LTCC Microstrip Parasitic Patch Antenna for 77 GHz Automotive Applications

A microstrip parasitic patch antenna consisting of four parasitic patches, fed by one active patch, with a stripline input, is presented in this paper. The antenna was designed for the Low Temperature Co-fired Ceramics (LTCC) technology and shows very good matching and radiation behavior in the 77 GHz band, with measured reflection losses lower than - 10 dB between 75.175-80.6 GHz and below - 40 dB at 77 GHz. Simulation results show a gain higher than 8 dBi in the 76-81 GHz frequency range, with a radiation efficiency higher than 80%. A separate structure, based on direct conversion (video) receiver was designed and fabricated for radiation pattern measurements. The E and H planes at 77 GHz were measured and show good agreement with simulation results, with a computed gain of 8.2 dBi for the direction normal to the patches.