Formation of Millimeter Waves with Electrically Tunable Orbital Angular Momentum

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.

Automated summary

The proposed method utilizes an electrically tunable ferroelectric lens to transform an incident plane wave into a helical one, forming electromagnetic waves with a tunable nonzero orbital angular momentum (OAM). It uses high-resistive thin/thick film electrodes and describes the correlation between film electrodes topology and the highest order of OAM modes that the lens can form.