In the IDU transmitter the MAX2870 generates a 1485MHz conversion clock for the high-speed DAC which synthesizes IF1 at 350MHz. The MAX2870 is next used in the ODU to generate the LO at 1485MHz for the RF up converter. PTP microwave radios use constellations up to 2048QAM or 4096QAM to achieve high spectral efficiency and deliver high capacity. The PLL synthesizer requires very low phase noise and excellent spurious performance to support high order modulation with adequate phase noise margin. This preserves signal-to-noise ratio allowing the system to achieve maximum capacity throughput.