EMI / RFHigh Performance Absorbers

Global EMC provide a wide range of anechoic absorber for RF, EMC and microwave applications. Specifically designed to reduce or eliminate the reflections from electromagnetic waves by absorbing the energy, dissipating the waves and turning it into heat energy. Designed to cover a wide frequency range, our portfolio of anechoic absorbers range from microwave absorbers, through to high power and hybrid absorbers.

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Microwave Absorbers


Microwave Pyramidal absorbers are designed specifically for the use in Antenna measurement, 5G and Radar test chambers. The absorber using ‘progressive impedance’ absorbs the radio wave/microwave through a resistive structure having a progressive shape, this converts the electromagnetic energy to heat energy.

Global EMC offers two different types of Microwave pyramidal absorber: The RLTF-xxx range and the GDSxxx range. All products meet NRL8093 parts I, II and III fire safety.

GDSxxx - This is the doped foam type, used for many years and has proved to be fully compliant in antenna measurement test chambers. This traditional option is more cost-effective.

RLTF-250/450/650 – This NEW product is a solid homogeneous resistive doped polystyrene system. This product has some major advantages including zero shedding (to cleanroom standard), precise fit and gap-less fit, extended lifespan, damage resistant and cleanable.

RLTFxxx Range


Length (mm) Part No. Base size (mm) Weight Kg/m² Normal incidence return loss (-dB)
200 MHz 300 MHz 500 MHz 3 GHz 10 GHz 40 GHz
250 RLTF-250 600x600 7.1   N/O N/O 17 40 >55 >55
450 RLTF-450 600x600 10.2   N/O 17 25 45 >55 >55
650 RLTF-650 600x600 14.0   20 25 30 50 >55 >55

GDSxx Range


Length (mm) Part No. Base size (mm) Weight Kg/m² Normal incidence return loss (-dB)
500 MHz 1 GHz 3 GHz 5 GHz 10 GHz 20 GHz
50 GDS50 500x500 2.5   N/O N/O 30 35 40 60
100 GDS100 500x500 3.8   N/O N/O 32 40 50 60
300 GDS300 500x500 11   30 35 40 50 60 60
500 GDS500 500x500 18   32 40 45 55 60 60
700 GDS700 500x500 25   35 45 50 60 60 60
1000 GDS1000 500x500 36   40 50 55 60 60 60

Hybrid Pyramidal Absorbers


Hybrid Pyramidal absorbers are designed specifically for the use over ferrite tiles. The resistive doping is far less than normal pyramidal absorbers and is very specific.

Global EMC offers two different types of Hybrid pyramidal absorber: The RLTxxx range and the GDSxxx-H3 range. All products meet NRL8093 parts I, II and III fire safety.

GDSxxx-H3 - This is the doped foam type, used for many years and has proved to be fully compliant in CISPR16-4-1 3m, 5m and 10m EMC test chambers. This traditional option is more cost-effective.

RLT250/RLT450/RLT650 – This NEW product is a solid homogeneous resistive doped polystyrene system. This product has some major advantages including zero sheddings (to cleanroom standard), precise fit and gap-less fit, extended lifespan, damage resistant and cleanable.

Compatible Chamber Type/Applications: SAC-3m-C, SAC-10m-C, FAC-3m-PCE, FAC-3m-C, CISPR12/25-V, CISPR12/25-C, MIL-STD461G, DEF-STAN59-411

RLT-xxx Range


Length (mm) Part No. Base size (mm) Weight Kg/m² Normal incidence return loss (-dB)
100 MHz 500 MHz 1 GHz 5 GHz 10 GHz 40 GHz
450 RLT-450 600x600 5.8   20 17 20 25 35 40
650 RLT-650 600x600 8.2   22 20 22 28 40 50
RLT250 applied to doors and access points

GDSxx-H3 Range


Length (mm) Part No. Normal incidence return loss (-dB)
30 MHz 100 MHz 500 MHz 1 GHz 5 GHz 10 GHz 18 GHz
300 GDS300-H3   15 22 20 15 17 20 22
500 GDS500-H3   15 23 22 17 18 20 >30
850 GDS850-H3   17 25 27 25 25 35 >45

High Power Absorbers


Global EMC’s High powered phenolic layered honeycomb is constructed into lossy carbon pyramidal absorber.

The GDS500-HPP and GDS900-HPP are built with high temperature tolerant phenolic cement into a hollow profile so as to minimise airflow impedance. Available in two lengths of 500mm and 900mm.

The heat resistant honeycomb construction allows heat dissipation and inhibits heat build-up.

Base Dimensions: 500mm x 500mm.

Full Specification


Length (mm) Part No. Static handling 3m/second handling Normal incidence return loss (-dB)
200 MHz 500 MHz 1 GHz 10 GHz
500 GDS500-HPP >15Kw/m² >20Kw/m²   15 25 35 50
900 GDS900-HPP >15Kw/m² >15Kw/m²   20 25 45 50

Long Hollow Absorbers


The Global EMC ‘Hollow pyramid absorber’ is designed to give excellent return loss performance and compliance.

The GDS-CAH system has a rigid structure so that it does not deflect under its own weight even when 2 metres long.

This absorber system has a true broadband performance from 30MHz to 18GHz+ and does not suffer the problems of employing two technologies: Magnetic permeability of Ferrite tiles versus Progressive Impedance of resistive pyramidal absorbers.

This multi-layered absorber system is unique to Global EMC and the resultant performance causes compliance to CISPR EMC emission standards and all IEC/EN 61000.4.3 EMC immunity standards.

Base Dimensions: Base dimensions: GDS-CAH1300 – 334 x 334mm, GDS-CAH1600 – 400 x 400mm, GDS-CAH2000 – 500 x 500mm, GDS-CAH2400 – 600 x 600mm.

Compatible Chamber: SAC-10m-C-LP (10m CISPR16-1-4 compliant).

Full Specification


Length (mm) Part No. Normal incidence return loss (-dB)
30 MHz 150 MHz 300 MHz 500 MHz 3 GHz 10 GHz
1300 GDS-CAH1300   15 27 30 35 50 50
1600 GDS-CAH1600   17 30 35 40 50 50
2000 GDS-CAH2000   20 33 37 45 50 50
2400 GDS-CAH2400   22 35 40 50 50 50

Wedge Absorbers


Wedge absorbers give around 20% more anechoic performance than full peak absorbers at frequencies below 1 GHz, due to their greater mass. The wedge system is used where a low-frequency bias is required.

Using the 20% mass the Wedge absorber system can save money by using smaller pyramids and the microwave performance is excellent with a return loss of -40dB at 8 x wavelength.

Global EMC’s wedge pyramid absorber gives excellent performance in compact chambers. The absorber fully complies with NRL 8093 parts I, II and III Fire safety standard.

Compatible chambers/applications: MIL-STD461G, CISPR12/25, ETSI, Radio/Low Microwave Work.

Full Specification


Length (mm) Part No. Normal incidence return loss (-dB)
50 MHz 100 MHz 300 MHz 1000 MHz 5 GHz 10 GHz
300 GDS300-W   N/O N/O 18 30 35 40
400 GDS400-W   N/O 12 20 30 40 40
500 GDS500-W   N/O 17 25 32 40 40
700 GDS700-W   15 20 30 35 40 40

Special Absorbers


The principal of this type of absorber is to mimic free space by ‘progressive impedance’ that is, to progressively absorb the radio wave/microwave through a resistive structure having a progressive shape, this converts the electromagnetic energy to heat energy.

The available thicknesses are:
25mm thick (part No GLD - block 25).
50mm thick (part No GLD - block 50).
75mm thick (part No GLD – block 75).

Block foam absorbers use graded doping, the available thicknesses are:
25mm thick, performance >-17dB above 5GHz (part No GLD-FL-25).
50mm thick, performance >-17dB above 2.5GHz (part No GLD-FL-50).
100mm thick, performance >17dB above 1.2GHz (part No GLD-FL-100).

Other Special Absorbers products: Machinable bar/sheet stock, rubber flat sheet 1.2mm~10mm thickness, walkway block absorber (for antenna measurement chambers), thin layer (lossy) doped foam, ultra-performance microwave absorbers that can reach -70dB return loss, anti-back-scatter absorbers, Chebyshev absorber layouts.