Microstrip parasitic patch array with substrate integrated waveguide feed for 35 GHz applications

A microstrip patch antenna with four parasitic patches for 35 GHz is presented in this paper. The antenna structure is fed by a substrate integrated waveguide (SIW) and opens up the way to 3D integration of large scale arrays for high gain applications. A SIW to grounded coplanar waveguide (GCPW) transition was designed and added to the antenna element for on wafer characterization. A test structure was fabricated in a six tape LTCC process. The measured reflection losses are lower than – 10 dB between 34.94 GHz – 36.2 GHz, while the simulated directivity was about 8.8 dBi at 35 GHz