TABLE OF CONTENTS Until now, the dominant technique for EMF measurement was to use an antenna (mainly a dipole or a loop) loaded with a detector (diode or, more rarely, thermocouple) and transfer the DC voltage from the probe to an indicator (in the case of the most popular designs of two-piece meters) through a high resistance (transparent) transmission line (Figure 9.1a). The technique's most important inconvenience is the vanishing of phase information that is (sometimes) indispensable; similarly, the spectral information is lost as well. Although the latter is usually unnecessary, especially where wideband measurements are of concern, we will see in further considerations that it is possible and advantageous to perform wideband measurements using spectral information as well.
The use of photonic media amongst all considered media of information transmission seems to be, in our field of involvement, the most promising one. Only recently have proposals been worked out for photonic field meters and the first designs are being investigated and even applied under laboratory conditions. This technique is often applied for data transmission and for remote reading of measured values. An example of this meter design is shown in Figure 9.1b.
The advantages of this concept are illustrated by the EMF meter designed at the Technical University of Wroclaw and used mainly for EMF measurements in proximity to transmitting antennas. The measurements were and are performed for experimental verification of theoretical hypotheses...
