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The results are shown in the figure below. v(2) is the equal to the transmitted signal, and v(6) is the amplified receiver signal. The blue signal v(9) is the output beat signal, which has a measured period of 1.009μs. Therefore, f<sub>b</sub> = 1MHz.
{{Note|Radar system simulations usually involve time scales of different orders. They typically require a large transient time interval with a very fine time step ceiling.}}
As you can see from the figure, the voltage signal v(7) at the output of the peak detector (plotted in dark blue) is a good reconstructed replica of the baseband 300MHz sinusoidal signal. Compare this signal to the envelope of the input AM-modulated signal plotted in yellow. You can use the "Delta Line Mode" of the graph window to measure the period or clock rate of the binary output, which is about 3.34ns consistent with the signal frequency of fs = 300MHz.
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[[File:SysTUT7 15.png|thumb|750px|The graph of the analog input voltage transmitted signal (yellow), output of the QAM block vreceived signal (4light blue), mixer output of the peak detector v(7dark red) and the digital filter output of the QAM Demodulator circuit(dark blue).]]
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In this simulation, the stop time was 20μs to cover both the transmitted and received signals adequately. On the other hand, the periods of the signals were on the order of 1ns. Therefor, a step ceiling of 50ps was chosen. From the above figure, you can see that the received signal starts at t = τ = 10μs.
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