Dr. Robert Romanofsky has over 75 publications and holds five patents in the fields of microwave device technology, high-temperature superconductivity, and the use of thin ferroelectric films in microwave applications. A recipient of NASA’s Exceptional Service Medal, Exceptional Technology Achievement Medal, the Federal Executive Board “Wings of Excellence” award, and the Rotary National Stellar Space Award, he currently serves as senior engineer for the Antenna and Optical Systems Branch at the NASA Glenn Research Center where he works on advanced antenna systems designs.
NASA Tech Briefs: As a senior scientist for NASA’s Antenna and Optical Systems Branch, what types of projects do you typically get involved with?
Dr. Robert Romanofsky: It’s a fairly diverse portfolio. Most of my work for the last several years has been supported by the Space Communications and Navigation (SCAN) project in NASA’s Space Operations Missions Directorate. I’ve been working primarily on the development of an electronically steerable antenna based on some novel thin film ferroelectric devices that were invented here at Glenn. I’m also working on a technology program to accelerate the development of large deployable Ka band antennas. There’s a considerable amount of work that I do for certain DoD interests, as well as industry. We have a number of reimbursable Space Act Agreements with both large and small companies.
NTB: It sounds like a pretty diverse array of jobs.
Dr. Romanofsky: It’s pretty exciting.
NTB: One of your areas of expertise is cryogenic microwave electronics. What is cryogenic microwave electronics, and what are some of its potential applications in terms of both the space program and commercial use?
Dr. Romanofsky: Cryogenic electronics, in general, simply means that the components are deliberately cooled to a certain temperature. The exact threshold of where cryogenic begins is somewhat nebulous, but we do a lot of work at liquid nitrogen temperatures and below.
There are many advantages in cooling electronics. For example, a very important parameter of semiconductors is the mobility, and the mobility has a lot to do with device speed. Of course, there’s a tremendous amount of interest in making logic faster and faster. One way of making that happen is to increase the velocity of the carriers within the semiconductor. These mobilities can increase from perhaps a factor of several thousand centimeters squared per volt second at room temperature to, perhaps, tens-of-thousands of centimeters squared per volt second at 77 Kelvin. So it has an enormous impact on device speeds.
Also, cooling electronics, especially microwave receivers, improves the sensitivity of the receivers, and in a communications system, signal-to-noise ratio is everything. You must be able to extract extremely weak signals from an extremely noisy background. So cooling the electronics, which is exactly what has been done for many decades with the Deep Space Network, allows us to do things like pick up inordinately weak signals from spacecraft like Voyager. That’s a phenomenal accomplishment.
As far as commercial applications, I think they are evolving thanks to the fairly recent development of miniature cryogenic coolers. To the best of my knowledge, only one domestic company is still doing low-temperature superconducting electronics, and that’s HYPRES. They’ve been quite successful in demonstrating an all-digital receiver, and that’s kind of the holy grail of communications engineering, to move digital electronics as close as you possibly can to the antenna. With superconducting technology, you can make extremely fast analog-to-digital converters, and that’s kind of the direction that things are heading in.
NTB: You’ve also done a lot of work in the area of thin film ferroelectric technology. What potential applications do you envision for that?
Dr. Romanofsky: We started working on microwave applications of thin film ferroelectric films roughly ten years ago and it was a novel way of building tunable smart electronics. For example, instead of just having a filter, or an antenna, or something that would just kind of sit there and serve one function, it allowed much greater flexibility.