%% Modulate Two-Tone DC Signal Using IQ Modulator
% Use the IQ Modulator block to Modulate a two-tone DC signal to RF
% level. Observe the impairments in the modulated output signal 
% such as images due to gain imbalance, intermodulation distortion, and
% output third-order intercept (OIP3).
%%
% The two tones are at 10MHz and 15 MHz.The power of each tone is -30 dBm.
% The carrier frequency is 0 GHz.
%% IQ Modulator
% The IQ modulator parameters are :
% 
% * Available power gain: 10 dB
% * Local oscillator frequency: 2 GHz
% * I/Q gain mismatch: 0.1 dB
% * LO to RF Isolation: 90 dB
% * Noise Floor: -160 dBm/Hz
% * IP3: 10 dBm
%
%%
% Open the model.
open('model_IQmod')
%%
% Run the model and observe the spectrum analyzers.
%
%% Complex Output Power Density
% 
% <<../iqmod_complex_output_power_density.png>>
% 
%
% In the complex output power density spectrum analyzer, you see the noise
% floor of the signal at -160 dBm/Hz.
%% Complex Output Spectrum Analyzer
% 
% <<../iqmod_complex_spectrum_analyzer.png>>
% 
%
% In the complex output spectrum analyzer, you see the whole modulated
% signal including the imaginary parts. The output power level of the two
% tones (10 MHz and 15 MHz)is -20 dBm. 
% 
% $$Output power level = Input power level + gain = -30dBm+10dB = -20dBm$$
% 
% 
% The output third-order intercept( OIP3) is at 10 dBm. The spectrum
% analyzer measures this value.

%% Image Rejection Ratio
% The images of the two tones are at -10 MHz and -15 MHz. The output power
% level of the two images are -67.8 dBm. Image rejection ratio is given by
% the formula:
%%
% 
% $$IMRR = [(gain imbalance)^2+1-2*(gain imbalance)] / [(gain imbalance)^2+1+2*(gain imbalance)]$$
% 
% where,
% 
% $$Gain Imbalance = 10^ (0.1/20) = 1.0116$$
% 
% 
% 
% $$IMRR dB = 10*log10(3.3253e-05) = -44.78 dB$$
% 
% The image power level is given by the formula:
%
% $$Image level = -23 dBm-44.78 dB = -67.78 dBm$$
%


%% 
% Copyright 2012 The MathWorks, Inc.