TEM & LaplaCells for EMC Immunity & Emissions Testing

TEM Cell (Closed)

TEMZ 5233

TEM Cell - Closed

DC to 600 MHz

Closed, unsymmetrical 50 W stripline (also
called Crawford-TEM-Cell or TransverseElectroMagnetic cell) for E- and H-field probe calibration and immunity testing of components.

The TEMZ 5233 complies to the requirements of ISO 11452-3, IEEE 1309 and EN 61000-4-20.

TEM 2000

TEM Cell - Closed

0.01 to 1,000 MHz

GTEM Italia TEM Cell (Closed)

TEM Cells - Closed

DC to 3 GHz

Transverse Electro Magnetic (TEM) cell or Crawford cell (named after its inventor) is used to generate accurate electromagnetic waves over a wide frequency range: DC (0 Hz) to GHz.

EM waves generated in the cell propagate in transverse mode and have the same characteristics as a plane wave. It can be used to calibrate E-field broadband probes for testing radiated E-field immunity as well as for measuring radiated emission from a product with a spectrum analyzer/EMI receiver.

TEM cell generates a consistent electromagnetic field for testing small RF devices such as wireless pagers, receivers, portable phones, etc. An external test signal applied through the input port of the TEM cell generates a consistent and predictable (plane wave) test field inside the TEM cell. The radiation field emanating from a device (under test) located in the cell can also be detected through the signal generator port  connected to an EMI receiver or a spectrum analyzer.

The Equipment Under Test (EUT) is placed on the bottom ground plane as in Open Area Test Site (OATS) and in accordance with the shielded enclosure conditions.

TEM cells are used in final compliance certification tests. There IEC 61000-4-3  EMC standard, require a TEM cell for radiated susceptibility and radiated emission tests. Integrated Circuits (IC), Micro Electro-Mechanical Systems (MEMS) devices and PCBs can also be tested according to the standard SAE J1752-3 . 

TEM cells can deliver an equivalent OATS performance inside the comforts of a lab with minimum OATS errors. The main advantage of a TEM cell over a strip-line is that in the former, the EUT is completely shielded (except a window to insert/monitor the EUT) from the external environment, thus producing results with negligible errors. It is one of the reasons why a TEM cell is qualified to perform final compliance tests.

TEM Test Cell (Open)

TEM Cells - Open

DC to 3 GHz

These open TEM cells (tri-plate cells) are well suited for immunity testing of small objects according to European (CE) and automotive standards (SAE J1113-25) or for biological experiments.

The advantage of these TEM cells is that they are open and it is very easy to control the functions of the equipment under test.

Open TEM-cells are well suited for immunity testing of small objects according to European (CE) and automotive standards (SAE J1113-25) or for biological experiments.

The advantage of these O-TEM cells is that they are open and it is very easy to control the functions of the EUT (Equipment Under Test).

The applications are for instance the immunity testing of watches, pagers, telephones or PCB�s. In comparison with other closed TEM-cells, the price is low.

The field decreases rapidly outside the Open TEM-cells (approx. 33 dB at 1 meter) and it is, therefore, possible to use an Open TEM-cell in ordinary facilities.

Another interesting application is the calibration of field probes as the generated field inside the Open TEM-cell is very exact. Open TEM-cells are the most precise structures for field calibrations.

LaplaCell600/2

&

LaplaCell600/6

EMC Compliance Test Cell

30 MHz to 3 GHz or 6 GHz

Immunity
IEC61000-4-3

Emissions
EN, FCC, As/NZ, and CISPR standards

Same RF features as the LaplaCell300/2 below, but with eight times the EUT test volume.

EUT Size: 23.64" x 23.64" x 23.64"

60cm x 60cm x 60cm

Usable EUT Test Volume: 30.7" x 32.3" x 34.2"

78cm x 82cm x 87cm
 

This is the view of the rear of an LC600/2.

 On the left is the filter block access door, on the right is the main access to the EUT volume.

The cell is shown here with its main access door open.

 

LaplaCells

LaplaCell300/2

&

LaplaCell300/6

EMC Compliance Test Cell

30 MHz to 3 GHz

Immunity
IEC61000-4-3

Emissions
EN, FCC, As/NZ,

and

CISPR standards

The cell provides the core of a totally integrated system which will deliver a complete, PC controlled Emissions and Immunity test package.

EUT Size: 11.8" x 11.8" x 11.8"

30cm x 30cm x 30cm

Usable EUT Test Volume: 20.0" x 18.9" x 16.1"

51cm x 48cm x 41cm

• You can easily self certify & self calibrate your own test cell

• The cell is a stainless steel fabrication with continuously welded joints all round, giving a totally screened enclosure which is completely maintenance free and will not degrade with time.

• The main body of the cell is made from 18swg sheet giving a very strong unit but with an overall weight of only 100kg. 

• The EUT usable area is contained within a Polypropylene enclosure. 

• All calibration & correction factor data for Emissions & Immunity provided to you.

• 100 Watts Maximum

Rear view of an LC300/2 showing the main door for access to the EUT volume.
On the right side, is the access for the filter block terminations.

LC300/2, view showing the typical layout of an LC300/2 filter block output. Cables from the EUT in the volume of the cell are terminated here.

Immunity
IEC61000-4-3 sets the requirements for RF immunity testing. It specifies fields of up to 10V/m over the range 80MHz to 1GHz and provides minimum performance requirements. The LaplaCell range fully meets these requirements and when used in conjunction with the Laplace synthesizer and power amplifier, provides a complete integrated solution .

Emissions
EN, FCC, As/NZ, and CISPR standards all require the use of an OATS (Open Area Test Site) for the measurement of emissions. This is a demanding requirement in terms of space, resources, calibration and expertise. The LaplaCell range provides an ideal alternative solution, delivering equivalent OATS performance without OATS problems.

 

Uniformity: The balanced septum design ensures good uniformity, even when compared with the "industry standard" GTEM type.

The above views make this obvious.

Impedance: The aim of a test cell is to emulate an OATS test. Free space impedance as applies to OATS sites is 377 ohm. Conventional test cells are 50 ohm systems. The unique design of the LaplaCell matches the incoming 50 ohm impedance to around 200 ohm inside the cell, a much closer match to free space impedance.