A waveguide circulator system for an E-plane-layer transition of an electro-magnetic field having a wavelength (λ), the waveguide circulator comprising: a first waveguide including: at least N waveguide arms (105-(1-N)), where N is a positive integer, and a first-interface aperture spanning a first X-Y plane (X1-Y1) on a bottom surface of a first waveguide arm of the first waveguide; a ferrite element having N segments (111-(1-N)) protruding into the N respective waveguide arms of the first waveguide, theN segments including a first segment protruding into the first waveguide arm of the first waveguide; an E-plane-transition waveguide having a first open-end and a second opposing open-end defined by side-walls having a length; and a second waveguide including a second-interface aperture spanning a second X-Y plane (X2-Y2) on a top surface of the second waveguide, the first X-Y plane offset from the second X-Y plane along a Z axis by the length of the E-plane-transition waveguide, wherein the first open-end of the E-plane-transition waveguide has approximately the same shape as the first-interface aperture of the first waveguide and the first-interface aperture is arranged to proximally overlap the first open-end, wherein the second open-end of the E-plane-transition waveguide has approximately the same shape as the second second-interface aperture of the second waveguide and the second-interface aperture is arranged to proximally overlap the second open-end, and wherein at least a portion of the first segment of the ferrite element protrudes into a volume extending between the first-interface aperture on the bottom surface of the first waveguide arm and an opposing top surface of the first waveguide arm. a first waveguide including: at least N waveguide arms (105-(1-N)), where N is a positive integer, and a first-interface aperture spanning a first X-Y plane (X1-Y1) on a bottom surface of a first waveguide arm of the first waveguide; at least N waveguide arms (105-(1-N)), where N is a positive integer, and a first-interface aperture spanning a first X-Y plane (X1-Y1) on a bottom surface of a first waveguide arm of the first waveguide; a ferrite element having N segments (111-(1-N)) protruding into the N respective waveguide arms of the first waveguide, theN segments including a first segment protruding into the first waveguide arm of the first waveguide; an E-plane-transition waveguide having a first open-end and a second opposing open-end defined by side-walls having a length; and a second waveguide including a second-interface aperture spanning a second X-Y plane (X2-Y2) on a top surface of the second waveguide, the first X-Y plane offset from the second X-Y plane along a Z axis by the length of the E-plane-transition waveguide, wherein the first open-end of the E-plane-transition waveguide has approximately the same shape as the first-interface aperture of the first waveguide and the first-interface aperture is arranged to proximally overlap the first open-end, wherein the second open-end of the E-plane-transition waveguide has approximately the same shape as the second second-interface aperture of the second waveguide and the second-interface aperture is arranged to proximally overlap the second open-end, and wherein at least a portion of the first segment of the ferrite element protrudes into a volume extending between the first-interface aperture on the bottom surface of the first waveguide arm and an opposing top surface of the first waveguide arm.