Rf Photonic Vector Modulation and Demodulation Techniques for Millimeter-wave Communications

Title of dissertation: RF PHOTONIC VECTOR MODULATION AND DEMODULATION TECHNIQUES FOR MILLIMETER-WAVE COMMUNICATIONS Vincent R. Pagán, Doctor of Philosophy, 2015 Dissertation directed by: Professor Thomas E. Murphy Department of Electrical and Computer Engineering RF photonic techniques for modulating and demodulating microwave and millimeter-wave signals on RF carriers are theoretically analyzed and experimentally demonstrated. The two demodulating configurations utilize cascaded electrooptic phase-modulation followed by optical filtering. The spurious free dynamic ranges of these configurations are measured and a technique to intrinsically linearize the latter system to fifth-order is experimentally confirmed. Measurements are then performed at frequencies between 7 and 70 GHz that verify RF photonic based downconversion using a harmonic of the electrical local oscillator (LO). Furthermore, this architecture is extended to allow for vector demodulation of digitally-encoded signals. Results of RF photonic demodulation of 4-quadrature amplitude modulation (QAM) and 16-QAM RF encoded millimeter-wave signals are presented. Two RF photonic techniques for generating and encoding millimeter-wave RF signals are analyzed and experimentally demonstrated. The first uses phasemodulation and optical filtering in an interferometric configuration. Phase-shift keyed encoded microwave and millimeter-wave signals are electrooptically synthesized using a harmonic of the electrical LO at data-rates of up to 6 Gbps and frequencies of up to 40 GHz. A second RF photonic scheme is developed to allow for vector modulation and upconversion using dual-drive Mach-Zehnder modulators. Vector modulation and upconversion are then shown at harmonics of the LO up to the fourth-order and at frequencies up to 60 GHz. Moreover, generation of 2.488 Gbps 4-QAM signals on a 36 GHz carrier using the second harmonic of the LO are demonstrated with this approach. Wired and wireless microwave and millimeterwave transmission experiments are successfully conducted with the RF photonic systems detailed above in a laboratory environment. RF PHOTONIC VECTOR MODULATION AND DEMODULATION TECHNIQUES FOR MILLIMETER-WAVE COMMUNICATIONS by Vincent Richard Pagán Dissertation submitted to the Faculty of the Graduate School of the University of Maryland, College Park in partial fulfillment of the requirements for the degree of Doctor of Philosophy 2015 Advisory Committee: Prof. Thomas E. Murphy, Chair Prof. Mario Dagenais Prof. Julius Goldhar Prof. Maio Yu, Dean’s Representative Dr. Bryan M. Haas