20130045008 | Electric Field Measuring Apparatus - An electric field measuring apparatus measures electric field intensity of an electromagnetic wave generated from equipment under test installed in an area in which electromagnetic waves are detected. The apparatus includes an antenna, an RF amplifier amplifying an output signal of the antenna, a signal intensity detector detecting whether intensity of the output signal is higher than a predetermined level, a signal generator generating a detection result signal on the basis of a detection result of the signal intensity detector, a multiplexer multiplexing an output signal of the RF amplifier, the detection result signal, and a DC bias voltage, and an optical intensity modulator having a Mach-Zehnder type optical waveguide performing an optical modulation operation on the basis of an output signal of the multiplexer are arranged inside the area. Arranged outside the area are a light source unit, a receiver unit, a DC bias controller, and a display unit. | 02-21-2013 |