GTemCell GTEM-250 User manual

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GTEM-250
For emission and immunity testing according to
IEC/EN 61000-4-20
Introduction
The GTEMCELL GTEM-250 is a TEM waveguide with the upper frequency li it extended to the GHz range. It is
under consideration as an alternative easure ent facility for both radiated e ission and i unity
easure ents. It is included in the standard IEC 61000-4-20 “E ission and I unity Testing in Transverse
Electro agnetic (TEM) Waveguides”.
Co pared to other easuring ethods like EMC test in anechoic cha bers or OATS (Open Area Test Sites),
GTEM-cells offer so e significant advantages for the testing of s all and ediu sized EUT´s (Equip ent Under
Test) up to a frequency range of 20 GHz. Quick turnarounds of the EUT as well as nu erous testing variations are
easy and fast to handle. Switching fro e ission to i unity testing requires only si ple adjust ents fro
receiver input to a plifier output.
You are irrespective of long waiting ti es associated with off-site test labs or weather and a bient delays that
can occur at OATS facilities. Whether you are at the design qualification, pre-co pliance, co pliance, or
production sa pling stage, the GTEM is the right choice for you!
GTEM di E.S. Benites. - 106, Ponte Str. Loc. Ponton 37015 – SANTAMBRO IO DI VALPOLICELLA (VR) ITALY.
Tel. [phone], Fax [phone]. Mail: [email protected],
www.gtem.it, www.gtem.eu, www.gtemcell.com Managing Director: Fiorenzo De Lucia.
Commercial Chamber of Verona Register No: VR-412395, VAT No.: IT-03969480403

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ey Features
Ruggedized fully hot galvanized and INOX steel construction
Unique co pact design with new Apex i pedance atching transition
Opti ized for EMI and EMC
Strong fields achieved with low input power
Broadband line and ter ination up to 20GHz
Excellent quality at low cost
Technical panel Line filters box
GTEM di E.S. Benites. - 106, Ponte Str. Loc. Ponton 37015 – SANTAMBRO IO DI VALPOLICELLA (VR) ITALY.
Tel. [phone], Fax [phone]. Mail: [email protected],
www.gtem.it, www.gtem.eu, www.gtemcell.com Managing Director: Fiorenzo De Lucia.
Commercial Chamber of Verona Register No: VR-412395, VAT No.: IT-03969480403

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GTEM di E.S. Benites. - 106, Ponte Str. Loc. Ponton 37015 – SANTAMBRO IO DI VALPOLICELLA (VR) ITALY.
Tel. [phone], Fax [phone]. Mail: [email protected],
www.gtem.it, www.gtem.eu, www.gtemcell.com Managing Director: Fiorenzo De Lucia.
Commercial Chamber of Verona Register No: VR-412395, VAT No.: IT-03969480403
Technical specifications
Frequency range
For e issions: 9KHz - 3 Ghz,
For i unity applications: 80MHz – 6GHz
* DC-20GHz optional
Septu height 250
Max EUT size (LxWxH) 20x20x15 c
Defined test volu e 8,3 x 8,3 x 8,3 c
Typical VSWR (average value) 1:1.2 (for i unity test range)
Typical VSWR at critical frequency (average
value) < 1:1.6 (for i unity test range)
Max. input power, W continuous/pulsed 1 kW/2.5 kW
Input connector 7/16“ or N UG-21
No inal i pedance 50 Oh
Mechanical
Construction Materials
Hot galvanized steel, Door Inox steel, Carbon
loaded poliurethan foa 15c Height
Outer di ensions (LxWxH) 125 x 64 x 44c
Door (WxH) Standard: 20 x 30c
Window in the door (WxH) * Optional: 24x14c
Weight Approx. 35kg
Wheeled undercarriage (with brakes) * Optional: 75c , high
Electrical
Mains connectors Fix/CEE
Main switch agneto-ther al 16A ono phase
Input socket plug 16 AC IEC Type ( ono phase + ground)
Output socket EUT tape 16 AC SHUCO type ( ono phase + ground)
Additional EUT sockets * Optional
Ground connection M6 bolt,(it is required be always connected)
EMI AC Line filter ( ono phase + ground) 16A 250V n.2 ter inals +ground
Channel for fiber optic leads 3 couples (18GHz Cut-off frequency)
RF feed-thru connector N.1 N-N fe ale
RF feed-thru SMA connectors N.2 SMA-SMA fe ale
Technical panel pre-drilled for options supplied
Options
Midia filter unit
*Optional: N.1 RJ45, N.1 DB9-RS232, N.2 USB-2, N.1
DC filter.
Wheeled undercarriage
Video ca era syste M6 bolt,(it is required be always connected)
Indoor lighting 10W LED

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Installation manual and general safety instructions
The GTEM (Giga Hertz Transverse Electro agnetic) cell is a precision electro agnetic co patibility (EMC) test
instru ent pri arily intended for use as radiated i unity and radiated e ission test facility without
environ ental electro agnetic interference. The cell is electrically si ilar to a coaxial cable with one side open
(the apex) and other side closed on the i pedance of the generator or receiver connected. In this case with a
ulti eter appears a 50 Oh resistance.
Measurement setup
The setup for e ission easure ents in a GTEM cell is shown in Fig. 1. The EUT is placed inside the GTEM and its
radiation is easured with a receiver. The receiver can be software controlled and so e software that includes
the GTEM to OATS correlation is co ercially available.
Fig. 1
Testing Volume
GTEM di E.S. Benites. - 106, Ponte Str. Loc. Ponton 37015 – SANTAMBRO IO DI VALPOLICELLA (VR) ITALY.
Tel. [phone], Fax [phone]. Mail: [email protected],
www.gtem.it, www.gtem.eu, www.gtemcell.com Managing Director: Fiorenzo De Lucia.
Commercial Chamber of Verona Register No: VR-412395, VAT No.: IT-03969480403

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Fig.2 - Maximum EUT size and maximum size of the usable
test volume in a GTEM cell, longitudinal section
Fig.3 Maximum EUT size and maximum size of the usable
test volume in a GTEM cell, cross section
GTEM di E.S. Benites. - 106, Ponte Str. Loc. Ponton 37015 – SANTAMBRO IO DI VALPOLICELLA (VR) ITALY.
Tel. [phone], Fax [phone]. Mail: [email protected],
www.gtem.it, www.gtem.eu, www.gtemcell.com Managing Director: Fiorenzo De Lucia.
Commercial Chamber of Verona Register No: VR-412395, VAT No.: IT-03969480403

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Calculating Power Required - Theory
Basically, we have to consider the volts per eter, the height of the septu , the allowance of voltage peaks
caused by a plitude odulation and the flatness with frequency. For flatness, we generally allow 3 dB, this only
takes effect after the first resonance point. The exa ple above shows 10 V/ with a
GTEM 250 Septu height = 0,25
Flatness = 3 dB = 2
Power Required = [ (E x h)2 /R] x Flatness x Modulation Allowance
E [V/ ] = required field strength: (i.e. 10V/ )
h [ ] = septu height
R = GTEM input i pedance (50 Oh )
Power Required = [(10 x 0.25)2/ 50] x 2 x 3.24 = 0,25 Watt
GTEM-250 Power requirement
Field Strenght E Flatness Modulation allowance Required power modulated Required power CW
V/m 3dB = 2 80% AM, 1kHz Watts Watts
3 2 3,24 0,073 0,0225
10 2 3,24 0,81 0,25
30 2 3,24 7,29 2,25
100 2 3,24 81 25
Factory control s - Performance test:
A verification test was perfor ed on site of the installation with a Network analyzer VNA Tiny.
REFLECTION COEFFICIENT: S11 magnitude of GTEM-250 in the range 80-3000MHz
GTEM di E.S. Benites. - 106, Ponte Str. Loc. Ponton 37015 – SANTAMBRO IO DI VALPOLICELLA (VR) ITALY.
Tel. [phone], Fax [phone]. Mail: [email protected],
www.gtem.it, www.gtem.eu, www.gtemcell.com Managing Director: Fiorenzo De Lucia.
Commercial Chamber of Verona Register No: VR-412395, VAT No.: IT-03969480403

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REFLECTION COEFFICIENT: S11 magnitude of GTEM-250 in the range 80-3000MHz
Guaranteed reflection coefficient S11
GTEM-250
Reflection coefficient S11 S11 accuracy magnitude/phase
<-14 dB in 80 MHz -4GHz ± 2 dB / 1 degrees
GTEM di E.S. Benites. - 106, Ponte Str. Loc. Ponton 37015 – SANTAMBRO IO DI VALPOLICELLA (VR) ITALY.
Tel. [phone], Fax [phone]. Mail: [email protected],
www.gtem.it, www.gtem.eu, www.gtemcell.com Managing Director: Fiorenzo De Lucia.
Commercial Chamber of Verona Register No: VR-412395, VAT No.: IT-03969480403

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Electronic Components list (Filter box):
16A, 250V IEC input power line panel ale socket (external)
16A, 250V SCHUCO output power line fe ale tape (internal)
FILTER CONCEPTS 250Vac 2x20A, 50/60 Hz
L=2x60uH+2x8.3 H, Cx=2x2,2uF, Cy=2x0.0068uF, R=1.2MOh
N.2 Feed-thru filter Arcotronics 16A 250Vac
N.1 Magnet-ther ally switch GEWISS Mod. C-16, 16A p.* Mains switch
WARNINGS! READ BEFORE USING
HANDLE CAREFULLY
The GTEM cell is professional test equip ent intended for EMC e issions and i unity test purposes operated by
trained personnel. So e care are necessary:
Don’t push or pull the apex to ove the cell, ove only fro the fra e trolley.
Before ove the cell, loosen the unlock the wheel brake than when you finish lock again.
- Open or close the door softly . Handle carefully.
- Insert always straight the N and SMA connectors, don’t tight too uch, it is not necessary!
- One N type corner adaptor connector is supplied to protect the apex, please don’t re ove it. If it brokes
replace with one of the sa e quality
RADIO FREQUENCY RADIATION
Personnel should not be exposed to the icrowave energy which ay radiate fro this device. All inputs or output
RF connection gaskets ust be leak proof. Never look inside or leave doors open when this device is energized!
ELECTROMAGNETIC FIELD
Strong RF levels ay cause de- agnetization and interference to others services. Operate always with the door
closed and keep sensitive devices far fro the door.
SHOC HAZARD
Accidental short circuit or leakage current ay occurs: Supply the unit through agneto-ther al differential
switches lines. Keep always the GTEM cell grounded also with power supply disconnected. During nor al tests
operation connect energy only with the door closed.
ELECTROSTASTIC DISCHARGE
To avoid ESD keep always the GTEM cell grounded fitted with a per anent earth 16 q. wire conductor.
DANGER
Risk of injury at hands and head or cuts around the etallic surfaces of the cha ber ay occur. Leave around the
cell a free area fro obstacles.
MAINTENANCE
Verify periodically:
- the status of the door gasket,
GTEM di E.S. Benites. - 106, Ponte Str. Loc. Ponton 37015 – SANTAMBRO IO DI VALPOLICELLA (VR) ITALY.
Tel. [phone], Fax [phone]. Mail: [email protected],
www.gtem.it, www.gtem.eu, www.gtemcell.com Managing Director: Fiorenzo De Lucia.
Commercial Chamber of Verona Register No: VR-412395, VAT No.: IT-03969480403

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- I/O connectors integrity.
- Oil the wheels of the trolley and the door hinges.
Clean inside the cha ber excess of dust with a vacuu cleaner.
Protect etallic surfaces against corrosion, clean it with a soft cloth wet of Vaseline, Silicon or Paraffin oils.
Avoid cleaning with water based products or chlorine solutions!
Maintenance
-When you are not operating live partially open the door avoiding stressing too uch the gasket (they could
take “ e ory for ” reducing the shielding properties).
-Avoid touching the anechoic pyra ids with the fingers or objects as they can be da aged easily.
-Take care at the N input connector, do not re ove the protection angle adaptor, if da aged occurs replace
urgently the adaptor with one si ilar: straight or angular just to save the input connector.
-For cleaning purposes re ove before any power supply source fro the GTEM cell, then use only a wet of
water added with soft detergent tissue for the window, avoid aggressive products: they can da age the
eta-acrylate glass.
-Periodically re ove dust inside the cell with a vacuu cleaner
Troubleshooting
No power supply in the plugs : fuse interrupted in the socket (replace with the sa e value 16A to protect the line
filter) or agneto-ther all switch off.
No field with RF power applied: pin of the corner coaxial adaptor broken: replace urgently with a si ilar one
Additional info
Power supply: when necessary connect the AC 230V or 400V power cord, verify the presence of differential
switch and agneto-ther al switches.
Load: Do not apply over load to the line filter: re e ber the ax. load is 16A for the plug and 10A ps for the
banana jacks.
Ground: A ground connection is necessary for your safety: please connect a 16 2 wire at the building earth
syste per anently by the screw placed down the filter box . Verify periodically the status of the connection.
Keep in ind that the etallic structure in case of leackage is conductive!
Door: During i unity test the door (if necessary) could re ain also opened; the field losses are negligible and
the result of the test do not suffer a lot.
Additional holes: You can ake feed-throught passages only on the technical panel (re ove it if necessary)
RF Max Power input: No care are necessary, the ter inations are over di ensioned, the li it is 1200W and
Peack pulse power up to 2,5KW (2uSec) with operating te perature up to 100°C.
GTEM di E.S. Benites. - 106, Ponte Str. Loc. Ponton 37015 – SANTAMBRO IO DI VALPOLICELLA (VR) ITALY.
Tel. [phone], Fax [phone]. Mail: [email protected],
www.gtem.it, www.gtem.eu, www.gtemcell.com Managing Director: Fiorenzo De Lucia.
Commercial Chamber of Verona Register No: VR-412395, VAT No.: IT-03969480403