Hrl Laboratories, LLC

John L Visher

John Jacob Ottusch

Daniel Frederic Sievenpiper

Joseph S Colburn

Bryan Ho Lim Fong

Jonathan James Lynch

Matthew W Ganz

Mark F Gyure

Geoffrey P McKnight

Chia-Ming Chang

Adour Vahe Kabakian

Bryan H Fong

Paul Richard Herz

An acoustic absorber is disclosed. The acoustic absorber contains a plurality of adjacent passages defined by walls configured to generate alternating high and low pressure zones as an acoustic energy travels though the acoustic absorber.

Acoustic absorber

A method and system for determining an optimized artificial impedance surface is disclosed. An artificial impedance pattern is calculated on an impedance surface using an optical holographic technique given an assumed surface wave profile and a desired far field radiation pattern. Then, an actual surface wave profile produced on the impedance surface from the artificial impedance pattern, and an actual far field radiation pattern produced by the actual surface wave profile are calculated. An optimized artificial impedance pattern is then calculated by iteratively re-calculating the artificial impedance pattern from the actual surface wave profile and the desired far field radiation pattern. An artificial impedance surface is determined by mapping the optimized artificial impedance pattern onto a representation of a physical surface.

Method and system for determining an optimized artificial impedance surface

A method for designing artificial impedance surfaces is disclosed. The method involves matching impedance component values required for a given far-field radiation pattern (determined, for example, by holographic means) with measured or simulated impedance component values for the units of a lattice of conductive structures used to create an artificial impedance surface, where the units of the lattice have varied geometry. For example, a unit could be a square conductive structure with a slice (removed or missing material) through it. The measured or simulated impedance components are determined by measuring wavevector values for test surfaces in three or more directions over any number of test surfaces, where each unit of a given test surface has the same geometric shape and proportions as all of the other units of that test surface, but each test surface has some form of variation in the unit geometry from the other test surfaces. These test measurements create a table of geometry vs. impedance components that are used to design the artificial impedance structure. Since polarization can be controlled, the structure can be an artificial impedance surface characterized by a tensor impedance having complex components.

Method for designing artificial surface impedance structures characterized by an impedance tensor with complex components

An artificial impedance structure and a method for manufacturing same. The structure contains a dielectric layer having generally opposed first and second surfaces, a conductive layer disposed on the first surface, and a plurality of conductive structures disposed on the second surface to provide a preselected impedance profile along the second surface.

Artificial impedance structure

A method for guiding waves over objects, a method for improving a performance of an antenna, and a method for improving a performance of a radar are disclosed. The methods disclosed teach how an impedance structure can be used to guide waves over objects.

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Malibu, CA, United States of America

John L Visher