N211-075 TITLE: Active Nano Antenna Emulator for Electromagnetic Simulation
RT&L FOCUS AREA(S): Directed energy
TECHNOLOGY AREA(S): Battlespace Environments
The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 3.5 of the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.
OBJECTIVE: Develop a tabletop radar range leveraging high-resolution 3D printing and nanophotonics to serve as an optical emulator for complex electromagnetic (EM) systems.
DESCRIPTION: The Navy currently uses both simulation and measurement of a ship�s Antenna- Radar Cross Section (RCS) to improve the design of new stealthy antenna on platforms and to ensure the accurate measure beam profile of the antenna in an environment. However, EM simulations are extremely challenging for large and complex objects that involve multiple constituent materials and fine details. Direct Antenna-RCS measurements may not be possible if the ship is part of an adversarial navy or if the ship is at sea. Currently DoD evaluates its antenna EM radiation beam profile using simulation and an actual measurement in anechoic chamber and field measurement. The process of doing such measurement is expensive and time consuming. It is also impossible to create a real-life scenario of EM reflection from other structure during actual operation of the system. This topic shall address such real-life scenarios with fabrication in nanophotonics and use nanaophotonic radiation to characterize and simulate the EM scattering map without any anechoic chamber or infield measurement. This approach shall also reduce cost two orders of magnitude and time reduction from a year to a week.
Submarines may be subjected to high power laser beams and microwave radiation, which may damage optics and sensors in beam directors and periscopes. The Navy is seeking a technology that would demonstrate the possibility to accurately measure the radar antenna cross section & beam profile of large and complex antenna with a scaling factor of 100,000 under different environments such as sea surface with varying degrees of wave action and other EM radiation interference from adjacent masts on own-ship and nearby vessels. The advantages of this scaling approach is its versatility, and the possibility to perform fast, convenient, and inexpensive measurements on structures whose sizes prevent simulation, even with today�s computers. This proposed technique shall also reduce cost (two orders of magnitude) and time (from a year to a week). This technique, based on the scale invariance of Maxwell�s equations, leverages nano-scale 3D printing, as well as the availability of a variety of laser sources and high resolution detectors in 1 micron near infrared wavelength.
Interaction with Naval Information Warfare Systems Command (NAVWAR) personnel has revealed that one of the difficulties facing the development of new Navy platforms is optimizing the placement of antennas to minimize interference between antennas. The proposed method of using small-scale models and plasmonic-nanoantennas to simulate the EM field is estimated to provide a reduction in cost by a factor 1/150, and time by a factor 1/365.
Instead of needing a large anechoic chamber, the RCS measurements are done on a tabletop setup with highly detailed micron scale model. The models are illuminated with an external source of light, and the scattered energy is detected with a charge couple device (CCD), similarly to a monostatic radar configuration. The direct 2D imaging of the scattered field allows us to identify the parts of the structure responsible for the RCS signal. This information is similar to what is obtained with an Inverse Synthetic Aperture Radar (ISAR) measurement but without the back projection computation. Measurement reliability shall also be demonstrated by comparing the results with a theoretical EM model for any shape under different environments.
The EM signatures of an antenna in a platform, such as a ship or a submarine, are of particular importance for the Navy since they allow the detection and identification of the antenna system and its performance on the platform. The vessel�s active EM signature (EM Antenna), known as its radar cross section (Antenna-RCS), is proportional to the reflectivity of the structure and varies with relative spatial orientation of the vessel and the radar source. Minimizing this reflection improves the antenna performance of a radar system. The observed Antenna-RCS can also be used to improve the platform antenna performance.
The goal of the Nano antenna compact radar range program is to design and develop a tabletop radar-range system capable of measuring the EM signature of large and complex structures, including the antenna emission (gain) and their interference.
PHASE I: Provide a concept and determine the feasibility of the concept for the EM emission of a nanoantenna in the framework of tabletop radar range as well as simulations of antenna emission in the presence of simple geometrical shapes. Provide an assessment on how the dipole plasmonic nanoantenna will be manufactured using liftoff microstructuring technique as well as characterize the antenna emission direction. Liftoff lithography is a method of creating structures (patterning) of a target material on the surface of a substrate (e.g., wafer) using a sacrificial material (e.g., photoresist). It is an additive technique as opposed to more traditional subtracting technique like etching. The scale of the structures can vary from the nanoscale up to the centimeter scale or further, but are typically of micrometric dimensions. The nanoantenna will potentially be transferred on a relevant model and the gain compared to its original profile as well as the simulation.)
The Phase I Option, if awarded, will include the initial design specifications and capabilities description to build a prototype solution in Phase II.
PHASE II: Develop a prototype system for testing and evaluation based on the results of Phase I and the Phase II Statement of Work (SOW). Design, build, and demonstrate a prototype tabletop RCS system based on the proof of concept developed during Phase I. Demonstrate the ability to collect antenna emission measurements of a vessel of interest in near marine boundary conditions including realistic sea clutter. Fabricate a RCS system based on the prototype developed in the base period.
Field test the nanophotonic radar-range system at one of the Navy�s facilities. Fabricate an active nanoantenna device that can be used to simulate the radar signal generated by the vessel�s radar systems. The testing will consist of measuring the RCS of a specific model, of which the design will be provided by the Navy. A scaled model will be made using a nano-3D printer (not deliverable), and the RCS measurement will be measured using the nanophotonic radar-range. The result of the measurement will be a RCS polar plot that can used by the Navy to compare with life scale measurement and/or simulation.
PHASE III DUAL USE APPLICATIONS: Assist the Navy in transitioning the technology to Navy use for antenna performance evaluation and location of the antenna for best performance. Army and Navy can use this technology to simulate the environment scenario to optimize the EM beam profile and its performance.
The nanophotonic radar-range system can be used for emulating the RCS of a large variety of platforms, from small boats like the 4M RX Rigid Inflatable with 12ft length to much larger vessels like the Gerald R. Ford class super carrier. The system can also be applied to all classes of submarines in near boundary conditions, including the Virginia and Columbia classes, as well as to measure the RCS of the AN/BVS-1 photonic mast. The nanophotonic radar-range system can find commercial use with any DoD branches and contractors desiring to understand the radar cross section properties of their platforms. This technique can be used during any phase of construction: development, production or refurbishing. It can also be used to acquire the RCS of structures that are inaccessible such as non-friendly nation platforms. For example, a contractor such as General Dynamics can use the system to better understand the RCS of the next generation of ships such as the USS Zumwalt. A contractor such as Raytheon can use the system to better understand the RCS of an enemy target to better detect, acquire, and follow that target with radar.
The technology shall also be used in telecommunication industry and TV to survey the antenna site before they actually do the field survey to optimize the reception and service broader spectrum customers. The system can find dual use application for the development of the 5G telecommunication to better understand the propagation of the signal in cluttered environment such as dense urban center. A Global System for Mobile operator can potentially use the nanophotonic radar-range system to optimize the location of their antennas to avoid dead signal zone.
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KEYWORDS: Plasmonic; Nano-antenna; Antenna radar cross section; Antenna-RCS; electromagnetic; EM; NanoPhotonics; optical emulator