Ewch i’r prif gynnwys
Ehsan Azad

Dr Ehsan Azad

Myfyriwr ymchwil

Yr Ysgol Peirianneg

Adeiladau'r Frenhines-Adeilad Canolog, Ystafell Ystafell C/3.10, 5 The Parade, Ffordd Casnewydd, Caerdydd, CF24 3AA


I am a PhD research student at the Centre for High Frequency Engineering (CHFE), School of Engineering; under the supervision of Dr Roberto Quaglia, Dr James J. Bell, and Prof. Paul J. Tasker.

My research addresses the problems encountered in the field of non-linear RF and microwave power amplifier design. My research activities include design, modelling and characterisation of non-linear RF and microwave transistors and power amplifier circuits.

I have published several peer-reviewed scientific papers. 

My peers and I participated in two High Efficiency Power Amplifier (HEPA) student design competitions. Our team won second place in the 2022 RWW/ARFTG MTT-S HEPA Student Design Competition, Las Vegas, USA; and the third place award in the 2021 IMS  HEPA Student Design.











My PhD research project is in collaboration with Ampleon Netherlands B.V to design highly efficient power amplifiers capable of working at multiple DC supply voltages. The design is based on the state of the art Gallium Nitride (GaN) high electron mobility transistor (HEMT)  devices for sub-6 GHz 5G base stations. 

The Cardiff nonlinear behavioural model is a critical element in the design process as it allows us to directly use the nonlinear load-pull measurement data within the CAD simulator environment. Hence; increasing the chance of "first pass" successful design.

We have developed a new mathematical formulation for the Cardiff model which is capable to predict the device behaviour at various DC supply voltages. The result of this achievement has been published in several peer-reviewed scientific papers.



Efficiency Improvement in Base Station Power Amplifiers


I have more than 250 hours of experience as a lab demonstrator and teaching assistant in both undergraduate and postgraduate ectrical and electronic enginieering Modules. The modules which I have participated in are listed as below:

  • MSc: Microwave and Millimetre-Wave Integrated Circuit Design and Technology.
  • MSc: RF circuit design & CAD.
  • Year one: Electrical and electronic engineering lab.
  • Year one: Analogue and digital communication systems.
  • Year one: Matlab surgery.
  • Year one: Electrical and Electronic Engineering 1.


Roberto Quaglia

Roberto Quaglia

Research Fellow