Where To Find This Example
Please note that this particular script is only available in V13.02 and earlier.
Select Help > Open Examples... from the menus and type either the example name listed above or one of the keywords below.
Or in Version 13 you can open the project directly from this page using this button.
This project illustrates how to use VSS primitive blocks to construct a chirp signal. A SAW source in combination with a TONE source is used to drive an FM transmitter.
The saw tooth's amplitude swing in conjunction with the frequency sensitivity (K) of the FM transmitter sets the bandwidth (frequency range) of the chirp signal.
With the amplitude swing of the sawtooth set to +/-2 and K of the FM transmitter at 3.5MHz, the bandwidth of the chirp signal is 14MHz.
The chirp signals center frequency can be changed by setting the variable fc to another frequency.
The time domain waveforms of the chirp and sawtooth signal are shown.
The "Spectrum" graph has its RBW set to 0.25 MHz and its VBW set to 0.25 KHz. A Blackman-Harris window is applied to the time domain signal prior to generating the spectrum.
System Diagram - Chirp Generator
Graph - Spectrum
Graph - Saw Tooth
Graph - Chirp Signal