George A. Campbell, 1870 - 1954

George Ashley Campbell was born on November 27, 1870, in Hastings, Minnesota, USA.He was one of the pioneers in developing and applying quantitative mathematical methods to the problems of long-distance telegraphy and telephony.His many contributions became essential tools of the communication engineering in daily use in ever-widening fields of application.

After graduating from M.I.T. in 1891, and receiving a master´s degree from Harvard in 1893, Campbell spent three years doing graduate study in Europe at Göttingen, Vienna, and Paris.In 1897 he joined the American Telephone and Telegraph company (AT&T).At that time the art of telephone transmission was still in its infancy, one of the main problems being that the signal quickly became distorted as the distance between points increased. Following the theoretical groundwork laid by Oliver Heaviside in 1887, Campbell began developing the loading coils that would keep the signal clear as it traveled. Campbell succeeded in the last months of the 19th century.Unfortunately for him, so had another inventor, Michael Pupin. Hoping to avoid exorbitant fees of a legal battle, AT&T paid Pupin $435,000 for his patents and stopped the dispute in its tracks.

Campbell´s career was extremely productive with discoveries, inventions, and patents. He recognized the importance of Maxwell´s capacity coefficients early on, and designed his well-known shielded balance to measure direct capacities.He also invented an electric filter to avoid "singing" in repeater circuits.He authored numerous and influential papers, among them "Loaded lines in telephonic transmission" (1903), "Cisoidal oscillations" (1911), and the classic 1922 paper on the "Physical theory of the electric wave-filter."

Campbell was awarded the IRE Medal of Honor in 1936, "For his contributions to the theory of electrical network."He died on November 10, 1954.

From Proceedings of the IRE