Teaching High-Frequency Circuit Design in Online Environment.

COVID-19 pandemic has affected engineering education worldwide with most departments opting to switch to an online (remote) mode of instruction. At our institution, the switch happened in a matter of weeks which presented significant problems in teaching the fourth year Microwave Circuit Design courses. These courses were originally designed with a “studio” component where much of the design and experimentation happened during the so-called lab hours. Experimentation was very dependent on access to specialized and very expensive equipment, most importantly to VNA-s (vector network analyzers) and TDR oscilloscopes (time-domain reflectometry). Several compromises were made for online instruction: a) reduction of teaching material to essential components, b) use of inexpensive instrumentation, c) redesign of labs for off-line work, and d) reduction in the size of teams to two members instead of three. While the first may be advisable in any circumstances, the last two were driven primarily by logistical or organizational considerations. We report on how our “studio” environment was transformed into online “lab” assignments and how this affected course content. Key aspect of it is the development of affordable instrumentation that students can purchase themselves. This includes VNA-s and software-defined radios which are utilized as spectrum analyzers. We describe the initial uses of such instrumentation in our courses, their pros and cons, and the remaining issues. These developments have the potential to fundamentally change how we teach these and similar courses and we expect that many of the ideas being implemented will carry over into face-to-face instruction.