As an engineering manager, Cooper worked on many new products, including the first push button mobile phones. He soon became a specialist in digital electronics and was one of the first engineers to put transistors into a commercial application.
“Our first all-transistor mobile telephone had less than 100 transistors, but we were always trying to reduce that number because they cost us 50 cents each!” recalls Martin. He marvels over the fact that transistor counts in the billions are routine today.
The idea of Motorola developing a cellular telephone was an obvious next step. “We had been dreaming about this technology for a long time and had people in our own research labs working on all of the parts,” says Martin. “But though I knew that it could be done, at the same time we were pushing the technology envelope on almost every front.”
Nobody, for example, had ever built an antenna operating at 1 GHz in the small form factor needed. And nobody had ever designed a frequency synthesizer that could work reasonably well with low power drain. In fact, very few people were designing anything at all for battery operation.
“We needed power amps, we needed receiver amps, we needed synthesizers and we had to go to experts for every one of them, and then someone had to integrate the whole thing together,” says Cooper.
In spite of the daunting technological challenges, Motorola managed to crank out a working prototype in three months.
“First thing I told the engineers was to forget about the form factor and just get something to work,” says Cooper.
Under the leadership of Engineer Don Linder, engineers figured out how to combine some 300 to 400 parts together into a working phone and then squeeze the design into a 9 x 5 x 1.75 inch form factor. A huge nickel-cadmium battery, which had a charge of about 20 minutes, accounted for 40% of the weight of the 2.5-lb prototype.
Almost as soon as Cooper made his famous call, Motorola began working on a smaller, lighter, more affordable version of the phone that was reproducible. But it would be ten years and more than $100M dollars spent before Motorola began selling the DynaTAC8000x, for $3995 in 1983.
It included two features: You could make and receive phone calls.
Given that making a phone call is almost secondary to a modern day phone’s other capabilities, did Cooper envision the path of the first handheld cell phone’s trajectory?
“We knew that wireless was going to revolutionize us and that everybody was going to have a phone,” he says. “But the one thing I could not have begun to imagine was the impact of digital technology. Remember we were just getting started. If I had talked about putting 1,000 transistors in a phone, people would have assumed I was out of my mind.”