Amos E. Joel Jr., 90; his invention paved way for cellphone

NEW YORK - Amos E. Joel Jr., an inventor whose switching device opened the way for the cellular phone business, died Saturday at his home in Maplewood, N.J. He was 90.

The death was confirmed by his daughter Stephanie.

Mr. Joel received more than 70 patents, but he was perhaps best known for No. 3,663,762, a 1972 patent that allows a cellphone user to make an uninterrupted call while moving from one cell region to another.

"Without his invention, there wouldn't be all these people walking around with cellphones," said Frank Vigilante, who was one of Mr. Joel's supervisors at Bell Labs. "He really allowed that business to form and to be a business."

A native of Philadelphia who grew up partly in New York City, Mr. Joel liked to tinker with electronics from an early age. As a boy, he wired a communication system for his friends, using old phone equipment that was left behind in vacant apartments, and he built a crude switchboard with knife switches, only to be caught by a repairman, his daughter said.

In an interview with The Star-Ledger in New Jersey this year, Mr. Joel traced his career back to childhood fascinations: the switches on his electric train and his family's first dial telephone. "I wanted to know, how does this thing work?" he said.

He earned bachelor's and master's degrees in electrical engineering from the Massachusetts Institute of Technology, where he collected and posted patents in his dorm room. While in college, he met his wife, the former Rhoda Fenton, on a blind date and invited her up to his room to look at his patents.

"She thought patents was a code name for something else," Stephanie Joel said. "What she didn't realize is that our father always had a lifelong fascination with patents." Fenton came away from the date thinking that Mr. Joel was crazy, but he eventually won her over. They were married for 58 years.

Mr. Joel spent his professional career at Bell Labs, working 43 years there until he retired in 1983.

During World War II, Mr. Joel designed circuits for early digital computers, and he played a key role in the creation of encryption machines for military and domestic use, according to the National Inventors Hall of Fame. Mr. Joel was inducted into the hall this year.

After the war, he developed and taught a course on switching systems and circuit design and eventually designed the first automatic telephone-billing equipment, according to IEEE, a professional organization of engineers. His patent for an automatic accounting system for customers' charges on long-distance dialing filled more than 500 pages and weighed 11 pounds.

His wife died in 2000, as did his son, Jeffrey, in 2003. Besides his daughter Stephanie, of New York City, he leaves another daughter, Andrea of Burbank, Calif.