1. An impact absorber for an exhaust sensor, the impact absorber comprising:
a collar of deformable material disposed around a housing of the exhaust sensor, the collar extending radially outward from the housing, wherein the collar bends to absorb at least a portion of an impact force resulting from the exhaust sensor being dropped;
wherein the collar is formed from a material selected to degrade at exhaust temperature.
2. The impact absorber of claim 1, wherein the collar is at least partially bent.
3. The impact absorber of claim 1, wherein the collar further comprises a perforation, to allow for removal of the impact absorber.
4. The impact absorber of claim 1, wherein an outer edge of the collar is bent.
5. An impact absorber for an exhaust sensor, the impact absorber comprising:
a collar of deformable material disposed around a housing of the exhaust sensor, the collar extending radially outward from the housing, wherein the collar bends to absorb at least a portion of an impact force resulting from the exhaust sensor being dropped; wherein the collar is disposed around a sealing gasket, the sealing gasket being disposed around the housing.
6. An impact absorber for an exhaust sensor, the impact absorber comprising:
a collar of deformable material disposed around a housing of the exhaust sensor, the collar extending radially outward from the housing, wherein the collar bends to absorb at least a portion of an impact force resulting from the exhaust sensor being dropped; wherein a wall is disposed around at least a portion of a perimeter of the collar, the wall being spaced apart from a plurality of facets formed on the housing to form a recess for receiving a socket wrench tool.
7. The impact absorber of claim 6, wherein a bump is formed on the wall, the bump extending toward the plurality of facets to increase resistance between the socket wrench tool and the wall.
8. An exhaust sensor comprising:
a housing; and, a collar of deformable material disposed around the housing, the collar extending radially outward from the housing, wherein the collar bends to absorb at least a portion of an impact force resulting from the exhaust sensor being dropped; wherein the collar is formed from a material selected to degrade at exhaust temperature.
9. The exhaust sensor of claim 8, wherein the collar is at least partially bent.
10. The exhaust sensor of claim 8, wherein the collar further comprises a perforation to allow for removal of the impact absorber.
11. The exhaust sensor of claim 8, wherein the collar is disposed around a sealing gasket, the sealing gasket being disposed around the housing.
12. The exhaust sensor of claim 8, wherein an outer edge of the collar is bent.
13. The exhaust sensor of claim 8, wherein a wall is disposed around at least a portion of a perimeter of the collar, the wall being spaced apart from a plurality of facets formed on the housing to form a recess for receiving a socket wrench tool.
14. The exhaust sensor of claim 13, wherein a bump is formed on the wall, the bump extending toward the plurality of facets to increase resistance between the socket wrench tool and the wall.
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 method of phase compensation in a power amplifier system, the method comprising:
amplifying an input radio frequency (RF) signal to generate a first amplified RF signal using a first amplification stage of a power amplifier;
generating a power amplifier supply voltage using an envelope tracker;
controlling a voltage level of the power amplifier supply voltage based on an envelope of the input RF signal using the envelope tracker;
powering a second amplification stage of the power amplifier using the power amplifier supply voltage from the envelope tracker;
amplifying the first amplified RF signal to generate a second amplified signal using the second amplification stage; and
compensating for a variation in an input impedance of the second amplification stage associated with changes in the voltage level of the power amplifier supply voltage using a compensation circuit.
2. The method of claim 1 further comprising providing a matching impedance between the first and second amplification stages that is in the range of about 60\u03a9 to about 70\u03a9 using the compensation circuit.
3. The method of claim 1 wherein amplifying the first amplified RF signal to generate the second amplified signal includes receiving the first amplified RF signal at a base of a bipolar transistor and generating the second amplified RF signal at a collector of the bipolar transistor.
4. The method of claim 3 further comprising compensating for a variation in a parasitic capacitance between the base and the collector of the bipolar transistor associated with changes in the voltage level of the power amplifier supply voltage using the compensation circuit.
5. The method of claim 1 further comprising generating the RF signal and the envelope of the RF signal using a transceiver.
6. A power amplifier system comprising:
a first power amplifier stage including an input configured to receive an input radio frequency (RF) signal and an output configured to generate a first amplified RF signal;
an envelope tracker configured to generate a power amplifier supply voltage and to control a voltage level of the power amplifier supply voltage based on an envelope of the input RF signal;
a second power amplifier stage including an input configured to receive the first amplified RF signal and an output configured to generate a second amplified RF signal, the second power amplifier stage configured to be powered by the power amplifier supply voltage from the envelope tracker; and
a compensation circuit electrically connected between the output of the first power amplifier stage and the input of the second power amplifier stage, the compensation circuit configured to compensate for variation in input impedance of the second power amplifier stage associated with changes in the voltage level of the power amplifier supply voltage.
7. The power amplifier system of claim 6 wherein the compensation circuit is configured to provide a matching impedance between the first and second power amplifier stages that is in the range of about 60\u03a9 to about 70\u03a9.
8. The power amplifier system of claim 6 wherein the second power amplifier stage includes a bipolar transistor including a base configured to receive the first amplified RF signal and a collector configured to generate the second amplified RF signal.
9. The power amplifier system of claim 8 wherein the compensation circuit is configured to compensate for a variation in a parasitic capacitance between the base and the collector of the bipolar transistor associated with changes in the voltage level of the power amplifier supply voltage.
10. The power amplifier system of claim 6 wherein the compensation circuit includes a first compensation capacitor electrically connected between the input of the second power amplifier stage and an output of the first power amplifier stage.
11. The power amplifier system of claim 10 wherein the compensation circuit further includes a first compensation inductor electrically connected between the output of the first power amplifier stage and an input stage power supply.
12. The power amplifier system of claim 11 wherein the compensation circuit further includes a second compensation inductor electrically connected between the first compensation inductor and the input stage power supply, the first and second compensation inductors electrically connected at a first node.
13. The power amplifier system of claim 12 wherein the compensation circuit further includes a third compensation inductor and a second compensation capacitor electrically connected in series between the first node and a power low supply.
14. The power amplifier system of claim 11 further comprising an output stage bias current generation circuit configured to provide a bias current to the input of the second power amplifier stage.
15. The power amplifier system of claim 14 wherein the compensation circuit further includes a bias inductor configured to provide the bias current from the output stage bias current generation circuit to the input of the second power amplifier stage, the bias inductor configured to provide a portion of the first amplified RF signal to the output stage bias current generation circuit so as to provide phase compensation.
16. A mobile device comprising:
a transceiver configured to generate a radio frequency (RF) signal and an envelope signal corresponding to an envelope of the RF signal;
an envelope tracker configured to generate a power amplifier supply voltage and to control a voltage level of the power amplifier supply voltage based on the envelope signal;
a plurality of power amplifier stages including a first power amplifier stage and a second power amplifier stage, the first power amplifier stage including an input configured to receive the RF signal and an output configured to generate a first amplified RF signal, the second power amplifier stage including an input configured to receive the first amplified RF signal and an output configured to generate a second amplified RF signal, the second power amplifier stage further configured to be powered by the power amplifier supply voltage from the envelope tracker; and
a compensation circuit electrically connected between the output of the first power amplifier stage and an input of the second power amplifier stage, the compensation circuit configured to compensate for variation in input impedance of the second power amplifier stage associated with changes in the voltage level of the power amplifier supply voltage.
17. The mobile device of claim 16 wherein the compensation circuit is configured to provide a matching impedance between the first and second power amplifier stages that is in the range of about 60\u03a9 to about 70\u03a9.
18. The mobile device of claim 16 wherein the second power amplifier stage includes a bipolar transistor including a base configured to receive the first amplified RF signal and a collector configured to generate the second amplified RF signal.
19. The mobile device of claim 18 wherein the compensation circuit is configured to compensate for a variation in a parasitic capacitance between the base and the collector of the bipolar transistor associated with changes in the voltage level of the power amplifier supply voltage.
20. The mobile device of claim 16 wherein the transceiver includes an envelope shaping block for shaping the envelope signal to control a gain compression associated with the envelope tracker.