SWIFT: Reconfigurable Microwave Silicon Photonics Filters and Passive-User-Friendly Protocols for Spectrum Coexistence

Wireless passive systems such as radio astronomy receivers, or atmospheric and geo-space science and climatological observation receivers are extremely sensitive to other active wireless interferences such as terrestrial cellular communications signals. As a result, they typically require dedicated radio frequency bands along with guard frequency bands around them.

In many cases, active users may not physically co-exist in such areas, and many passive user infrastructures have therefore been built in remote areas. Such scenarios generally reduce the effective spectrum efficiency hindering the deployment of passive systems and creating barriers against future scientific discoveries. A new approach would be to allow both passive and active users to operate in adjacent frequency bands and in neighboring locations.

This will allow active users to operate in previously unallowable guard frequency bands thereby significantly enhancing spectrum efficiency. This project introduces innovations on chip-scale microwave silicon photonics (SiP) adaptive filter architectures on the passive user side and passive-user-friendly protocols for resource allocation on the active (mobile) user side and thus addresses effective spectrum utilization/coexistence between passive and active (mobile) users.

The research proposed in this project on microwave SiP filters along with wireless protocols can potentially revolutionize the future of wireless communication industries and provide further technological diversification for the photonic and semiconductor industries. Besides the technical impacts, the proposed project also promotes outreach activities to increase participation of students in science and engineering, including annual one-week summer camps for high school students.

The research and educational results of this work will be disseminated to academic, industrial and government sectors.

This project intends to develop (1) novel chip-scale microwave SiP reconfigurable/adaptive filter architectures on the passive user side, using a Silicon-on-Insulator (SOI) optical chip controlled by a nanometer Complementary Metal-Oxide Semiconductor (CMOS) SOI-chip that both allows for electrically controlled filter configuration and jammer rejection to dynamically protect passive users’ bands and (2) passive-user-friendly protocols for resource allocation on the active (mobile) user side. The research objectives are the development of: (1) a microwave SiP/CMOS adaptive filter architecture and its photonics/electronics components, along with algorithms/hardware for their automatic tuning on the passive user side, (2) online policies with provable service guarantees for the proposed passive-user-friendly protocol, and the (3) hybrid integration of the proposed adaptive filter on the passive user and resource allocation protocols in the active user sides using a test bench for verification of effective spectrum utilization.

A versatile microwave SiP adaptive filter unit will be potentially connected to a passive user receiver in room temperature after the main antenna and low noise amplifier (either in room or cryogenic temperature). This unit includes highly selective reconfigurable SiP bandpass and notch filters to dynamically select the desired passive user band within 10-50 GHz range and reject active users as jammers.

On the other hand, a passive-user-friendly protocol for resource allocation on the active (mobile) user side will be developed. This protocol will specifically consider both the sensitivity and linearity of the proposed electrooptic receiver on the passive user side, and the diverse features and service requirements of heterogeneous active user applications. Online algorithms with provable service guarantees will be developed for this protocol.

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.