Mihajlo Idvorski Pupin, Ph.D., LL.D. (Serbian Cyrillic: Михајло Идворски Пупин; 9 October 1858 – 12 March 1935), also known as Michael I. Pupin, was a Serbian American physicist and physical chemist. Pupin is best known for his numerous patents, including a means of greatly extending the range of long-distance telephone communication by placing loading coils (of wire) at predetermined intervals along the transmitting wire (known as "pupinization").