Formation of Millimeter Waves with Electrically Tunable Orbital Angular Momentum

Andrey Altynnikov,Peter K Petrov,Andrey Tumarkin,Andrey Kozyrev,Roman Platonov

doi:10.3390/coatings11050569

Andrey Altynnikov, Peter K Petrov + Show 3 more

Open Access

https://doi.org/10.3390/coatings11050569

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Abstract

A method for forming electromagnetic waves with a tunable nonzero orbital angular momentum (OAM) is proposed. The approach is based on transforming an incident plane wave into a helical one using an electrically tunable ferroelectric lens. It uses high-resistive thin/thick film electrodes with a special discrete topology. The correlation between film electrodes topology and the highest order of OAM modes that the lens can form is described. A lens prototype based on Ba0.55Sr0.45TiO3 ferroelectric material and operating at a frequency of 60 GHz was designed, manufactured, and tested. The amplitude and phase distribution of the OAM wave with l = +1 formed by prototype were measured to confirm the effectiveness of the proposed method. The proposed lens has a combination of advantages such as low dimensions, electrical control over the OAM modes, and the possibility to operate in the millimeter wavelength range.

Highlights

The proposed lens has a combination of advantages such as low profile, electrical controlling over the orbital angular momentum (OAM) modes and the possibility to operate in the millimeter wavelength range
Experimental measurements of the ferroelectric lens prototype were performed in a microwave chamber
Modes formation, and the possibility to operate in the millimeter wavelengths

Summary

Introduction

The price and restraint of the available frequency spectrum call for improvement of the wireless communication systems’ transmission data rate This could be achieved using electromagnetic waves carrying orbital angular momentum (OAM). Several device types were proposed for the generation of OAM waves in the millimeter wavelength range These include spiral phase plates (SPP) [4,5], spiral reflectors [6,7], metasurfaces [8,9,10,11]. The main advantage of implementing the proposed ferroelectric lens (in comparison to the other tunable devices used for OAM-wave generation or conversion) is the higher operating frequency (up to 100 GHz). The analysis of the recent progress in the design of OAM-wave-forming devices [17] shows that the operating frequency of the current devices (based on meta-lenses and metasurfaces) or tunable lumped elements (varactors, pin-diodes, etc.) does not exceed 20–30 GHz

Theoretical Part

Prototype Description

Calculation and Simulation

Experimental Results

Discussion and Conclusions