Scientists question Cambridge research report claiming antenna breakthrough

Call it a case of gridlock among the scientific community. A group of scientists challenged the published work of some Cambridge researchers, who are standing by their findings while the challengers are standing by theirs as well.

A group of scientists from Russia's ITMO University, Australian National University and Finland's Aalto University called into question the results of a study that was published earlier this year by researchers from Cambridge University in the scientific journal Physical Review Letters.

In the original study, covered here by FierceWirelessTech, the British scientists claimed they managed to find the missing link in the electromagnetic theory. According to the scientists, the findings could help decrease the size of antennas in electronic devices like cell phones manifold, promising a major breakthrough in wireless communications.

However, a group of technologists known for their expertise in the field of dielectric nanoantennas for optical and microwave ranges challenged their "breakthrough" findings, saying the results were based on an erroneous interpretation of experiments and lack of understanding of theory. "The main claim of the Letter [1] on the structural asymmetry of radiators as a condition of their efficient radiation emission is incorrect," they wrote in a comment that also was published in Physical Review Letters. "The asymmetry of the field lines has nothing to do with the geometric asymmetry of a source, either metallic [4] or dielectric resonator antennas (DRAs) [5]. The radiation is formed due to the open topology of radiating resonators, implying radiation losses and a finite quality factor even for absorption-free resonators."

The authors of the original report, Dhiraj Sinha and Gehan A.J. Amaratunga of the Department of Engineering at the University of Cambridge, said in reply comments that the phenomenological foundation of their work was erroneously interpreted. "The central thesis of our Letter is that explicit symmetry breaking of the electric field associated with asymmetric excitation of an electrodynamic system causes electromagnetic radiation [2]. Examples of symmetry of an electric field associated with a pair of transmission lines which do not result in radiation … and radiation from the flared ends of transmission lines … where electric lines of the field have broken symmetries have been mentioned. We do not claim that geometric asymmetry is an essential condition of electromagnetic radiation. If an asymmetric electromagnetic excitation is fed to a geometrically symmetric structure such as a metal sphere, plane, wire or cylinder, it would result in radiation, as there would be an associated electric field with broken symmetries and associated non-conserved Noether current," they wrote.

Constantin Simovski, a professor at Aalto University, told FierceWirelessTech that he and others in the scientific community found mistakes in the original published work and felt compelled to point them out. He stood by his earlier critique. In a subsequent comment, he and his colleagues said "our point was that it presents a hundred years old textbook example as their own new discovery," they wrote. "We would like to point out that the observation of that radiation from a system of accelerating charges is possible only when there is explicit breaking of symmetry was done by J.J. Thomson more than 120 years ago."

The situation brought up the issue of peer review in scientific journals. The scientists who commented on the Cambridge study expressed concern with respect to how the review process is carried out in many high-impact journals. But Sinha and Amaratunga said their work was misinterpreted and not fully understood.  

Asked for comment, a Cambridge spokesperson responded with the following statement: "Debate is an important part of the scientific process, particularly when it comes to theoretical models related to empirical observations," with a  reference to the reply comment in Physical Review Letters that was published by the researchers.

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