Novel On-chip Helical Antenna for 77GHz Automotive Radars

Helical antennas have high gain, circular polarization and wide bandwidth characteristics. In this book, novel designs for dielectrically loaded helical antennas are investigated for on-chip 77GHz automotive radar. High substrate losses in the silicon core reduces the antenna gain. Therefore, silicon is etched from the core to lower its effective permittivity and decrease substrate losses. For fabrication of antenna on a wafer-scale level, a low-loss mechanical support is also introduced. As compared to unloaded helical antenna, the novel dielectric core loaded helical antenna has an improvement of 1dBi in maximum gain, 15dBi improvement in front-to-back ratio and 15dB improvement of return loss. The proposed antenna occupies 3.3 and 10 times less chip area than patch and horn antenna, respectively. Furthermore, the performance (in terms of gain, bandwidth for equal footprint size) of proposed antenna is better than previously investigated automotive radar antennas.