Measuring Distance and Speed with a thumbtack-sized Radar Sensor
The SUCCESS consortium has developed and implemented a fully integrated 122 GHz Radar sensor. The surface-mountable package has a size of 8 mm x 8 mm. It includes a mixed-signal Silicon Germanium (SiGe) chip and two antennas for transmitting and receiving. The prototype is a breakthrough towards a miniaturized, low-cost and high-resolution millimeter-wave sensor for distance and speed measurements.
Prof. Thomas Zwick from KIT who initiated the project together with Prof. Christoph Scheytt from IHP says: "This revolutionary technology of a miniaturized, low cost and SMD-solderable distance sensor will bring a broad range of new functionalities to consumer products and industrial applications." It is expected that low cost and miniaturization of mm-wave sensor systems will enable a great variety of distance sensing applications such as industrial sensing (distance, speed, material characterisation), public and private safety (motion detectors, even behind wall paper), automotive (wheel suspension measurement, pedestrian safety), replacement of cheap ultra-sonic sensors (distance measurement) and others.
Silicon technology has made tremendous progress towards ever higher device cut‐off frequencies. Nowadays all RF components up to 120 GHz can be realized in silicon. Monolithic integration of the digital baseband processor, data converters, and mm-Wave circuitry on the same chip enables the fabrication of complete mm-wave sensor electronics at cost of well below 1 €. Furthermore mm-wavelengths radio waves result in mm-size antennas that can be integrated in the chip package. Hence complete miniaturized mm-Wave sensor systems can be realized using a System-in-Package approach.
Tiny 122 GHz Radar System
The first prototype of an integrated sensor was implemented in July 2012. The sensor is based on a mixed signal chip fabricated in a 0.13 µm SiGe BiCMOS technology from IHP. The homodyne transceiver, that was designed by IHP and Silicon Radar GmbH, includes a 120 GHz Voltage-Controlled-Oscillator, several amplifiers, an IQ-mixer and filters. Additional circuits are added that allow built-in-self-testing, such as power detectors and a frequency measurement unit. Parts of the transceiver are controlled digitally using an SPI interface. The chip is packaged in a novel technology developed by the Karlsruhe Institute of Technology (KIT), Robert Bosch GmbH, Selmic and Hightec MC AG. The package is fabricated in Low Temperature Co-fired Ceramic Technology by Selmic. KIT designed the transmitting and receiving antennas that are integrated into the package. As the antennas are integrated into the package, only DC and baseband signals need to be transmitted to the package. The antennas are fabricated on a thin, flexible polyimide material using the HiCoFlex® technology from Hightec MC AG. The metallic ground plane of the ceramic housing acts as a reflector for the antenna and causes the desired radiation direction upwards (perpendicular to the printed circuit board). The packaged sensor has a size of 8 mm x 8 mm and can be soldered onto a printed circuit board. A test board was fabricated by Robert Bosch GmbH to demonstrate the functionality of the packaged sensor. This allowed measuring a Doppler signal when detecting a moving object.
The SUCCESS consortium consists of nine partners made up of research centres, universities and companies of six countries. The project has been financed by the 7th Framework Programme of the European Commission and has a budget of over 4.5 Million Euros for the next three years. The partners are the following ones: IHP, Robert Bosch GmbH, the Karlsruhe Institute of Technology and Silicon Radar GmbH from Germany, ST Microelectronics from France, SELMIC from Finland, Hightec MC AG from Switzerland, Evatronix from Poland, and the University of Toronto from Canada.
SUCCESS (Silicon-based Ultra Compact Cost-Efficient System Design for mmWave-Sensors) – http://www.success-project.eu