Electromagnetic Tuesday 25. 2. 2025

Come again after a year to see an informal performance of the Department of Electromagnetic Field. In the second week of the summer semester, we are preparing for you the 7th annual Electromagnetic Tuesday event, where you can watch interesting experiments, try to build something and learn something new. And we won’t let you die of hunger or thirst either. 

This time we have the following demonstrations and experiments for you:

Energy harvesting by rectenna in the 70cm band
We will extract harvest – not from the vacuum, but from electromagnetic waves provided by a handheld UHF radio. Harvesting will be handled by a reactively loaded circular antenna array, and the harvested RF energy will be converted to direct current using a rectifier.

Polarization viewfinder
The radar corner will offer a demonstration of the functioning of FMCW automotive radar. In the experiments, we will focus on target detection, determination of their parameters, tracking algorithms, object cloaking, and 3D scene reconstruction.

Radar Corner V
Everyone knows reflections from glass but could you exploit them usefully? In this task you will construct a viewfinder based on Brewster angle reflection. You will watch just one polarization component. The viewfinder can be used to eliminate reflections from glass or to detect tension in transparent material.

How to wake up antennas
Designing a suitable antenna usually requires determining its shape and method of feeding. These two factors are interrelated. The method of decomposing the current into characteristic modes allows the whole process to be divided into two steps: first, we determine the appropriate shape. Then, by analyzing the characteristic modes, we find the correct position and form of power supply.
Come to the CEM booth where we will explain how the method works, show you the different resonant modes of the antenna, and give you the opportunity to put them together so that the antenna works properly.

Tones over photons
Did you know that you can also receive the radio signal wirelessly using an optical communication system? We will let you have air communication, which we will transport directly to the laboratory using an optical network and show other possibilities of transmitting different frequencies (tones) in the optical domain.

From waves to heat: Demonstration of the principle of microwaves in cancer treatment
To demonstrate the application of microwaves in the treatment of cancer, we will use a poster that describes the biological basis of microwave hyperthermia. Its physical principle will be explained by calculating the 3D treated area heating (with respect to time) with the EM field simulator Sim4Life. With an emphasis on the information we must first simulate the 3D distribution of EM wave absorption and consequently the 4D temperature distribution. We will support this simulation by experimenting with microwave heating of an agar phantom and monitoring the temperature increase using an IR camera.

Make Your Own Antenna IV
The “Make your own antenna” stand has become a permanent feature of the EMiT event and will not be missing this year either. Traditionally, you will design and make your own small multiband antenna for modern mobile devices (laptop, tablet, phone). You will be able to measure the resulting product and take it home … in your pocket.

And there’s more…

Photos from previous years:

EMiT 2024 – photo
EMiT 2023 – photo
EMiT 2022 – photo
EMiT 2020 – photo
EMiT 2019 – photo
EMiT 2018 – photo