This example illustrates how the PLL synthesizer is used as the LO in a typical radio receiver. The LO working with the down mixer is used to frequency translate an RF carrier down to a lower intermediate frequency. In this case the RFIN spectrum ranges from 5725MHz to 5825MHz. The RF spectrum example is the upper range of the Unlicensed National Information Infrastructure ISM band. For this example, the radio receiver will sequentially tune to one of four 20MHz channels occupying the RF input spectrum.