Macquarie University
01whole.pdf (3 MB)

Q-band mixers in newly released 0.15 µm GaN process

Download (3 MB)
posted on 2022-03-28, 14:33 authored by Nethini Thilanga Weerathunge Imiyage
Recent advancements in communication systems have created a demand for circuits and subsystems with wide bandwidth at higher frequencies. Being one of the fundamental building blocks of transmitter and receiver chains, mixers play a major role in communication systems. Gallium-nitride (GaN) is an emerging semiconductor technology that has gained interest in realising a fully integrated transceiver chain. Therefore, it is interesting to investigate mixer designs in GaN technology which have not addressed much in literature. This thesis presents the implementation of a resistive single-ended mixer (SEM) and a single-balanced mixer (SBM) in WIN Semiconductor's newly released 0.15 m GaN process. The SEM operates over the entire Q-band and indicates a minimum conversion loss of 9 dB at midband. The SBM was realised using two SEMs connected with a Marchand balun and a Wilkinson power divider. It indicates a minimum conversion loss of 9.3 dB close to mid-band and 12.3 dB across the frequency band from 32.7 GHz to 53.6 GHz. An improved LO-RF isolation better than 47 dB was achieved using balanced LO signals. The IIP3 values of SEM and SBM are 26.6 dBm and 24.6 dBm respectively which conrm the high linearity of both mixers. The designed Marchand balun operates over a wide bandwidth from 27 GHz to 99 GHz. Furthermore, this research explores a capacitive loading technique to improve the input matching of the balun.


Table of Contents

1 Introduction -- 2 Background and Literature Review -- 3 Methodology -- 4 Single-Ended Mixer -- 5 Marchand Balun and Wilkinson Power Divider -- 6 Single-Balanced Mixer -- 7 Conclusion and Future Work -- 8 Abbreviations.


Bibliography: pages 54-60 Theoretical thesis.

Awarding Institution

Macquarie University

Degree Type

Thesis MRes


MRes, Macquarie University, Faculty of Science and Engineering, School of Engineering

Department, Centre or School

School of Engineering

Year of Award


Principal Supervisor

Michael Heimlich


Copyright Nethini Thilanga Weerathunge Imiyage 2019




1 online resource (xi, 60 pages) illustrations

Former Identifiers