On-Chip antenna integration for single-chip millimeter-wave FMCW radars

The feasibility of on-chip antennas for single-chip millimeter-wave FMCW radar has been investigated. The FMCW radar is configured to have one transmitting and two receiving monopole antennas. The performance of each antenna (matching, gain, isolation and surface wave suppression) is improved by adding a cavity backed wide slot on a PCB ground plane for each antenna, optimizing the PCB packaging environment, grinding the silicon substrate below 350 μm to reduce the substrate modes and optimizing the thickness of the environmental hazard protection globe top layer. Simulation results show that the on-chip antenna integrated on a 200 μm thick, 20 Ocm silicon IC and mounted on an optimized PCB environment has more than 30% impedance bandwidth. In addition, the proposed approach suppresses surface waves, resulting in a relative high gain of 5 dBi with an overall efficiency of 41% at center frequency of 60 GHz. Furthermore, it meets the specific FMCW-radar requirements such as high isolation (more than 25 dB) between transmitting and receiving antennas and a ripple-free broadside radiation pattern.