Fig. 1. Simulation of the circulator (color online) (a) Shape of the circulator, (b) Simulation of small signal insertion loss, (c) Small signal transmission loss simulation, (d) Small signal insertion loss simulation- total reflection

Fig. 2. Simulation of the magnetic field (a) Magnetic field position distribution, (b) Top view magnetic field distribution

Fig. 3. Thermal simulation of the circulator (a) Normal working state, (b) Total reflection state

Fig. 4. Block diagram of the temperature compensation unit (a) Forward control mode, (b) Feedback control mode

Fig. 5. Photograph of the on-site circulator test setup

Fig. 6. Test results of small signal (S parameter) (color online)

Fig. 7. Test results of temperature compensation unit