li nk Microtek, the manufacturer of RF and microwave components and subsystems, has introduced a new GTEM (gigahertz transverse electromagnetic) cell as a cost-effective alternative to an anechoic chamber for high-frequency EMC emissions and immunity testing.
Primarily aimed at those needing to carry out precompliance testing of portable equipment, the new AM18-GTEM can handle microwave frequencies up to 18GHz, compared with a maximum of only about 500MHz for traditional TEM cells.
In essence, the GTEM cell consists of a tapered coaxial transmission line, with a flat inner conductor and an outer conductor formed by the aluminium walls. Producing a uniform magnetic field of known pattern and intensity, the fully shielded GTEM has a characteristic impedance of 50 ohms and is terminated by a combination of resistive card and free-space microwave absorbers.
It has a maximum input power of 50W and features an N-type input connector, as well as a screened side-access door to enable the equipment-under-test to be placed inside. The overall dimensions of the GTEM cell are 125 (L) x 65 (W) x 45 (H) cm.
Designed, manufactured and calibrated in-house by li nk Microtek's engineering team, the AM18-GTEM offers major space and cost savings, excellent long-term stability, and the capability for making rapid and reproducible EMC measurements.