Emerson & Cuming offers a variety of material solutions to address stray free-space and cavity-resonance radiation problems encountered by automotive radar module designers and manufacturers. Absorber solutions include: • VSWR suppressant • Side lobe attenuation • Radome refraction mitigation (sharp radome corners can refract light nonlinearly) • Surface reflectivity absorber (cavity resonance and propagating wave) • Feedline termination Low loss dielectric solutions include: • Ultra low loss radomes • Molded antenna spacing material (patch, phased array, etc.) • Custom lenses (Fresnel, Lunenberg, etc.) • MMIC chipset caps
Automotive Applications & Solutions
Operating up as high as 77 GHz antenna engineers regularly seek solutions to push their already great designs even further. In today’s day and age as frequencies increase well into the mm range, electronic packages are becoming increasingly smaller making for very tightly packed designs. The close proximity of these components to one another is now bringing about electromagnetic interference (EMI) problems such as cross-talking and RF leakage, which can cause a once well operating design to fall well below FCC regulations.
• Long Range Forward Looking Radar – Adaptive Cruise Control (ACC) o Pulsed Doppler, forward looking, 3-beam switched antenna o 77 GHz o

150 Meter Range (492’) o ECCOSORB® MIP absorber cast in place
• Short Range – High Resolution Radar o Multiple Sensors in bumpers, connected to central processor o 24 GHz o Distance to 20 meters (65.5 feet) o Supports Parking Assist, Pre-Crash Detection, Stop & Go Driving, Back-Up Warning, Blind Spot Detection and Side Impact o

ECCOSORB® GDS/SS6M absorber cut via water jet to print
• High Frequency Microwave Terminations o Precision waveguide assemblies o 76.5 GHz o ECCOSORB® CR-124 cast to print

• Blind Spot Detection o Cavity resonances within the transmit & receive antenna area o 24 GHz o ECCOSORB® BSR-2/SS6M offered in kiss-cut

• RF leakage at 12.5 GHz through connector pins was being transmitted to the wafer board below interfering with overall performance
• A viable, inexpensive and durable solution was required to eliminate any stray EMI
• A custom designed Mold-in-Place (MIP) material was used and cast directly into the connectors underside cavities around the pins to eliminate the problem
• Cavity resonances at 24 GHz was causing interference with other internal components within the housing
• An inexpensive and durable solution was required to eliminate resonances
• An off the shelf microwave absorber was chosen after passing extensive environmental and RF testing. It is supplied in a custom configuration with a self-adhesive backing.
• Operating at 76.5 GHz an extremely small precision waveguide assembly required a termination to reduce reflections
• Seen at right this small termination is sitting on a sheet of .25” x .25” graph paper
• Due to the high cost of machining such a small part extensive R&D was done to eventually mold this part to shape
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