GCPW to stripline vertical transition for K-band applications in LTCC

Vertical transition structure between grounded coplanar waveguide (GCPW) and stripline with Low Temperature Co-fired Ceramic (LTCC) technology is presented in this paper. In this structure, the top ground of the stripline is used as the GCPW lower ground, and the signal via goes through the middle ground plane. The increase of vertical signal via height can be more widely used in the higher height of multilayer System in Package (SiP) module packaging. The circular openings in the ground plane and additional shield vias around the transmission lines can provide a great advantage in the radiation loss and decrease some parasitic effects. The measurement results show that the return loss is less than -10 dB from 6GHz to 35GHz and the insertion loss is better than -2dB up to 28.4GHz. The measurement results of the fabricated prototype agree closely with the simulation.