Fabrication and Characterization of Polarization Independent 3D Printed Frequency Selective Structures with Ultra-Wide Fields of View
Contributing USMA Research Unit(s)
Electrical Engineering and Computer Science
Recently, a robust and versatile Multi-Objective Lazy Ant Colony Optimization (MOLACO) technique was introduced for inverse design of three-dimensional (3D) Frequency Selective Structures (FSSs) with remarkable polarization independent filtering performance for incidence angles up to 80°. However, fabricating and characterizing these elements presents many challenges that have yet to be addressed. For example, conventional free space measurement techniques require intractably large arrays to uniformly illuminate the sample and mitigate edge diffraction at extreme incidence angles. To mitigate these effects, a broadband focused beam measurement technique is proposed to characterize a finite 24x48 element 3D FSS array optimized for C-band operation. Elements are fabricated using PolyJet 3D Printing, metallized, and encapsulated in a Sylgard-527 substrate over a Polymethylmethacrylate (PMMA) lattice resulting in a low-loss, low-cost, low-profile and light-weight array that is suitable for conformal surfaces and can be easily repaired. A comparison of simulated and measured results is presented, and a discussion of the implications of the array and measurement system are offered. The fully fabricated 3D FSS array achieves a 6.25% -10 dB rejection band and 8.26% 3 dB pass band at 5.6 GHz and 7.75 GHz respectively, for both TE and TM polarizations and incidence angles up to 72°.
Zhu, Danny; Gregory, Micah D.; Werner, Douglas H.; and Werner, Pingjuan L., "Fabrication and Characterization of Polarization Independent 3D Printed Frequency Selective Structures with Ultra-Wide Fields of View" (2018). USMA Research Papers. 10.