Direct loop gain and bandwidth measurement of phase-locked loop

Area of Science:

• Electrical Engineering
• Control Systems
• Signal Processing

Background:

• Phase-locked loops (PLLs) are critical components in modern electronics.
• Accurate measurement of loop gain and bandwidth is essential for PLL performance.
• Existing methods for PLL parameter measurement can be complex or disruptive.

Purpose of the Study:

• To propose a simple and robust technique for directly measuring PLL loop gain and bandwidth.
• To enable real-time measurement of loop gain in a closed PLL system.
• To validate the proposed measurement technique against theoretical calculations.

Main Methods:

• A novel, non-invasive technique is introduced for direct loop gain measurement.
• The method operates in real-time without interrupting the PLL's locked state.
• The configuration is designed for simplicity and ease of implementation.

Main Results:

• The proposed technique successfully measures the real loop gain of a PLL.
• Measured loop gain values show strong agreement with theoretical predictions.
• The technique's validity is confirmed through experimental results.

Conclusions:

• The developed technique provides a simple, robust, and accurate method for PLL parameter measurement.
• This approach facilitates real-time monitoring of PLL performance.
• The technique's applicability can be extended to various phase-locking systems requiring precise gain and bandwidth assessment.