Simulating Dynamic Load Modulated Amplifiers
Presented by: Dominic FitzPatrick, Specialist Consultant in RF and Microwave Amplifier Design, PoweRFul Microwave
Sponsored by: National Instruments
It is interesting how many of the techniques for improving amplifier performance, such as Doherty and Envelope Tracking, have their roots in early days of Vacuum Tube Devices, and so it is with Dynamic Load Modulation. The latest generation of device technology and the introduction of nonlinear simulation tools have breathed new life into this latter technique.
This presentation will introduce the concept of Dynamic Load Modulation and demonstrate how amplifiers can be designed using this approach. The ability of the modern CAD tools to model nonlinear components, such as varactor diodes, using discrete components and parameterised variables will be covered. This capability, coupled with the nonlinear models of GaN FET devices, gives the designer access to a fully dynamic simulation of the amplifier, opening up numerous other possibilities for performance improvement.