Developed using the ferrite gyromagnetic effect, the stripline circulator is a planar passive non-reciprocal RF device. It adopts a three-layer sandwich stripline structure, typically arranged as a three-port Y-junction. It enables unidirectional signal circulation and highly efficient reverse signal isolation, with a key advantage in miniaturization and integration. It is widely used in communication, radar, RF modules, and other applications.
Working Principle
Inside the device, a Y-shaped stripline path is sandwiched with ferrite dielectric and paired with permanent magnets to provide a biasing magnetic field. When an electromagnetic wave enters the junction region, it decomposes into counter-rotating circularly polarized waves. Phase differences create an interference effect, allowing signals to pass with low loss along the intended path while greatly suppressing reverse transmission signals. The standard transmission logic is: Port 1 in → Port 2 out, Port 2 in → Port 3 out, Port 3 in → Port 1 out, with the reverse paths maintained in a state of high isolation.
