Handheld antenna lets you make EMI and RF measurements

-- Test & Measurement World, 3/18/2008 7:34:00 AM

When making EMI measurements, you must first measure the strength of ambient fields in your test area so you can subtract them from your radiated-emissions measurements. When you characterize intended RF and wireless transmissions, you also need to measure E-fields at numerous locations relative to the transmitting antenna.

The Omnifield Antenna from EMC Test Design connects to any spectrum analyzer so you can measure E-fields. It consists of an antenna head, a handle, and an amplifier unit. A cable then connects the amplifier to your spectrum analyzer. The antenna head consists of three antennas and the amplifier combines the three received field signals, making the Omnifield Antenna omnidirectional. It covers the 30-MHz to 3-GHz frequency range with a field strength range from 3 mV/m to 300 V/m. Ferrites in the cable decouple the antenna from your spectrum analyzer.

You can use the Omnifield as a handheld or stationary antenna. A tripod lets you mount it on a table or other nonmetal flat surface. The Omnifield Antenna comes with measured antenna factors documented in its calibration certificate. You can use the antenna factors to compensate for nonlinearities in your measurements.

The amplifier is powered by a rechargeable battery. The battery charger is a linear power supply so it doesn’t emit RF signals that can interfere with your measurements. Thus, you can make measurements with the amplifier connected to the charger.

Price: $3800. EMC Test Design, www.emctd.com.