2,462 research outputs found
A three-dimensional backward-wave network matched with free space
A backward-wave slab based on a capacitively and inductively loaded
three-dimensional transmission-line network is designed in such a way that
impedance-matching with free space is obtained. To enable field propagation
from free space to the network and vice versa, the use of a transition layer is
proposed. Matching of the designed network with free space and negative
refraction occurring at the slab interfaces are confirmed with full-wave
simulations.Comment: 8 pages, 5 figure
Experimental verification of broadband cloaking using a volumetric cloak composed of periodically stacked cylindrical transmission-line networks
Cloaking using a volumetric structure composed of stacked two-dimensional
transmission-line networks is verified with measurements. The measurements are
done in a waveguide, in which an array of metallic cylinders is inserted
causing a short-circuit in the waveguide. The metal cylinders are cloaked using
a previously designed and simulated cloak that hides the cylinders and thus
enables wave propagation inside the waveguide.Comment: 8 pages, 3 figure
Experimental verification of the key properties of a three-dimensional isotropic transmission line based superlens
Design and experimental realization of a three-dimensional superlens based on
LC-loaded transmission lines are presented. Commercially available components
and materials are used in the design. Transmission properties of the designed
structure are studied experimentally and the observed lens properties are
compared with analytical predictions. Backward-wave propagation and
amplification of evanescent waves in the prototype structure are verified both
analytically and experimentally.Comment: 12 pages, 10 figure
Three-dimensional isotropic perfect lens based on LC-loaded transmission lines
An isotropic three-dimentional perfect lens based on cubic meshes of
interconnected transmission lines and bulk loads is proposed. The lens is
formed by a slab of a loaded mesh placed in between two similar unloaded
meshes. The dispersion equations and the characteristic impedances of the
eigenwaves in the meshes are derived analytically, with an emphasis on
generality. This allows designing of transmission-line meshes with desired
dispersion properties. The required backward-wave mode of operation in the lens
is realized with simple inductive and capacitive loads. An analytical
expression for the transmission through the lens is derived and the
amplification of evanescent waves is demonstrated. Factors that influence
enhancement of evanescent waves in the lens are studied and the corresponding
design criteria are established. A possible realization of the structure is
outlined.Comment: 22 pages, 15 figure
Broadband cloaking with volumetric structures composed of two-dimensional transmission-line networks
The cloaking performance of two microwave cloaks, both based on the recently
proposed transmission-line approach, are studied using commercial full-wave
simulation software. The cloaks are shown to be able to reduce the total
scattering cross sections of metallic objects of some restricted shapes and
sizes. One of the studied cloaks is electrically small in diameter, and the
other is electrically large, with the diameter equal to several wavelengths.Comment: 6 pages, 7 figure
Impedance-matched microwave lens
A microwave lens with highly reduced reflectance, as compared to conventional
dielectric lenses, is proposed. The lens is based on two-dimensional or
three-dimensional transmission-line networks that can be designed to have an
effective refractive index larger than one, while having almost perfect
impedance matching with free space. The design principles are presented and an
example lens is studied using commercial simulation software.Comment: 11 pages, 8 figure
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