“One Perspective on the 40-Year Evolution of Software-Defined Radio Signals Intercept Systems"
Dr. Donald H. Steinbrecher, Chief Scientist, Electromagnetic Systems Division, Navy Undersea Warfare Center
Instantaneous signal dynamic range, ISDR, is a principal metric for high-performance software-defined radio signals intercept systems. ISDR is measured as the available input power difference between the maximum allowable signal amplitude and the minimum detectable signal amplitude that can be simultaneously resolved by a system’s digital process. The maximum allowable signal amplitude is defined as the sinewave power available from the input source that corresponds to full-scale in the analog-to-digital conversion process. The minimum detectable signal amplitude is defined as the sinewave power available from the input source that is equal to kT0FSB in which T0 is standard temperature, FS is the system noise Figure, k is the Boltzmann constant and B is the receiver detection bandwidth.
Software-Defined-Radio evolution can be envisioned as extending along a coordinate of increasing ISDR as new techniques and architectures have increased the ISDR available at a reasonable cost. Today, we are witnessing the dawn of a new coordinate of ISDR expansion as the parallel architectures found in the digital processing domain are reaching toward the air interface and permitting designers to envision the software definition of the entire signals acquisition system including the antenna characteristics of the air interface. A future paradigm is now predictable in which new architectures will enable radically new software-defined signals acquisition systems with wide bandwidths and adequate ISDR to be deployed in almost all signal environments. A fundamental performance limit defining the growth of ISDR within this new paradigm will be introduced as a prediction of the future performance limitations of software-defined signals acquisition systems.
Biography
Dr. Donald H. Steinbrecher currently holds the position of Chief Scientist in the Electromagnetic Systems Division of the Navy Undersea Warfare Center in Newport, RI where he has been employed for the past 10 years. His research activity has focused on establishing a leadership role for the Navy in the field of software-defined electromagnetic-signals acquisition systems. Dr. Steinbrecher was named a winner of the 2007 Department of the Navy Top Scientists and Engineers of the Year Award for his innovative work in the field of high-performance digital signals acquisition systems. He is also a winner of the 2007 Chief of Naval Research Million-Dollar Challenge.
Dr. Steinbrecher received a BSEE degree, with highest honors, from the University of Florida in June 1960. He entered the Massachusetts Institute of Technology (MIT) graduate studies program in Electrical Engineering and Computer Science (EECS), received a Master of Science in 1963 and completed the Ph.D. degree in June 1966. He remained with the MIT Department of Electrical Engineering and Computer Science and The Research Laboratory of Electronics (RLE) until June 1972. As a member of the EECS Department, he taught courses specializing in solid-state device properties and applications and was promoted to Associate Professor in June 1969. As a member of the RLE, he conducted research in microwave and millimeter wave circuits with an emphasis on communications applications. His research provided a technical foundation for early experiments in millimeter wave communications satellites developed by the MIT Lincoln Laboratory, the LES 8-9 Programs.
Dr. Steinbrecher founded Steinbrecher Corporation. The company became a leading supplier of software-defined signals acquisition systems. He developed concepts that convert high-bandwidth, high dynamic-range RF signals to a digital format and made possible direct digital signal processing of the RF signals, which is now known as “software-defined radio”. His receivers were the building blocks of wide-band digital signals acquisition systems used in a wide range of surveillance applications. His receivers were also the enabling technology for the US Navy ROTHR radar systems that remain in operation today. Beginning in 1990, the wide-band digital receivers were adapted to several applications in the cellular-telephone infrastructure.
In 1975, Dr. Steinbrecher established a fundamental performance limit for the dynamic range of frequency converters, which resulted in two patents defining the ParamixerTM frequency translator. The Paramixer became the core technology for the development of numerous broadband software-defined signals acquisition systems. He later derived a fundamental performance limit for the dynamic range of the RF-to-digital conversion process and teamed with Professor fred harris of San Diego State University to teach a series of short courses on the optimum design of software-defined radios. Dr. Steinbrecher has recently discovered a fundamental performance limit on the ability of signals-acquisition systems to create wide-band high dynamic-range digital images of propagating RF signals. This fundamental performance limit incorporates the method of RF-energy capture and shows that there is an optimum air interface for software-defined radio systems. The predicted optimum air interface design is described in three patents. Dr. Steinbrecher has been allowed 14 patents for his work on high performance signals intercept concepts.