Anton Christian Jacobæus (1911 in Stockholm, Sweden–1988) was a Swedish electrical engineer, known for his contributions to teletraffic engineering

Teletraffic engineering

Telecommunications traffic engineering, teletraffic engineering, or traffic engineering is the application of traffic engineering theory to telecommunications...

, especially in the design of the modern crossbar switch

Crossbar switch

In electronics, a crossbar switch is a switch connecting multiple inputs to multiple outputs in a matrix manner....

 used for telephone switching.

Jacobæus graduated from the Royal Institute of Technology

Royal Institute of Technology

The Royal Institute of Technology is a university in Stockholm, Sweden. KTH was founded in 1827 as Sweden's first polytechnic and is one of Scandinavia's largest institutions of higher education in technology. KTH accounts for one-third of Sweden’s technical research and engineering education...

 (KTH) in 1933 with a master's degree

Master's degree

A master's is an academic degree granted to individuals who have undergone study demonstrating a mastery or high-order overview of a specific field of study or area of professional practice...

 in electrical engineering. In 1935 he went to work for L. M. Ericsson, where he would spend his entire professional career. In 1950 he received his doctorate

Doctorate

A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder to teach in a specific field, A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder...

 in electrical engineering, also from KTH. His dissertation entitled A study of congestion in link systems became instrumental in the efficient design of crossbar switches. He became technical director in 1950, then senior vice president

Vice president

A vice president is an officer in government or business who is below a president in rank. The name comes from the Latin vice meaning 'in place of'. In some countries, the vice president is called the deputy president...

 from 1963 until his retirement in 1976. He then continued to serve as a consultant

Consultant

A consultant is a professional who provides professional or expert advice in a particular area such as management, accountancy, the environment, entertainment, technology, law , human resources, marketing, emergency management, food production, medicine, finance, life management, economics, public...

 to the company's management.

He was a member of the Royal Swedish Academy of Engineering Sciences

Royal Swedish Academy of Engineering Sciences

The Royal Swedish Academy of Engineering Sciences or Kungl. Ingenjörsvetenskapsakademien , founded in 1919 by King Gustaf V, is one of the Royal Academies in Sweden...

 1957–88, serving as its vice chairman 1979–81, and a member of the Royal Swedish Academy of Sciences

Royal Swedish Academy of Sciences

The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the Royal Academies of Sweden. The Academy is an independent, non-governmental scientific organization which acts to promote the sciences, primarily the natural sciences and mathematics.The Academy was founded on 2...

 from 1974. He was a fellow of IEEE from 1977.

In 1979, he was awarded the IEEE Alexander Graham Bell Medal

IEEE Alexander Graham Bell Medal

The IEEE Alexander Graham Bell Medal is an award honoring "exceptional contributions to the advancement of communications sciences and engineering" in the field of telecommunications...

.

Christian Jacobæus was the son of Hans Christian Jacobæus.