VCO_plot_dbc_per_hz.m

% Plot simulation results with log x axis. 
% Plot only + freq terms.
% Per common practice, do not show carrier term.
% Plot 1/f for reference, plus measured, plus specification 
% Copywrite 2004-2010 The MathWorks, Inc.
index_start = 3;              % move out from carrier at DC and fft window effects
Frame_Length = length(Normalized_Spectrum);
Fvec_meas = Spectrum_dF*((index_start-1):Frame_Length/2);

h2  =  findobj('Tag','plot_VCO');
if isempty(h2) 
   h2 =  figure('Tag','plot_VCO')
else
   figure(h2)
end

semilogx(Fvec_meas,10*log10(Normalized_Spectrum(index_start:(Frame_Length/2+1))),....
         Fvec,Lvec,'o');
xlabel('Hz from Carrier'); ylabel('dBc/Hz'); grid on;
legend('Measured', 'specification');
axis([Fvec(1),Fvec_meas(end),-130,-30])