SHAPE: Dynamic and Reconfigurable Multiband and Ultra-Wideband RF Spectral Tailoring

University Of Georgia Research Foundation Inc, Athens GA

Investigators

Abstract

Multiband radio frequency (RF) systems are essential for commercial, defense, and everyday consumer uses. Further multiband RF resources have recently been released for new applications such as the 5G system. Although these new developments could lead to useful new applications being supported and more people able to enjoy the associated advantages, we can only realize these benefits if we can ensure high-quality transmission performance. This outcome is challenging to achieve because the bandwidth of multiband RF signals can be several gigahertz wide, and current electronic technologies are not capable of dynamically manipulating such a wide spectrum. This research aims to overcome this challenge by making use of photonics, an alternative signal processing method that has much wider bandwidth and faster speed than its counterpart in electronics. With the proposed photonics techniques, the RF signal is first converted to an optical signal, which can then be processed almost instantaneously and dynamically. This research focuses on the dynamic and precise tailoring and equalizing of RF spectral response over ultra-wide/multiple frequency bands. We will also carry out a comprehensive education plan closely related to the research that includes developing mobile apps for learning fiber optics, visiting local elementary and high schools, developing undergraduate freshman seminars and cross-disciplinary courses, and providing research experiences for high school and undergraduate students. This research will strengthen vital wireless services in the United States, including smart home system control, augmented reality learning, and surveillance and reconnaissance efforts. While new RF resources from MHz to tens of GHz have been made available to emerging wireless technologies such as the 5G system, the inability to dynamically and precisely manipulate the whole available RF spectrum hinders the performance of the associated multi-/wideband systems. The mission of this research is to use photonics to enable effective and precise manipulation of wide radio spectrum of tens of GHz. Two closely related research themes are proposed: (i) Developing a photonics-based radio frequency spectrum shaper that can achieve tens of GHz bandwidth of continuous spectral tailoring capability with greater than 50-dB dynamic amplitude compensation, and (ii) Developing a radio frequency photonic subsystem to enable independent multiband RF spectral shaping and chirp control. The radio frequency spectral shaper exploits the multi-point spectral control capabilities of a uniquely designed RF multiband filter, the heterogeneous spectral property control algorithm, and the instantaneous response of existing optical devices to achieve dynamic radio frequency spectrum tailoring from low- to high-frequency bands. The dynamic spectral manipulation of radio frequency spectrum enables independent control of frequency, amplitude, spectral shape, bandwidth, and group delay slope at each spectral control point. This proposal presents a comprehensive, interdisciplinary, and innovative approach to solve the challenging wideband radio frequency channel response problem while offering a solution to individually and precisely tailor the wideband and multiband radio frequency spectrum. The proposed research involves a close coupling of system design and experimental validation, and thus will yield laboratory prototypes to demonstrate more effective operation of wideband and multiband radio frequency systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.