Plasma-based lens for microwave beam steering

Peter, Lars; Borg, G. G.; Martin, Nivetha

doi:10.1049/el:20064259

Cited by 19 publications

(16 citation statements)

References 3 publications

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“…The electromagnetic coupling between the plasma and the enveloping coil produces a rapidly oscillating electromagnetic field. The corresponding electric current J IN and magnetic field B IN are involved in the momentum and energy source terms in the conservation equations (7), (8), and (11). These coupling terms are obtained as follows.…”

Section: Electromagnetic Inductionmentioning

confidence: 99%

“…Equations (6)-(8), (10), (11), and (21), along with equations (9), (12), (13) (15)- (20), and (23)- (25), are integrated subject to the following initial and boundary conditions. At the cylinder walls, r ¼ R, z ¼ 0, and z ¼ L, the electron density vanishes while the plasma velocity and temperature satisfy, respectively, non-slip and isothermal boundary conditions…”

Section: E Initial and Boundary Conditionsmentioning

confidence: 99%

“…is a large quantity of order C À $ 10 3 -10 4 , and therefore the temperature slip between the electron gas and the plasma T tends to persist because of the rapidity with which equilibrium is reached between the collision and energy-deposition terms on the right hand side of the electron-energy balance equation (11). Near the wall, however, the electron gas develops temperature gradients that lead to heat conduction and energy loses.…”

Section: Thermal-energy-transfer Scalesmentioning

confidence: 99%

“…In plasmas, a tunable refractive-index distribution can be achieved through concentration gradients in the population of free electrons. 7,[9][10][11][12][13][14][15] A brief explanation of this phenomenon is provided below.…”

Section: Introductionmentioning

confidence: 99%

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Computational hydrodynamics and optical performance of inductively-coupled plasma adaptive lenses

2015

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This study addresses the optical performance of a plasma adaptive lens for aero-optical applications by using both axisymmetric and three-dimensional numerical simulations. Plasma adaptive lenses are based on the effects of free electrons on the phase velocity of incident light, which, in theory, can be used as a phase-conjugation mechanism. A closed cylindrical chamber filled with Argon plasma is used as a model lens into which a beam of light is launched. The plasma is sustained by applying a radio-frequency electric current through a coil that envelops the chamber. Four different operating conditions, ranging from low to high powers and induction frequencies, are employed in the simulations. The numerical simulations reveal complex hydrodynamic phenomena related to buoyant and electromagnetic laminar transport, which generate, respectively, large recirculating cells and wall-normal compression stresses in the form of local stagnation-point flows. In the axisymmetric simulations, the plasma motion is coupled with near-wall axial striations in the electrondensity field, some of which propagate in the form of low-frequency traveling disturbances adjacent to vortical quadrupoles that are reminiscent of Taylor-G€ ortler flow structures in centrifugally unstable flows. Although the refractive-index fields obtained from axisymmetric simulations lead to smooth beam wavefronts, they are found to be unstable to azimuthal disturbances in three of the four three-dimensional cases considered. The azimuthal striations are optically detrimental, since they produce high-order angular aberrations that account for most of the beam wavefront error. A fourth case is computed at high input power and high induction frequency, which displays the best optical properties among all the three-dimensional simulations considered. In particular, the increase in induction frequency prevents local thermalization and leads to an axisymmetric distribution of electrons even after introduction of spatial disturbances. The results highlight the importance of accounting for spatial effects in the numerical computations when optical analyses of plasma lenses are pursued in this range of operating conditions. V C 2015 AIP Publishing LLC.

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Section: Electromagnetic Inductionmentioning

confidence: 99%

Section: E Initial and Boundary Conditionsmentioning

confidence: 99%

Section: Thermal-energy-transfer Scalesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Computational hydrodynamics and optical performance of inductively-coupled plasma adaptive lenses

2015

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“…Transient medium is used in the light-modulated photo-induced method for the development of a non-mechanical millimeter wave scanning technique [3]. Plasma based lenses with properties electronically adjusted can offer an alternative to the existing electronic beam steering systems by varying the density of plasma in time [4]. In practice, temporal switching of the material refractive index can be realized by varying the input signal in a nonlinear structure [5], by voltage control [6], by a focused laser beam as a local heat source [7], or by plasma injection of free carriers [8].…”

Section: Introductionmentioning

confidence: 99%

Complex source point concept in the modelling of dynamic control for optical beam deflection

Sakhnenko¹

2012

Semicond. Phys. Quantum Electron. Optoelectron.

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Abstract.A rigorous analytical method for transient dynamics description in a cylindrical lens is developed and used to describe a possibility of beam controlled deflection via material tuning. The complex source point concept is used to simulate beam passing through the lens. Details of both the transient response and steady-state regime are described. The excited fields are described using a rigorous mathematical approach based on analytical solution in the Laplace transform domain and accurate evaluation of residues at singular points of the obtained functions.

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Reconfigurable biconcave lens antenna based on plasma technology

Sadeghikia

Zafari

Dorbin

et al. 2023

Sci Rep

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This article is focused on the application of plasma technology for the development of microwave lens antennas with electronically controllable radiation gain. With this aim, the analytical background and design procedure for designing a biconcave lens based on plasma dielectric material are presented. The procedure is used to design a plasma lens antenna with a pyramidal horn feed. The effect of switching the designed lens ON and OFF on the radiation gain of the lens antenna is investigated. It is also shown that the plasma frequency of the lens can be used to dynamically adjust the radiation gain. A one-dimensional version of the proposed plasma lens operating at 10 GHz has been developed to validate the concept. Experimentally measured characteristics of a fabricated prototype of the lens antenna based on commercially available fluorescent lamps confirm the presented design procedure and numerical results. The results also show that changing the plasma frequency of the lens can be used to adjust the radiation gain of the proposed lens antenna.

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Plasma-based lens for microwave beam steering

Cited by 19 publications

References 3 publications

Computational hydrodynamics and optical performance of inductively-coupled plasma adaptive lenses

Computational hydrodynamics and optical performance of inductively-coupled plasma adaptive lenses

Complex source point concept in the modelling of dynamic control for optical beam deflection

Reconfigurable biconcave lens antenna based on plasma technology

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