Surpassing the fundamental limits that govern all electromagnetic structures, such as reciprocity and the delay-bandwidth-size limit, will have a transformative impact on all applications based on electromagnetic circuits and systems. For instance, violating principles of reciprocity enables non-reciprocal components such as isolators and circulators, which find application in full-duplex wireless radios, radar, bio-medical imaging, and quantum computing systems. Overcoming the delay-bandwidth-size limit enables ultra-broadband yet extremely-compact devices whose size is not fundamentally related to the wavelength at the operating frequency.

The focus of my talk will be on using time-variance as a new toolbox to overcome these fundamental limits and re-imagine circuit design. Specifically, I will focus on CMOS-integrated time-varying circuits and systems that have enabled: (i) integrated non-reciprocal components operating across frequencies ranging from RF to millimeter waves with multi-watt power handling, (ii) reconfigurable microwave passive components with 100-1000× form-factor reduction, (iii) integrated full-duplex wireless radios with wideband self-interference cancellation, and (iv) the first non-reciprocal Floquet electromagnetic topological insulator with an ultra-wide bandgap. Our prototypes achieve the stringent performance envelopes that are required by practical wireless applications, thus bringing the fields of integrated non-reciprocity and synthetic topological insulators to real-world applications.

Looking to the future, I will briefly describe early-stage cross-disciplinary collaborative research projects that investigate the use of time-varying circuits in cryogenic quantum computing applications and simultaneous-transmit-and-receive MRI.