EG 1 Millimeter-wave & Integrated Antennas

Transcription

1 EuCAP 2010 ARTIC Workshop 5-12 July, San Diego, California EG 1 Millimeter-wave & Integrated Antennas Ronan SAULEAU Ronan.Sauleau@univ-rennes1.fr IETR (Institute of Electronics and Telecommunications, Rennes) University of Rennes 1 Rennes, France, 1

2 Motivations for automotive radars (1/2) Road safety: a priority in many countries - In the world: statistics / year million people die in road accident - 50 millions people are injured - In Europe: about 1.2 million traffic accident / year. They cause: Safety system evolution - More than fatalities - Economical damage of more than 200 billion - Human error is involved in over 90% of accidents - White Paper of the EC on the Common Transport Policy, Sept To reduce road death by 50% by the end of 2010 Airbag Pretensioning of seat belts. Break assistance - Global trend: 2/22 From comfort systems via driver assistance systems (e.g. ACC) Towards safety systems Object detection

3 Why radar safety for automobiles? Radar is a robust solution compared to other technologies 3/22

4 Collision avoidance covers many types of systems 24 GHz systems: NB (narrow band, 200 MHz) or UWB systems (5 GHz) 77 GHz systems (ACC radars) Classification of mm-wave automotive radars: range and frequency bands 4/22

5 Long Range Radars (LRR) - Range up to ~ m Classification of mm-wave automotive radars: range and frequency bands - Vehicle velocity typically above 30 km/h - Narrow beams to control driving path in front of the car to determine distance of vehicle driving ahead for maintaining minimum safety distance - Bandwidth below 1 GHz and typical spatial resolution of 0.5m Short Range Radars (SRR) - Range up to 30 m - Speed range from 5 km/h to 150 km/h - Wide field of view Lane change ( ) 2013 (77-81) - Bandwidth below 5 GHz and typical spatial resolution of approx. 0.1m D=1.5m 5/22

6 Classification of mm-wave automotive radars: range and frequency bands From Henderson et al., /22

7 Automotive radar applications Adaptative Cruise Control (ACC) Stop & Go functionality Collision warning / mitigation / avoidance Pre-crash sensing / controlled firing of restraints, airbags / brake boosting Lane change warning, lane change aid Blind spot detection Parking aid, back drive assisance Rasshofer et al., /22

8 77 GHz automotive radars: Focus: lens antennas Lens antennas (TRW Autocruise, Bosch) Autocruise AC20 (Monopulse) Bosch (ACC 2) Lens + Patch with dielectric rods for additional beam collimation GaAs technology 4 channels with fixed beams Frequency: GHz Range: 1 to 180m Accuracy: ±5% for d > 20m ±1m for d < 20m Speed range: 30 to 180km/h FoV: ~±10 (AZ), 5 (EL) Angular accuracy: 0.3 EIRP: 35dBm Weight: 480g 8/22 Bosch (LRR 3) since 2009 SiGe technology

9 77 GHz automotive radars: Focus: lens antennas Lens antennas: SLIMSENS project (UK, BAE) From Henderson et al., /22

10 77 GHz automotive radars: Other concepts (1/2) Printed antennas + BFN (phase shifters, Rotman lens) From J. Schoebel, MTT 2005 Planar antenna arrays (SIW approach) 10/22 From Ettorre and Sauleau, 2009

11 Solutions with polarization twisting 77 GHz automotive radars: Other concepts (2/2) Mechanically scanned polarization twisting Cassegrain type antenna, /22 Folded reflectarray, Beam switching (7 beams)

12 Short Range Radars (1/4) Diverse applications: UWB & NB - Most of the safety relevant applications need BW classified as UWB - UWB radar (5 GHz band) for high resolution (~10 cm) - Sensing the near-range environment (< 30m) - Safety radar belt around the car - Multi-target capabilities Target acquisition time < 20~30ms NB NB 12/22 - Today s market penetration of UWB SRR technology: Smaller than 0.02%

13 Short Range Radars (2/4) European regulation: the package solution 24-GHz band: interim solution To open the market To allow an early contribution to road safety Benefits of SRR at 79 GHz compared to 24 GHz Suitable band for long term development of SRR Sensor size reduc. (1/3) Accept. size < 50 cm² Improved speed information (better Doppler resolution) Integration (single chip and packaging is possible). SiGe technology. Similar technology as for GHz band can be used 13/22

14 Short Range Radars (3/4) Tentative antenna specifications - Examples of specifications for: - ACC (Adaptative Cruise Control) - PCS (Pre-Crash Sensor) - Specifications strongly dependent on the radar signal processing! (e.g. SLL, X-pol) (from IMST) (Rogers substrates) 14/22

15 Short Range Radars (4/4) Synergies within higher frequency bands 15/22