100MHz to 1GHz On-Chip Circulator with Integrated Driver Amplifiers

The tight restrictions on RF spectrum usage have laid the foundation for a novel on-chip architecture that can separate transmit and receive radio traffic over a large bandwidth. Nonreciprocity from 0.1 to 1GHz is experimentally verified with isolation between transmit and receive paths from 20 to almost 60dB based on the concept of sequentially-switched delay lines, which breaks the time-reversal symmetry of electromagnetic wave propagation through time-switching.