Systematic Design of a Microwave GaN Doherty Power Amplifier

Doherty PAs are the standard for efficient transmission of amplitude modulated signals. However, its design process varies tremendously across use case, frequency range, power range, and device technology. Due to this, the design procedure of a Doherty PA is often subjected to tuning and optimization. A step-by-step systematic approach in designing a Doherty PA is introduced in this thesis as a consequence of a novel method to match devices to their optimum terminations. The design methodology introduced in this thesis can be applied to any use case irrespective of the operating conditions. To display the functionality of this procedure, a microwave GaN Doherty PA is designed from simulations using Agilent's Advanced Design System (ADS). It is then fabricated and measured for performance. Good agreement between measured and simulated data is demonstrated.M.A.S