Seminar: Graduate Seminar
Metagrating superstrates for enhancement of ultra-sparse phased arrays
Date:
September,04,2023
Start Time:
14:30 - 15:30
Location:
1061, Meyer Building
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Lecturer:
Yaniv Kerzhner
Research Areas:
| We develop a methodology for devising highly directive ultra-sparse antenna arrays for scanning applications, based on semianalytically designed metagratings (MGs). The proposed scheme does not rely on intricate excitation profiles or irregular element arrangements, often involving time-consuming full-wave optimizations and complex structural manipulations on the active array. Instead, the array directivity is restored by judicious placement of passive subwavelength polarizable particles (meta-atoms), forming a MG superstrate. Extending the common MG analytical models and design formalism to include localized source excitations, harnessing rigorous Floquet-Bloch theory, the meta-atom distribution and dimensions can be conveniently set as to suppress grating lobes emanating from the sparse array. This is achieved through meticulous tailoring of the near-field mutual coupling between all meta-atoms in a way that the interference pattern formed by them and the active array antennas yields the desired radiation profiles. The resultant methodology, verified via simulations in commercial solvers, offers an original path for mitigating grating lobes in sparse arrays with scanning capabilities using static and passive MGs, yielding a complete PCB-compatible design without relying on full-wave optimization. Lastly, we apply classical antenna array theory to examine the fundamental operational principles of our model and its inherent constraints. It becomes evident that our semianalytical synthesis technique adeptly and elegantly calculates the requisite, nearly optimal, embedded element factor essential for achieving the desired grating-lobe-free radiation pattern—a task that is typically highly complex for ultra-sparse configurations. M.Sc. student under the supervision of Prof. Ariel Epstein.
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