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/m²Normal incidence return loss (-dB)
200 MHz300 MHz500 MHz3 GHz10 GHz40 GHz
450RLTF-450600x60010.2 N/O202845>55>55
650RLTF-650600x60014.0 20253050>55>55

GDSxx Range


Length (mm)Part No.Base size (mm)Weight Kg/m²Normal incidence return loss (-dB)
500 MHz1 GHz3 GHz5 GHz10 GHz20 GHz
50GDS50500x5002.5 N/ON/O30354060
100GDS100500x5003.8 N/ON/O32405060
300GDS300500x50011 303540506060
500GDS500500x50018 324045556060
700GDS700500x50025 354550606060
1000GDS1000500x50036 405055606060

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/m²Normal incidence return loss (-dB)
100 MHz500 MHz1 GHz5 GHz10 GHz40 GHz
450RLT-450600x6005.8 201720253540
650RLT-650600x6008.2 222022284050
RLT250 applied to doors and access points

GDSxx-H3 Range


Length (mm)Part No.Normal incidence return loss (-dB)
30 MHz100 MHz500 MHz1 GHz5 GHz10 GHz18 GHz
300GDS300-H3 15222015172022
500GDS500-H3 152322171820>30
850GDS850-H3 172527252535>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 handling3m/second handlingNormal incidence return loss (-dB)
200 MHz500 MHz1 GHz10 GHz
500GDS500-HPP>15Kw/m²>20Kw/m² 15253550
900GDS900-HPP>15Kw/m²>15Kw/m² 20254550

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 MHz150 MHz300 MHz500 MHz3 GHz10 GHz
1300GDS-CAH1300 152730355050
1600GDS-CAH1600 173035405050
2000GDS-CAH2000 203337455050
2400GDS-CAH2400 223540505050

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 MHz100 MHz300 MHz1000 MHz5 GHz10 GHz
300GDS300-W N/ON/O18303540
400GDS400-W N/O1220304040
500GDS500-W N/O1725324040
700GDS700-W 152030354040

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.