Alexander Meissner (in German: Alexander Meißner) (September 14, 1883 – January 3, 1958) was Austrian engineer and physicist. He was born in Vienna and died in Berlin.
His field of interest was: antenna design, amplification and detection advanced the development of radio telegraphy. In March 1913 he discovered the principle of positive feedback independently of Edwin Armstrong, and applying positive feedback to vacuum tube amplifiers co-invented the electronic oscillator, which became the basis of radio transmission by 1920 and has innumerable uses today. The inductively-coupled oscillator circuit he invented is today known as the Meissner oscillator.