CMOS transceiver improves performance of automotive radar systems

New Products |
By Christoph Hammerschmidt

High-performance radar systems are considered key components for advanced driver assistance systems and autonomous driving. New functions, such as advanced emergency braking systems (AEBs) that react to crossing motorcyclists, require higher performance and at the same time a larger number of modules per vehicle. The main drivers of this growth are NCAP programmes and legal regulations.

Against this backdrop Infineon has developed its latest development in radar sensing – the Rasic CTRX8181 transceiver, the first product in a series of new 76- to 81-GHz radar MMICs based on 28-nm CMOS technology. The transceiver’s improved signal-to-noise ratio (SNR) and linearity provide high performance and system-level resilience. In addition, the easy-to-integrate radar transceiver simultaneously provides a scalable platform approach for different sensors, such as corner, front and short-range sensors, as well as the necessary flexibility for new software-defined car architectures. This will enable 77 GHz automotive radar applications with lower development costs. Infineon thus aims to contribute to the development of systems that ensure reliable object separation and detection. Such systems are necessary for the protection of vulnerable road users such as motorcyclists, cyclists or pedestrians.

The CTRX8181 has been developed according to the latest ISO26262 safety standards and has four transmit and four receive channels. The component offers an excellent signal-to-noise ratio and increases the range of the standard module by up to 25 percent – for example, from 250 to over 300 metres. The higher number of RF channels with simultaneous improved linearity also allows for 33 per cent higher vertical or horizontal resolution to enable better separation between different objects, for example to detect pedestrians next to cars. These features allow the development of radar modules for all applications – from corner radar to high-resolution radar.

The digital phase-locked loop (PLL) on the chip enables faster ramps for better range resolution and fast return times, improved by a factor of four compared to the best solutions currently available. This new feature reduces power requirements and enables more accurate velocity information needed to distinguish objects with similar velocities. Furthermore, this enables a freely configurable ramp without affecting phase noise, making the radar robust and reliable in different scenarios. This makes it perfect for interference-resistant frequency schemes, such as the compass method.

The new CTRX product family is best combined with the radar-specific Aurix TC3x and TC4x microcontrollers (MCUs) from the same manufacturer, both of which have an integrated signal processing unit (SPU) and non-volatile memory for storing the programme code on the chip. The Aurix chipset and CTRX enable the best performance for future NCAP and real-world scenarios, such as improved reliability of the speed camera function in poor weather conditions.

System partitioning gives vendors the flexibility to offer traditional solutions with full radar processing capabilities. However, it also allows other architectures such as pre-processed data streaming over 100 Mbit/s or 1 Gbit/s Ethernet to be implemented with minimal development effort. The partitioning also allows the selection of an appropriate MMIC and microcontroller for the target applications to allow easy scaling to support different cost and performance requirements. The connection to the MCU is made via either LVDS or CSI-2, allowing greater flexibility in combining components.

Development samples of the new CMOS MMIC CTRX8181 transceiver are available and will be presented at electronica 2022 in Munich.



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