Surge Suppression Filters

N-Type Surge Suppressors Surge Suppression Filters

In addition to our large range of EMI power and signal filters, Global EMC can supply surge suppression filters suitable for protecting vital equipment from LEMP (Lightning Electromagnetic Pulse) or NEMP (Nuclear Electromagnetic Pulse) spikes on RF equipment.

The N-Type fitting is available in both Female and Male connection types. The suppression filters for 0Hz (DC) to 6000 MHz are based upon the replaceable gas discharge tube (GDT) technology and designed for RF line surge protection.

Global EMC prides ourselves on providing our clients with a complete and turnkey solution to their shielded rooms, shielded containers and Faraday cage requirements.
Using our supply chain partners Global EMC can offer Surge Suppression filters as part of the complete service we provide to all our clients.

Technical Data:

Port 1 N female (50 Ω)
Port 2 N socket bulkhead (50Ω)
Frequency range: DC to 6 GHz
VSWR, max: <1.1
Power, max: 240W
Insertion loss: <0.2 dB Return loss > 19 dB
Materials and surfaces:
Housing material: Brass/Surface plating: Cu Zn Sn
Contacts: Bronze/Surface Au-Ag
Insulation: PTFE
Operating temperature: -40°C to +85 °C
Max. Load current 10A
Nominal discharge current 5 kA (8/20μs test x 10 – C2 Category)
Max. Discharge current 20 kA (max. withstand @ 8/20 μs)
Impulse current 1kA (2 x 10/350μs Test - D1 Category)
Protection level < 2300 V
Failsafe behaviour Short-circuit
RohS compliance Yes
Mounting: Feedthrough
Ingress protection: IP 66 (in mated condition)
Plastic tethered duct cap included
Standards: IEC 61643-21 / EN 61643-21 / UL497C / UL497E

Further Information

• Please contact us for bespoke variations to the technical data provided above.

Shielded Rooms for Forensic Interrogation

Shielded Rooms for Forensic Interrogation

Global EMC has successfully delivered a new shielded room for the Forensic Interrogation of electronic devices.


The shielded room was designed specifically to prevent electronic devices inside the room such as mobile phones, laptops and other Sim card or WiFi enabled devices from connecting to wireless signals that are present outside of the room. Such as 5G, 4G, GSM, Bluetooth and WiFi signals.


Designed and manufactured in our facility in the United Kingdom each part of the room was made to fit the unique shape of the host building precisely.


The bespoke design fitted intrinsically into the surrounding area providing the maximum available space whilst maintaining the aesthetic qualities of an office environment.

Secure and Functional.

A vestibule (lobby area) was designed to enable technicians to enter or exit the room whilst maintaining the integrity of the shield. Using an airlock style door arrangement, enabled users to continue working inside the room whilst allowing other users could enter or exit. This minimised the “downtime” of the facility and also gave added security, that the integrity of the shielding would not be compromised accidentally during testing.


The high performance shielding provided over -100dB of signal attenuation (over 100,000:1 reduction). This stopped any mobile phone inside the room from transmitting too, or receiving from, a source outside of the room.


The shielding stopped the mobile phone or any other Sim card enabled device from connecting to a cellular network, the internet, making a call or receiving any other type of signal from outside of the room. WiFi connectivity and Bluetooth where also prevented.


Delivered in component form and hand built onsite, provided minimal disturbance to the existing building and staff during construction. The shielding effectiveness was verified by an independent ISO 17025 test laboratory to EN50147-1 standard.

Additional Information

Onsite Consultancy

Specifying the correct shielded room for your requirements is simple with Global EMC. We take care of every step of the way. Onsite consultancy service including measurements, in house design and bespoke high level design drawings. All this makes choosing the right shielded room for your needs straight forward and effortless.

Device Interrogation - Forensic Shielded Rooms

Electronic Devices

Suitable to effectively stop any mobile phone or Sim enabled device inside the shielded room from connecting to an external cellular or WiFi network. Independently tested and verified ensures impartial certification of our shielding effectiveness.

Gloval EMC Ltd - 25 Years in the industry

Made In England

The tailor made design and manufacture from high quality raw materials, manufactured by Global EMC to the unique shape of each project ensures every installation is both technically capable and aesthetically finished.

Shielded Anechoic Test Cabinets

Research and Development.

Global EMC has successfully delivered 3 new double tiered research and development test cabinets for mobile phones (cell phone) product development. The test cabinets have a high performance shielded enclosure to isolate any ambient signals from the internal testing environment and an interior fully lined with anechoic microwave absorber.

Simplicity and Universal.

The shielded anechoic cabinets where delivered fully assembled with no assembly required for the end user. Simple to use and designed to accept a wide range of requirements each cabinet was designed to be future proof and versatile.

Designed specifically to fit through a standard sized door the cabinets are transportable without needing to dis-assemble any parts.
Feature packed with filtered internal mains power sockets, Fibre waveguides, ethernet and coaxial sockets the cabinet gave the client a flexible and all-round testing environment.

Further Information

• Fully anechoic internal lining of GDS100 anechoic absorber.
• Shielded enclosure of bespoke dimensions of up to -100dB of shielding effectiveness.
• RF shielded, easy opening access door.
• Heavy duty wheels for ease of transportation.
• 2 x 1 Gigabit internal ethernet ports.
• 2 x High quality forced air fans.
• 4 x 230V AC 13A internal mains sockets.
• 1 x Fibre optic waveguide.
• Delivery and 12 month warranty included.

EEG Shielded Rooms, Durham University

The Challenge

The client approached Global EMC to provide two shielded enclosures for their new electroencephalogram (EEG) room. The rooms required shielding to enable highly sensitive measurements to take place within the room without the possibility of ambient interference.
The client also required a testing environment where anyone inside the room would feel comfortable and also free from distraction. This would enable the measurements taken to be isolated from external influence.
The room was also required to be as compact as possible to fit inside the allocated host building.

The Solution

The rooms where specially designed using Global EMC’s high permeability shielding to provide attenuation to magnetic fields caused by nearby electrical equipment and cabling. This gave the client a controlled and repeatable environment to perform their measurements and tests. The resultant field inside the room was <0.2µT, well within the allowable tolerance limits of the EEG equipment.
To provide a comfortable environment for the user, noise reduced air conditioning was supplied which had user control for temperature adjustment. Dimmable fibre optic lighting was installed to eliminate interference but also allow user control to create a low light level during testing.
Sound (voice and vibration) attenuation was provided using specialist sound absorbing materials and the whole chamber was mounted on anti-vibration mounts to reduce vibration noise transmitting from the floor below.
Dark blue walls and carpet was provided to give the enclosure a more “office-style” comfortable feel. Mains power outlets, data points and EEG equipment signal cable sockets where provided to make the room practicable and versatile.

Benefits To The Customer

The client benefited from two new bespoke shielded enclosures for EEG use. Each room was entirely separate enabling two separate tests to be carried out independent of each other.
The bespoke nature of Global EMC’s EEG-SR means that the dimensions of the room could be adjusted to maximize the available space in the host building. Global EMC worked with other contractors as part of the rooms internal fit out as a coordinated project, to make the room available before students returned for the first term after summer.
The chamber is delivered in component form to enable the shielded room to be delivered into the host building with minimum disruption. All components can pass through a standard single door of the host building and is assembled onsite.

(Shielded rooms during construction)

Product Information

• Two Shielded enclosures with sound dampening.
• Air conditioning with sound deadening.
• Large shielded doors with wheel chair access ramp.
• Dimmable fibre optic lighting.
• Small power and data points.
• Integration of clients EEG equipment.
• Independent testing and certification.

Material Science, Cambridge University

The Challenge

To provide a shielding solution for the new FEI TEM Microscope installed at Cambridge University. The shielded enclosure was designed to enable the microscope to perform at its maximum resolution without interference from magnetic fields. The shielded enclosure would need to be able to provide a “quietness” zone around the microscope of less than 10nT p-p.

The Solution

Global EMC provided a multi-layer high permeability Faraday cage to line the walls, ceiling and floor of the host building. This enabled the user to maximize the internal space of the room, whilst not enclosing the microscope to permit ease of maintenance and workspace around the microscope.
Shielded doors, waveguides and honeycomb vents completed the installation to allow penetrations and services to be brought into the room.
The shield effectiveness was stringently tested by putting adjoining electrical cables under full load condition whilst performing the “quietness” commissioning certification tests.

Benefits To The Customer

The client received a shielded enclosure that exceeded the required magnetic field shielding required. The room post mitigation achieved a <5nT p-p in magnetic field perturbations as measured over the allotted time.

Magnetic Shielded Rooms - Global EMC

Product Information

Location – Materials science, Cambridge University
Machine – FEI Transmission Electron-Microscopy
Room Dimensions – 7m x 7m x 7m
Quasi-DC slow moving field disturbance sources – local delivery vehicles/lifts/pallet trucks etc.
Mains power magnetic field disturbance – 400A feeder cable close to room.
Magnetic field ‘quietness’ target - <10nT p-p
Resultant worst case magnetic field VLF/ELF/DC perturbations (post mitigation) – 5nTp-p as measured over time.
Mitigation methods:
• Active cancellation system – None
• Passive shield – Multi-layer high permeability Faraday cage

Cyber Essentials


Global EMC has been awarded Cyber Essentials Plus accreditation via independent certification body. The Cyber Essentials Plus accreditation scheme by the National Cyber Security Centre (NCSC) ensures any data we keep is secure and protected from Cyber attacks.

Government Contracts

Having Cyber Essentials Plus certification enables Global EMC to meet the criteria required to handle sensitive and personal information to enable Global EMC to bid for central government and defense contracts in the United Kingdom and EU.

Further Information

• Certification number is available on request.

Leonardo, Basildon, UK.

The Challenge

To design, manufacture, install and commissioning a new 8.1m (L) x 5.2m (W) x 3.2m (H) fully anechoic test chamber. The client required the chamber to be complaint to DEF-STAN 59-411, RTCA DO160 and MIL-STD-461G for military testing. The chamber had a secondary use for pre-compliant EMC testing to CISPR16-1-4 for commercial applications.
The project also included the relocation of two shielded rooms (Faraday cages) connecting one of the shielded rooms to the new anechoic test chamber for use as a control room.
In addition the client asked for the design, manufacture, install and commissioning a new 2.5m (L) x 2.5m (W) x 2.5m (H) shielded room (Faraday cage) that required shielding effectiveness of greater than 100dB in the frequency range of 1 GHz to 6 GHz.

The Solution

A Faraday cage was constructed using galvanised sheet steel in modular “pan” type construction connected to a self-supporting steel structure. The internal surfaces of this was fitted-out with Ferrite tiles and hybrid anechoic absorbers to give a lining of absorbing materials.
An existing shielded room was then relocated and installed adjoining the new chamber. This was to provide a control room to the new facility. The chamber was independently tested and verified and exceed the client’s requirements.

Customer Testimonial

"EMC Chamber performance very good - Shielding Tested >120dB, Calibrated for NSIL (DEF STAN 59-411), FAR Site Attenuation & Site VSWR (CISPR 16.1.4) & Field Uniformity (EN 61000-4-3)"


The ability of Global EMC to dismantle and relocate test facilities enabled us to reduce the capital expenditure of the project making the project more economically viable for the client. The fully anechoic chamber was designed to give the client the broadest range of testing applications possible within the confines of the space available.
The chamber had fantastic results for a pre-compliant chamber to CISPR 16-1-4 emissions test standard.

Product Information

Fully Anechoic Chamber -
• Shielded room (Faraday cage) of dimensions 8.1m (L) x 5.2m (W) x 3.2m (H).
• Structural steel supports for the chamber.
• RLT450 hybrid pyramidal absorber and Ferrite tiles.
• Electrical installation including small power and lighting.
• Single personnel door.
• Control room
• Penetration panels, honeycomb ventilation panels, filters and false floor.
• Testing and Commissioning by an independent UKAS testing company.
Shielded room (Faraday cage) –
• Shielded room (Faraday cage) of dimensions 2.5m (L) x 2.5m (W) x 2.5m (H).
• Single personnel door
• Penetration panels, honeycomb ventilation panels, filters and false floor.
• Electrical installation including small power and lighting.
• Shielding performance >100dB @ 100 kHz to 6 GHz.

Manchester University - High Voltage Lab

Under Construction

Global EMC is currently installing shielding to the new UHV laboratory at UoM.
The client required the design, manufacture and installation of a brand new, state of the art High Voltage Laboratory for research and education purposes. The new laboratory will keep the University at the cutting edge of High Voltage research. Ensuring it is one of the country’s leading academic providers in High Voltage experimentation and development.
The client approached Global EMC to provide shielding to the new facility to exclude (or sufficiently attenuate) frequencies of less than 1000 kHz (1 MHz). This would attenuate any high pd background noise level that was present in the non-shielded areas.

The Solution

Global EMC provided shielding as per the Faraday Cage principle of a six sided enclosure. Due to the high voltages that would be present inside the laboratory, specialist contractors provided Earthing and Grounding and was interfaced to the shielding and a copper mesh floor.
The shielding was electrically isolated using dielectric spacers from the host building to create an electrically isolated laboratory. This created a structure within a structure concept including the large overhead crane that would be provided by others.
The isolated structure would be constantly monitored during the construction phase and would instantly alert if the shielding became in contact with the host building.
A control room would be installed to give the end user both a safe place to control the experiments whilst also providing an educational platform through a large shielded window into the laboratory.
Construction is on-going and is due to complete in 2020.

Design Process

Due to the complex and bespoke nature of the laboratory a detailed and intricate design and development process was undertaken. Using AutoCAD, Solidworks and Revit a co-ordinated design approach was achieved. Regular onsite meetings with the client’s design team, other contractors and client workshops, helped progress and refine the design to construction. Workshops with specialist design consultants Haefly were also held to provide specialist knowledge and design information. During construction, Global EMC’s design team provided on-going site visits to monitor the design during the installation process.

Product Information

• Shielded enclosure of approximate dimensions 20.0m (L) x 22.0m (W) x 19.5m (H).
• Adjoining control room.
• Large Roller Shutter doors.
• Pedestrian entrance doors.
• Overhead Crane integration.
• Copper Mesh floor with grounding points.
• Waveguides and penetrations.
• Air conditioning integration.

Vehicle Test Chamber - Abu Dhabi - UAE

The Challenge

To design, manufacture, install an anechoic test chamber compliant to MIL-STD-461G to be used for radiated emission vehicle tests.
The chamber shall be suitable for large heavy vehicles to be driven into the chamber and also provisions for components to be tested on a large test-bench.
The chamber needs to meet the clients' bespoke requirements, so a careful and accommodating design consultation process was required.

View Full Product Specification

The Solution

A shielded room (Faraday cage) was installed including a steel support structure. The steel support structure was self-standing and fully independent of taking any loads from the host building.

A large sliding door was installed including an automatic pneumatic ramp. The ramp was surface mounted and did not require excavation of the host buildings floor. The sliding door had a clear opening dimension of 4.0m (W) x 5.0m (H) to allow large vehicles to enter the chamber as a complete unit. The door was automated to enable the operators of the chamber to open and close the door with ease.

SMA550 Pyramidal absorber was used to completely cover all walls and ceiling as much as physically possible. The absorber exceeds the requirements of -6dB at 70 MHz and -10dB at 250 MHz and above (at normal incidence).

Benefits To The Customer

The client received a new test chamber complete with all new parts covered by Global EMC’s warranty and after-sales support.
The client (having an expanding product portfolio) now had the benefits of its own on-site test facility to quickly and efficiently test its products as per business requirements. The chamber can be used when required and no logistics were required to an off-site test facility.

Product Information

• This is a link
• Large MIL-STD-461G test chamber for vehicles.
• Component test-bench for MIL-STD-461G testing.
• Large shielded sliding door of clear opening dimensions 4.0m (W) x 5.0m (H)
• Personnel shielded door.
• SMA550 Pyramidal absorber.
• Full electrical installation including small power and lighting.
• Vehicle fume extract system.
• Floor access hatches.
• Testing and Commissioning.

RSE Kazakhstan Institute of Metrology

The Challenge

The client required the design, manufacture, installation and commissioning of a new 10 meter compliant EMC military vehicle test chamber. The chamber required compliance to Class I GOST 30373-95 / GOST R 50414-92 in the frequency range from 9 kHz to 18 GHz. The chamber was also designed to enable testing to 36 other standards including CISPR, GOST and IEC/EN61000-x-x standards.

The client also required a 16-meter diameter turntable, one of the largest ever installed in an EMC chamber. This coupled with temperatures of -40⁰C, limited timescales and the high-performance specification made for a very complex delivery of a prestigious project.

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The Solution

Global EMC utilised our 2400mm long hollow pyramid absorbers as the anechoic lining of the chamber. The length of these absorbers enabled us to meet the specification without the use of ferrite tiles and hybrid absorbers. This gave the client a reduction in the cost, weight and installation time for the chamber.

Shield effectiveness of greater than -80db from 10 kHz to 18 GHz was achieved using our modular “pan” type shielding system, effective integration of numerous peripheries and specialist sliding door. The shield effectiveness was tested by an independent ISO 17025 test company to IEE Std. 299 to ensure an unbiased test report.

To enable the client to enter heavy vehicles into the chamber, a specially designed 10 tons per square meter floor was installed between the 4.2m (H) x 4.2m (W) sliding door and 16-meter diameter turntable. The turntable was designed to have a loading of 20 tons.

Benefits To The Customer

The client received a compliant 10-meter test chamber of all new components covered by warranty. The chamber enables the client to perform both emission and immunity tests to the standards they required. The chamber was built to be robust and durable for the heavy-duty environment of large vehicle testing. The large turntable, crane, extract system and sliding door gave the client scope for a wide and varied testing facility.
Using the long hollow absorbing material gave a cost-effective solution to the anechoic requirements for the chamber.

Product Information

• Shielded enclosure of dimensions 30.0m (L) x 21.0m (W) x 10.0m (H).
• Supporting steel structure.
• 4.2m x 4.2m Pneumatic sliding door with automatic ramp.
• 3 Pedestrian entrance doors.
• 20 Ton Overhead Crane.
• 16.5m Turntable with a maximum load of 20 tons.
• Anechoic lining of walls & ceiling with 2400mm long hollow pyramid absorbers.
• Vehicle fume extract system, extract fans and ventilation panels.
• Filters, CCTV, audio links and power/lighting.
• Testing and Commissioning.