The filter serves three main purposes. Firstly, it removes the analogue filtering
requirement by pushing the image frequencies higher in the spectrum. Secondly, it
reduces the burden of in-system transmit FIFO size by band-limiting the DAC input
signals. Thirdly, it relaxes the computational burden of the microcontroller when the
transmit signal is generated by the embedded system. The test signal is reconstructed
using Equation 2, where N is the number of samples in total; n is the index running
from 1 to N step by 1; cycle is the number of sine wave cycles.