Open loop modulation techniques for wide bandwidth digital frequency synthesis

Modern wireless standards require phase modulators to be low power and have wideband transmission capability, while meeting strict out-of-band emission requirements. A review of traditional approaches to system and circuit architectures for such modulators, is presented. Open loop phase modulation presents an attractive alternative and has the potential to be used in other systems, like DDFS. An overview of problems with this architecture and recent solutions will be presented, followed by the description of a new open loop modulation technique with phase quantization noise cancellation and phase calibration.