Radio telescopes are used to observe our universe and to provide astronomers with detailed images and spectra. We use antenna technology to receive radio signals from the universe. There are different types of antennas: dishes like the Westerbork Synthesis Radio Telescope (WSRT), and dipoles like the Low Frequency Array (LOFAR). We require many antennas to get the sharpest images from very weak signals. Combining the signals from all antennas is called interferometry and requires electronic boards, photonic links, supercomputers and a lot of algorithms and software.