Non-Linearity - Part II — Lesson 2

This lesson covers amplifier characteristics and the concept of intermodulation products and their potential issues. It also explains how the nonlinearity can be expressed in terms of Taylor coefficient. It also introduces the definitions of nonlinearity, such as the 1 dB compression point and the third order intercept point. The lesson concludes with an explanation of how non-linear devices behave when cascaded and how to calculate the third order intercept point in such scenarios.

Video Highlights

00:17 - Introduction
02:11 - Amplifier characteristics and the 1 dB compression point
06:24 - How the nonlinearity can be expressed in terms of Taylor coefficient
11:13 - What happens when two non-linear devices are cascaded
20:08 - Converting the voltage into power
23:08 - Power addition in case of coherent and non-coherent
24:15 - How manufacturers quantitatively measure and specify the inter mod product

Key Takeaways

- Non-linear devices can produce intermodulation products, which can cause issues if they fall within the filter bandwidth of one of the fundamentals.
- The 1 dB compression point and the third order intercept point are key definitions of nonlinearity.
- The third order intercept point can be defined from both the input and output sides.
- When two non-linear devices are cascaded, the third order intercept point can be calculated using the individual intercept points and gains of the devices.
- The concept of carrier to third order intermodulation ratio is used to measure the intermodulation noise in non-linear devices.