Beyond passive safety systems, active safety systems play a major role in reducing traffic fatalities. Active safety systems include adaptive cruise control and collision warning systems with automatic steering and braking intervention.
In a collision warning system, a 77 GHz transmitter emits signals reflected from objects ahead, at the side and to the rear of the vehicle and are captured by multiple receivers integrated throughout the vehicle. The radar system can detect and track objects in the frequency domain triggering a driver warning of an imminent collision and initiate electronic stability control intervention.
Advancements in SiGe:C HBT technology pushed the emerging arena of high-frequency (>60 GHz) millimeter-wave (mm-wave) applications such as WLAN (60 GHz) and automotive radar (77 GHz) circuits into the reach of low-cost silicon technology.
Freescale's expertise in SiGe:C bipolar development has been leveraged to provide a mm-wave-capable variation of the 180 nm SiGe:C BiCMOS platform. Announced in 2006, this technology features bipolar transistors with a 300 GHz maximum oscillation frequency and active and passive models optimized for mm-wave applications.
Freescale 77 GHz Technology Advantages
Multi-mode, multi-application capability
- Simultaneous long- and mid-range functionality
- Allows one radar to be used for multiple safety systems:
- Adaptive cruise control
- Headway alert
- Collision warning
- Mitigation and brake support