Finally, the receiver tunes to a channel at the 5805MHz RF carrier so the LO is set at 4805MHz to yield 1000MHz IF. In this manner, the IF frequency and IF filter are fixed but the PLL frequency synthesizer is agile and wideband. Therefore, the PLL can tune the radio receiver to any 20MHz channel across the 5725MHz to 5825MHz spectrum and down convert to a single common IF.