AD-PLL for WiMAX with Digitally-Regulated TDC and Glitch Correction Logic
In this paper, the authors describe the design of an All-Digital Phase Locked Loop (AD-PLL) for wireless applications in the WiMAX 3.3 - 3.8GHz bandwidth. The Time/Digital Converter (TDC) sets the in-band noise and it may be responsible for the presence of spurious tones at the PLL output. The TDC is implemented as a Delay-Locked Loop (DLL) to be insensitive to process spreads and it uses a lead-lag phase detector and a digital loop filter to further take advantage of the digital approach. The most important source of spurs is identified in the time skew between counter and TDC in the PLL.
Provided by: Hindawi Publishing
Topic: Hardware
Date Added: Sep 2009
Format: PDF