Design of 3 GHz stripline ferrite circulator for radar applications

This paper presents a design of three port stripline circulator using magnetized ferrite. The design is proposed to comply a radar system at 3 GHz operation. The geometry design consists of two ferrite planar disk resonators separated by a disk center conductor symmetrically coupled by three port of transmission line. In the design process, the ferrite material is magnetized perpendicularly to the plane of the device by a static magnetic field to obtain all three port are matched. The ferrite of Ni-Zn material, the saturation magnetization of 2400 Gauss and ferromagnetic linewidth of 200 Oe were used for disk resonator and Cu metal as conductor of the transmission line. The EM simulation software was used to simulate, optimize and record the design parameter in order to achieve good insertion loss (S21), return loss (S11) and isolation (S31). The simulation experiment has done by the difference of magnetization. The best result recorded for 3 GHz at 1600 Oe of magnetization, namely; -0.411 dB of S21, -28.111 dB of S11, and -41.831 dB of S31.