre-driver circuitry comprised of devices with a first gate oxide thickness;

an output stage having amplifier circuitry comprised of devices with a second gate oxide thickness, wherein the first gate oxide thickness is less than the second gate oxide thickness; and

tuning circuitry coupled to the output stage to form a tuned circuit, wherein the tuning circuitry includes an inductor.

2. The power amplifier of claim 1, wherein the first gate oxide thickness is approximately 70 Angstroms.

3. The power amplifier of claim 1, wherein the second gate oxide thickness is approximately 140 Angstroms.

4. The power amplifier of claim 1, wherein the input stage further comprises one or more inverters.

5. The power amplifier of claim 4, wherein the output stage further comprises a plurality of switching devices.

6. The power amplifier of claim 1, further comprising a transformation network that generates a high voltage RF signal suitable for wireless transmissions coupled to the output stage.

7. The power amplifier of claim 1, wherein the amplifier circuitry includes a plurality of switching devices connected together to form a push-pull amplifier circuit.

8. The power amplifier of claim 7, further comprising a bypass capacitor coupled to the push-pull amplifier circuit, wherein the bypass capacitor is formed with the first gate oxide thickness.

9. A method of providing a CMOS RF power amplifier for a wireless transmission system comprising the steps of:

providing an input stage including one or more devices that have a first gate oxide thickness;

providing an output stage including a plurality of switching devices having a second gate oxide thickness;

providing tuning circuitry coupled to the output stage to form a tuned circuit; and

selecting the thickness of the first and second gate oxides such that the second gate oxide thickness is greater than the first gate oxide thickness.

10. The method of claim 9, further comprising the step of forming the RF power amplifier on a single integrated circuit.

11. The method of claim 9, wherein the first gate oxide thickness is approximately 70 Angstroms.

12. The method of claim 9, wherein the second gate oxide thickness is approximately 140 Angstroms.

13. The method of claim 9, wherein the input stage forms a preamplifier circuit.

14. The method of claim 9, wherein the output stage forms a push-pull amplifier circuit.

15. The method of claim 9, further comprising the step of coupling a transformation network to the output stage for generating a high voltage RF signal suitable for wireless transmissions.

16. The method of claim 9, wherein the tuning circuitry is provided with an inductor.

17. The method of claim 9, further comprising the step of providing a bypass capacitor coupled to the output stage, wherein the bypass capacitor is formed with the first gate oxide thickness.

18. A CMOS-based RF power amplifier for a wireless transmission system comprising:

an input stage having a plurality of devices with a first gate oxide thickness;

an amplifier circuit comprised of first and second switching devices coupled between a voltage source and ground, wherein the first and second switching devices have a second gate oxide thickness, wherein the first gate oxide thickness is less than the second gate oxide thickness; and

tuning circuitry coupled to the amplifier circuit to form a tuned circuit.

19. The power amplifier of claim 18, wherein the input stage includes buffer circuitry.

20. The power amplifier of claim 19, wherein the buffer circuitry includes one or more inverters having the first gate oxide thickness.

21. The power amplifier of claim 18, further comprising the step of providing tuning circuitry coupled to the output stage for tuning the power amplifier.

22. The power amplifier of claim 21, wherein the tuning circuitry includes an inductor.