High frequency power amplifier and wireless communication module
The present invention provides a high frequency power amplifier of an open-loop type, which outputs a signal having a level corresponding to an output level required under control of a power supply voltage for each output power FET, based on a control signal for the output level. The high frequency power amplifier is provided with a bias voltage generating circuit which generates a gate bias voltage of each output power FET according to an output voltage of a power control circuit for controlling the power supply voltage for the output power FET, based on the control signal for the output level.
1. A high frequency power amplifier module, comprising:
a first power amplifying transistor having an input terminal, and an output terminal, and which is adapted to amplify a first signal having a first frequency;
a second power amplifying transistor having an input terminal, and an output terminal, and which is adapted to amplify a second signal having a second frequency being a different frequency from the first frequency; and
a power control circuit which receives a power supply voltage and a third signal and which supplies an operation voltage to the output terminals of the first power amplifying transistor and the second power amplifying transistor in accordance with the third signal.
2. The high frequency power amplifier module according to claim 1 , wherein the power control circuit includes a first transistor which is used for supplying the operation voltage to the output terminals of the first power amplifying transistor and the second power amplifying transistor.
3. The high frequency power amplifier module according to claim 1 , further comprising:
a bias voltage generating circuit which receives the operation voltage and outputs a bias voltage to be applied to the input terminals of the first power amplifying transistor and the second power amplifying transistor,
wherein the bias voltage generating circuit generates the bias voltage in accordance with the operation voltage.
4. The high frequency power amplifier module according to claim 1 , the power control circuit comprising:
an amplifier circuit which amplifies a differential voltage between the third signal for designating an output level for one of the first power amplifying transistor and the second power amplifying transistor and a feed back voltage; and
a MOSFET whose gate terminal connects an output of the amplifier circuit, a source terminal connects the power supply voltage, and a drain terminal connects the first power amplifying transistor and the second power amplifying transistor,
wherein the MOSFET is controlled in accordance with an output of the amplifier circuit and outputs the operation voltage for the first power amplifying transistor and the second power amplifying transistor from the drain terminal thereof, and
wherein a drain voltage of the MOSFET is fed back to the amplifier circuit as the feed back voltage.
5. The high frequency power amplifier module according to claim 4 , wherein the power control circuit comprising:
a phase compensating circuit is provided between the amplifier circuit and the gate terminal of the MOSFET which outputs the operating voltage for the output terminals of the first power amplifying transistor and the second power amplifying transistor.
6. The high frequency power amplifier module according to claim 1 , further comprising:
a third power amplifying transistor which is coupled to the first power amplifying transistor in series; and
a fourth power amplifying transistor which is coupled to the second power amplifying transistor in series,
wherein the third and the fourth power amplifying transistors are supplied output terminals thereof with and operation voltage from the power control circuit.
7. The high frequency power amplifier module according to claim 3 , further comprising:
a second transistor having a control terminal, an input terminal, and an output terminal and which is provided between the power supply voltage and the bias voltage generating circuit, and the control terminal of the second transistor is connected to an output of the power control circuit; and
a voltage terminal which is connected to the output terminal of the second transistor, and receives a voltage,
wherein the operation voltage is based on the voltage when the second transistor is turned off.
8. The high frequency power amplifier module according to claim 1 , comprising:
a select terminal which receives a band select signal; and
a power amplifying transistor control circuit which is coupled to the select terminal and the first power amplifying transistor and the second power amplifying transistor,
wherein the power amplifying transistor control circuit controls the first power amplifying transistor and the second power amplifying transistor in accordance with the band select signal so that one designated by the band select signal in the first power amplifying transistor and the second power amplifying transistor is activated.
9. The high frequency power amplifier module according to claim 6 , wherein each of the first, second, third and forth power amplifying transistor is one of a MOSFET and a HBT (Heterojunction Bipolar Transistor).
10. The high frequency power amplifier module according to claim 3 , wherein the power control circuit includes a first transistor which is used for supplying the operation voltage to the output terminals of the first power amplifying transistor and the second power amplifying transistor.
11. The high frequency power amplifier module according to claim 8 , wherein the power control circuit includes a first transistor which is used for supplying the operation voltage to the output terminals of the first power amplifying transistor and the second power amplifying transistor.
12. A high frequency power amplifier system, comprising:
a first power amplifying transistor having an input terminal, and an output terminal, and which is adapted to amplify a first signal having a first frequency;
a second power amplifying transistor having an input terminal, and an output terminal, and which is adapted to amplify a second signal having a second frequency being a different frequency from the first frequency; and
a power control circuit which receives a power supply voltage and a third signal and which supplies an operation voltage to the output terminals of the first power amplifying transistor and the second power amplifying transistor in accordance with the third signal.
13. The high frequency power amplifier system according to claim 12 , wherein the power control circuit includes a first transistor which is used for supplying the operation voltage to the output terminals of the first power amplifying transistor and the second power amplifying transistor.
14. The high frequency power amplifier system according to claim 12 , further comprising:
a bias voltage generating circuit which receives the operation voltage and outputs a bias voltage to be applied to the input terminals of the first power amplifying transistor and the second power amplifying transistor,
wherein the bias voltage generating circuit generates the bias voltage in accordance with the operation voltage.
15. The high frequency power amplifier system according to claim 12 , the power control circuit comprising:
an amplifier circuit which amplifies a differential voltage between the third signal for designating an output level for one of the first power amplifying transistor and the second power amplifying transistor and a feed back voltage; and
a MOSFET whose gate terminal connects an output of the amplifier circuit, a source terminal connects the power supply voltage, and a drain terminal connects the first power amplifying transistor and the second power amplifying transistor,
wherein the MOSFET is controlled in accordance with an output of the amplifier circuit and outputs the operation voltage for the first power amplifying transistor and the second power amplifying transistor from the drain terminal thereof, and
wherein a drain voltage of the MOSFET is fed back to the amplifier circuit as the feed back voltage.
16. The high frequency power amplifier system according to claim 15 , wherein the power control circuit comprising:
a phase compensating circuit is provided between the amplifier circuit and the gate terminal of the MOSFET which outputs the operating voltage for the output terminals of the first power amplifying transistor and the second power amplifying transistor.
17. The high frequency power amplifier system according to claim 12 , further comprising:
a third power amplifying transistor which is coupled to the first power amplifying transistor in series; and
a fourth power amplifying transistor which is coupled to the second power amplifying transistor in series,
wherein the third and the fourth power amplifying transistors are supplied output terminals thereof with operation voltage from the power control circuit.
18. The high frequency power amplifier system according to claim 14 , further comprising:
a second transistor having a control terminal, an input terminal, and a output terminal and which is provided between the power supply voltage and the bias voltage generating circuit, and the control terminal of the second transistor is connected to an output of the power control circuit; and
a voltage terminal which is connected to the output terminal of the second transistor, and receives a voltage,
wherein the operation voltage is based on the voltage when the second transistor is turned off.
19. The high frequency power amplifier system according to claim 12 , comprising:
a select terminal which receives a band select signal; and
a power amplifying transistor control circuit which is coupled to the select terminal and the first power amplifying transistor and the second power amplifying transistor,
wherein the power amplifying transistor control circuit controls the first power amplifying transistor and the second power amplifying transistor in accordance with the band select signal so that one designated by the band select signal in the first power amplifying transistor and the second power amplifying transistor is activated.
20. The high frequency power amplifier system according to claim 17 , wherein each of the first, second, third and forth power amplifying transistor is one of a MOSFET and a HBT (Heterojunction Bipolar Transistor).
21. The high frequency power amplifier system according to claim 14 , wherein the power control circuit includes a first transistor which is used for supplying the operation voltage to the output terminals of the first power amplifying transistor and the second power amplifying transistor.
22. The high frequency power amplifier system according to claim 19 , wherein the power control circuit includes a first transistor which is used for supplying the operation voltage to the output terminals of the first power amplifying transistor and the second power amplifying transistor.