1. An RF power amplifier comprising:
a first transistor and a second transistor each being an active device of a push-pull power amplification circuit; and
a transformer being an output matching circuit of the push-pull power amplification circuit,
wherein a non-inverted input signal and an inverted input signal can be supplied respectively to an input terminal of the first transistor and an input terminal of the second transistor,
wherein the transformer has a primary coil and a secondary coil which are magnetically coupled to each other,
wherein one end and the other end of the primary coil of the transformer are coupled respectively to an output terminal of the first transistor and an output terminal of the second transistor,
wherein an output signal can be generated from between one end and the other end of the secondary coil of the transformer, and
wherein the primary coil of the transformer includes at least a first coil and a second coil which are coupled in parallel between the output terminal of the first transistor and the output terminal of the second transistor, and each being magnetically coupled to the secondary coil of the transformer,
wherein the primary coil and the secondary coil of the transformer are formed of respective metal thin-film wires having annular shapes, and each being formed in a flat shape over a surface of a substrate, and
wherein the primary coil of the transformer is formed in a symmetrical shape.
2. An RF power amplifier according to claim 1,
wherein the primary coil of the transformer is supplied with a power supply voltage at a position on an imaginary line of symmetry of the primary coil formed in the symmetrical shape.
3. An RF power amplifier according to claim 1,
wherein the metal thin-film wire forming the primary coil of the transformer is formed to have a width larger than a width of the metal thin-film wire forming the secondary coil of the transformer.
4. An RF power amplifier according to claim 2,
wherein the metal thin-film wire forming the primary coil of the transformer and the metal thin-film wire forming the secondary coil of the transformer are formed around the respective annular shapes, and
wherein the primary coil and the secondary coil of the transformer are set to a predetermined ratio of turns to allow the transformer to execute an output matching operation in accordance with an impedance transformation ratio determined by the ratio of turns.
5. An RF power amplifier according to claim 4,
wherein the first and second coils of the primary coil of the transformer are formed respectively of an outer metal thin-film wire and an inner metal thin-film wire,
each having the annular shape, and
wherein the secondary coil of the transformer is formed of a middle metal thin-film wire formed between the outer metal thin-film wire and the inner metal thin-film wire.
6. An RF power amplifier according to claim 5,
wherein the secondary coil of the transformer formed of the middle metal thin-film wire between the outer metal thin-film wire and the inner metal thin-film wire is formed with a plural number of turns.
7. An RF power amplifier according to claim 4,
wherein the first coil, the secondary coil of the transformer, and the second coil are formed of a multilayer wiring structure formed over the surface of the substrate, and
wherein, in the multilayer wiring structure, the secondary coil of the transformer is interposed between the first coil and the second coil.
8. An RF power amplifier according to claim 4,
wherein the substrate is a semiconductor chip,
wherein the first transistor and the second transistor are formed in the semiconductor chip, and
wherein the transformer is formed as an on-chip transformer on the semiconductor chip.
9. An RF power amplifier according to claim 4,
wherein the substrate having the transformer formed thereover is a wiring substrate,
wherein the first transistor and the second transistor are formed in a semiconductor chip, and
wherein the transformer formed over the wiring substrate is electrically coupled to each of the first transistor and the second transistor which are formed in the semiconductor chip by a coupling wire.
10. An RF power amplifier according to claim 4,
wherein each of the first transistor and the second transistor is a MOS transistor.
11. An RF power amplifier according to claim 2,
wherein the one end and the other end of the primary coil of the transformer which are coupled to the first and second transistors and the one end and the other end of the secondary coil of the transformer between which the output signal can be generated are formed at mutually opposing locations in the annular shapes.
12. An RF power amplifier comprising:
a first transistor and a second transistor each being an active device of a push-pull power amplification circuit; and
a transformer being an output matching circuit of the push-pull power amplification circuit,
wherein a non-inverted input signal and an inverted input signal can be supplied respectively to an input terminal of the first transistor and an input terminal of the second transistor,
wherein the transformer has a primary metal thin-film wire and a secondary metal thin-film wire,
wherein the primary metal thin-film wire and the secondary metal thin-film wire are magnetically coupled to each other, and have respective annular shapes each formed flat over a surface of a substrate,
wherein one end of the primary metal thin-film wire of the transformer is coupled to an output terminal of the first transistor, while the other end of the primary metal thin-film wire of the transformer is coupled to an output terminal of the second transistor,
wherein an output signal can be generated from between one end and the other end of the secondary metal thin-film wire of the transformer,
wherein the one end and the other end of the primary metal thin-film wire of the transformer and the one end and the other end of the secondary metal thin-film wire of the transformer are formed respectively in a first portion and a second portion of each of the annular shapes,
wherein, in the first portion of the annular shape, the one end and the other end of the primary metal thin-film wire of the transformer are disposed proximate to each other while, in the second portion of the annular shape, the one end and the other end of the secondary metal thin-film wire of the transformer are disposed proximate to each other,
wherein the primary metal thin-film wire of the transformer includes at least a first wire and a second wire which are coupled in parallel between the output terminal of the first transistor and the output terminal of the second transistor, and each being magnetically coupled to the secondary metal thin-film wire,
wherein the primary metal thin-film wire and the secondary metal thin-film wire of the transformer are formed in respective symmetrical shapes each with respect to an imaginary line coupling the first portion and the second portion to each other.
13. An RF power amplifier according to claim 12,
wherein the primary metal thin-film wire of the transformer is supplied with a power supply voltage at a position on an imaginary line of symmetry of the primary metal thin-film wire of the transformer formed in the symmetrical shape.
14. An RF power amplifier according to claim 13,
wherein the primary metal thin-film wire of the transformer is formed to have a width larger than a width of the secondary metal thin-film wire of the transformer.
15. An RF power amplifier according to claim 14,
wherein the first portion and the second portion of each of the annular shapes which oppose each other.
16. An RF power amplifier according to claim 14,
wherein the primary metal thin-film wire of the transformer and the secondary metal thin-film wire of the transformer are formed around the respective annular shapes, and
wherein the primary metal thin-film wire of the transformer and the secondary metal thin-film wire of the transformer are set to a predetermined ratio of turns to allow the transformer to execute an output matching operation in accordance with an impedance transformation ratio determined by the ratio of turns.
17. An RF power amplifier according to claim 13,
wherein the number of turns of the secondary metal thin-film wire of the transformer is set to generally be an integral multiple of the number of turns of the primary metal thin-film wire of the transformer.
18. An RF power amplifier according to claim 12,
wherein the first wire and the second wire of the primary metal thin-film wire of the transformer are formed respectively of an outer metal thin-film wire and an inner metal thin-film wire, each having the annular shape, and
wherein the secondary metal thin-film wire of the transformer is formed of a middle metal thin-film wire formed between the outer metal thin-film wire and the inner metal thin-film wire.
19. An RF power amplifier according to claim 18,
wherein the secondary metal thin-film wire of the transformer formed of the middle metal thin-film wire between the outer metal thin-film wire and the inner metal thin-film wire is formed with a plural number of turns.
20. An RF power amplifier according to claim 17,
wherein the first wire, the secondary metal thin-film wire, and the second wire are formed of a multilayer wiring structure formed over the surface of the substrate, and
wherein, in the multilayer wiring structure, the secondary metal thin-film wire of the transformer is interposed between the first wire and the second wire.
21. An RF power amplifier according to claim 17,
wherein the substrate is a semiconductor chip,
wherein the first transistor and the second transistor are formed in the semiconductor chip, and
wherein the transformer is formed as an on-chip transformer on the semiconductor chip.
22. An RF power amplifier according to claim 17,
wherein the substrate having the transformer formed thereover is a wiring substrate,
wherein the first transistor and the second transistor are formed in a semiconductor chip, and
wherein the transformer formed over the wiring substrate is electrically coupled to each of the first transistor and the second transistor which are formed in the semiconductor chip by a coupling wire.
23. An RF power amplifier according to claim 17,
wherein each of the first transistor and the second transistor is a MOS transistor.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
We claim:
1. A gas turbine engine component comprising one or more surfaces wherein at least one of said surfaces comprises an ultrasonic hammer peened surface and wherein a region of deep compressive residual stress caused by ultrasonic hammer peening is provided in said treated surface.
2. A gas turbine engine component as claimed in claim 1 wherein said component is a gas turbine engine aerofoil blade or vane comprising a leading edge and a trailing edge.
3. A gas turbine engine component as claimed in claim 2 wherein said leading and trailing edges comprise said hammer peened surface wherein a region of deep compressive residual stress is caused by ultrasonic hammer peeing is provided in at least one of said leading and trailing edges.
4. A gas turbine engine component as claimed in claim 3 wherein said aerofoil blade or vane comprises a fan blade.
5. A gas turbine engine component as claimed in claim 3 wherein said region of deep compressive residual stress extends up to 20% of the chord width on both the pressure side and suction side of the blade or vane.
6. A method of ultrasonic hammer peening a gas turbine engine component comprising the step of ultrasonic hammer peening at least one surface of said component so as to provide a region of deep residual compressive stress.
7. A method of ultrasonic hammer peening a gas turbine aerofoil blade or vane comprising the step of ultrasonic hammer peening at least one of the leading and trailing edges of said blade or vane on at least one of the suction and pressure sides thereof.
8. A method of ultrasonic hammer peening a gas turbine aerofoil blade or vane wherein both the pressure side and suction side of the blade is ultrasonic hammer peened simultaneously.
9. A method of ultrasonic hammer peening according to claim 6 wherein said ultrasonic hammer peening apparatus vibrates at a frequency greater than 20 kHz.
10. A method of ultrasonic hammer peening as claimed in claim 6 wherein the ultrasonic hammer peening apparatus operates at a power of up to 5 kW.