Hermetic sealing technique for F-band waveguides and packages

This paper presents a hermetic sealing technique for rectangular waveguides and packages to improve the reliability of systems in the F band (90-140 GHz). The technique features a new sealing structure, which is a laminate composed of two sealing plates and a spacer with a WR-8 waveguide. The sealing plate has the fused glass window and separates inside air from the ambient atmosphere. The laminated structure with the two sealing plates provides larger passband width than that with one sealing plate and is suitable for broadband wireless systems. The insertion loss of the fabricated sealing structure is 0.35 dB at 125 GHz. From 116 to 136 GHz, the return loss and a variation of group delay are better than 15 dB and 10 ps, respectively. We verified that the sealing structure has good simulation fidelity and that packages sealed with this technique meet the hermetic-seal standard in MIL-STD-883.