A HTCC-Based Hermetically Sealed Transition from Stripline to Vertical Waveguide for Sub-Thz Sips

This paper presents a transition structure based on high-temperature co-fired ceramic (HTCC) technology, which connects the stripline to a vertical rectangular waveguide (RWG) for W-band hermetic packaging. The transition utilizes the stripline to isolate the air cavity of the RWG from the chip cavity, effectively achieving the hermetic sealing of the chips. The transition adopts a probe-type structure, successfully converting between the stripline and the RWG, with the shorted plane integrated into the multilayered HTCC substrates, forming an integrated hermetic transition. Measurement results show that, within the 96.5 to 106 GHz frequency range, the back-to-back transition exhibits a return loss better than $\mathbf{8} \mathbf{~ d B}$; the insertion loss of the single-ended transition ranges from 1.2 to 2.55 dB between 95.4 and 105.9 GHz, demonstrating good performance.