Transmitter with improved power efficiency
View Patent ↗A power amplifier (PA) line-up ( 210 ) and a method ( 500 ) for more efficiently utilizing battery power are disclosed. PA line-up ( 210 ) includes a driver ( 220 ), a matching circuit ( 214 ), and a PA ( 230 ) coupled to a matching circuit ( 216 ), wherein matching circuit ( 216 ) is configured to be coupled to a filter ( 260 ). PA line-up ( 210 ) includes a transmission line ( 260 ) coupled to matching circuit ( 216 ) and a switch ( 262 ) configured to selectively couple driver ( 220 ) to either matching circuit ( 214 ) or matching circuit ( 216 ) such that signal ( 205 ) is capable of by-passing PA ( 230 ) when signal ( 205 ) does not need to be amplified by PA ( 230 ). Furthermore, PA line-up ( 210 ) may include a second transmission line ( 250 ) so that signal ( 205 ) is capable of by-passing a driver ( 220 ) and a PA ( 230 ) when signal ( 205 ) does not need to be amplified by driver ( 220 ) and PA ( 230 ).
1. A power amplifier (PA) line-up comprising:
a driver having a driver output;
a PA having a PA input and a PA output;
a first matching circuit having a first matching circuit output coupled to the PA input and having a first matching circuit input, the first matching circuit configured to receive a signal from the driver output and impedance match the signal to the PA input and the driver output;
a second matching circuit having a second matching circuit input coupled to the PA output, a third matching circuit input, and a second matching circuit output configured to be coupled to a filter input, the second matching circuit configured to impedance match the signal to the filter input and at least one of the PA output and the driver output;
a first transmission line coupled to the third matching circuit input; and
a first switch coupled to the driver output, the first switch having a first switch output configured to selectively couple the driver to one of the second matching circuit via the first transmission line and the first matching circuit based upon a pre-determined output power level for the signal.
2. The PA line-up of claim 1 , wherein the second matching circuit comprises a fourth matching circuit input, the PA line-up further comprising:
a pre-driver having a pre-driver output;
a third matching circuit having a third matching circuit output coupled to the driver input and a fifth matching circuit input, the third matching circuit configured to impedance match the signal to the pre-driver output and the driver input;
a second transmission line coupled to the fourth matching circuit input; and
a second switch having a second switch input coupled to the pre-driver output and a second switch output configured to selectively couple the pre-driver to one of the third matching circuit and the second matching circuit via the second transmission line based upon a pre-determined output power level for the signal, wherein the second matching circuit is configured to impedance match the signal to the filter input and at least one of the driver output, the PA output, and the pre-driver output.
3. The PA line-up of claim 2 , further comprising a third switch configured to selectively couple the first transmission line to the third matching circuit input, wherein the third switch is configured to be open when the first switch selectively couples the driver output to the first matching circuit input and configured to be closed when the first switch selectively couples the driver output to the first transmission line.
4. The PA line-up of claim 3 , further comprising a fourth switch configured to selectively couple the second transmission line to the fourth matching circuit input, wherein the fourth switch is configured to be open when the second switch selectively couples the pre-driver output to the fifth matching circuit input and configured to be closed when the fourth switch selectively couples the pre-driver output to the second transmission line.
5. The PA line-up of claim 2 , wherein the second matching circuit is a variable matching circuit.
6. The PA line-up of claim 1 , further comprising a second switch configured to selectively couple the first transmission line to the third matching circuit input, wherein the second switch is configured to be open when the first switch selectively couples the signal generator output to the first matching circuit input and configured to be closed when the first switch selectively couples the signal generator output to the first transmission line.
7. The PA line-up of claim 1 , wherein the second matching circuit is a variable matching circuit.
8. The PA line-up of claim 7 , wherein the second matching circuit further comprises at least one variable capacitor coupled in parallel with at least one inductor.
9. The PA line-up of claim 7 , wherein the second matching circuit further comprises at least one capacitor coupled in parallel with at least one inductor, and a second switch configured to selectively short circuit the at least one capacitor.
10. The PA line-up of claim 7 , wherein the second matching circuit is variable based upon whether the second matching circuit is impedance matching the one of the PA and the driver.
11. The PA line-up of claim 7 , wherein the second matching circuit further comprises:
a first node;
a second node;
a first variable capacitor coupled to the first node and the second node;
a first inductor coupled to the first node and the second node, and coupled in parallel with the first variable capacitor;
a third node coupled to the second node;
a second variable capacitor coupled to the third node and configured to be coupled to ground;
a fourth node coupled to the third node; and
a first capacitor coupled to the fourth node and configured to be coupled to ground.
12. The PA line-up of claim 11 , wherein the second matching circuit further comprises:
a fifth node coupled to the fourth node;
a sixth node;
a third variable capacitor coupled to the fifth node and the sixth node;
a second inductor coupled to the fifth node and the sixth node, and coupled in parallel with the third variable capacitor;
a seventh node coupled to the sixth node;
a fourth variable capacitor coupled to the seventh node and configured to be coupled to ground;
an eighth node coupled to the seventh node; and
a second capacitor coupled to the eighth node and configured to be coupled to ground.
13. The PA line-up of claim 7 , wherein the second matching circuit further comprises:
a first node;
a second node;
a first switch coupled to the first node;
a first capacitor coupled in series with the first switch and coupled to the second node;
a first inductor coupled to the first node and the second node, and coupled in parallel with the first switch and the first capacitor;
a third node coupled to the second node;
a second switch coupled to the third node;
a second capacitor coupled to the second switch and configured to be coupled to ground;
a fourth node coupled to the third node; and
a third capacitor coupled to the fourth node and configured to be coupled to ground.
14. The PA line-up of claim 13 , wherein the second matching circuit further comprises:
a fifth node coupled to the fourth node;
a sixth node;
a third switch coupled to the fifth node;
a fourth capacitor coupled in series with the third switch and coupled to the sixth node;
a second inductor coupled to the fifth node and the sixth node, and coupled in parallel with the third switch and the fourth capacitor;
a seventh node coupled to the sixth node;
a fourth switch coupled to the seventh node;
a fifth capacitor coupled to the fourth switch and configured to be coupled to ground;
an eighth node coupled to the seventh node; and
a sixth capacitor coupled to the eighth node and configured to be coupled to ground.
15. A power amplifier (PA) line-up comprising:
a pre-driver having a pre-driver output;
a driver having a driver input and a driver output;
a first matching circuit having a first matching circuit output coupled to the driver input and having a first matching circuit input, the first matching circuit configured to receive a signal from the pre-driver output and impedance match the signal to the first driver input and the pre-driver output;
a PA having a PA input and a PA output;
a second matching circuit having a second matching circuit input coupled to the driver output and having a second matching circuit output coupled to the PA input, the second matching circuit configured to receive the signal from the driver output and impedance match the signal to the driver output and the PA input;
a third matching circuit having a third matching circuit input coupled to the PA output, a fourth matching circuit input, and a third matching circuit output configured to be coupled to a filter input, the third matching circuit configured to impedance match the signal to the filter input and at least one of the PA output and the pre-driver output;
a transmission line coupled to the fourth matching circuit input; and
a first switch having a first switch input coupled to the pre-driver output, wherein the first switch is configured to selectively couple the pre-driver to one of the third matching circuit via the transmission line and the first matching circuit based upon a pre-determined output power level for the signal.
16. The PA line-up of claim 15 , further comprising a second switch configured to selectively couple the transmission line to the fourth matching circuit input, wherein the second switch is configured to be open when the first switch selectively couples the pre-driver to the first matching circuit and configured to be closed when the first switch selectively couples the pre-driver to the third matching circuit via the transmission line.
17. The PA line-up of claim 15 , wherein the third matching circuit further comprises at least one variable capacitor coupled in parallel with at least one inductor.
18. The PA line-up of claim 15 , wherein the third matching circuit further comprises at least one capacitor coupled in parallel with at least one inductor, and a second switch configured to selectively short circuit the at least one capacitor.
19. The PA line-up of claim 15 , wherein the third matching circuit further comprises:
a first node;
a second node;
a first variable capacitor coupled to the first node and the second node;
a first inductor coupled to the first node and the second node, and coupled in parallel with the first variable capacitor;
a third node coupled to the second node;
a second variable capacitor coupled to the third node and configured to be coupled to ground;
a fourth node coupled to the third node; and
a first capacitor coupled to the fourth node and configured to be coupled to ground.
20. The PA line-up of claim 19 , wherein the third matching circuit further comprises:
a fifth node coupled to the fourth node;
a sixth node;
a third variable capacitor coupled to the fifth node and the sixth node;
a second inductor coupled to the fifth node and the sixth node, and coupled in parallel with the third variable capacitor;
a seventh node coupled to the sixth node;
a fourth variable capacitor coupled to the seventh node and configured to be coupled to ground;
an eighth node coupled to the seventh node; and
a second capacitor coupled to the eighth node and configured to be coupled to ground.
21. The PA line-up of claim 15 , wherein the third matching circuit further comprises:
a first node;
a second node;
a first switch coupled to the first node;
a first capacitor coupled in series with the first switch and coupled to the second node;
a first inductor coupled to the first node and the second node, and coupled in parallel with the first switch and the first capacitor;
a third node coupled to the second node;
a second switch coupled to the third node;
a second capacitor coupled to the second switch and configured to be coupled to ground;
a fourth node coupled to the third node; and
a third capacitor coupled to the fourth node and configured to be coupled to ground.
22. The PA line-up of claim 21 , wherein the third matching circuit further comprises:
a fifth node coupled to the fourth node;
a sixth node;
a third switch coupled to the fifth node;
a fourth capacitor coupled in series with the third switch and coupled to the sixth node;
a second inductor coupled to the fifth node and the sixth node, and coupled in parallel with the third switch and the fourth capacitor;
a seventh node coupled to the sixth node;
a fourth switch coupled to the seventh node;
a fifth capacitor coupled to the fourth switch and configured to be coupled to ground;
an eighth node coupled to the seventh node; and
a sixth capacitor coupled to the eighth node and configured to be coupled to ground.