A GCPW to waveguide transition in 60GHz LTCC SiP

This paper proposes a low loss and broadband grounded coplanar waveguide (GCPW) to waveguide (WG) transition in a low temperature co-fired ceramic (LTCC) multi-layer structure for 60 GHz applications. The GCPW and WG are fully integrated on the same substrate, and the ground wall of the embedded WG is made up of a staggered via fence. A 3lambda/4 bent short stub is connected between signal line of GCPW and WG ground wall for effective coupling. The WG dimension is gradually increased for broadband characteristic. Measured results for a single transition show that the insertion loss is 0.775 dB at 58.3 GHz and the 3-dB bandwidth is 6.8 GHz from 53.1GHz to 59.9 GHz. The proposed transition structure has been packaged in 60 GHz LTCC System-in-Package(SiP) receiver module, and a 60 GHz wireless data link at 648 Mbps over 3 m has been demonstrated.