If you want to transmit data, listen to the radio or use a radio, you can use a so-called 'Software Defined Radio' (SDR). The signal processing of these high-frequency transmitters and receivers is carried out using software. The advantages are a reduced device infrastructure and good adaptation to changing transmission standards. Lukas Lao Beyer (18), the national winner in the technology category, has developed a low-cost SDR. In principle, an SDR consists of an antenna for transmitting and receiving data and an analog-to-digital converter. The input signals are processed in a processor and forwarded to a PC via a USB interface. The young researcher realized the SDR on a printed circuit board. The aim was to ensure good signal quality and to develop the software in such a way that large amounts of data can be transmitted in real time.