RF amplifying device

1. An RF amplifying device comprising:

a power transistor for generating transmission power to be fed to an antenna of a wireless device; and

a transmission line transformer which uses an inductive capacitive coupling and which is thereby coupled to an output electrode of the power transistor,

wherein the transmission line transformer includes a main line, and a secondary line,

wherein the transmission power from the output electrode of the power transistor is fed to one end of the main line while one end of the secondary line is coupled to an AC grounding node,

wherein the other end of the secondary line is coupled to the one end of the main line, thereby generating the transmission power to be fed to the antenna from the other end of the main line,

wherein coupling energy is transmitted from the secondary line to the main line at an energy coupling part where the main line of the transmission line transformer is in close proximity of, and opposite to the secondary line, and

wherein coupling members electrically coupled to the output electrode of the power transistor are electrically coupled to a joint formed in either the main line, or the secondary line, at part of the energy coupling part.

2. The RF amplifying device according to claim 1 ,

wherein an operating voltage differing in level from a ground voltage level is applied to the AC grounding node at the one end of the secondary line, thereby causing the operating voltage to be fed to the output electrode of the power transistor via the secondary line.

3. The RF amplifying device according to claim 1 ,

wherein both the main line and the secondary line of the transmission line transformer are comprised of multilevel interconnections formed over an insulated board.

4. The RF amplifying device according to claim 3 ,

wherein the power transistor is formed over a semiconductor chip,

wherein the coupling members electrically coupled to the output electrode of the power transistor formed over the semiconductor chip are either bonding wires, or bonding balls, and

wherein the joint electrically coupled to the coupling members and formed in the part of the energy coupling part is a bonding pad joint formed over the insulated board.

5. The RF amplifying device according to claim 1 ,

wherein the power transistor, and both the main line and the secondary line of the transmission line transformer are formed over a semiconductor substrate of a monolithic microwave integrated circuit.

6. The RF amplifying device according to claim 1 ,

wherein the power transistor is either a hetrojunction bipolar transistor, or an LDMOS.

7. An RF amplifying device comprising:

a power transistor for generating transmission power to be fed to an antenna of a wireless device; and

a transmission line transformer coupled to an output electrode of the power transistor,

wherein the transmission line transformer includes a main line, and a secondary line,

wherein the transmission power from the output electrode of the power transistor is fed to one end of the main line while one end of the secondary line is coupled to an AC grounding node,

wherein the other end of the secondary line is coupled to the one end of the main line, thereby generating the transmission power to be fed to the antenna from the other end of the main line,

wherein coupling energy is transmitted from the secondary line to the main line at an energy coupling part where the main line of the transmission line transformer is in close proximity of, and opposite to the secondary line,

wherein coupling members electrically coupled to the output electrode of the power transistor are electrically coupled to a joint formed in either the main line, or the secondary line, at part of the energy coupling part, and

wherein both the main line and the secondary line of the transmission line transformer are formed of a common interconnection layer in the shape of a spiral in a single layer.

8. An RF amplifying device comprising:

a first power amplifier for amplifying a first RF transmission input signal having a first frequency band; and

a second power amplifier for amplifying a second RF transmission input signal having a second frequency band higher in frequency than the first frequency band,

wherein the first power amplifier includes a first power transistor for generating a first transmission input power to be fed to an antenna of a wireless device by amplifying the first RF transmission input signal, and a first transmission line transformer coupled to a first output electrode of the first power transistor,

wherein a second power amplifier includes a second power transistor for generating a second transmission power to be fed to the antenna of the wireless device by amplifying the second RF transmission input signal, and a second transmission line transformer coupled to a second output electrode of the second power transistor,

wherein the first transmission line transformer, and the second transmission line transformer each include a main line and a secondary line, respectively,

wherein the transmission power from the output electrode of the power transistor is fed to one end of the main line while one end of the secondary line is coupled to an AC grounding node,

wherein the other end of the secondary line is coupled to the one end of the main line, thereby generating the transmission power to be fed to the antenna from the other end of the main line,

wherein coupling energy is transmitted from the secondary line to the main line at an energy coupling part of each of the transmission line transformers, where the main line of the transmission line transformer is in close proximity of, and opposite to the secondary line thereof, and

wherein coupling members electrically coupled to the output electrode of the power transistor are electrically coupled to a joint formed in either the main line, or the secondary line, at part of the energy coupling part.

9. The RF amplifying device according to claim 8 ,

wherein an operating voltage differing in level from a ground voltage level is applied to the AC grounding node at the one end of the secondary line of each of the transmission line transformers, thereby causing the operating voltage to be fed to the output electrode of the power transistor via the secondary line.

10. The RF amplifying device according to claim 8 ,

wherein both the main line and the secondary line of each of the transmission line transformers are comprised of multilevel interconnections formed over an insulated board.

11. The RF amplifying device according to claim 8 ,

wherein each of the power transistors, and both the main line and the secondary line of each of the transmission line transformers are formed over a semiconductor substrate of a monolithic microwave integrated circuit.

12. The RF amplifying device according to claim 9 ,

wherein the power transistors each are formed over a semiconductor chip,

wherein the coupling members electrically coupled to the output electrode of each of the power transistors formed over the semiconductor chip are either bonding wires, or bonding balls, and

wherein the joint formed in the part of the energy coupling part electrically coupled to the coupling members is a bonding pad joint formed over insulated board.

13. The RF amplifying device according to claim 8 ,

wherein the first RF transmission input signal is either GSM850 or GSM900, and the second RF transmission input signal is any of DCS1800, PCS1900, and WCDMA1900.

14. The RF amplifying device according to claim 8 ,

wherein the power transistors each are either a hetrojunction bipolar transistor, or an LDMOS.

15. An RF amplifying device comprising:

first and second power transistors for generating transmission power to be fed to an antenna of a wireless device;

a stripline for output synthesizing, having first and second inputs coupled to first and second output electrodes of the first and second power transistors, respectively; and

a transmission line transformer coupled to an output of the stripline for output synthesizing,

wherein the transmission line transformer includes a main line, and a secondary line,

wherein the transmission power from the output of the stripline for output synthesizing is fed to one end of the main line while one end of the secondary line is coupled to an AC grounding node,

wherein the other end of the secondary line is coupled to the one end of the main line, thereby generating the transmission power to be fed to the antenna from the other end of the main line,

wherein coupling energy is transmitted from the secondary line to the main line at an energy coupling part where the main line of the transmission line transformer is in close proximity of, and opposite to the secondary line, and

wherein coupling members electrically coupled to the output of the stripline for output synthesizing are electrically coupled to a joint formed in either the main line, or the secondary line, at part of the energy coupling part.

16. The RF amplifying device according to claim 15 ,

wherein an operating voltage differing in level from a ground voltage level is applied to the AC grounding node at the one end of the secondary line, thereby causing the operating voltage to be fed to the first and second output electrodes of the first and second power transistors, respectively, via the secondary line, and the stripline for output synthesizing.

17. The RF amplifying device according to claim 15 ,

wherein both the main line and the secondary line of the transmission line transformer are comprised of multilevel interconnections formed over an insulated board.

18. The RF amplifying device according to claim 15 ,

wherein the respective power transistors, and both the main line and the secondary line of each of the transmission line transformers are formed over a semiconductor substrate of a monolithic microwave integrated circuit.

19. The RF amplifying device according to claim 17 ,

wherein the first and second power transistors are formed over a semiconductor chip,

wherein the first and second output electrodes of the first and second power transistors, formed over the semiconductor chip, are coupled to the first and second inputs of the stripline for output synthesizing, respectively, via, first bonding wires and second bonding wires, respectively, and

wherein the output of the stripline for output synthesizing is coupled to the one end of the main line via a fourth bonding wire.

20. The RF amplifying device according to claim 15 ,

wherein the first and second power transistors each are either a hetrojunction bipolar transistor, or an LDMOS.