We have developed a free-space near-field scanning
millimetre and Terahertz wave microscope with two tapered
probes facing each other and the sample in between. The 3D
printed probe is proposed. The working principle of the 3D
printer and the inner structure of the 3D printed products are
analysed and the dielectric property of ABS is deduced by
means of broad band dielectric spectroscopy using MVNA.
ABS is a medium loss material in the W-band. From the
simulation of tapered Teflon and ABS 3D printed focusing
tips, we found the optimal parameters and the influence of the
metal cover and different materials. We designed tips that can
identify at least 260 μm metal strips with long distance
interval. Until now 0.7 mm metal circles and 0.7 mm interval
space was distinguished also. Compared with Teflon and ABS
3D printed focusing tips, we found out that the phase of the
transmission is more sensitive than the amplitude in some case
and the 3D printed focusing probe has higher resolution than
Teflon in terms of transmission amplitude, however, the phase
information contains more noise because of the inner structure
of the 3D printed probe. However, the sharpness of the 3D
printed is limited by the 3D printer layers and this leads to the
limited images resolution.