Emerson & Cuming microwave absorbers for high frequencies used in automotive applications

Transcription

1 Emerson & Cuming Microwave Products NV, Belgium Emerson & Cuming microwave absorbers for high frequencies used in automotive applications HF Technology Seminar 2012 Eindhoven

2 Content : Emerson& Cuming Microwave Products global presence Eccosorb absorber material with its different applications Increasing frequencies in electronic equipment Automotive radar and sensors in their frequency range and usage Challenge to develop and measure absorber material at high frequencies High frequency application using broadband absorber versus narrow band Eccosorb MMI and Eccosorb MF at high frequencies & high quantities Emerson & Cuming Microwave absorbers used in automotive radar systems.

3 Emerson & Cuming Microwave Products Global presence Sales outlet UK Manufacturing plant Westerlo Belgium Sales outlet Hong Kong Manufacturing plant Massachusetts USA Sales outlet France Manufacturing plant Hyderabad India Agents & distributors

4 Emerson & Cuming Microwave Absorbers What are microwave absorbers? - Products to modify, absorb or control unwanted microwave radiating signals Where are absorbers mainly used? - Reduction radar cross section signature - Antenna pattern improvement - Test environments (enclosures) - Circuit board cavity resonance surpression

5 Eccosorb absorber material on different applications Space (Galileo satellite) Military (naval) Antennas Telecom Automotive RFID

6 Increasing frequencies!!! Pro s & Con s: - Accurate and fast signal processing - Compact housings (miniaturization) - Expensive components Frequency bands : - Millimetre wave (GHz) : GHz (λ = 10-1mm) - Sub-millimetre / Terrahertz / Far-Infra-Red : 300 GHz- ~10 THz (λ = 1mm 30µm) Applications : - Military (radar and detection) - Telecommunication (point to point links) - Astronomy (ALMA) - Automotive (adaptive cruise control, lane control, parking aid)!!!

7 OVERVIEW AUTOMOTIVE RADAR SYSTEMS FRONT LOOKING SR-RADAR 24 GHz BLIND SPOT SENSOR 24 GHz REAR LOOKING RADAR (Video) LIDAR (IR+Video) VIDEO (24GHZ/IR) FRONT LOOKING LR- RADAR 77 GHz BLIND SPOT SENSOR 24 GHz PARKING AID SENSOR 48 KHz

8 Radar distance coverage and dedicated frequencies

9 Market penetration (mio.) for obstacle detection sensors in passenger cars (Europe) Today Emerson & Cuming served > 3 million radar systems

10 Specific frequencies used in automotive radar systems 24 GHz 77 GHz Narrowband absorber Eccosorb SF-U-24 Eccosorb MF-PP Broadband absorber Eccosorb MMI- (W) Eccosorb MF-PP

11 Resonances & cavities 10 GHz cavity Clear resonance Hot spots Resonant absorber 30 GHz cavity Resonance more spread Many hot spots 60 GHz cavity Sporadic resonances Quasi free space Broadband absorber

12 Challenges to develop high frequency absorber material Short wavelength = errors on parameter measurements Understanding ε and μ when simulating absorber at high frequencies Minor measurement inaccuracies can induce large errors in defining RF-parameters. Measurement samples : very small dimensions and tight tolerances Define adequate measurement set-up related to chemical composition Health and safety requirements, Reach and RoHS. High investment cost for RF measurement equipment.

13 Low frequency measurement set-up NRL-Arch set-up Frequency band : 2 GHz 40 GHz Bi-static measurement at 10 angle of incidence (=normal incidence), reflectivity measurement only Large flat samples are required 300 x 300mm Dynamic range = 50 db. High sensitivity with increasing frequency

14 High frequency measurement set-up Gaussian beam <> Flat wave front Frequency band : 40 GHz 110 GHz Quasi-optical measurement system Flat sample 30 x 30 mm (radiation area) 100 x 100 mm (clamping) Dynamic range = 100 db. S11/S21 <> Refl / IL and calculate Eps/Mu

15 Measurements at high frequencies with quasi optical set-up Epsilon/Mu : Would be ideal for use in RF-simulations Lots of errors Reflectivity (db) and Insertion Loss (db) measurement : Gives data about free space behaviour, far field near field condition No information for in cavity situation Attenuation (db/cm) : expresses the amount of energy loss when a wave goes through the material Is calculated out of ε and μ Does not give data on the reflected power Absorption loss (%) expresses the amount of absorption calculated from both components reflectivity level and insertion loss.

16 Examination magnetic & dielectric material at high frequency Reduced attenuation with magnetic based material above 35 GHz Dielectric absorbers significant better performance Dielectric Magnetic

17 Reflectivity level Eccosorb MMI-U-W Eccosorb MMI-U-W = dielectric filled absorber. Wedge 3,5 mm thickness with excellent reflectivity performance MMI-U-W Horizontal polarization Refl (db) Frequency (GHz)

18 Reflectivity level Eccosorb MMI-U-W on both polarisations

19 Typical absorption loss with Eccosorb MMI Eccosorb MMI = dielectric filled absorber, flat sheet 0,5 mm thickness with excellent performance and low production cost Frequency (GHz)

20 Typical absorption loss with Eccosorb MF-PP Eccosorb MF-PP = magnetic absorbing material. Flat sheet 1,7 mm thickness with excellent performance and low production cost. Frequency (GHz)

21 Development mouldable absorber : ECCOSORB MMI-PP + ECCOSORB MF-PP FROM GRANULATE TO APPLICATION!!

22 Moulded absorbers cost effective answer to high volume opportunities Main DRIVER = COST!!... moulding vs. machining Opportunity to design complex 3D shapes General tolerances : +/- 0,1mm (max. : 0,03mm) Schrinkage : < 0,5% Draft angles on specific surfaces : < 2 MOQ : > 1k (related to shape complexity) Minor deficiencies on product due to injection moulding technique

23 77 GHz Automotive radar system equipped with ECCOSORB moulded absorber materials

24 Examples of moulded absorber covers using Eccosorb MF-PP-120 and Eccosorb MMI-PP

25 Automotive applications using Eccosorb absorber materials

26 Emerson & Cuming Microwave Products NV Mr. J. Kenis Tel. : jkenis@eu.eccosorb.com EEMC - Coimex Mr. A. Naus Tel. : info@eemc.nl