RF power amplifier performance by clipping prevention of large PAPR signals

1. An apparatus for preventing RF signal distortion and signal error producing memory events in a Radio Frequency (RF) power amplifier (RFPA), comprising:

the Radio Frequency (RF) power amplifier (RFPA), wherein the RFPA resides in a communication device operable within a Hybrid Fiber Coax (HFC) system; and

an element, disposed prior to the RFPA in a signal path of a RF signal input to the RFPA, operable to enforce a maximum allowable amplitude in a high peak to average power ratio (PAPR) instantaneous high peak of the RF signal.

2. The apparatus of claim 1 , wherein the element does not experience the signal error producing memory events, and wherein said signal error producing memory events cause distortions in the RF signal over time in response to the RF signal having a high PAPR instantaneous high peak beyond a threshold amplitude.

3. The apparatus of claim 1 , wherein the maximum allowable amplitude corresponds to a determined amplitude above which a signal error producing memory event is induced in said RFPA.

4. The apparatus of claim 1 , wherein the maximum allowable amplitude is configured to be an amplitude that is less than a determined amplitude above which a signal error producing memory event is induced in said RFPA.

5. The apparatus of claim 1 , wherein the maximum allowable amplitude is enforced in an analog domain.

6. The apparatus of claim 5 , wherein the enforcement of the maximum allowable amplitude in the analog domain is performed using one or more Schottky diodes.

7. The apparatus of claim 5 , wherein the enforcement of the maximum allowable amplitude in the analog domain is performed using a pair of Schottky diodes.

8. The apparatus of claim 1 , wherein the maximum allowable amplitude is enforced in a digital domain prior to being received at a digital-to-analog converter (DAC).

9. An apparatus for preventing RF signal distortion and signal error producing memory events in a Radio Frequency (RF) power amplifier (RFPA), comprising:

the Radio Frequency (RF) power amplifier (RFPA), wherein the RFPA resides in a communication device operable within a Hybrid Fiber Coax (HFC) system; and

an element, disposed prior to the RFPA in a signal path of a RF signal input to the RFPA, operable to enforce a maximum allowable amplitude in a high peak to average power ratio (PAPR) instantaneous high peak of the RF signal,

wherein the maximum allowable amplitude is enforced against both positive amplitude peaks and negative amplitude peaks of the RF signal.

10. An apparatus for preventing RF signal distortion and signal error producing memory events in a Radio Frequency (RF) power amplifier (RFPA), comprising:

the Radio Frequency (RF) power amplifier (RFPA), wherein the RFPA resides in a communication device operable within a Hybrid Fiber Coax (HFC) system; and

an element operable to increase or supplement a bias of the RFPA when a high peak to average power ratio (PAPR) instantaneous high peak is detected in the RF signal prior to receipt by the RFPA,

wherein the element increases or supplements the bias of the RFPA gradually using a low pass filter from a normal level to an elevated level while the high PAPR instantaneous high peak is being processed by the RFPA, and wherein the element decreases the bias of the RFPA gradually from the elevated level to the normal level when the high PAPR instantaneous high peak is no longer being processed by the RFPA.

11. The apparatus of claim 10 , wherein the element is a first element, and wherein the apparatus further comprises:

a second element, disposed prior to the RFPA in a signal path of a RF signal input to the RFPA, operable to detect the high PAPR instantaneous high peak in the RF signal by comparing a measured amplitude of the RF signal to a predetermined amplitude.

12. The apparatus of claim 10 , wherein said RFPA comprises a first amplifier and a second amplifier different than the first amplifier, and wherein the bias of each of the first and second amplifier is modified independently of the other.

13. An apparatus for preventing RF signal distortion and signal error producing memory events in a Radio Frequency (RF) power amplifier (RFPA), comprising:

the Radio Frequency (RF) power amplifier (RFPA), wherein the RFPA resides in a communication device operable within a Hybrid Fiber Coax (HFC) system;

a first element operable to detect when an instantaneous output voltage of the RFPA is below a predetermined voltage; and

a second element operable to supply additional current to prevent the output voltage of the RFPA from falling below a predetermined threshold voltage.

14. An apparatus of claim 13 , wherein the second element comprises a capacitor which recharges from a DC power line of the RFPA or another DC power line.

15. An apparatus of claim 13 , wherein the first element comprises one or more Schottky diodes.

16. An apparatus of claim 13 , wherein the second element supplies said additional current only over a duration commensurate to a length of time in which a RF signal that is input to the RFPA has a high PAPR instantaneous high peak beyond a threshold amplitude.

17. A method for preventing RF signal distortion and signal error producing memory events in a Radio Frequency (RF) power amplifier (RFPA), comprising:

an element, disposed prior to the Radio Frequency (RF) power amplifier (RFPA) in a signal path of a RF signal input to the RFPA, enforcing a maximum allowable amplitude in a high peak to average power ratio (PAPR) instantaneous high peak of the RF signal,

wherein the RFPA resides in a communication device operable within a Hybrid Fiber Coax (HFC) system.

18. A method for preventing RF signal distortion and signal error producing memory events in a Radio Frequency (RF) power amplifier (RFPA), comprising:

an element increasing or supplementing a bias of the Radio Frequency (RF) power amplifier (RFPA) when a high PAPR instantaneous high peak is detected in the RF signal prior to receipt by the RFPA,

wherein the RFPA resides in a communication device operable within a Hybrid Fiber Coax (HFC) system,

wherein the element increases or supplements the bias of the RFPA gradually using a low pass filter from a normal level to an elevated level while the high PAPR instantaneous high peak is being processed by the RFPA, and wherein the element decreases the bias of the RFPA gradually from the elevated level to the normal level when the high PAPR instantaneous high peak is no longer being processed by the RFPA.

19. A method for preventing RF signal distortion and signal error producing memory events in a Radio Frequency (RF) power amplifier (RFPA), comprising:

a first element operable to detect when an instantaneous output voltage of the Radio Frequency (RF) power amplifier (RFPA) is below a predetermined voltage; and

in response to the first element detecting that instantaneous output voltage of the RFPA is below a predetermined voltage, a second element operable to supply additional current to prevent the output voltage of the RFPA from falling below a predetermined threshold voltage,

wherein the RFPA resides in a communication device operable within a Hybrid Fiber Coax (HFC) system.

20. The method of claim 18 , wherein the element does not experience the signal error producing memory events, and wherein said signal error producing memory events cause distortions in the RF signal over time in response to the RF signal having a high PAPR instantaneous high peak beyond a threshold amplitude.