Search ETDs:
Design and Location Optimization of Electrically Small Antennas Using Modal Techniques
Chalas, Jeffrey Michael

2015, Doctor of Philosophy, Ohio State University, Electrical and Computer Engineering.
In this dissertation, the Theory of Characteristic Modes is used as a framework for the design, optimization, and benchmarking of electrically small radiating systems. The foundation of this work is in the theory of Characteristic Modes, an eigenvalue equation of the Method of Moments impedance matrix [Z], that leads to derive the fundamental radiation modes of arbitrary-shaped bodies. After an overview of small antenna theory, we derive a new method for computing the Q factor of arbitrary-shaped radiating bodies using CMs using only the Method of Moments impedance matrix [Z]. Following this derivation, we present a new method for computing the fundamental limits on Q (and thus bandwidth) for arbitrary-shaped antennas. As a by-product of this method, we extract the optimal current distribution as a function of antenna shape for design guidelines. We further extend this theory to find the Q limits of arbitrary-shaped antennas and antenna-platform systems, subject to specific radiation pattern requirements.

In the second part of the thesis, we use the Theory of Characteristic Modes to optimize the location and excitation of single and multiple in-situ ESAs mounted on finite, sub-wavelength platforms as relates to unmanned aerial vehicles (UAVs). By properly analyzing the CMs of the supporting platform, we show that a complex, multivariate optimization problems can by radically simplified using CMs. Based on this capability, we present a new, systematic design methodology for location optimization of small antennas on-board finite platforms. The approach is shown to drastically reduce the time, computational cost, and complexity of a multi-element in-situ antenna design, as well as providing significant performance improvements in comparison to a typical single-antenna implementations.
John Volakis, Dr. (Advisor)
Kubilay Sertel, Dr. (Advisor)
Robert Burkholder, Dr. (Committee Member)
122 p.

Recommended Citations

Hide/Show APA Citation

Chalas, J. (2015). Design and Location Optimization of Electrically Small Antennas Using Modal Techniques. (Electronic Thesis or Dissertation). Retrieved from https://etd.ohiolink.edu/

Hide/Show MLA Citation

Chalas, Jeffrey. "Design and Location Optimization of Electrically Small Antennas Using Modal Techniques." Electronic Thesis or Dissertation. Ohio State University, 2015. OhioLINK Electronic Theses and Dissertations Center. 25 Sep 2017.

Hide/Show Chicago Citation

Chalas, Jeffrey "Design and Location Optimization of Electrically Small Antennas Using Modal Techniques." Electronic Thesis or Dissertation. Ohio State University, 2015. https://etd.ohiolink.edu/

Files

jeffrey chalas - final dissertation - 1 9 15.pdf (4.8 MB) View|Download