Delta and Sigma Modulation — Lesson 6

This lesson covers the delta and sigma modulation technique. It discusses the problem of spurious frequency in fractional n synthesis and the need to redesign the frequency divider circuit. The lesson also introduces a feedback control system used in Analog to Digital conversion. It explains how the loop gain in this system affects the output and input relationship. The lesson further delves into the concept of quantization noise and how it can be managed. It also discusses the design of sigma delta modulator and its role in reducing face noise.

Video Highlights

00:25 - Introduction
04:18 - Analog to digital converter and filter
14:02 - Impact of quantization noise on output
29:50 - Output spectrum of sigma delta modulator
45:50 - Design of sigma delta modulator and phase noise requirements

Key Takeaways

- Fractional length frequencies synthesis is a crucial aspect of CMOS Radio Frequency Integrated Circuit.
- Spurious frequency is a significant problem in fractional n synthesis, necessitating a redesign of the frequency divider circuit.
- The sigma delta or delta sigma modulator, a feedback control system, plays a vital role in Analog to Digital conversion.
- The loop gain in the sigma delta modulator system influences the relationship between output and input.
- Quantization noise is a common issue in this system, and its management is crucial for effective functioning.
- The design of the sigma delta modulator is critical in reducing face noise and ensuring the system's efficiency.