Johns Hopkins University

Other

Paul A Vichot

John Albert Olenick

Timothy Joseph Curry

Timothy A Sleasman

David B Shrekenhamer

Robert A Bourdelaise

Chun-Huei Bair

Eli A Richards

Samuel F Wilderson

Stephanie D Lashley

Barry E Grabow

A method for constructing a multifunctional antenna structure configured to generate a plurality of radiation patterns includes determining a desired source field associated with the plurality of radiation patterns, and receiving feed locations for a waveguide to an antenna aperture surface. The method may further include placing a metasurface resonator at a first resonator location that exhibits a minimum error relative to the desired source field and satisfies a maximum error threshold relative to the desired source field. The metasurface resonator may be determined based on the feed locations and a plurality of degrees of freedom for the first resonator location. The method may also include discarding a second resonator location in response to determining that no metasurface resonator at the second resonator location satisfies the maximum error threshold. The plurality of degrees of freedom may include metasurface resonator geometries that exhibit different polarizabilities defined in a candidate library.

Multifunctional metasurface antenna

A system for use with a transmitter and an antenna includes a radio frequency power detection portion, a tunable matching network, and a phase lock loop. The tunable matching network has a modifiable impedance to account for impedance mismatch between the transmitter and the antenna. The phase lock loop tunes the tunable matching network to modify the modifiable impedance.

System and method for impedance matching in antennas

A high-temperature seal having in-situ integrity monitoring capability includes a quantity of dielectric material sealing an interface between adjacent structures and an electrical transmission line embedded within the dielectric material. A signal injection port is provided for exciting the transmission line with an excitation signal. One or more sample ports are provided for sampling the transmission line to obtain signal samples resulting from the excitation signal. The sample port(s) are adapted for connection to a signal analyzer adapted to analyze the signal samples for indications of seal integrity problems. Using a technique such as time domain reflectometry or frequency response analysis, the transmission line can be monitored for changes in characteristic impedance due to changes in seal dielectric constant and/or disruption of the transmission line. Such evaluation provides useful information for making determinations about seal integrity in a manner that permits safe seal operation and minimization of resultant stress modes.

In-situ seal integrity monitoring

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Eldersburg, MD, United States of America

Paul A Vichot