Valdemar Poulsen
（重定向自Telegraphone）
Valdemar Poulsen (23 November 1869 – 23 July 1942) was a Danish engineer who made significant contributions to early radio technology. He developed a magnetic wire recorder in 1899 and the first continuous wave radio transmitter, the Poulsen arc transmitter, in 1903, which was used in some of the first broadcasting stations until the early 1920s.