Synchronizing WiMAX synthesizer TRF1x21/TRF1x12 to arbitrary reference
Author: Russell Hoppenstein

Texas Instruments has a WiMAX RF chipset for basestation and CPE applications that include integrated synthesizers to realize the superheterodyne architecture. For optimum channel resolution, these devices must be tied to an 18MHz reference frequency. In some systems, the synthesizer reference frequency needs to be synchronized to a system reference frequency that may not be an integral multiple of 18MHz. This application report presents the circuitry required to synchronize the 18MHz reference to an arbitrary system reference clock and illustrates that negligible degradation occurs in the RF performance of the radio.