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Sporting a six-floor and 17,000-square-foot facility, the ATF’s indoor anechoic chambers and compact ranges are protected against environmental conditions and exterior RF interference. The chambers’ exterior RF interference attenuation is greater than 100 dB to 100 GHz. There are four chambers within the ATF that can be used simultaneously. Chambers 1 and 2 feature compact ranges integrated within the anechoic chamber. Each chamber is equipped with positioners for rotating antennas, analysis software equipment, control-room instrumentation, and processing equipment.

An anechoic tapered chamber provides NF and far-field (FF) measurement capability with cylindrical, spherical, or planar methods. This chamber can be equipped with instruments that enable testing from 0.2 to 34 GHz, 0.1 to 110 GHz, and even to 140 GHz. The planar-near-field (PNF) range has a 10-×-10-ft. chamber that can house antennas to 8 ft. for 6-to-18-GHz testing using Nearfield Systems’ PC-driven data-acquisition software. Additional equipment can enhance this chamber for analysis to 110 GHz. For antenna heavy lifting, the Georgia Tech Research Institute (GTRI) offers a variety of test chambers and ranges to support the largest loads.

Compact anechoic chamberIn fact, the GTRI also boasts electromagnetic test and evaluation facilities spanning 200 MHz to 110 GHz in the NF and FF ranges. The GTRI features a planar/cylindrical NF range, a spherical NF range, an anechoic chamber, an outdoor FF range, and a turntable range. The turntable range can support a load in excess of 200,000 lbs. and can elevate approximately 90 ft. above the tower base. This elevation capability enables the range to test tank-sized targets to 32 deg. of elevation at different angles. It also can support vehicle-mounted antennas. On the outdoor FF range, a three-axis positioner can support 30-ft.-diameter antennas to 30,000 lbs. while providing high mechanical precision.

For those engineers looking to test high frequencies in small spaces, the Microwave Vision Group offers the μ-Lab (Fig. 3). This portable millimeter-wave test chamber  measures 7 × 5 × 5 ft. It is mounted on caster wheels with a folding tabletop side for an attached peripheral computer. The test chamber can support devices to laptop size. It boasts an offset column for chip measurements that can support devices to 5 × 5 cm. The frequency capability of the μ-Lab is 50 to 110 GHz with add-ons that can drop the frequency range to 18 GHz. To specifically test NF and FF chips, miniature connectorized antennas, and portable electronics, the μ-Lab has highly refined elevation and azimuth-axis control assemblies.

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