High-Efficiency Low-Cost Power Amplifiers for Millimetre-Wave Massive MIMO Systems (HELOPA)
Lead Research Organisation:
Queen's University Belfast
Department Name: Sch of Electronics, Elec Eng & Comp Sci
Abstract
The dramatic improvements in capacity (as much as 1000x the current level) and spectral efficiency that are needed for future wireless communication systems to accommodate the rapidly increasing number of wireless electronic gadgets and users who require access to ubiquitous high-speed wireless links can be achieved by adopting mm-wave (mmW) massive multiple-input multiple-output (MIMO) technologies. The realization of mmW massive MIMO requires a radical change in base station architecture wherein hundreds of power amplifiers are required to feed a large array of small antennas. The development of mmW massive MIMO transceivers has been hampered to date by the power amplifier's (PA) poor efficiency and high implementation cost. Nonlinear switch-mode power amplifiers (SMPAs) such as Class E and F offer high efficiency but require fast (power-hungry, expensive) transistors to allow the generation of higher order harmonics. Moreover, an abrupt drop during ON-to-OFF or OFF-to-ON transition in the idealised switch current or voltage waveform of existing SMPA topologies results in substantial power dissipation in the practical implementation, and hence reduces the PA efficiency. The proposed research ambitiously aims to produce a new type of highly-efficient, highly-linear power amplifier that offers true soft-switching characteristics to permit the use of low-cost, slow-switching transistors for effective deployment in mmW massive MIMO systems and thus open the way for very power-conservative high-performance systems.
Planned Impact
Successful outcomes of this research will catalyse widespread exploitation of mmW massive MIMO, enabling access to global ubiquitous ultrafast wireless links which provide a platform for easy access to a wide range of information and entertainment, convenient online shopping experience, to name few. The proposed concepts can also be adopted for other mmW applications such as intelligent transport systems, autonomous vehicles, and health monitoring systems which will have essential roles in enhancing the overall quality of people's life.
Signal coverage has been a persistent problem since the first ever mobile phone call was made in Britain 30 years ago. Last year, the UK government and mobile networks struck a £5bn deal to tackle this issue. The proposed low-cost mmW massive MIMO technology will benefit the end-users of wireless communication systems by delivering improved quality of service (QoS) including better signal coverage, faster data rate and enhanced efficiency.
Through synergistic collaboration with the industrial partner, prospective commercialisation pathways for the proposed technology have been identified. Successes in this project would accelerate the translation of massive MIMO research into new products. In addition, it is anticipated that the innovative concepts proposed in this research would generate IP which could then lead to the creation of a spin-out company or licencing opportunity. The funding also provides the opportunity of developing the PI's independent research career in a new area of endeavour as well as the development of the career of the appointed postdoctoral researcher in both technical and soft skills.
Signal coverage has been a persistent problem since the first ever mobile phone call was made in Britain 30 years ago. Last year, the UK government and mobile networks struck a £5bn deal to tackle this issue. The proposed low-cost mmW massive MIMO technology will benefit the end-users of wireless communication systems by delivering improved quality of service (QoS) including better signal coverage, faster data rate and enhanced efficiency.
Through synergistic collaboration with the industrial partner, prospective commercialisation pathways for the proposed technology have been identified. Successes in this project would accelerate the translation of massive MIMO research into new products. In addition, it is anticipated that the innovative concepts proposed in this research would generate IP which could then lead to the creation of a spin-out company or licencing opportunity. The funding also provides the opportunity of developing the PI's independent research career in a new area of endeavour as well as the development of the career of the appointed postdoctoral researcher in both technical and soft skills.
People |
ORCID iD |
Mury Thian (Principal Investigator) |
Publications
Love M
(2019)
Lumped-Element Wilkinson Power Combiners Using Reactively Compensated Star/Delta Coupled Coils in 28-nm Bulk CMOS
in IEEE Transactions on Microwave Theory and Techniques
Love M
(2019)
Lumped-Element Wilkinson Power Combiners Using Reactively Compensated Star/Delta Coupled Coils in 28-nm Bulk CMOS
in IEEE Transactions on Microwave Theory and Techniques
Mugisho MS
(2019)
Analysis and design of a high-efficiency Class-EM power amplifier
Description | We have developed an exact analysis and systematic method to design a compact integrated Wilkinson power combiner (WPC) for use in high-efficiency power amplifier (PA) systems and phased array radars. Star and delta equivalent circuits of a coupled coil are for the first time proposed to be used in the WPC design, reducing the electrical size of the state of the art by a factor of 13. The concept was independently verified through robust simulations and high-precision measurements of the WPC circuits implemented in advanced 28 nm bulk CMOS. The circuit footprint is reduced through employing a coupled coil to realize two series inductors by taking advantage of the mutual inductance of the coupled coil. In addition, each series inductor is replaced by a parallel LC resonator to provide the required inductance at fundamental frequency and a transmission zero at the second harmonic frequency, further reducing the circuit footprint by 25%. We also developed a generalized analysis of the Class-E PA with a shunt capacitance and a shunt filter. When compared to its predecessors, the new PA can be operated at higher frequencies (for a given transistor), or alternatively, at higher output power levels (for a specified operating frequency). It has the ability to absorb the transistor output inductance, which, if not taken into account in the analysis, will have detrimental impact on the PA performance at high frequencies. A novel transmission line load network that is useful for IC implementations at millimeter-wave frequencies is proposed as an alternative to the lumped-element load network. A circuit prototype was built using GaN transistors, achieving around 90% efficiency and 40 dBm output power at 1.37 GHz. We also developed the analysis of a new topology of the Class-EM PA incorporating a finite dc-feed inductance (as opposed to ideal RF choke) and an isolation circuit, rendering it more attractive for implementations when compared with its predecessors. The PA is comprised of a main circuit that fulfills both ZVS/ZVDS and ZCS/.ZCDS conditions and an auxiliary circuit that fulfils ZVS condition, resulting in a true soft switching and high efficiency operation. The auxiliary circuit plays an important role to supply the main circuit with a second harmonic current with a specific amplitude and phase value in order to reshape the switch current waveform of the main circuit. Furthermore, we propose a novel transmission-line load network that provides the drain of the transistor with the required load impedances at the fundamental frequency as well as even and odd harmonic frequencies for the main and auxiliary circuits. The concept was verified through harmonic balance simulations with the PA exhibiting a peak power added efficiency of 86.7% and a peak output power of 41.2 dBm at 1.5 GHz. |
Exploitation Route | In order to protect our inventions for potential licensing to major RF industries, we filed two UK patent applications in September and October 2018. Our industrial partner, Catena, has expressed strong interest in adopting our technology in the near future. We have also approached one of our collaborators, who is the author of a well-known switched-mode PA textbook, to include the two new PA topologies derived from this research, namely 'generalized Class-E PA with shunt capacitance and shunt filter' and 'Class-EM PA with finite dc-feed inductance and isolation circuit' in his future edition textbook. |
Sectors | Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Education,Electronics,Energy |
Description | New Technologies for Efficient Wireless Power Transfer at Distance |
Amount | £875,376 (GBP) |
Funding ID | EP/S007954/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 04/2019 |
End | 12/2023 |
Description | PhD Stipend Top Up |
Amount | £14,000 (GBP) |
Organisation | Catena Holding BV |
Sector | Private |
Country | Netherlands |
Start | 10/2017 |
End | 03/2021 |
Description | Travel Grant |
Amount | £950 (GBP) |
Organisation | Queen's University Belfast |
Sector | Academic/University |
Country | United Kingdom |
Start | 12/2018 |
End | 12/2018 |
Description | First Grant External Collaborators |
Organisation | Catena Holding BV |
Country | Netherlands |
Sector | Private |
PI Contribution | We contribute to the concept development, design, and implementation of (1) compact power combiners/dividers in advanced 28 nm CMOS, (2) high-efficiency Class-EM power amplifier, and (3) high-efficiency Class-E power amplifier with shunt capacitance and shunt filter. |
Collaborator Contribution | Catena provides (1) access to 28 nm CMOS technology that enables our circuits to be fabricated and measured, (2) monthly technical consultancy, and (3) trainings through internships. Sumitomo Electric Europe provides technical consultancy. |
Impact | 2 patent applications, 1 journal paper, 7 conference papers, 1 Best Paper Award, 1 invited talk |
Start Year | 2017 |
Description | First Grant External Collaborators |
Organisation | Sumitomo Corporation |
Department | Sumitomo Electric Europe Ltd |
Country | United Kingdom |
Sector | Private |
PI Contribution | We contribute to the concept development, design, and implementation of (1) compact power combiners/dividers in advanced 28 nm CMOS, (2) high-efficiency Class-EM power amplifier, and (3) high-efficiency Class-E power amplifier with shunt capacitance and shunt filter. |
Collaborator Contribution | Catena provides (1) access to 28 nm CMOS technology that enables our circuits to be fabricated and measured, (2) monthly technical consultancy, and (3) trainings through internships. Sumitomo Electric Europe provides technical consultancy. |
Impact | 2 patent applications, 1 journal paper, 7 conference papers, 1 Best Paper Award, 1 invited talk |
Start Year | 2017 |
Title | RF Power Combiners Using Star and Delta Coupled Coil |
Description | Star and delta equivalent circuits of a coupled coil are used to synthesize and design a Wilkinson power combiner/divider, reducing the electrical size of the state of the art by a factor of 13 while providing added filtering functionality. The circuit footprint is reduced through (i) the use of a coupled coil to realize two series inductors by taking advantage of the mutual inductance of the coupled coil, and (ii) replacing each series inductor with a parallel LC resonant circuit to provide the required inductance at fundamental frequency and a transmission zero at the second harmonic frequency. |
Type Of Technology | New/Improved Technique/Technology |
Year Produced | 2018 |
Impact | No impact yet |
Description | Power Amplifier Workshop |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | I was invited to give a talk on high-efficiency power amplifier to postgraduate research students and engineers from all over the world during the International Microwave Symposium (IMS) 2018 in Philadelphia, Pennsylvania. The talk was generally well received and sparked discussions afterwards. |
Year(s) Of Engagement Activity | 2018 |
Description | Work Experience for Sixth-Form Students from Schools across Northern Ireland |
Form Of Engagement Activity | Participation in an open day or visit at my research institution |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Schools |
Results and Impact | 16 sixth-form students visited my research group for a one-day work experience designing and measuring a microwave circuit. At the end of the session, all of them but one expressed increased interest in studying electronics engineering. |
Year(s) Of Engagement Activity | 2017 |