Nonreciprocal Phase-Shifting in Linear Magnet-Free Reconfigurable Temporal Loops

Recently, nonreciprocal (NR) phase shifters have attracted a surge of interest thanks to the advent of NR electromagnetic systems, such as NR metasurfaces, nonreciprocal-beam antennas, and invisibility cloaks. To overcome the limitations associated with conventional technologies for realizing NR phase shifters and gyrators, here we propose a magnet-free NR phase shifter comprising temporal loops. The proposed temporal device is lightweight and offers low-profile and linear responses. Such a unique nonmagnetic NR device operates based on the generation of time-harmonic signals and destructive/constructive interferences for the spurious side-band and targeted time harmonics (THs), respectively, at different locations of the structure. We utilize a time-harmonic signal to temporally modulate varactor diodes and control the phase and frequency of two temporal loops. Our temporal NR phase shifter is equipped with low insertion loss, and high power handling. Furthermore, this controllable NR phase shifter is compatible with integrated circuit technology,