Events Calendar

Integrated Systems Seminar Series - Dr. Ronald Pogorzelski, JPL

Coupled Oscillator Based Transmitters and Receivers: Theory and Experiment at JPLFor roughly ten years the Spacecraft Antenna Research Group at JPL has been developing and studying phased array antennas based on a concept of phase control introduced by Professor Robert A. York and his students at the University of California, Santa Barbara. In York's concept, a set of voltage controlled oscillators are coupled with their nearest neighbors in an array and are thus induced to mutually injection lock and oscillate as an ensemble. What York, et al. noted is that in such an ensemble, if one detunes the perimeter oscillators away from the ensemble frequency, one can induce linear phase progressions in the oscillator output signals. Thus, if these signals are used to excite the elements of a phased array antenna, beam agility is achieved. Since in these antennas, the signal sources for the transmit function and the local oscillators and mixers for the receive function are distributed over, and integrated with, the antenna aperture, we have termed these devices "agile beam transmitters and receivers." The JPL work has been both theoretical and experimental. The theoretical work began with a collaboration with the York group in developing a "continuum model" of such oscillator arrays. This model revealed that the dynamic behavior of the phase distribution behaves as a diffusion process. The theory was applied to linear and planar array geometries and to Cartesian, triangular, and hexagonal coupling topologies. The linear and Cartesian arrays were also studied experimentally. Most recently, coupling delay was built into the theoretical treatment resulting in some fascinating Laplace transformations leading to a simple prediction of the impact of such delays on the array dynamics. This presentation will review the development work over the past ten years both theoretical and experimental ending with the most recent work on coupling delays.

Location: Kaprielian Hall (KAP) - 156

Audiences: Everyone Is Invited

Contact: Hossein Hashemi