Automotive radar is a hot topic with vehicle autonomy and advanced safety systems being quickly commercialized. Radar sensors have many advantages over LIDAR and cameras since they operate in poor weather and other extreme conditions where optical sensors have issues. Radar can also determine the speed of objects and therefore predict if they will collide with the vehicle. However, current radars lack 3D vision and detail mapping that optical sensors provide but this is changing as the resolution and processing power of radar modules is rapidly improving.
Due to spectrum regulations and standards developed by the European Telecommunications Standards Institute (ETSI) and the Federal Communications Commission (FCC), the UWB band 24 GHz frequency range will be phased out by the beginning of 2022 in Europe and the US. The 76-77 GHz band has been available for vehicular long-range radar applications for many years. This band has the benefit of high allowed equivalent isotropic radiated power (EIRP) that enables functions like adaptive cruise control.
The 77-81 GHz short range radar band is newer and gaining significant traction both from a worldwide regulation perspective, as well as industry adoption. The availability of the wide bandwidth of up to 4 GHz in this band makes it attractive for applications requiring high range resolution and will replace the 24 GHz band solutions. The next generation of radars will use the large available bandwidth of the 79 GHz frequency band improving their resolution plus adding AI and other advanced data processing techniques will make them capable of full 3D imaging.
Yole Développement estimates the radar market will reach US$8.6 billion by 2025, at a 2015 CAGR of 15.6%. As you can see, 24 GHz radar will grow slightly until 2020 before being replaced by 79 GHz high-resolution shortrange radar that enables mapping of the entire car’s surroundings.
In this survey, I only included 77 and 79 GHz radar sensors and ICs as 24 GHz sensors will be sunset by 2022. Therefore, companies like ADI, Valeo, Hella, UMS, etc., that are currently mostly involved in only the 24 GHz solutions are not included but expect many of them to move into the higher frequency solutions soon.
Ainstein was founded in 2015 and makes radar sensors mainly targeted toward drones and automotive applications. Ainstein Automotive Safety Radar Kanza-77 combines a wide field of view at midrange with long-range coverage to provide two measurement modes within a single package. Built with RF CMOS technology, powerful computing platforms and advanced signal processing algorithms, it offers the maximum bandwidth of 2 GHz, a range of more than 180 meters, minimum distance resolution of 15 cm, and detects & tracks both static and dynamic objects. It is highly customizable for the customers’ environment. The wide, mid-range coverage not only allows vehicles cutting in from adjacent lanes to be detected but also identifies vehicles and pedestrians across the width of the equipped vehicle. The long-range coverage provides accurate object discrimination, range and speed data that can identify up to 64 targets in the vehicle’s path.
Their T-79 product is the new generation short range, wideband, high resolution automotive radar sensor. It is built on RF CMOS IC technology allowing for ultra-low power consumption and low unit cost. The highly integrated hardware design paired with Ainstein’s proprietary advanced radar signal processing algorithms makes it capable of high resolution 360° detection when multiple units are configured on the vehicle. This allows for semi-autonomous or fully autonomous driving.
In August of 2017, PARC (a Xerox company) spun off Metawave Corporation which builds technology solutions based on engineered metamaterials and Artificial Intelligence (AI). Metawave is commercializing smart beamsteering antenna systems for autonomous vehicles and 5G markets. Leveraging machine learning and artificial intelligence, Metawave is building the first analog beamsteering radar system capable of distinguishing between objects close in proximity, and in difficult driving scenarios and in all-weather conditions, making cars safer and smarter. The company has been delivering its Proof of Concept to leading automakers and Tier 1 transportation providers since 2019.
It’s product, SPEKTRA, utilizes analog beam-forming and beamsteering with advanced digital signal processing techniques to deliver a low-cost solution that drives the evolution of highly automated driving and the deployment of advanced automated safety features, such as left turn assist, blind spot monitoring, automatic emergency braking, adaptive cruise control, traffic jam pilot, highway pilot, etc. The product enables 3D imaging, identification and classification of objects, non-line-of-sight object detection, and accident anticipation by analyzing traffic patterns, with smart functionality in all-weather conditions. These capabilities are needed for the future of automotive radar, which will make self-driving cars a reality. Metawave’s SPEKTRA™ can detect and classify vehicles beyond 350 meters and pedestrians beyond 200 meters which is farther than current products.
About a year ago, we were introduced to Uhnder who was coming out of stealth mode as a semiconductor startup headquartered in Austin, TX. They are supplying the first all-digital automotive radar chips according to the company. Uhnder uses a combination of advanced CMOS and digital code modulation (DCM) technology to deliver radars with improved performance, smaller size, lower power and cost. Their radar sensors map the environment in 3D with a range of up to 300 meters.
The radar on chip (RoC) has 12 transmit antennas and 16 receive to form 192 virtual elements using the 77/79 GHz band. They presented a proto-type at ISSCC 2019 that uses a 15.2-to-16.2GHz LO that is generated by an external PLL: the differential LO input is converted to quadrature by using a polyphase filter. The filter output is buffered and distributed to all TX/RX channels with a differential 100 ohm-terminated transmission line. All channels use limiting amplifiers and Sub-Harmonic Quadrature-Injection-Locked Oscillators to generate the mm-wave carrier at 5× the injected LO frequency. Digital signal processing and other radar signal computational power is supported on the same chip by two CPUs with floating point support and two DSPs. The overall software-defined hardware pipeline is capable of up to 20 Tera-Ops baseband processing. That is quite a lot of analog and digital content packed onto one chip.
The antenna elements are waveguide coupled with low loss to the chip using substrate integrated waveguide. The radar was tested with an external PLL, and the 77.5GHz TX phase-noise at 1MHz offset is -110dBc/Hz. During described in the paper, 8 TXs were operating at the same time in MIMO mode. The authors reported more than 30 dB cancellation which allows concurrently lowering the correlation noise floor by about 20 dB compared to when the self-interference is present.
The sensor can use MIMO or beamforming/beamsteering modes to realize more range and sense in 3D. Uhnder’s approach of using CMOS combined with advanced digital processing techniques borrowed from cellular communications gives them a competitive advantage over existing radar sensor and could even apply to 5G mmWave communications, robotics and surveillance applications.
Vayyar has developed chips to cover imaging and radar bands from 3 to 81 GHz with up to 72 transmitters and 72 receivers. Enhanced by an integrated, high-performance DSP with large internal memory, Vayyar’s sensors execute complex imaging algorithms without any need for an external CPU. Using MIMO, Vayyar technology creates high-resolution 4D images. Because of the large number of transceivers and an advanced DSP, they are able to create high-resolution contour with high accuracy. Vayyar’s RF sensor on a chip has 48 transceivers at 60 GHz and 79 GHz wide-bands, allowing over thousands of virtual channels. The chip also consists of an internal DSP for real-time signal processing saving the need for an external ECU. This dual-band solution is easily integrated into existing automotive framework, and offers multi-function capabilities to reduce the overall cost and number of sensors needed for a vehicle. In Jan, their 60 GHz automotive-grade MIMO radar-on-chip was added to compliment their 79 GHz chip.The 60 GHz solution offers the complete functionality of Vayyar’s 79 GHz reference-design, enabling the automotive industry to meet global EU NCAP and U.S. Hot-Car needs. Vayyar’s solution displays the dimension, location, breathing pattern and movement of people, utilizing proprietary 4D point-cloud VOXEL imaging. The 60 GHz solution offers manufacturers and Tier 1 suppliers the same ROC functionality as the 79 GHz one, thus providing full flexibility to start global mass-production preparations without the regulatory pains.They are also selling a 60 GHz band developer's kit through Mini-Circuits with 20 transmit and 20 receive antennas for the development of imaging and detection applications and produce the famous Walabot sensor that detects wires and pipes through your walls.
The Old Guard
In 2017, Delphi Automotive split the company and created Aptiv to concentrate on technology related to self-driving vehicles and Delphi Technologies to concentrate on powertrain development. According to Systems Plus Consulting in their 2018 report, Aptiv’s SRR3 device is a side and backside radar sensor certified in 2015. It is designed for various ADAS applications such as blind spot, lane change assist and cross traffic warning. It has three different PCB substrates with two dedicated to RF signal processing and transmission. Working in the 76-77 GHz band, the device contains forty H-pole planar antennas fed by cavity waveguides. With its small form factor, it could compete with the standard dual board radar modules. They were still using discrete devices in this module while many other companies had shifted to a MMIC approach.
In June of 2018, Autoliv spun off its safety systems products as Veoneer. They have delivered more than 38 million radar sensors (their radar sensor product line was originally with MACOM and sold to Autoliv before the spin off). Veoneer’s high-resolution radars allow for increased detection points, leading to improved ability to understand free space, better object separation in multiple target environments, and more precise detections in blind spot warning and rear cross traffic alert. Veoneer’s 77 GHz radar systems see oncoming vehicles and autonomously manage lane changes during highway driving. Veoneer offers 77 GHz high-resolution radars and 77 GHz multi-mode radars. They feature: Active Blind Spot, Rear Cross Traffic Alert, Adaptive Cruise Control, Lane Change Assist, Safe Door Opening, Forward/Rear Collision Warning, Free Space Detection and Autonomous Emergency Braking.
Bosch is producing their 4th generation long-range radar sensor (LRR4) that builds on their experience gathered during the development and manufacturing of the previous three radar generations. The LRR4 is a monostatic multimodal radar that has six fixed antennas. The central four antennas feature optimum properties for recording the vehicle’s surroundings at higher speeds. They create a focused beam pattern with an opening angle of ±6 degrees, providing excellent long-range detection with minimal interference from traffic in adjacent lanes. In the near range, the LRR4’s outer two antennas expand the field of view to ±20 degrees at up to five meters, making it possible to quickly detect vehicles entering or leaving the vehicle’s lane.
Continental’s ARS540 is a high-performance long-range radar sensor which enables highly automated driving in combination with other technologies. It provides best radar performance in a state-of-the-art sensor size. One of the benefits of the ARS540 lies in its compactness and flexible usage which makes it easier to use across entire vehicle platforms. Enhanced performance thanks to higher resolution and more precise detection. One of the features of the new radar generation is a higher resolution compared with the previous radar generations, so it can provide a better picture of the traffic situation. In addition, road limits such as curbstones as well as the height of objects like the tails of a traffic jam under a bridge are detected thanks to the sensors’ elevation measurement accuracy.
The ARS540 is also based on a scalable modular principle, which, with its graduated function scopes, flexibly supports vehicle manufacturers’ different requirements and electrical-electronic (E/E) architectures. Thanks to the worldwide trend of using 77 GHz technology, the resolution of the sensors is becoming higher and facilitating, for example, more accurate detection of smaller objects such as a lost spare wheel or an exhaust that has fallen off. It has a range of up to 300 m and scanning angle of ±60° is possible which enables in a first step the realization of premium driver assistance functionalities and in automated driving in the future.
Denso produces a mmWave radar sensors that measure the relative speed of and distance to vehicles and other objects ahead. Based on measurements from this sensor, the pre-crash safety system informs the driver of a possible collision, tightens the seatbelts to protect the occupants, applies additional pressure to the brakes, and activates other driving assist systems to minimize damage in the event of a collision. There is little information available online that I can find.
Infineon has been delivering automotive 77 GHz radar products for over 10 years with more than 100 million shipped. Infineon has a comprehensive XENSIV™ family of sensors that offer a range of RASIC™ 77-79 GHz front-end ICs specifically for radar-based driver assistance systems such as adaptive cruise control and collision warning. Capable of detecting and recognizing objects at a range of up to 250 meters, these RASIC™ solutions enable the driver assistance capabilities required to obtain a five-star rating from Euro NCAP (European New Car Assessment Program).
Infineon’s family of radar transceiver IC (RASIC™) addresses the needs of 77-79 GHz radar for all safety-critical applications from automatic emergency-braking (AEB) to high-resolution radars in automated driving. It supports high modulation bandwidth up to 2 GHz using fast ramps for precise distance measurement and simultaneous transmitter operation for MIMO. RXS816xPL is a highly integrated device that performs all functions of a radar front-end in a single device – from FMCW signal conditioning to generation of digital receive data output. On-chip sensors for temperature, output power and multiple monitors/supervisory circuits allow for calibration and monitoring. Programming and Status are communicated via SPI.
Nidec Elesys produces a 76 GHz radar sensor that determines the distance and relative speed of other objects for ACC and other safety applications. It operates to 150 m with only 16-degree horizontal viewing angle so seems very limited compared to competitors.
NXP’s TEF810X is a fully integrated single-chip RF CMOS 77 GHz automotive FMCW radar transceiver. This device is intended for usage in short-, medium- and long-range radar applications covering the full automotive radar frequency band from 76-81 GHz. TEF810X radar transceiver is a low power radar transceiver which integrates 3 transmitters, 4 receivers, Analog-to-digital converters and low phase noise Voltage Controlled Oscillator (VCO). It supports 2 GHz bandwidth and 4 GHz with chirp stitching. This automotive radar device enables several key driver assistance and safety applications such as Autonomous Emergency Braking (AEB), Adaptive Cruise Control (ACC), Blind-spot Detection/monitoring (BSD/BSM), Rear Cross Traffic Alert (RCTA), Front Cross, Traffic Alert (FCTA), Rear Collision Avoidance (RCA), Parking Assist (PA), Rear Occupant Detection/Alert (ROD/ROA), Cocoon Radar and Imaging Radar.
They also supply the MR3003, a high-performance, automotive qualified single chip 76–81 GHz transceiver for radar applications. The MR3003 transceiver includes 3 transmit and 4 receive channels. The MR3003 provides best in class performance such as high angular resolution with TX phase rotation, best in class separation of objects due to low phase noise and linearity, and long detection range due to high output power and low noise figure. This is a BiCMOS Radar Transceiver with 4 GHz chirps for highest object resolution and has separate LO in and LO out for cascading in master/slave setup.
Smartmicro reports they invented the Lane Change Assist (LCA) radar in partnership with Audi and started production in 2006 with a production partner. The patented technology was later enhanced by introducing additional functions like Blind Spot Detection (BSD), Rear Cross Traffic Assist (RCTA) and Rear Collision Warning (RCW). Longer range Forward Collision Warning (FCW) sensors went in production in 2008. Today, 76-81 GHz sensors are developed and mass-produced for all types of corner radar applications, with up to 4 GHz bandwidth and 120 m range, as well as for Adaptive Cruise Control (ACC), Automatic Emergency Braking (AEB) and other functions in the 4th generation. Customers like Audi, Volkswagen, BMW, Mazda, Porsche, PSA and Hyundai/Kia use smartmicro technology. They offer high performance automotive grade products made by smartmicro. They have special features for automated vehicle integration and represent the 4th generation of automotive radar sensors, introducing 4D/UHD technology. Features include 4D/UHD resolution featuring angular resolution and elevation measurement, up to 4GHz bandwidth, multi-mode (short/medium/long) switchable with single cycle latency, multi-band, featuring up to four center frequencies for interference-free operation, and adaptive antennas: wide/narrow or straight/squint software selectable.
ST Microelectronics supplies the STRADA770M, a dual-band 77 GHz radar transceiver with integrated FMCW chirp modulator and profiles-based chirps sequencer, targeting automotive radar applications, in both the 76-77 GHz and 77-81 GHz regulated frequency bands. It is designed to be integrated in a full-blown radar sensor along with a controller/processor in charge of: configuring it through the slave interface; receiving/processing the raw radar data (sampled IF from each RX channel) that it produces through the master interface.
The device can synthesize the low-phase-noise clock needed for optimal performance, with the help of an external 40 or 50 MHz crystal, but supports an external oscillator as well. Power can be provided to the device at a single supply voltage (3.3 V) or at two different ones (3.3 and 2.6 V); in both cases additional voltages (1.2 V and, possibly, 2.6 V) are produced internally by means of integrated LDOs relying on up to 6 external passive stabilization networks. A further external passive network is needed for implementing the loop filter for the internal modulator.
TI’s AWR1642 device is an integrated single-chip FMCW radar sensor capable of operation in the 76 to 81 GHz band. The device is built with TI’s low-power 45-nm RFCMOS process and enables unprecedented levels of integration in an extremely small form factor. The AWR1642 is an ideal solution for low-power, self-monitored, ultra-accurate radar systems in the automotive space.
The device is a self-contained FMCW radar sensor single-chip solution that simplifies the implementation of Automotive Radar sensors in the band of 76 to 81 GHz. It is built on TI’s low-power 45 nm RFCMOS process, which enables a monolithic implementation of a 2TX, 4RX system with built-in PLL and A2D converters. It integrates the DSP subsystem, which contains TI’s high-performance C674x DSP for the Radar Signal processing. The device includes an ARM R4F-based processor subsystem, which is responsible for radio configuration, control, and calibration. Simple programming model changes can enable a wide variety of sensor implementation (Short, Mid, Long) with the possibility of dynamic reconfiguration for implementing a multimode sensor. Additionally, the device is provided as a complete platform solution including reference hardware design, software drivers, sample configurations, API guide, and user documentation.
German auto supplier ZF Friedrichshafen AG acquired TRW Automotive Holdings in 2015. ZF Autocruise produces the AC1000T which is a 77 GHz mid-range radar system. It has improved speed resolution and a range of up to 200 m (it says in one place but the product web page 180 m). It has a horizontal scanning angle of up to 70 degrees (60 degrees on the product page) and is suited to applications such as adaptive cruise control, anticipatory collision warning and automatic emergency braking.