Processes for preparation of marek's disease virus using continuous avian cell lines

Abstract

An amplifier distortion reduction system obtains a distortion signal from the amplifier output and feeds the distortion signal back to the input side of the amplifier to cancel with the distortion produced at the amplifier output. For example, a signal to be amplified by an amplifier is received on a main signal path. The amplifier produces an amplified output with a non-distortion spectrum and a distortion spectrum. A sample of the amplified output is produced from the main signal path and placed on a feedback path. On the feedback path, the distortion spectrum is obtained from the sample amplified output. The distortion spectrum is phase and/or amplitude adjusted to produce the distortion signal. The distortion signal is placed onto the main signal path at the input side of the amplifier with the signal to be amplified to destructively combine with the distortion produced from the amplifier in amplifying the signal to be amplified.

1 . A method of producing an amplified signal, said method comprising the steps of: 
 amplifying an input signal on a signal path by an amplifier on said signal path to produce said amplified signal with distortion;    obtaining a distortion signal on a feedback path from said amplified signal with distortion; and    placing said distortion signal from said feedback path onto said signal path prior to said amplifier to reduce distortion produced from said amplifier.    
     
     
         2 . The method of  claim 1  comprising the steps of: 
 sampling an input signal to be amplified onto a carrier cancellation path;  
 sampling said amplified signal with distortion to produce a sample amplified signal with distortion on a feedback path;  
 combining said sample input signal on said carrier cancellation path with said sample amplified signal with distortion on said feedback path.  
 
     
     
         3 . The method of  claim 2  comprising the steps of: 
 phase shifting of said sample input signal on said carrier cancellation path prior to said step of combining; and  
 attenuating said sample amplified signal with distortion prior to said step of combining.  
 
     
     
         4 . The method of  claim 3  comprising the step of: 
 responding to an output of said step of combining by adjusting said steps of phase shifting said sample input signal and attenuating said sample amplified signal.  
 
     
     
         5 . The method of  claim 4  comprising the steps of: 
 sampling said output of said step of combining;  
 frequency down-converting said output sample to baseband;  
 low pass filtering said baseband output sample to produce a residual non-distortion signal;  
 generating a control signal from said residual non-distortion signal using a voltage differential amplifier and integrator.  
 
     
     
         6 . The method of  claim 4  wherein said input signal has multiple carriers and said step of responding comprises the step of: 
 responding to said portion of said output corresponding to the lowest carrier frequency of said multiple carriers.  
 
     
     
         7 . The method of  claim 1  comprising the steps of: 
 phase shifting and amplifying a distortion spectrum from said amplified signal with distortion to produce said distortion signal;  
 injecting said distortion signal on said signal path before said amplifier to cancel distortion generated by said amplifier in amplifying said input signal to be amplified.  
 
     
     
         8 . The method of  claim 7  comprising the steps of: 
 sampling said amplified signal with distortion to produce a sample amplified signal with distortion on said feedback path;  
 sampling said sample amplified signal with distortion to produce an output sample;  
 responding to said output sample to control said phase shifting and amplifying said distortion spectrum.  
 
     
     
         9 . The method of  claim 8  wherein said step of responding comprising the steps of: 
 attenuating said output sample;  
 frequency down-converting said output sample to baseband;  
 filtering said output sample using a low pass filter and a high pass filter to produce a residual distortion signal; and  
 providing said residual distortion signal to a voltage differential amplifier and integrator to control said steps of phase shifting and amplifying said distortion signal.  
 
     
     
         10 . The method of  claim 8  wherein said input signal has multiple carriers and said step of responding comprises the step of: 
 responding to said portion of said output sample corresponding to the highest carrier frequency of said multiple carriers.  
 
     
     
         11 . The method of  claim 1  comprising the steps of: 
 sampling said amplified signal with distortion on said signal path to produce a sample amplified signal with distortion on said feedback path; and  
 filtering a non-distortion spectrum from said sample amplified signal with distortion.  
 
     
     
         12 . The method of  claim 11  comprising the steps of: 
 down-converting said sample amplified signal with distortion on said feedback path to an intermediate frequency (IF);  
 producing an IF image of the distortion spectrum portion on said feedback path by low pass and high pass filtering of said IF sample amplified signal with distortion; and  
 up-converting said IF image of the distortion spectrum portion on said feedback path to radio frequency (RF) and recover a RF distortion spectrum.  
 
     
     
         13 . The method of  claim 11  comprising the steps of: 
 down-converting said sample amplified signal with distortion on said feedback path to a baseband frequency;  
 producing a baseband image of the distortion spectrum portion on said feedback path by low pass and high pass filtering of said baseband sample amplified signal with distortion; and  
 up-converting said image of said baseband distortion spectrum portion on said feedback path to radio frequency (RF) to recover a RF distortion spectrum.  
 
     
     
         14 . An amplifier distortion reduction system, said system comprising: 
 an amplifier on a signal path adapted to amplify an input signal on said signal path to produce an amplified signal with distortion; and    distortion feedback circuitry adapted to obtain a distortion signal from said amplified signal with distortion and to place said distortion signal on said signal path prior to said amplifier to reduce distortion from said amplifier.    
     
     
         15 . The system of  claim 14  wherein said distortion feedback circuitry comprising: 
 a splitting device adapted to place a sample of said input signal to be amplified onto a carrier cancellation path;  
 a coupler on said signal path adapted to produce a sample of said amplified signal with distortion on a feedback path;  
 a combining device adapted to combine said input signal sample on said carrier cancellation path with said sample amplified signal with distortion on said feedback path.  
 
     
     
         16 . The system of  claim 14  comprising: 
 a coupler adapted to produce on a feedback path a sample of said amplified signal with distortion on said signal path; and  
 said feedback distortion circuitry includes a filtering arrangement adapted to reduce a non-distortion spectrum of said sample amplified signal with distortion on said feedback path.  
 
     
     
         17 . The system of  claim 16  wherein said feedback distortion circuitry comprising: 
 a down-converter adapted to down convert said sample amplified signal with distortion on said feedback path;  
 said filtering arrangement adapted to reduce a down-converted non-distortion spectrum of said down-converted amplified signal with distortion to leave a down-converted distortion spectrum on said feedback path; and  
 an up-converter adapted to up-convert said distortion spectrum on said feedback path.  
 
     
     
         18 . The system of  claim 17  wherein said down-converter is adapted to down-convert said sample amplified signal with distortion on said feedback path to an intermediate frequency; and said up-converter is adapted to up-convert said distortion spectrum on said feedback path to radio frequency.  
     
     
         19 . The system of  claim 17  wherein said down-converter is adapted to down-convert said sample amplified signal with distortion on said feedback path to a baseband frequency; and said up-converter is adapted to up-convert said distortion on said feedback path to produce said distortion spectrum on said feedback path at radio frequency