Communications Blockset

Variables in the Model

When you load the model, it creates three variables besides n and m:

• Fr = frequency of the reference signal
• Fq = quiescent frequency in the Voltage-Controlled Oscillator (VCO) block
• Sen = Voltage-Controlled Oscillator input sensitivity

Note    If you change the values of these variables at the MATLAB command line, use the same upper and lower case letters in the variable names as given above. The variables in the Phase-Locked Frequency Synthesis demo have similar names, but with different cases.

The model initially assigns values to these variables as follows: n = 10, m = .3, Fr = 10 MHz, Fq = 90 MHz and Sen = 10 MHz/V. The frequency of the synthesized signal at the model's steady state is then 103 MHz. After running the simulation with these values, you can later change them by typing new values at the MATLAB prompt, if you want to experiment with the model.

Fractional-N Frequency Synthesis Demo

Blocks and Subsystems in the Model