## 7 Conclusions  
In summary, we presented an innovative, low-cost instrument developed specifically for the precise characterization of microwave metasurfaces, particularly in the Ka band spectrum. This instrument is designed to offer an in-depth understanding of complex metasurfaces, such as a metalens, by allowing a thorough analysis of the point spread function in relation to the critical parameters. These include depth of focus (DOF), full width at half maximum (FWHM), and gain--quantified in our study as 11 cm, 2.17 cm, and 8.05 dB, respectively. This systematic characterization is pivotal for understanding the intricate design and functionality of metasurfaces. A distinguishing feature of our proposed instrument is its capacity to generate data for 3D reconstruction of the metalens intensity distribution. This capability offers a comprehensive view of the metasurface properties, thus providing more robust analytical insights that go beyond conventional characterization methods. The integration of these features in a single, cost-effective tool represents a significant advancement in the field of microwave metasurface characterization. With its broad application potential, this instrument promises to revolutionize metasurface investigations, opening new avenues for advancements in telecommunications and beyond. Table 1 in our paper provides a detailed overview of the components of our instrument, itemizing each part, along with its respective cost, thereby demonstrating the affordability of our proposed tool. We believe this comprehensive cost breakdown will be beneficial for researchers aiming to replicate or build upon our design. Figure 19: The measurement cycle without the metalens positioned between the transmitting and receiving antennas: (**a**) the complete matrix extracted from the measurements; (**b**) the central part of the matrix, excluding 50 pixels on each side. Overall, these findings and their consequent implications underscore the substantial value of our proposed instrument in enabling precise and comprehensive metasurface characterization across a myriad of potential applications. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app13116581/s1](https://www.mdpi.com/article/10.3390/app13116581/s1)]([https://www.mdpi.com/article/10.3390/app13116581/s1](https://www.mdpi.com/article/10.3390/app13116581/s1)), The Supplementary Materials include all code files (instrument control firmwares and softwares), as well as all STL, DXF, and Gerber files to build the instrument. They can be downloaded at the article website. Conceptualization, R.G., A.M. and V.P. ; methodology, R.G., A.M. and V.P. ; software, R.G. ; validation, R.G. ; formal analysis, R.G. ; investigation, R.G. ; resources, R.G. and A.M.; data curation, R.G. ; writing--original draft preparation, R.G. ; writing--review and editing, R.G. and J.P.C. ; visualization, R.G., B.-H.V.B. and J.P.C. ; supervision, J.P.C. ; project administration, J.P.C. ; funding acquisition, B.-H.V.B. and J.P.C. All authors have read and agreed to the published version of the manuscript. This research work was supported by the National Council for Scientific and Technological Development (CNPq), which is a foundation linked to the Ministry of Science and Technology (MCT) to support Brazilian research. The CNPq process number is 303562/2017-0. [PERSON] was supported by a Coordination for the Improvement of Higher Education Personnel (CAPES) scholarship, with process number: 88887.4829072020-00. Professor [PERSON] was support by a PQ scholarship with the reference CNPq 304312/2020-7. Not applicable.