========================FM_2_PM=========================
                      
                      
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                                  Pure sign wave
                      
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                                 A Moving sign wave
                      
                        
                      Frequency Modulate a 1kHz carrier with a 1Hz signwave
                      
                               Freq(t) = [  1000 + sin(2*PI*t)  ]
                      
                        Signal= sin( (Freq(t))*2*PI*t)  <--FM format
                      
                          at time = 1/4  The Frequency is 1001 Hz
                          at time = 3/4  The Frequency is  999 Hz
                      
                      
                      Another way to think of it is Phase Modulation...
                      
                      
                        Signal= sin( (1000)*2*PI*t +Phase(t))    <-- PM format
                      
                         
                            the phase will be Integral of FM ...
                        
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                              Phase(t) =   | 2*PI*sin(2*PI*t)*dt = -cos(2*PI*t)
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                      So 1Hz peak FM over 1Hz will generate 1radian peak of PM
                      
                           And to convert FM to PM, just integrate 
                      
                                         and
                      
                          One Hz FM at One Hz equals One radian PM
                          The PM will lag the FM which causes it.
                      
                                      ^
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                           Freq=1001Hz|       Phase= +1radian
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                         Phase= -1radian                   Freq=999Hz