Microwave Absorbers

EverSorb EVC is a series of flexible sheets which absorb approximately 99% of incident RF energy at designated frequencies in the range of 1 to 35 GHz. This material will conform to complex shapes and is readily bonded to metal surfaces. EverSorb EVC is designed for board level electronics, radiating chips, radiating cavities, enclosures and other surfaces for the reduction of specular radar reflections.

EVC Series Silicone

Typical Hardness-Shore A: 45-70

Temperature Range: -80 to 300 ºF Advantages: Excellent heat resistance, good flexibility at low temperature, excellent ozone and sunlight. Disadvantages: Silicone adhesives are difficult to bond. Fair resistance to solvents, poor abrasion resistance.

Typical Use: The elastomer of choice for high and low temperature applications. Silicone finds wide acceptance in electronic housings.

EVC Series Urethane

Typical Hardness Shore A: 80-85

Temperature Range: -80 to 275 ºF

Advantages: Excellent abrasion resistance and tear, good weather resistance, excellent tensile strength and elongation.

Disadvantages: poor resistance to hot water, acids, and alkalis.

Typical Use: Because of its outstanding abrasion resistance urethane is widely used on aircraft. Urethane can be easily bonded with a variety of urethane adhesives. Urethanes are readily painted and accept rain erosions coatings.

EVC Series Neoprene

Typical Hardness Shore A: 60-80

Temperature Range: -45 to 212 ºF

Advantages: Excellent resistance to outdoor exposure, moderate resistance to oil and gas.

Disadvantages: limited low temperature flexibility, fair resistance to aromatic and oxygenated solvents.

Typical Use: Neoprene elastomers are ideally suited for marine environments. They are easily painted and adhered. They are resistant to stack gas and salt water.

TYPICAL PROPERTIES

Color: Grey

Flammability: Non-flammable

Reflectivity Performance: <-20 dB at the nominal resonant frequency. Typical performance is shown in the table below:

**TYPICAL Reflectivity Curve @ 3, 5, 10, & 15 GHz.**
(all graphs show performance 2-18 GHz; scale is 5 dB/division, with reference at top)
Part #	Thickness	Frequency Range GHz
EVC-1.0	6.4 (.250”)	1.0
EVC-1.5	5.3 (.210”)	1.5 hfGH
EVC-2.0	3.2 (.125”)	2.0
EVC-2.5	3.2 (.125”)	2.5
EVC-3.0	2.8 (.110”)	3.0
EVC-3.5	2.4 (.094”)	3.5
EVC-4.0	2.4 (.094”)	4.0
EVC-4.5	2.4 (.094”)	4.5
EVC-5.0	2.0 (.078”)	5.0
EVC-5.5	2.0 (.078”)	5.5
EVC-6.0	2.0 (.078”)	6.0
EVC-6.5	2.0 (.078”)	6.5
EVC-7.0	1.6 (.062”)	7.0
EVC-7.5	1.6 (.062”)	1.0
EVC-8.0	1.6 (.062”)	8.0
EVC-8.5	1.6 (.062”)	8.5
EVC-9.0	1.6 (.062”)	9.0
EVC-9.5	1.6 (.062”)	9.5
EVC-10	1.6 (.062”)	10.0
EVC-10.5	1.6 (.062”)	10.5
EVC-11	1.6 (.062”)	11.0
EVC-12	1.6 (.062”)	12.0
EVC-13	1.6 (.062”)	13.0
EVC-14	1.6 (.062”)	14.0
EVC-15	1.6 (.062”)	15.0
EVC-16	1.2 (.047”)	16.0
EVC-17	1.2 (.047”)	17.0
EVC-18	1.2 (.047”)	18.0
EVC-24	1.1 (.042”)	24.0
EVC-35	0.6 (.025”)	35.0

Method of Application

EverSorb EVC can also be supplied with a pressure sensitive adhesive backing. it will provide an excellent bond in many applications, particularly when bonding cut pieces to a surface. Simply peel off the backing, and press the part onto the cleaned substrate surface. CR Technology can also kiss cut any material for streamlined assembly of absorber pieces/parts.

Availability

Standard product sizes for all grades are flat sheets 310 x 310 mm (12 x 12 in) and 400 x 500 mm (16 x 20 in), in the nominal thicknesses given in the above table. Specify the part as EVC-xx, where xx is the nominal resonant frequency, and include the dimensions. Specify a urethane sheet as EVC-U, neoprene as EVC-N. EVC without a suffix designates silicone as a default. We can supply other dimensions, and can die- cut, knife cut, kiss cut or water-jet parts to your drawings.

Typical Reflection Loss

The graphs below show typical reflectivity performance of a few of the grades of EverSorb EVC expressed as a dB down from metal plate reflection, as a function of frequency. These are measured on NRL near-field type arches.

Microwave Absorbers