Ferrite-Loaded Substrate Integrated Waveguide Switch

A magnetically controlled switch based on ferrite-loaded substrate integrated waveguide (FLSIW) is proposed. FLSIW consists of rectangular ferrite slabs loaded on the sidewall slots of SIW where the magnetic fields are strongest. With the application of an external magnetic bias on the ferrite slabs, the cutoff frequency of the FLSIW is changed, thereby making the SIW switchable. An X-band reflective type single pole single through (SPST) switch is demonstrated. The switch has a 1.1 GHz switchable bandwidth centered at 10.1 GHz with an insertion loss of less than 1 dB in the on state and an isolation of 20 dB in the off state.