Abstract:

In the context of our modern society, a strong background in wireless communications becomes a must for future electronic and telecommunication engineers. In this regard, the capacity of the students for self-learning and the consolidation of theoretical concepts through experimental realizations become essential. The fabrication of electronic circuits operating at radiofrequency (i.e., in the gigahertz band) is neither a trivial task nor affordable in terms of cost and time if conventional integrated circuit technology is considered. However, the use of an automatic extrusion machine for drawing the metallic tracks that form the microwave transmission lines or eventual designed patterns that conform a planar antenna; and, at the same time, the use of an automatic drill to perform the location of the different electronic elements on a substrate, makes feasible the realization of exemplary radiofrequency circuits for improving the learning of engineering students in this especially important field.

In this work, we show the results of the work carried out by students along undergraduate courses of electronic and telecommunication engineering when performing a whole design-fabrication-characterization process. The targeted radiofrequency circuit consisted of a rectenna, which is a system formed by a planar antenna and a commercial diode playing the role of a rectifier. Rectennas are especially useful for energy harvesting, which is an application that also makes students be aware of the green deal, i.e., the importance of reducing the environmental footprint in electronic circuits. For the design task, the students combined CST Studio Suite for the electromagnetic simulation of the planar antenna, together with Keysight Pathwave Advanced Design Systems (ADS) for the electronic simulation of the rectenna. For the fabrication task, students used a Voltera V-One robot, which allows the automatic fabrication of printed circuits, the creation of vias and the deposition of conductive paste that ultimately was used to solder the passive elements, SMA-connectors and the commercial rectifier. Finally, for the characterization of the radiofrequency circuits, a basic vector network analyser from the microwave laboratory is used, including the calibration and the measuring operations (although, in the future, non-linear analysis will be considered).

In conclusion, this work has brought students closer to future tasks that they will face when working as designers of emergent 5G/6G wireless applications. Students had to learn the use of the likely most used software for microwave design, ADS; they had to learn how to design planar patch antennas in CST; they learnt common problems appearing during the automatic fabrication of radiofrequency printed circuits, together with the processes that involve the calibration and characterization of electronic circuits working at relatively high frequencies (reaching the gigahertz band).

Keywords:

Electronic and telecommunication engineering, self-learning, printed circuits.