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 soft (3500) and a hard (3501) variant. 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.

Part number examples

Typical applications

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

Versions

• A soft version (3500) 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 (3501) 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, soft version

Standard sheet
Temperature specification: – 40°C to +100°C
Hardness shore: 40 +/- 20
Die-cut: Material can be cut into any shape according to customer’s drawing.