Fractional-N PLL for RF Applications with Adaptive Intelligent Controller and AVLS Divider

This paper presents the design and simulation of a high-performance fractional-N phase-locked loop (PLL) frequency synthesizer with a ۶۰ kHz bandwidth, operating within a frequency range of ۲.۴ GHz to ۲.۵ GHz. The design integrates advanced features such as a sigma-delta modulator configured in a ۱-۱-۱ MASH architecture and a fractional divider, both implemented with intelligent control circuits to precisely determine the division ratio. These innovations aim to reduce delay and power consumption while enhancing phase noise performance and ensuring robust system stability. The fractional divider is a critical component of the PLL, enabling frequency division into fractional values with high precision. By incorporating intelligent control circuits, the design achieves accurate adjustments to the division ratio, contributing significantly to the overall reliability and efficiency of the PLL. Additionally, integrating advanced modulation and filtering techniques further optimizes the loop's performance by suppressing unwanted noise and ensuring stability under varying conditions. Simulation results demonstrate the effectiveness of the proposed design, achieving a fast frequency lock time of approximately ۳ µs, a stable phase margin of ۴۵ degrees, and an impressive phase noise performance of -۱۴۸.۱۳ dBc/Hz at a ۱ MHz offset. Furthermore, the system's total power consumption is only ۲.۳۶ mW, highlighting its exceptional balance between power efficiency and high performance.

Keywords:

Fractional-N Frequency Synthesizer , Fast locking , Divider , Sigma-Delta Modulator , Delay Locked Loops , AVLS