IET Journals: the papers that paved the way

Papers selected for publication by the editors of the various IET journals often show initial research at the cutting edge of technology that later becomes part of our daily lives: 5G, Wi-Fi access, hybrid vehicles and digital twins are all to be found in the dusty pages of the IET’s journals of yesteryear, often for the first time. Such is the importance of these scientific contributions that they routinely accrue powerhouse citations ratings on bibliographic database services such as Web of Science and Google Scholar. Over the decades, the IET and its predecessors have published thousands upon thousands of research papers. Here, today’s editors have cherry-picked a handful of what they consider to be the most groundbreaking.

The idea of the variable-speed drive was first described in a paper published in the IEE Proceedings in 1969. But it wasn’t until the end of the 20th century that a surge of interest propelled it into becoming one of the major research areas in electrical power engineering, sustained right through to the present day. This change was caused by new application areas such as electric ship propulsion, locomotive traction, electric and hybrid electric vehicles, ‘more electric’ aircraft and high-power industrial applications. “Renewable (wind) energy generation has been added to this list in the last ten years or so,” says Emil Levi, editor-in-chief of IET Electric Power Applications. “The green agenda is the major driving force behind the rapid developments in the multiphase drives/generators area.”

In 2007, a team of academic researchers collaborated to produce a paper for IET Electric Power Applications called ‘Multiphase induction motor drives – a technology status review’[1]. Written by authorities from world-leading laboratories, the paper was essentially a tutorial on current thinking, with an emphasis on induction motor drives which, says Levi, “were a prevailing solution. After surveying basic characteristics of multiphase machines, the paper progressed to explain modelling and control principles, including both vector control and direct torque control.” Since the publication of the paper, “multiphase drive and generation systems have gained enormously in significance and their industrial applications are becoming more and more widespread. This paper has become a standard reference for papers describing further advances in the multiphase machines/drives/power electronics areas.” The citation data (more than 800 in Web of Science, and 1,400 in Google Scholar) make this the third most-cited paper in the IEE/IET journals in the power engineering area.

The IET’s Radar, Sonar & Navigation journal covers the theory and practice of systems and signals for radar, sonar, radiolocation, navigation, and surveillance purposes in aerospace and terrestrial applications. Its pages include two of the first publications – today regarded as ‘classics’ – on passive radar, which has now become a mainstream subject within the overall radar domain. The first [1] investigated analogue television transmissions, while the second [2] covered FM radio transmissions. The editor-in-chief of Radar, Sonar & Navigation, Professor Hugh Griffiths at University College London, explains that both have been highly cited, and have helped lay the foundations for subsequent work, also published in the journal. Today, passive radar is used in diverse applications from air surveillance to the detection and tracking of humans within buildings, using transmissions from Wi-Fi access points.

Published in 1996, at a time when wind utilisation for electric energy generation was in its infancy, the paper entitled ‘Doubly fed induction generator using back-to-back PWM converters and its application to variable-speed wind-energy generation’ [4] appeared in IEE Proceedings – Electric Power Applications. The doubly fed induction generator (DFIG) would go on to become a ubiquitous technology in wind farms worldwide. Says editor-in-chief Professor Emil Levi: “Indeed, the type of solution developed in the paper is nowadays the most widespread one, and it appears in the vast majority of onshore and near-offshore wind farms. It is also one of the solutions for remote offshore wind farms.” The effect of the paper was so significant that “in the history of the IEE/IET publishing, this paper represents the most cited in the area of electrical power engineering. The citation data (over 1,600 in the Web of Science, more than 3,600 in Google Scholar) are exceptionally high for an original research paper in the electrical power engineering area and are the best proof of the importance, timeliness and archival value of the work.”

IET Microwaves, Antennas & Propagation is dedicated to the coverage of microwave and RF circuits, microwave and millimetre wave amplifiers, oscillators, switches, mixers, and other components. In June 2010, it published ‘Review of substrate-integrate waveguide circuits and antennas’ [5], a paper that has been “widely used in understanding and realising the use of substrate-integrated waveguides”. In February 2007, there was also the publication of a special edition of the journal co-authored by Sergei Tretyakov, whose ‘Contemporary notes on metamaterials’ [6] detailed developments in metamaterials since the Second World War that have led to many different applications through which antennas can be designed, as well as demonstrating the vast usage of metamaterials and new avenues of thought that have been further considered as materials have advanced.

Professor Farzin Deravi, editor-in-chief of IET Image Processing, says that with “the rapid rise of audio-visual communication in recent decades, there has been a continuous drive for developing more efficient encodings of video information to facilitate the ever-increasing demand for higher quality at lower transmission rates”. He draws attention to a seminal paper published in IEE Proceedings I in 1990 – ‘Variable size block matching motion compensation with applications to video coding’ [7] – that resulted “in a step change in automatic techniques for encoding differences between video frames caused by motion of camera and/or objects – a key stage in efficient video compression.”

In the same decade, IEE Proceedings: Generation, Transmission and Distribution published a paper anticipating today’s trend for digital twins. ‘Identifiability of load models’ [8] discussed how the modelling of electrical power systems is a key aspect of setting up digital twins for power system analysis in planning and operation. Editor-in-chief Christian Rehtanz says that “the approaches discussed in this paper are still a basis for today’s investigations”. In 1991, the journal also covered research into aspects of microgrid control [9]. Says Rehtanz: “This paper stands as an example for all kinds of agent-based approaches for the full automation of power systems towards an autonomous system operation in the future.”

IET Intelligent Transport Systems is an interdisciplinary journal devoted to research into the practical applications of ITS and infrastructures. According to its editor-in-chief David Fernández Llorca, “undoubtedly the most influential article in the specific field of short-term traffic forecasting” that the journal has published is ‘LSTM network: a deep learning approach for short-term traffic forecast’ [10]. With nearly a thousand citations (and counting) on Web of Science and Google Scholar, the figures “are impressive for a paper in the field with only four years of history”. Another highlight, published in 2010, is ‘Reinforcement learning-based multi-agent system for network traffic signal control’ [11], which is “probably the most relevant of the last decade in the specific context of the use of RL for traffic signal control”.

Accurate maintenance of a geometric configuration between multiple vehicles moving in formation has many applications including cooperative search, cooperative transport, and space-based interferometry. The idea is that through efficient coordination many inexpensive, simple vehicles can achieve enhanced coordinated performance superior to that of one single vehicle. A 2007 paper published in IET Control Theory & Applications entitled ‘Consensus strategies for cooperative control of vehicle formations’ [12] introduces extensions of a consensus algorithm for systems modelled by second-order dynamics. Editor-in-chief James Lam of the University of Hong Kong explains: “The basic idea of information consensus is that each vehicle updates its information state based on its local neighbours’ information states so that the final information state of each vehicle converges to a common value. Even in the absence of centralised leadership, the consensus-based formation control strategies can guarantee accurate formation maintenance in the general case of arbitrary (directed) information flow between vehicles.”

Today, Multiple-Input Multiple-Output (MIMO) is a de facto component of all modern communications systems, including the fifth-generation (5G) New Radio (NR) cellular standards. But towards the end of the 20th century a paper called ‘Detection algorithm and initial laboratory results using V-BLAST space-time communication architecture’ [13] was published in IEE Electronics Letters demonstrating one of the first real-time implementations of the V-BLAST MIMO system in a laboratory environment. The early results reported in this paper demonstrated the feasibility of the MIMO spatial-multiplexing concept in practice for the first time. Says associate editor Arman Shojaeifard of InterDigital: “MIMO is now fully incorporated in all modern air-​interface standards including full-​dimension/​massive MIMO in 5G NR cellular systems. This trend is anticipated to continue with the evolution of MIMO towards achieving the maximum information-theoretic capacity limits.”

For our last highlight we go back nearly half a century to revisit a paper published in IET Electronics Letters by Barrie Gilbert, entitled ‘Translinear circuits: a proposed classification’ [14]. Says Paolo S Crovetti, subject editor-in-chief for circuits and systems: “In this seminal Letter, the groundbreaking concept exploited in those circuits was formalised, generalised and designated as ‘translinear principle’ for the first time. The idea, indeed, is extremely simple, powerful and elegant.” He explains that over the years the translinear principle proved to be valuable beyond the original scope of bipolar circuit design and analogue computing. It has now been widely adopted to address the challenges related to the limited voltage swing of low power supply voltage analogue integrated circuits in modern CMOS technologies. “This further demonstrates the significance and the broad extent of the translinear principle, which can be surely counted among the very basic ones of analogue electronic circuit theory and design. A fundamental legacy left by Barrie Gilbert, an eclectic genius and an absolute master in this field.”