TEM1000

TEM250

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.

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SAE Frames option

TEM1000

TEM250ApexTrolley for TEM250, TEM500TEM3000 

TEM3000

TEM6000-Description 

TEM-3000, TEM-6000  STRIPLINE  Ic Testing

TEM3000 and TEM6000 Striplines are 3GHz and  6 GHz IC Stripline TEM Cell to generate EM fields for testing sample IC devices. They meet the requirements of IEC 61967-2/8, IEC 62132-8, and SAE 1752-3.

MARKETS: Automotive, CE Mark (Industrial & Residential), Components, Industrial, INFORMATION TECHNOLOGY, Medical Electronics, Military, Power Generation, RF, Wireless/Telecom,

Description

TEM-6000 STRIPLINE Mod.2020 is a DC-6 GHz IC Stripline TEM Cell for testing small devices such as IC’s, wireless communication modules, etc. An external test signal applied through the input port of the TEM-6000 STRIPLINE Mod.2020 generates a consistent and predictable TEM test field inside the cell. The radiation field from a device transmitting in the Cell can also be detected through the port using a test receiver. Requires 50Ω load for termination.

The high-quality compact design is optimized for measurements beyond the standard TEM Cell frequency range to 6 GHz. The E-H field inside the test volume is proportional to the input voltage and inversely proportional to the cell height. Since this apparatus is very broadband, it has many applications in the area of EMI, EMS, receiver sensitivity tests, etc.

Features:

• Up to 6 GHz bandwidth (Beyond normal TEM Cell bandwidth of 1 GHz)
• Can handle up to 5 kV high voltage pulse for Transient Field Injection Test

DTEM 500-1000-3000-6000

Dual TEM Cell (DTEM)

A dual TEM Cell test fixture is the only one that can separate the electric and magnetic field couples. Both the near-field and the far-field measurements can also be measured by this technique. The Dual TEM Cell System consists of two TEM cells, coupled through an aperture. The system has four ports as shown and numbered in Figure 1.

Fig. 1

The source is connected to the driving cell at port 1 terminated at 50 Ohm with port 4. Ports 2 and 3 are on the sensing cell. Port 2 is on the same end as port 1. The Dual TEM Cell System allows studying the electric and magnetic field couplings separately because of having two receiving ports. The TEM cell consists of a section of rectangular coaxial transmission line (RCTL) with two tapered sections at each end. The taper is used as a transition to match the RCTL to standard coaxial cable characteristic impedance connectors at the two ports of the cell. The center inner conductor, consisting of a tin metallic septum, is fixed by two dielectric supports. The cell is used as a broadband amplitude and phase linear transducer of RF signals into field strengths. The field inside the cell is uniform and so it is a good approximation to simulate a plane wave in open space (far-field). Since the TEM cell operates in the bi-directional mode it is assumed that two cells coupled through a common aperture may be used as a radiated field measurement system. The coupling between cells through their common aperture yields the basic result that the dual-cell correct operation relies on. Providing the upper side of the TEM cell with an aperture, the generated field, which is known and uniform, couples into a second similar above-standing cell. When mounting the shielding material sample on the aperture, the coupling between the source cell and the transducing one is reduced. The amount of this coupling reduction is a direct measure of the shielding effectiveness of the sample material under test.

The measurement system is made up with:

Both cells are terminated on their characteristic impedance to ensure a low VSWR level and to allow for the TEM mode propagation only. An automated PC-based control system handles both exchanging transmissions between instruments and data collection.

                                     VSWR                                             DTEM dynamic range [dB] measured with

                                                                                               0 dBm input, 1 kHz RES BW

Shielding Effectiveness Definitions

The measurement has a substituting approach and therefore is performed through two phases: In the first phase, called the calibration phase, the transduced signal power level is measured in a free aperture condition;

in the second phase, the same measurement is accomplished by mounting the sample on the aperture. The shielding effectiveness (SE) is so defined as:

SE = 10 Log A/B

where:

A = signal power level measured without the test sample

B = signal power level measured with the test sample mounted

DTEM1000

Dtem3000

DTEM6000

OPEN TEM CELLS 

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 PCBs. 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.

O-TEM250

OPEN TEM 250

7/16″ Hi-Power TEM model

O-TEM500

OPEN TEM 500 with Trolley

OTEM500 Movie

O-TEM 1000

O-TEM3000

Download OPEN TEM Cells

Automotive TEM filters

TRIPLATE

TRIPLATE

Automotive electronic components testing for radiated immunity can be facilitated by using the Tri Plate-Line (TPL) test method. It is specified in the Recommended Practice SAE J1113-25 “Electromagnetic Compatibility Measurement Procedure for Vehicle Components-Immunity to Radiated Electromagnetic Fields, 10-kHz to 500-MHz Tri-Plate-Line Method. “.

It is used for testing vehicular electronic components, such as: sensors, engine and transmission control modules, air-bag control modules, and other subsystems with associated wire harnesses connected to them and evaluate interference immunity.

Supported Standards:
SAE J 1113-25-2005 (SAE J1113-25-2005): “Electromagnetic Compatibility Measurement Procedure For Vehicle Components–Immunity To Radiated Electromagnetic Fields, 10 KHz To 1000 MHz–Tri-Plate Line Method”

Frequency range, test level

Tri-Plate Equipment

Description:

This procedure covers the recommended testing techniques for the determination of radiated immunity of an automotive electronic device. This technique uses a Tri-Plate Line (TPL) operating over a frequency range from 10 KHz to 1000 MHz. This technique is limited to components which have a maximum height of equal to or less than 1/3 the height between the driven element and the outer, ground plates.