Broadband Hybrid Pyramidal Absorbers

Broadband hybrid pyramidal absorbers

 PU foam based pyramid absorbers 3640

These PU foam based pyramid absorbers are the most popular solution for 3, 5 and 10 m EMC chambers in the market.


Solution for 3, 5 and 10 m EMC chambers in the market

These absorbers are the most popular solution for 3, 5 and 10 m EMC chambers in the market. They are composed of pyramidal, full tip SAM or truncated SMT pulsing the matching layer to separate the pyramidal part from the ferrite part. Through optimization, this product has a superb performance across 30 MHz to 18 GHz. The ferrite performs from 30 MHz to 1 GHz and the foam performs above 1 GHz.

Prototypes are made and the design is tested. Results become part of a valuable feedback loop for refining our design further.

Broadband Pyramidal Absorber is a low density polyurethane foam, filled with high loss dielectric material in open cell structure and finished with blue paint.

The general base size is 60 cm x 60 cm with 50 mm to 1200 mm height pyramidal. It’s flexible and light weight, can be attached on the wall easily. It is a high performance broadband RF absorber and widely used for Anechoic Chambers.

3640-300 (300 mm height PU foam based pyramid absorber)



  • Our Absorbers have a pyramid-shaped appearance, with blue color (it can be selected as request)
  • Pliable and flexible, these pyramids won’t bend after long-term use, and its absorbing properties is guaranteed for 10 years.
  • Oxygen index ≥ 29% (GB/T2406-93), which is B2 level (GB8624-1997) level flame retardant.
  • Good environmental performance, all raw materials can meet environmental requirements, non volatile, no smell and non-toxic.
  • Working conditions: general indoor application
    • Long-time working temperature: -50 °C ~ 90 °C Short-time working temperature: -100 °C ~ 120 °C
    • Relative humidity: 55% ± 15% Frequency range: 30 MHz ~ 110 GHz

Installation method:

An environmental protective adhesive is generally used to paste the absorbers on the shield body (inside of the Faraday cage). If the absorber height is below 500mm, Velcro installation can be applied. Fasteners can also be used to install the absorbers to facilitate the replacement of absorbers and the relocation of chambers when is  necessary.


Schematic diagram of PU foam based microwave absorbers

Technical drawing of PU foam based pyramid absorbers


Product specification and part numbers

Part numberBase size (mm*mm)Pyramid quantity per unitUnit size A*C*B (mm*mm*mm)Standard weight (kg/m2)
3640-50600 x 60090050 x 18.5 x 151.5
3640-96600 x 60022596 x 36 x 202.2
3640-190600 x 60081190 x 65 x 504
3640-300600 x 60036300 x 100 x 607
3640-495600 x 60016495 x 145 x 6511
3640-700600 x 6009700 x 195 x 13016
3640-1000300 x 30011000 x 300 x 15022
3640-1200400 x 30011200 x 400 x 20025
Bold items are 98% on stock


Reflection loss / Shielding performance

Part numberReflection loss under
vertical incidence (-dB @ GHz)
Power handling
3640-50      30354050451.5
3640-96     3035404550451.5
3640-190    273540455050481.5
3640-300   25354050505050471.5
3640-495  2030404550505050481.5
3640-700 82535405050505050481.5
3640-1000 113040455050505050471.5

These values are measured under laboratory conditions. Results may differ in other situation. Please read our Guarantee.

Please note:

  • For the data below 500 MHz is obtained by low-frequency coaxial test method (GJB5239-2004). 
  • For the data above 1 GHz is obtained by far-field RCS test method (GJB2038A-2011)
  • The performance data listed in the above table is the guaranteed data. The measured data is equal to or better than the guaranteed data.
  • The bold Part Number is a stock item and can be delivered immediately
  • Certification: CE RoHS

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