Our 5 m x 5 m x 4.5 m anechoic chamber is equipped with two independent field scanners located on two rotational axes (disks). Both disks can be moved with an accuracy of 0.1 deg. On the one hand these two independent scanners can be used to emulate a multipath propagation environment (MIMO, diversity). In this way over the air (OTA) measurements like total radiated power (TRP) or total isotropic sensitivity (TIS) can be performed. On the other hand the two scanners can be used for emission and immission testing of circuits and systems. For example, one of the two scanners can be used to provide a high level disturbance signal while the other one scans for spurious emissions caused by undesired interaction with the disturbance signal.
The chamber provides a screening attenuation better than 100 dB within the frequency range 400 MHz to 18 GHz. The broadband antennas mounted on the scanner support a frequency range of 400 MHz to 6 GHz. Other antennas for higher frequency scans are available.
The MIMO-OTA measurement system extends our anechoic chamber to perform wideband measurements. In the standard configuration 2x2 MIMO systems operating at frequencies below 6 GHz are supported. The extension to support higher order MIMO systems is prepared. The signal generation is accomplished either by a MIMO-fading vector signal generator or by wideband arbitrary baseband signal generators which are driving vector signal mixers. The signal capturing is performed using wideband signal analyzers. Phase coherence between the analyzers is established by characterization measurements. The MIMO-OTA performance is calculated offline at the host PC.The measurement system is prepared to conduct measurement in the mm-wave regime. Three local oscillator generators (100 kHz - 20 GHz, 1 GHz - 43 GHz and 60 GHz - 90 GHz) are available for up- and down-conversion of the baseband or RF signals.
By using the anechoic chamber we are able to perform EMC pre-compliance testing. Covering the frequency range from 400 MHz to 6 GHz the equipment under test (EUT) can be scanned from any arbitrary direction for signal emission. Measurements below 400 MHz are performed in collaboration with the Institute of Electronics using their TEM cells.
Institute of Microwave and Photonic Engineering
Inffeldgasse 12/I 8010 Graz Tel.: +43 (0)316 873-3301 Fax: +43 (0)316 873-3302 E-Mail: ihfnoSpam@tugraz.at Web: www.ihf.tugraz.at