about FSK data question....

super

Dear all :
              In fsk close loop direct Frequency modulation ,
          1.  data rate is higher than loop BW  or lower than loop BW ?
          2.  And what's the relation between data rate and Loop BW ?

           Because modulation from VCO , it's a high pass function for VCO vs PLL.
4 Q( t9 u" z4 e1 }* D& M7 ?. f           If modulation frequency > BW , it will be supress by VCO vs PLL transfer function.
           It will be trace and fix it.  So modulation function is fail.
             Is this concept is right ?
                  
                    Thanks .

simenkid

1.data rate可以高於loop bandwidth, 也不可以.端看用什麼architecture
' @% L# {/ D2 k& ^: J2.假使單純在multi-modulus或是由reference端做調制, data-rate高於loop bandwidth則勢必產生失真

% a& U. X3 b8 Z) Y6 U% j直接由PLL Synthesizer調制提升FSK, FM, GMSK等固定波包調制之data rate
8 o. E( w( j' F6 r可選擇如pre-emphasis或two-point modulation(同時兼顧inband與outband,理論上無頻寬限制)的方式