Análise eletromagnética modal em dispositivos de onda guiada: aplicações em microscopia de campo próximo e concentração de energia micro-ondas

Abstract

This work presents an analytical, numerical and experimental study about the electromagnetic analysis applied in the design of guided wave structures. Initially, transitions between coaxial and rectangular homogeneous waveguides are analyzed. The used approach is from analytical nature and it is named in literature as mode matching technique. This method is based on the modal expansion of the electromagnetic fields present in the waveguides and it is applied in the analysis and design of guided-wave devices. Then, in the simulation and experiments stage, a realistic prototype involving waveguides and many antennas was designed as a microwave energy concentration system. The focus of this system is the delivery of electromagnetic energy in precise spots causing over them heating, sintering, and melting of materials. The prototype targets future applications in 3D printing technology. On the other hand, a series of simulations and measurements were performed to assess the influence of liquid immersion in near-field microscopy tests. The results showed that the formation of nanometric water menisci contributes to the generation of images that reveal structures of nanometric resolution.