1 % This script calculates the SNR along the line that goes from the crystal
   2 % oscilaltor to the EOM of the 40 Upgrade RF plan.
   3 % It is intended for the RF plan as shown in the yEd schematic;
   4 
   5 s = [];
   6 n = [];
   7 gdB = [0 -1 8 -3.5 -3 7 -15 11 -3.5 -1.5 28.5];
   8 nf = [];
   9 numelements = 11;
  10 
  11 nf = zeros(numelements,1);
  12 nf(3) = 1.5;
  13 nf(8) = 7.5;
  14 nf(10) = 9;
  15 
  16 nf = 10.^(nf/10);
  17 
  18 s(1) = dBmtoWatts(13);
  19 n(1) = dBmtoWatts(-170 + 10*log10(s(1)*1e3));
  20 
  21 g = 10.^(gdB/10);
  22 
  23 Ptn = 4*1.38e-23*290*1e3;     % thermal noise power from a 50Ohm resistor
  24 
  25 for i = 2 : numelements
  26     s(i) = g(i) * s(i-1);
  27     n(i) = g(i) * ( n(i-1) + nf(i) * Ptn );
  28 end
  29 
  30 sdBm = Watts2dBm(s)'
  31 ndBm = Watts2dBm(n)'
  32 snrdBc = sdBm - ndBm