engleski

RF INVISIBILITY USING METAMATERIALS: HARRY POTTER’ S CLOAK OR THE EMPEROR’ S NEW CLOTHES

Recently the authors of an article [1] in Sciencexpress claim to have “ the first practical realization” of a cloak of invisibility that works over “ a narrow frequency band” . However, they do neither quantify the invisibility nor refer to other known and much simpler cloaks, which can work over a significant 20% bandwidth [2]. Also, the realization in [1] is limited to a single vertical polarization, which makes it inferior compared to existing realizations, which work for arbitrary and dual polarization. The purpose of the present paper is to explain the differences between the two cloaking approaches, by comparing performance of ideal and realized cloaks, in to find out if cloaking is a step towards realizing Harry Potter’ s cloak at RF, or is better described as the “ Emperor’ s new clothes” in the fairytale of H. C. Andersen from 1837. Media has already used the former Harry Potter term to describe their performance.

rf invisibility; metamaterials; hard surfaces

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