Improvement of transmitter efficiency for greener mobile networks

Van Den Heuvel, Indy 2026. Improvement of transmitter efficiency for greener mobile networks. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Modern communication systems have ever higher performance demands. Power Amplifiers (PAs) are a critical component of modern communication systems with a significant energy usage. A better understanding of PA design could lead to better performance or cheaper components, resulting in lower hardware costs and energy consumption. This thesis explores the impact of wideband modulation signals on PA design processes, and attempt to investigate various design improvements which could lead to better performance under wideband operation. Four main topics are discussed in this thesis. The first topic, the investigation of the simulation of wide band signals, resulted in the development of the Iterative Envelope Simulator, an alternative simulation method for wideband signals. This simulator solves an enve lope defined signal in the baseband domain through a converging iterative Harmonic Balance method. The sections discuss the development of the simulator through var ious improvements. The accuracy of the simulator was verified through simulations and measurements. The second topic covers a novel method of baseband impedance cancellation in multi transistor amplifier topologies. The method uses a transformer in between two amplifiers to apply a 180 degree phase delay in the baseband do main, cancelling out baseband impedance through active load modulation. A 3.5 GHz Doherty PCB was designed, and the measurements verified the effectiveness of the method. For the third topic, the baseband impedance of Doherty amplifiers was investigated. An inherent resonance between the bias network and the Doherty matching network was identified. An improved biasing network was proposed and implemented on a Ku-band simulated IC. Performance improvements were verified using simulations. The fourth topic discusses a method of linearizing Load Mod ulated Balanced Amplifier designs. A 28 GHz IC was designed and produced. Its performance was successfully measured under single tone excitation.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Schools > Engineering
Uncontrolled Keywords:	1. Power Amplifier 2. Efficiency 3. Wideband 4. Baseband 5. Modelling 6. Linearity
Date of First Compliant Deposit:	3 July 2026
Last Modified:	06 Jul 2026 13:17
URI:	https://orca.cardiff.ac.uk/id/eprint/187866

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