Tekbox TBTC0 / TEM mini cell

TEM cell "mini" for simple and cost-effective measurement of radiation and strength

Why a TEM cell?

A TEM cell (Transverse ElectroMagnetic Cell) is used to record test objects for measuring and testing the radiation or immunity of electronic devices. Usually, the radiation is measured in anechoic environments and the signals are picked up by antennas. Due to bandwidth limitations, different antennas are required to cover the entire frequency range. Furthermore, a lot of space is needed and the cost of the equipment for a standard compliant setup is enormous.

Nötig is an affordable laboratory setup for measuring radiation in your own laboratory before acceptance in the EMC test house. The TEM cells from Tekbox in four different sizes now cover a very wide frequency range. The new TBTC0 mini-TEM cell can be used for frequencies up to 6 GHz. In combination with a spectrum analyzer, products can be tested before and after EMC-relevant modifications. The test setup with a TEM cell provides valuable information on whether the design has rough edges with regard to radiated noise signals. The engineer can clearly see whether his changes have worsened or improved the EMC behaviour.

Benefits of the TEM cell from Tekbox:

The TBTC0 is a so-called “open TEM cell“ because it has no side walls to facilitate the placement of the DUT (Device-Under-Test). External radiation can penetrate the cell, but can be easily identified by measuring the output signal of the cell when the DUT is switched off and can thus be taken into account in the measurement result. A TEM cell consists of a septum, the conductive plane in the middle and outer walls connected to ground. The geometry is dimensioned to give an impedance of 50 Ω. The DUT is placed between the lower wall (floor) and the septum.

The TBTC0 from Tekbox offers a better frequency response than standard TEM cells of the same size. TEM cells suffer from unexpected vibration modes at higher frequencies, which limit the usable bandwidth. An outstanding design feature of Tekbox TEM cells is the implementation of a resistor normal to the propagation direction of the wave. Higher order modes and resonances are effectively suppressed. The TEM cell is supplied with a 50Ω/10W RF terminator and a DC blocker to protect the input of the spectrum analyzer or RF receiver.

Technical data:

TEM cell TBTC1

• Dimensions (L x W x H): 390 x 100 x 62 mm
• Rectangular area under the septum: 190 x 70 mm
• Septum height: 28 mm
• Maximum volume of test specimen (L x W x H): 114 mm x 42 mm x 15 mm
• Connectors TEM cell: N-sockets
• Nominal cell impedance: 50 Ω
• wave impedance: 377 Ω
• Maximum RF input power: 10 W (limited by 50 Ω terminating resistor, 50Ω-6GHz-10W-N)
• Rücflusssdümpfung* S₁₁: up to 3.15 GHz: < -15 dB
• Introduction* S₂₁: up to 3 GHz: < 3 dB, up to 6 GHz: < 4 dB

DC blocker 50V-6GHz-N

• Connections: N-plug/socket
• Nominal impedance: 50 Ω
• Max. HF continuous power: 2 W
• Max. HF continuous voltage: 50 V_RMS
• Frequency: 500 kHz to 6 GHz
• standing wave ratio: ≤1,2

Introduction DC blocker:

HF terminating resistor 50Ω-6GHz-10W-N

• connection: N-plug
• Nominal impedance: 50 Ω
• Max. HF continuous power: 10 W
• Frequency: DC up to 6 GHz
• standing wave ratio: ≤1,2
• 3rd order intermodulation product : ≤120 dBc

Scope of delivery:

TEM cell incl. DC blocker (N plug/N socket), 10W HF terminating resistor (N plug), 1m coaxial cable (N plug/N plug).

* Each TEM cell comes with a measurement protocol (plot) for flow S₁₁ and insertion S₂₁.