A GHz-band gasket-free electromagnetic shielding structure with built-in cascaded SIW resonators

As operating frequencies of electronic devices have become higher recently, GHz-band electromagnetic noise leakage from gaps of a shielded enclosure may become a problem. Conductive sealing gaskets are usually applied and mostly effective in this case, however, high contact pressure is required and deterioration is therefore inevitable. In this paper, a gasket-free electromagnetic shielding structure with built-in cascaded substrate integrated waveguide (SIW) resonators is proposed and evaluated. An SIW resonator is a kind of resonant cavity embedded in a dielectric substrate, and has been widely applied for recent microwave filtering technologies. In the structure, SIW resonators with different resonant frequencies are arranged in a cascaded configuration, and placed on the inner walls of a gap. A prototype structure is designed with FR4 substrates, and measured results showed more than 25-dB improvement in the shielding effectiveness at 12-16 GHz.