  Conventional circulators are made of magnetic ferrites and suffer from a
cumbersome architecture, incompatibility with integrated circuit technology and
inability for high frequency applications. To overcome these limitations, here
we propose a lightweight low-profile non-magnetic circulator comprising a
nonreciprocal time-varying phase shifter. This circulator is composing a
nonreciprocal temporal phase shifter and two reciprocal delay-line-based phase
shifters. The proposed nonreciprocal temporal phase shifter is based on the
generation of time-harmonic signals, enforcing destructive interference for
undesired time harmonics and constructive interference for desired time
harmonics at different locations of the structure. Such a unique task is
accomplished through two phase-engineered temporal loops. The phase and
frequency of these two loops are governed by external signals with different
phases, imparting an effective electronic angular momentum to the system. We
observe large isolation level of greater than 32 dB, a P1dB of +31.7 dBm and
IIP3 of +42.4 dBm. Furthermore, this circulator is endowed with a
reconfigurable architecture and can be directly embedded in a conventional
integrated circuit (IC) technology to realize a class of high power handling
and linear IC circulators.
