Characterization of millimeter wave photonic crystal circulator with a ferrite sphere

Abstract

In this work, a millimeter wave circulator based on photonic crystals (PCs) with a ferrite sphere is constructed and experimentally characterized. A ferrite sphere can be manufactured through compressed-air puffing method with low cost and high precision, and the symmetrical structure can also simplify the assembly. In photonic crystal waveguide (PCW), the waveguide mode and bandgap frequency range are analyzed to better understand the device design based on PCW. The gyromagnetic ferrite sphere and impedance matcher (consisting of two Teflon cylinder gaskets and two metallic triangular pedestals) provide excellent performance for circulator. The measured isolation and insertion loss within the operation band 24 ∼ 28 GHz is better than 15 dB and 1.5 dB, respectively.

Keywords

• Photonic crystals
• Ferrite
• Sphere
• Circulator