Active and Nonlinear Topological Surfaces for C-DEW (UCSD)
Abstract
In this proposed program, we will apply concepts from the emerging field of photonic topological insulators, (PTI) combined with approaches such as active modulation to produce microwave surfaces that support non-reciprocal propagation, or enhanced nonlinear response to create broadband absorbing surfaces. The end goal will be to build and measure practicalprototype surfaces that provide quantitative advantages for reducing the effects of microwave directed energy weapons, and that can be transitioned to emerging Navy platforms. Photonic topological insulators provide the new capability of unidirectional propagation, where waves can only travel forward and are not easily scattered into the backward direction. With the emergence of this new field, numerous ideas have become possible that have applications tocounter directed energy weapons (C-DEW) in the microwave regime. Many of these are enabled by adding nonlinear or active components. Expected advancements include:1. Designing topological structures that forbid wave propagation in a particular direction,for preventing ingress into a metallic enclosure or cavity. This can make use of the recently demonstrated concept of magnet-less nonreciprocal structures.2. Using nonlinear devices to create self-induced topological transitions, where the application of a high-power signal induces a change to a topological state in which that signal is then prevented from propagating.3. Using topology to significantly enhance nonlinear effects for efficient conversion of RF energy to higher frequencies where it is more efficiently absorbed.4. Nonlinear edge rectification, where RF currents that are naturally concentrated at problematic regions such as edges are efficiently converted to nonradiating DC currents using nonlinear devices. The goal of this program will be to explore each of the concepts, as well as others that may emerge during the course of this research. We will then develop these into practical structuresthrough a combination of electromagnetic and circuit simulations. The most promising ideas will then be built into prototypes that will be fabricated and tested. We will explore a range of designs based on the concepts noted above, and optimize those that show the most promise. After findingsuccessful designs, we will then construct and test prototypes.We expect that at the conclusion of this program we will have developed a new class of activeand/or nonlinear topological surfaces that will significantly exceed the capabilities of existing metasurfaces and other conventional approaches for suppressing high power microwave signals. New advancements may include surfaces supporting only one-way propagation so that systemscan still radiate while being protected from incoming electronic attack, surfaces that automatically transition into a topologically protected state when the incoming power exceeds a particular threshold, or highly nonlinear surfaces or edges that efficiently upconvert signals to frequency ranges where they are more efficiently absorbed. These broadband or frequencyreconfigurable materials can be integrated into edges or around apertures, or they can beembedded into the composite skins of future vehicles to protect against a broad range of emerging threats.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 20, 2020
- Source ID
- N000142012710
Entities
People
- Daniel F. Sievenpiper
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego