Paul O'Leary

3D metal printed sierpinski gasket antenna

In this research, the design, simulation, and fabrication of the first ever 3D metal printed Sierpinski gasket antenna, with multiple resonance characteristics is reported. The antenna is fabricated from Titanium alloy Ti-6Al-4V, using the Direct Metal Laser Sintering (DMLS) technique. Mechanical considerations like Rumseys principle and the support structures required for overhanging 3D printed structures have also been studied in detail and discussed. The validity of the DMLS technique for manufacturing a complex shaped (fractal) antenna is assessed, by comparing CST (Computer Simulation Technology) simulation results with the measured data.

Improved performance of 3D metal printed antenna through gradual reduction in surface roughness

The research presents the performance evaluation of a 3D metal printed antenna, as the inherent surface roughness is gradually reduced using different surface treatment techniques. In this work, surface treatment is performed on a complex shaped, 3D metal printed Sierpinski gasket antenna, fabricated from Ti-6A1-4V using a Direct Metal Laser Sintering (DMLS) technique on EOSINT M280 system. Following the initial assessment, the surface roughness has been reduced gradually, in stages, using surface treatment techniques such as wet blasting and polishing. To monitor the surface morphological changes on the antenna, a Scanning Electron Microscope (SEM) and White Light Interferometer (WLI) have been used. Finally, both the path loss (S21) and the return loss (S11) are measured, to track the RF performance changes on the 3D metal printed antenna, as a function of reducing surface roughness.

Bench test results on a new technique for far-infrared polarimetry

The results of bench tests performed on a new method of combined interferometry/polarimetry for the magnetic-field reconstruction of tokamak plasmas is presented. In particular, the sensitivity obtained in the polarimetric measurement shows the feasibility of Faraday rotation determination approaching a precision of ±0.2°. The method is based on an optically pumped far-infrared laser with a rotating polarization where both the interferometric and polarimetric information is determined from phase measurements. Specific sources that introduce disturbances in the optical arrangement and that can limit the attainment of the polarimetric precision, mentioned above, are discussed.