"If you build a car with a better engine, you don't move the steering wheel," says Luis Navarro, team leader for Tektronix's extremely popular digital oscilloscopes.
His Tektronix team used the same philosophy. It kept the existing control style of the popular analog oscilloscope, and just added "a few extra buttons" to the outside. What those extra buttons could do and what the oscilloscope showed, however, vastly differed from the analog versions.
Navarro's team obtained three patents for their new design. One involved the way the display processing was done. Navarro's display interpolator updated the screen faster and created "a smooth picture instead of just dots. We realized shading was important," says Navarro.
A second innovation corrected the technical difficulties with real-time sampling. "When you build a digital oscilloscope, you store a digital replica and you have to play it back, but the result isn't continuous. It is jittery.
A jitter-correction circuit corrected the inherent jumpiness. We solved both problems, not with faster computers, but with cleverness," he says. The third patent was for an "envelope mode," now called a peak detector, that lets the viewer detect a narrow pulse and eliminate "aliasing."
"One particular specification we needed had circuitry that was weak and marginal. As we kept building it, it became clear we had to deviate and make a major change to circuitry that we had not planned. An engineer said he'd do it, 'but no phone calls.'
Other engineers stepped forward volunteering to do other parts of his job. We put in a brand new IC in a week and a half. It was wonderful. I have so many good memories of that group of people." The ultimate result: in less than five years the world was buying more digital scopes than analog scopes."
What's the next frontier in oscilloscope design? Distributed remote wireless signal acquisition, says Navarro. "If you can put an acquisition probe right where the signal is and communicate without wires, you can acquire data with the least amount of distortion. You can put the acquisition unit in a harsh environment and still see what is happening."
While leisure time is scarce, Navarro does enjoy helping his wife, a Spanish teacher and head of the foreign language department at her school. He also coached soccer when his kids were in grade school and every two years they take 20 students to Spain for 10 days. He is additionally involved with Oregon's association for the mentally ill.
To recent graduates, Navarro advises: " Be honest with yourself. We all think that we can do more than we are able to. Stick to your principles. Don't let organizations or people suppress your opinions."
And to those specifically in engineering: "Don't ever believe in a random failure. If it happens once, it will happen again. Look for the root cause. There are no martians, no ghosts creating the failures. There's a very good natural reason for it and it will happen again. A perfect example is the latest shuttle disaster. With every flight, there's foam that would come off. Didn't they think that would ever cause a problem?"
"We are too much of an ostrich burying our head in the ground thinking it will not happen again," according to Navarro. "No, it will happen. It has a cause. We may not know the cause, it may be difficult to find out, but do find it or it will come back and bite you. We see that time and time again." On second thought, that's good advice for anyone.