Power amplifier of a transmitter

• US 7,288,995 B2
• Filed: 06/15/2005
• Issued: 10/30/2007
• Est. Priority Date: 06/15/2005
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Nokia Corporation
• Inventors: Väisänen, Risto
• Primary Examiner(s): Choe; Henry
• Application Number:
  US11/154,933
• Publication Number:
  US 20060284685A1
• Time in Patent Office: 867 Days
• Field of Search: 330/302, 330/303, 330/305, 330/306, 330/307
• US Class Current: 330/302
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H03F 1/0288 using a main and one or several auxiliary peaking amplifiers whereby the load is connected to the main amplifier using an impedance inverter, e.g. Doherty amplifiers
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 3/26 Push-pull amplifiers; Phase-splitters therefor duplicated single-ended push-pull arrangements or phase-splitters therefor H03F3/30
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H03H 7/42 Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns

Abstract

A power amplifier integrated into an RF-IC (integrated circuit carrying radio frequency signals) comprises an active stage (350) and a passive stage (360), the passive stage being electrically coupled between the active stage and a load of the power amplifier. Electrically conductive elements (305) accomplishing an electrical connection between the active part and the passive part of an RF-IC are designed in a way that the electrically conductive elements perform at least part of impedance transformation on a signal path from signal output terminals of the active stage to signal output terminals of the passive stage.

Claims

1. A power amplifier, comprising:

an active stage that is a subsystem of the power amplifier from a radio frequency input terminal to output terminals of output stage transistors,

a passive stage that is a subsystem of the power amplifier that is electrically coupled between the active stage and a load of the power amplifier;

the power amplifier being integrated into an integrated circuit that comprises the following physical parts;

a base plate, an active part comprising a signal output, a passive part comprising a signal input, and electrically conductive elements for connecting the signal output of the active part to the signal input of the passive part, wherein the electrically conductive elements are disposed to perform at least part of impedance transformation on a signal path from signal output terminals of the active stage to signal output terminals of the passive stage.

2. A power amplifier according to claim 1, wherein the active stage is a two-sided active stage with a 90 degrees phase shift.

3. A power amplifier according to claim 2, wherein the electrically conductive elements are disposed to act as a part of a system performing at least one of the following:

combination of radio frequency-signals from different sides of the two-sided active stage, impedance transformation on a signal path from the signal output terminals of the active stage to the signal output terminals of the passive stage, low-pass filtering.

4. A power amplifier according to claim 1, wherein the active stage is a single-sided active stage.

5. A power amplifier according to claim 4, wherein the electrically conductive elements are disposed to act as a part of a system performing at least one of the following:

impedance transformation on a signal path from the signal output terminals of the active stage to the signal output terminals of the passive stage, low-pass filtering.

6. A power amplifier according to claim 1, wherein the active stage is a push-pull type active stage and the passive stage comprises a balanced to unbalanced transformer, hereinafter balun, comprising an electrical conductor forming a signal input side of the balun and an electrical conductor forming a signal output side of the balun.

7. A power amplifier according to claim 6, wherein the power amplifier comprises a capacitive element in parallel with the signal input side of the balun, and the electrically conductive elements are disposed to perform the impedance transformation in co-operation with said capacitive element.

8. A power amplifier according to claim 6, wherein the electrical conductor forming the signal input side of the balun and the electrically conductive elements are disposed to conduct operating point currents received at a middle node of the signal input side of the balun to signal output terminals of output stage transistors of the push-pull type active stage.

9. A power amplifier according to claim 6, wherein the balun comprises an electrically conductive ground plane common for both the signal input side and the signal output side of the balun, and

the electrical conductor forming the signal input side of the balun is an electrically conductive microstrip that is an integral part of the passive part, and

the electrical conductor forming the signal output side of the balun is an electrically conductive microstrip that is an integral part of the passive part, and

the electrically conductive ground plane of the balun is an integral part of the base plate.

10. A power amplifier according to claim 9, wherein said electrically conductive microstrip forming the signal input side of the balun and said electrically conductive microstrip forming the signal output side of the balun are located on a surface of the passive part that faces towards the base plate and, said electrically conductive ground plane of the balun is located on a surface of the base plate that faces towards the passive part.

11. A power amplifier according to claim 9, wherein said electrically conductive ground plane of the balun is electrically connected with a ground of a circuit board.

12. A power amplifier according to claim 1, wherein the electrically conductive elements are realized with the flip-chip technique.

13. A power amplifier according to claim 1, wherein the electrically conductive elements are realized with the wire-bonding technique.

14. A power amplifier according to claim 9, wherein the distance between the passive part and the base plate is determined by solder bumps between the passive part and the base plate.

15. A power amplifier according to claim 9, comprising one or more spacer elements for determining the distance between the passive part and the base plate.

16. A power amplifier according to claim 9, wherein a surface of the passive part comprises one or more elevated areas for determining the distance between said electrically conductive microstrips and said electrically conductive ground plane.

17. A power amplifier according to claim 9, wherein a surface of the base plate comprises one or more elevated areas for determining the distance between said electrically conductive microstrips and said electrically conductive ground plane.

18. A power amplifier according to claim 6, wherein the power amplifier comprises a capacitive element in parallel with the signal input side of the balun, and the electrically conductive elements between the active and the passive part of the integrated circuit are disposed to form a balanced low-pass filter in co-operation with said capacitive elements.

19. A method for implementing a power amplifier into an integrated circuit comprising the following physical parts of the integrated circuit:

a base plate, an active part, a passive part, and electrically conductive elements for connecting the active part to the passive part, wherein the method comprises designing electromagnetic properties of the electrically conductive elements in a way that impedance transformation on a signal path from signal output terminals of an active stage that is a subsystem of the power amplifier to signal output terminals of a passive stage that is a subsystem of the power amplifier is at least partially performed by the electrically conductive elements.

20. A method according to claim 19, wherein the designing the electromagnetic properties of the electrically conductive elements comprises sizing geometrical dimensions for at least one of the following

the electrically conductive elements,

electrically and magnetically conductive elements within the radio frequency-electromagnetic proximity of the electrically conductive elements,

electrically conductive elements within the radio frequency-electromagnetic proximity of the electrically conductive elements,

magnetically conductive elements within the radio frequency-electromagnetic proximity of the electrically conductive elements.

21. A method according to claim 20, wherein the method comprises realizing the electrically conductive elements with a flip-chip technique and the sizing said geometrical dimensions of the electrically conductive elements comprises selecting lengths, widths, thicknesses, mutual distance of conductors, and shapes of routes of conductors.

22. A method according to claim 20, wherein the method comprises realizing the electrically conductive elements with a wire-bonding technique and the sizing said geometrical dimensions of the electrically conductive elements comprises selecting lengths, thicknesses, mutual distance of conductors, and shapes of routes of conductors.

23. A method according to claim 19, wherein the designing the electromagnetic properties of the electrically conductive elements comprises selection of manufacturing materials for at least one of the following

the electrically conductive elements,

electrically and magnetically conductive elements within the radio frequency-electromagnetic proximity of the electrically conductive elements,

electrically conductive elements within the electromagnetic radio frequency-proximity of the electrically conductive elements,

magnetically conductive elements within the radio frequency-electromagnetic proximity of the electrically conductive elements.

24. A method according to claim 19, comprising realizing a balanced to unbalanced transformer, hereinafter balun, that comprises an electrically conductive ground plane common for both a signal input side and a signal output side of the balun, and

an electrical conductor forming the signal input side of the balun is an electrically conductive microstrip that is an integral part of the passive part, and

an electrical conductor forming the signal output side of the balun is an electrically conductive microstrip that is an integral part of the passive part, and

the electrically conductive ground plane of the balun is an integral part of the base plate.

25. A method according to claim 24, wherein the impedance of the electrically conductive microstrip forming the signal input side of the balun is determined by selecting the width of the electrically conductive microstrip.

26. A method according to claim 24, wherein the impedance of the electrically conductive microstrip forming a signal output side of the balun is determined by selecting the width of the electrically conductive microstrip.

27. A mobile phone, comprising:

a power amplifier comprising an active stage and a passive stage, the active stage being a subsystem of the power amplifier from a radio frequency signal input terminal to output terminals of output stage transistors and the passive stage being a subsystem of the power amplifier that is electrically coupled between the active stage and a load of the power amplifier;

the power amplifier being integrated into an integrated circuit comprising the following physical parts;

a base plate, an active part comprising a signal output, a passive part comprising a signal input, and electrically conductive elements for connecting the signal output of the active part to the signal input of the passive part, wherein the electrically conductive elements are disposed to perform at least part of impedance transformation on a signal path from signal output terminals of the active stage to signal output terminals of the passive stage.

28. A mobile phone according to claim 27, wherein the active stage is a two-sided active stage with a 90 degrees phase shift.

29. A mobile phone according to claim 28, wherein the electrically conductive elements are disposed to act as a part of a system performing at least one of the following:

combination of radio frequency-signals from different sides of the two-sided active stage, impedance transformation on a signal path from the signal output terminals of the active stage to the signal output terminals of the passive stage, low-pass filtering.

30. A mobile phone according to claim 27, wherein the active stage is a single-sided active stage.

31. A mobile phone according to claim 30, wherein the electrically conductive elements are disposed to act as a part of a system performing at least one of the following:

impedance transformation on a signal path from the signal output terminals of the active stage to the signal output terminals of the passive stage, low-pass filtering.

32. A mobile phone according to claim 27, wherein the active stage is a push-pull type active stage and the passive stage comprises a balanced to unbalanced transformer, hereinafter balun, comprising an electrical conductor forming a signal input side of the balun and an electrical conductor forming a signal output side of the balun.

33. A mobile phone according to claim 32, wherein the power amplifier comprises a capacitive element in parallel with the signal input side of the balun, and the electrically conductive elements are disposed to perform the impedance transformation in co-operation with said capacitive element.

34. A mobile phone according to claim 32, wherein the electrical conductor forming the signal input side of the balun and the electrically conductive elements are disposed to conduct operating point currents received at a middle node of the signal input side of the balun to signal output terminals of output stage transistors of the push-pull type active stage.

35. A mobile phone according to claim 32, wherein the balun comprises an electrically conductive ground plane common for both the signal input side and the signal output side of the balun, and

the electrical conductor forming the signal input side of the balun is an electrically conductive microstrip that is an integral part of the passive part, and

the electrical conductor forming the signal output side of the balun is an electrically conductive microstrip that is an integral part of the passive part, and

the electrically conductive ground plane of the balun is an integral part of the base plate.

36. A mobile phone according to claim 35, wherein said electrically conductive microstrip forming the signal input side of the balun and said electrically conductive microstrip forming the signal output side of the balun are located on a surface of the passive part that faces towards the base plate and, said electrically conductive ground plane of the balun is located on a surface of the base plate that faces towards the passive part.

37. A mobile phone according to claim 35, wherein said electrically conductive ground plane of the balun is electrically connected with a ground of a circuit board.

38. A mobile phone according to claim 27, wherein the electrically conductive elements are realized with the flip-chip technique.

39. A mobile phone according to claim 27, wherein the electrically conductive elements are realized with the wire-bonding technique.

40. A mobile phone according to claim 35, wherein the distance between the passive part and the base plate is determined by solder bumps between the passive part and the base plate.

41. A mobile phone according to claim 35, wherein the power amplifier comprises one or more spacer elements for determining the distance between the passive part and the base plate.

42. A mobile phone according to claim 35, wherein a surface of the passive part comprises one or more elevated areas for determining the distance between said electrically conductive microstrips and said electrically conductive ground plane.

43. A mobile phone according to claim 35, wherein a surface of the base plate comprises one or more elevated areas for determining the distance between said electrically conductive microstrips and said electrically conductive ground plane.

44. A mobile phone according to claim 35, wherein the power amplifier comprises a capacitive element in parallel with the signal input side of the balun, and the electrically conductive elements between the active and the passive part of the integrated circuit are disposed to form a balanced low-pass filter in co-operation with said capacitive elements.