Jonathan_Zenneck

Jonathan Adolf Wilhelm Zenneck (15 April 1871 – 8 April 1959) was a German physicist and electrical engineer who contributed to researches in radio circuit performance and to the scientific and educational contributions to the literature of the pioneer radio art.
Zenneck improved the Braun cathode ray tube by adding a second deflection structure at right angles to the first, which allowed two-dimensional viewing of a waveform. This two-dimensional display is fundamental to the oscilloscope.