Stealthness

Stealthness research activities consists in design and optimize multilayer structures. The aim is to reduce as much as possible the Microwave Reflection Coefficient and the Microwave Transmission Coefficient, in other words target is to miximize the loss factor of the strucutre. Simultaneously the total thickness of strucutres must be minimized. These target must be satisfied in the frequency band and for all of the electromagentic wave incidence angles. The immediate consequence is a reduction of the radar corss section (RCS) when the object is covered or builted using such type of materials.

Data base of microwave absorbing materials are continously updated. Such materials are used to built the multilayer structures.

The microwave characterization has been carried out performing scattering measurements and extracting the electrical permittivity through canonical algorithms.. We adopted and compared Nicholson-Ross and New Non Iterative algorithms..
Measurements setup consists of a vector network analyzer (VNA) Agilent PNA L working up to 20 GHz, wave guide calibration kit in the X-band (8.2-12.4 GHz), sample holder hosting the material under test (MUT) of 9.77 mm thickness. Permittivity results give wave impedance values.

Several technique of design and optimization are used, some of them adopt Genetic Algorithms and Particle Swarm Optimization and Winning Particle Optimization

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SASLAB Stealth Research Activities example link

Poster IEEE nanotechnology, link