3500 - Microwave absorber foam

These absorbers can be used at higher frequencies than traditional shielding and can also be used with other EMI/RFI shields to extend frequency range. The microwave absorbers can be installed easily with pressure-sensitive adhesive (PSA), often directly onto high-frequency board-level components, to absorb unwanted radiated and surface-wave EMI/RFI and to meet FCC requirements without shielding.

Our 3500 series Microwave absorber foam is RoHS compliant. It is a coated, open-cell foam and is used as a microwave absorbing material, especially for applications with frequencies of 1 to 17 GHz. The product acts like a free-space resistor to incoming electromagnetic energy.

The 3500 series Microwave absorber foam is available in a hard variant and a soft one. The type you choose depends on the force you want the foam to be able to withstand, if necessary.

Microwave absorber products can solve EMI/RFI problems without additional shielding and enable advanced technologies including automotive radar, military, and commercial wireless applications.

Typical applications

  • Antenna hats
  • Test boxes
  • PCB shielding/housings
  • Military applications
  • EMI reduction
  • Antenna pattern shaping
  • Radar cross reduction


  • A soft version which can be easily compressed to 75% is available as die cut or in the form of sheets. The soft microwave absorber sheets are available with thicknesses of 3, 5, and 15 mm and with or without PSA (pressure-sensitive adhesive).
  • A hard version which can carry more weight and keeps its shape and position more easily is available with a thickness of 6 mm. Other thicknesses are available on request.
Microwave absorber foam
Microwave absorber foam
Microwave absorber foam used in shielded housing
Microwave absorber foam (hard version) used in shielded housing. This hard version remains in place easily

Microwave absorber foam, soft version

Standard sheet

Size: 200x300 mm
Temperature specification: - 40 to +100 degrees Celsius
Hardness shore: 40 +/- 20
Die-cut: Material can be cut into any shape according to customer's drawing. For a quote, please send a drawing with the desired quantities

Absorption rate

Microwave absorber foam absorption rate
Microwave absorber foam, absorption rate

Reflection loss

Microwave absorber foam reflection loss
Microwave absorber foam, reflection loss

Part numbers

Part number Features
3500-200-300 Standard sheet size: 200 x 300
3500-x-x Foam customized settings

Microwave absorber foam, hard version

Product specifications

Property ISO Unit IP 45
Density 845 Kg/m3 42 - 48
Tensile strength 1798 kPa 298-337
Elongation strength 1798 % 30 - 41
Compression deflection strength 844 kPa  
25% 844 kPa 55 - 75
50% 844 kPa 123 - 145
24h 1856 % 6.0
Working temperature range   Celcius -60/+80
Thermal conductivity at 0 degrees Celcius 8301 W/mK 0.04
Water absorption 7 days   Vol. % <1
Flammability FMVSS302   Pass
Surface resistivity IEC-61340 Ohm 10^7

Part numbers

Part number Features
Standard sheet size: 555x355 or 355x255
3501-x-x Foam customized settings

To get a quotation for EM absorber Schaum within 24 hours fill in the form below.

Select an option:
3500 : Soft EM absorber foam
3501 : Hard EM absorber foam
Width (mm)
Specify the width in mm
Length (mm)
Specify the length in mm
Select an option:
3 : 3 mm thick (soft)
5 : 5 mm thick (soft)
15 : 15 mm thick (soft)
6 : 6 mm thick (hard)
Select an option:
PSA : With pressure sensitive adhesive
NA : No adhesive
* Note: The red blocks are required


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