On-die harmonics filtering for radio frequency power amplifiers
A power amplifier architecture for connecting a radio frequency (RF) transceiver to an antenna. An input matching circuit is connected to its input port, and an output matching circuit is connected to its output port. An amplifier circuit includes at least one amplifier active device with a first terminal connected to the input matching segment and a second terminal connected to the output matching segment. A first harmonic feedback circuit is connected across the amplifier active device. Voltage components of emissions of one or more harmonic frequencies of a carrier fundamental frequency generated by the amplifier active device is fed back with opposite phase to the first terminal of the amplifier active device. A negative feedback is defined at a level correlated with a gain level of the amplifier active device at the harmonic frequencies of the carrier fundamental frequency. Negative feedback is minimized at the carrier fundamental frequency.
1. A power amplifier architecture for connecting a transceiver generating a radio frequency (RF) signal defined by a carrier fundamental frequency to an antenna including an input port and an output port comprising:
an input matching circuit connected to the input port;
an output matching circuit connected to the output port;
an amplifier circuit including at least one amplifier active device with a first terminal connected to the input matching segment and a second terminal connected to the output matching segment; and
a first harmonic feedback circuit connected across the amplifier active device, voltage components of emissions of one or more harmonic frequencies of the carrier fundamental frequency generated by the amplifier active device being fed back with opposite phase to the first terminal of the amplifier active device by the first harmonic feedback circuit;
wherein a negative feedback at a level correlated with a gain level of the amplifier active device at the one or more harmonic frequencies of the carrier fundamental frequency is defined, and the negative feedback is minimized at the carrier fundamental frequency.
2. The power amplifier architecture of claim 1 , wherein the first harmonic feedback circuit is connected to the first terminal of the amplifier active device and the second terminal of the amplifier active device.
3. The power amplifier architecture of claim 2 , wherein the amplifier active device has a third terminal.
4. The power amplifier architecture of claim 3 , wherein the first harmonic feedback circuit is connected to the second terminal of the amplifier active device and the third terminal of the amplifier active device.
5. The power amplifier architecture of claim 3 , further comprising:
coupled inductors connected to a respective one of the third terminal of the amplifier active device and the first harmonic feedback circuit;
wherein the first harmonic feedback circuit is further connected to the second terminal of the amplifier active device.
6. The power amplifier architecture of claim 3 , further comprising:
a second harmonic feedback circuit connected across the amplifier active device, the voltage components of emissions of one or more harmonic frequencies of the carrier fundamental frequency generated by the amplifier active device being fed back with opposite phase to the first terminal of the amplifier active device by the second harmonic feedback circuit.
7. The power amplifier architecture of claim 3 , wherein the amplifier active device is a bipolar type transistor defined by a base corresponding to the first terminal, a collector corresponding to the second terminal, and an emitter corresponding to the third terminal.
8. The power amplifier architecture of claim 3 , wherein the amplifier active device is a field effect type transistor defined by a gate corresponding to the first terminal, a source corresponding to the second terminal, and an drain corresponding to the third terminal.
9. The power amplifier architecture of claim 3 , wherein the input matching circuit, the output matching circuit, the amplifier circuit, and the first harmonic feedback circuit are fabricated on a semiconductor substrate selected from a group consisting of metal oxide semiconductor field effect, bipolar junction, heterojunction bipolar, metal semiconductor field effect, and high electron mobility.
10. The power amplifier architecture of claim 1 , wherein the input matching circuit, the output matching circuit, the amplifier circuit, and the first harmonic feedback circuit are implemented on a single semiconductor die.
11. The power amplifier architecture of claim 2 , wherein the first harmonic feedback circuit includes:
a passive harmonics phase shift component;
a control voltage source;
a bias voltage source; and
a first feedback active device with a first terminal connected to the control voltage source, a second terminal connected to the bias voltage source and the passive harmonics phase shift component, and a third terminal connected to the first terminal of the amplifier active device;
wherein the first feedback active device, together with the passive harmonics phase shift component, the control voltage source, and the supply voltage source are tuned to shift the emissions of the one or more harmonic frequencies of the carrier fundamental frequency to the opposite phase.
12. The power amplifier architecture of claim 11 , wherein the passive phase shift component is a capacitor.
13. The power amplifier architecture of claim 11 , wherein the first harmonic feedback circuit further includes:
a passive gain shaping component connected to the first feedback active device.
14. The power amplifier architecture of claim 13 , wherein the passive gain shaping component is connected to the first terminal of the first feedback active device and the second terminal of the first feedback active device.
15. The power amplifier architecture of claim 13 , wherein the passive gain shaping component is a capacitor.
16. The power amplifier architecture of claim 13 , wherein:
the control voltage source has a resistance of 300 Ohm;
the bias voltage source has a resistance of 160 Ohm;
the passive gain shaping component has a capacitance of 0.18 pico Farad;
the passive harmonics phase shift component has a capacitance of 0.75 pico Farad.
17. The power amplifier architecture of claim 13 , wherein the passive gain shaping component is connected to the second terminal of the first feedback active device and the third terminal of the first feedback active device.
18. The power amplifier architecture of claim 11 , wherein the first harmonic feedback circuit further includes:
a first passive gain shaping component connected to the first feedback active device between the first terminal thereof and the second terminal thereof;
a second passive gain shaping component connected to the first feedback active device between the third terminal thereof and the second terminal thereof.
19. The power amplifier architecture of claim 11 , wherein the first feedback active device is a bipolar type transistor defined by a base corresponding to the first terminal, a collector corresponding to the second terminal, and an emitter corresponding to the third terminal.
20. The power amplifier architecture of claim 11 , wherein the first feedback active device is a field effect type transistor defined by a gate corresponding to the first terminal, a source corresponding to the second terminal, and an drain corresponding to the third terminal.
21. The power amplifier architecture of claim 11 , wherein the first feedback active device is a bipolar type transistor defined by a base corresponding to the first terminal, an emitter corresponding to the second terminal, and an collector corresponding to the third terminal.
22. The power amplifier architecture of claim 1 , further comprising:
a second-harmonic rejection filter connected to the second terminal of the amplifier active device and tuned for series resonance at a second harmonic frequency of the carrier fundamental frequency generated by the amplifier active device.
23. The power amplifier architecture of claim 22 , wherein first harmonic feedback circuit includes:
a passive harmonics phase shift component;
a control voltage source;
a bias voltage source;
a first feedback active device with a first terminal connected to the control voltage source, a second terminal connected to the bias voltage source and the passive harmonics phase shift component, and a third terminal connected to the first terminal of the amplifier active device;
a first passive gain shaping component connected to the first terminal of the first feedback active device and the second terminal of the first feedback active device; and
a second passive gain shaping component connected to the third terminal of the first feedback active device and the second terminal of the first feedback active device;
wherein the first feedback active device, together with the passive harmonics phase shift component, the control voltage source, and the supply voltage source are tuned to shift the emissions of the one or more harmonic frequencies of the carrier fundamental frequency to the opposite phase.
24. The power amplifier architecture of claim 22 , wherein first harmonic feedback circuit includes:
a passive harmonics phase shift component;
a control voltage source;
a bias voltage source;
a first feedback active device with a first terminal connected to the control voltage source, a second terminal connected to the bias voltage source and the passive harmonics phase shift component, and a third terminal;
a passive gain shaping component connected to the first terminal of the first feedback active device and the second terminal of the first feedback active device;
a second feedback active device with a first terminal, a second terminal, and a third terminal, the first terminal of the second feedback active device being connected to the third terminal of the first feedback active device and the second terminal of the second feedback active device being connected to the second terminal of the first feedback active device in a Darlington configuration, and the third terminal of the second feedback active device being connected to the first terminal of the amplifier active device;
wherein the first feedback active device, together with the passive harmonics phase shift component, the control voltage source, and the supply voltage source are tuned to shift the emissions of the one or more harmonic frequencies of the carrier fundamental frequency to the opposite phase.
25. The power amplifier architecture of claim 22 , further comprising:
a third-harmonic rejection filter connected to the output port and tuned for series resonance at a third harmonic frequency of the carrier fundamental frequency generated by the amplifier active device.
26. The power amplifier architecture of claim 25 , wherein first harmonic feedback circuit includes:
a passive harmonics phase shift component;
a control voltage source;
a bias voltage source; and
a first feedback active device with a first terminal connected to the control voltage source, a second terminal connected to the bias voltage source and the passive harmonics phase shift component, and a third terminal connected to the first terminal of the amplifier active device;
a first passive gain shaping component connected across the first feedback active device between the first terminal thereof and the second terminal thereof;
a second passive gain shaping component connected across the first feedback active device between the third terminal thereof and the second terminal thereof
wherein the first feedback active device, together with the passive harmonics phase shift component, the control voltage source, and the supply voltage source are tuned to shift the emissions of the one or more harmonic frequencies of the carrier fundamental frequency to the opposite phase.
27. The power amplifier architecture of claim 25 , wherein the output matching circuit is an inductor-capacitor (LC) network, and including a secondary inductor connected to the output port.
28. The power amplifier architecture of claim 22 , wherein first harmonic feedback circuit includes:
a passive harmonics phase shift component;
a control voltage source;
a bias voltage source;
a first feedback active device with a first terminal connected to the control voltage source, a second terminal connected to the bias voltage source and the passive harmonics phase shift component, and a third terminal connected to the first terminal of the amplifier active device;
a first passive gain shaping component connected to the first terminal of the first feedback active device and the second terminal of the first feedback active device; and
a second passive gain shaping component connected across the first feedback active device between the third terminal thereof and the second terminal thereof;
wherein the first feedback active device, together with the passive harmonics phase shift component, the control voltage source, and the supply voltage source are tuned to shift the emissions of the one or more harmonic frequencies of the carrier fundamental frequency to the opposite phase.
29. The power amplifier architecture of claim 28 , wherein the output matching circuit is an inductor-capacitor (LC) network, and including a secondary inductor connected to the output port.