Wireless communications and sensing have become ubiquitous. With the proliferation of wireless technologies, however, the electromagnetic (EM) spectrum has become increasingly congested. New concepts and technologies, such as artificial intelligence assisted collaborative radio networks, simultaneous-transmission-and-reception-based wireless systems, and large antenna arrays, have emerged to efficiently utilize the spectrum, which necessitate signal processing in the radio frequency (RF) domain. Linear periodically time-variant (LPTV) switched-capacitor circuits have been studied extensively in the past decade as they enable high-quality, widely tunable, and non-reciprocal RF signal processing components on chip. However, existing LPTV circuits are fundamentally limited to low-order, short-delay, and sub-6 GHz operations. This project, by introducing new commutated-inductor-capacitor (commutated-LC) circuits, aims to tackle the fundamental limits of existing switched-capacitor circuits, which has the potential to substantially reduce the cost and size of next-generation wireless systems, thereby benefiting society through increasing access. The PI will develop new courses at the University of Illinois at Urbana Champaign (UIUC) that will integrate the research outcomes of this project. Introductory high-school-level curriculum development in collaboration with established UIUC outreach programs is also planned. The PI established an institute of electrical and electronics engineers (IEEE) Solid-State-Circuits chapter at UIUC and will organize seminars, short courses, and other events in collaboration with other faculty and students.
In this project, the introduction of inductors or magnetic fields to commutated circuits provides new degrees of freedom to existing LPTV switched-capacitor circuits, opening new design spaces at both architecture and component levels. The intellectual merit of this project is in the advancement of knowledge and understanding related to (1) theoretical frameworks of high-order, long-delay commutated-LC circuits operating at beyond 6-GHz RF, (2) practical design considerations with silicon-based implementations of the commutated-LC circuits, and (3) development of next-generation wireless systems with unique RF-domain signal processing capabilities enabled by the commutated-LC circuits. Specifically, this project will investigate the commutated-LC circuits in the mixing region for reconfigurable filtering front-ends that cover a wider frequency tuning range, operate at a higher RF, and provide steeper filter roll-offs. It will also study the commutated-LC circuits when they are used as delay elements, targeting on breaking the limit of delay-frequency product in existing switched-capacitor delays. Leveraging this new delay component, this project will develop next-generation simultaneous-transmission-and-reception systems and many-element antenna arrays. Finally, this project will study the impact of local oscillator circuitry on commutated-LC circuits in terms of operation frequency, noise, and power consumption. New high-frequency oscillators with low phase noise and phase noise cancellation techniques will be developed.
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.
