1. A continuously variable valve lift system for actuating a combustion valve of an internal combustion engine, said continuously variable valve lift system comprising:
an engine camshaft having an engine camshaft lobe, said engine camshaft lobe being rotatable about an engine camshaft axis of rotation;
a rocker assembly that is pivotable for providing reciprocating motion to said combustion valve, said rocker assembly having a rocker assembly input member for receiving motion from said engine camshaft lobe and a rocker assembly output member for transmitting motion to said combustion valve;
a control shaft rotatable about a control shaft axis of rotation, wherein rotation of said control shaft about said control shaft axis of rotation changes the position of said rocker assembly, thereby varying the lift of said combustion valve;
an actuator for selectively rotating said control shaft between a minimum lift position and a maximum lift position;
and a bias spring surrounding said control shaft axis of rotation for biasing said control shaft only from said minimum lift position to a predetermined position which is intermediate said minimum lift position and said maximum lift position upon failure of said actuator.
2. A continuously variable valve lift system as in claim 1 wherein only forces generated by one of said engine camshaft and said combustion valve bias said control shaft from said maximum lift position to said predetermined position upon failure of said actuator.
3. A continuously variable valve lift system as in claim 1 wherein said actuator is connected to said control shaft through a gear set.
4. A continuously variable valve lift system as in claim 3 wherein said gear set includes a drive gear connected to said actuator and a driven gear connected to said control shaft such that said driven gear rotates with said control shaft in a one-to-one relationship and such that rotation of said drive gear causes said driven gear to rotate.
5. A continuously variable valve lift system as in claim 4 wherein said bias spring includes a stationary end grounded to said internal combustion engine and a moveable end for applying a biasing force to a reaction surface of said driven gear only when said control shaft is positioned from said minimum lift position to said predetermined position.
6. A continuously variable valve lift system as in claim 5 wherein said reaction surface is defined by a cutaway sector of said driven gear.
7. A continuously variable valve lift system as in claim 5 wherein said moveable end rotates with said driven gear when said control shaft is rotated from said minimum lift position to said predetermined position or from said predetermined position to said minimum lift position.
8. A continuously variable valve lift system as in claim 5 wherein said moveable end does not contact said driven gear when said control shaft is between said predetermined position and said maximum lift position.
9. A continuously variable valve lift system as in claim 5 wherein said moveable end is stationary when said control shaft is rotated between said predetermined position and said maximum lift position.
10. A continuously variable valve lift system as in claim 5 further comprising a spring stop fixed to said internal combustion engine to prevent said moveable end of said bias spring from applying said biasing force on said driven gear when said control shaft is between said predetermined position and said maximum lift position.
11. A continuously variable valve lift system as in claim 10 wherein said moveable end of said bias spring contacts said spring stop when said control shaft is positioned from said predetermined position to said maximum lift position.
12. A continuously variable valve lift system as in claim 11 wherein said moveable end of said bias spring is not in contact with said spring stop when said control shaft is positioned between said predetermined position and said minimum lift position.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A power amplifier circuit assembly comprising:
a power amplifier including an input and an output, the input configured to receive a radio frequency signal having a fundamental frequency and the output configured to provide an amplified radio frequency signal; and
an impedance matching network operatively associated with the power amplifier and configured to provide a load line impedance between about 6 \u03a9 and about 10 \u03a9 at the fundamental frequency, the impedance matching network including a fundamental matching circuit and one or more termination circuits, the fundamental matching circuit and each of the of the one or more termination circuits including separate input terminals for coupling to the output of the power amplifier so as to allow the fundamental matching circuit and each of the one or more termination circuits to be separately tuned.
2. The power amplifier circuit assembly of claim 1 wherein the one or more termination circuits includes a second harmonic termination circuit and a third harmonic termination circuit.
3. The power amplifier circuit assembly of claim 1 further comprising an envelope tracker configured to generate a power supply voltage for the power amplifier.
4. The power amplifier circuit assembly of claim 3 further comprising a bias network for supplying the power amplifier with the power supply voltage, the bias network including a choke inductor electrically connected between the envelope tracker and the power amplifier and a bypass capacitor electrically connected between the power supply voltage and a ground node.
5. The power amplifier circuit assembly of claim 4 wherein the bypass capacitor has a capacitance in the range of about 50 pF to about 200 pF.
6. The power amplifier circuit assembly of claim 1 further comprising an input bias circuit configured to generate a bias current for the input of the power amplifier, the input bias circuit configured to decrease a magnitude of the bias current when a power level of the amplified radio frequency signal decreases.
7. A mobile device comprising:
a power amplifier including an input and an output, the input configured to receive a radio frequency signal having a fundamental frequency and the output configured to provide an amplified radio frequency signal;
an impedance matching network operatively associated with the power amplifier and configured to provide a load line impedance between about 6 \u03a9 and about 10 \u03a9 at the fundamental frequency, the impedance matching network including a fundamental matching circuit and one or more termination circuits, the fundamental matching circuit and each of the of the one or more termination circuits including separate input terminals for coupling to the output of the power amplifier so as to allow the fundamental matching circuit and each of the one or more termination circuits to be separately tuned;
an antenna electrically connected to the output of the power amplifier through the impedance matching circuit; and
an envelope tracker configured to generate a power supply voltage for the power amplifier.
8. The mobile device of claim 7 further comprising a bias network for supplying the power amplifier with the power supply voltage, the bias network including a choke inductor electrically connected between the envelope tracker and the power amplifier and a bypass capacitor electrically connected between the power supply voltage and a ground node.
9. The mobile device of claim 8 wherein the bypass capacitor has a capacitance in the range of about 50 pF to about 200 pF.
10. The mobile device of claim 7 wherein the power amplifier is embodied on a power amplifier die and the fundamental matching circuit and each of the one or more termination circuits are external to the power amplifier die, the fundamental matching circuit and the one or more termination circuit each including a different bond wire electrically connected to the output of the power amplifier.
11. The mobile device of claim 7 wherein the one or more termination circuits includes a second harmonic termination circuit and a third harmonic termination circuit.
12. The mobile device of claim 7 further comprising a transceiver configured to generate the radio frequency input signal.
13. The mobile device of claim 7 further comprising an input bias circuit configured to generate a bias current for the input of the power amplifier, the input bias circuit configured to decrease a magnitude of the bias current when a power level of the amplified radio frequency signal decreases.
14. A multi-chip module comprising:
a substrate;
an input pin configured to receive a radio frequency signal having a fundamental frequency;
a power amplifier die mounted on the substrate, the power amplifier die including an input electrically connected to the input pin and an output configured to provide an amplified radio frequency signal; and
an impedance matching network disposed on the substrate and electrically connected to the output of the power amplifier, the impedance matching network configured to provide a load line impedance between about 6 \u03a9 and about 10 \u03a9 at the fundamental frequency, the impedance matching network including a fundamental matching circuit and one or more termination circuits, the fundamental matching circuit and each of the of the one or more termination circuits including separate input terminals for coupling to the output of the power amplifier so as to allow the fundamental matching circuit and each of the one or more termination circuits to be separately tuned.
15. The multi-chip module of claim 14 wherein the impedance matching network includes an inductive circuit component and a capacitive circuit component, and the capacitive circuit component is formed from a surface mount component mounted on the substrate.
16. The multi-chip module of claim 14 wherein the impedance matching network includes an inductive circuit component and a capacitive circuit component, and the inductive circuit component includes a spiral inductor formed from a conductive trace of the substrate.
17. The multi-chip module of claim 14 wherein the impedance matching network includes an inductive circuit component and a capacitive circuit component, and the inductive circuit component includes a surface mount component mounted to the substrate.
18. The multi-chip module of claim 14 further comprising a power supply pin and a ground pin, the power supply pin configured to receive a power supply voltage from an envelope tracker.
19. The multi-chip module of claim 18 further comprising a bias network for supplying the power amplifier with the power supply voltage, the bias network including a choke inductor electrically connected between the power supply pin and the power amplifier and a bypass capacitor electrically connected between the power supply pin and the ground pin.
20. The multi-chip module of claim 19 wherein the bypass capacitor has a capacitance in the range of about 50 pF to about 200 pF.
21. The multi-chip module of claim 14 wherein the fundamental matching circuit and each of the one or more termination circuits each include a different bond wire electrically connected to the output of the power amplifier.
22. The multi-chip module of claim 21 wherein the fundamental matching circuit and each of the one or more termination circuits are electrically connected to the power amplifier die using different pads of the power amplifier die.
23. The multi-chip module of claim 14 further comprising a power amplifier bias die disposed on the substrate and configured to provide a bias signal for controlling a quiescent current of the power amplifier die.
24. A tuning circuit assembly for use in a power amplifier system, the tuning circuit assembly comprising:
an impedance matching network operatively associated with a power amplifier and configured to provide a load line impedance between about 6 \u03a9 and about 10 \u03a9, the impedance matching network including a fundamental matching circuit and one or more termination circuits, the fundamental matching circuit and each of the of the one or more termination circuits including separate terminals for coupling to an output of the power amplifier so as to allow the fundamental matching circuit and each of the one or more termination circuits to be separately tuned; and
a biasing network operative associated with said impedance matching network, the biasing network operatively associated with an envelope tracker and configured to provide a bypass capacitance in the range of about 50 pF to about 200 pF.
25. The tuning circuit assembly of claim 24 wherein the one or more termination circuits include a plurality of termination circuits for even harmonics but do not include any termination circuits for odd harmonics.
26. The tuning circuit assembly of claim 24 wherein the one or more termination circuits include a plurality of termination circuits for odd harmonics but do not include any termination circuits for even harmonics.
27. The tuning circuit assembly of claim 24 wherein the one or more termination circuits include a second harmonic termination circuit and a third harmonic termination circuit.