Measurements using Optic and RF Waves

Chapter 6Exposimetry – Measurements of theAmbient RF Electromagnetic Fields¹

 

 

 

6.1. Introduction

Any moving electric charge produces an electromagnetic radiation which is propagated in space. This property is at the base of the production of electromagnetic radiations used in the devices of radio, television, telecommunication, heating by microwaves, emission radar. Consequently, any system fed in electricity or with stronger reason containing an aerial element emits an electromagnetic radiation or generates an electric and/or magnetic field in its close or even distant vicinity, that we will characterize in this article using the generic term of RF electromagnetic field. Two concerns emerge from this electromagnetic presence:

– one relates to the electronic systems and thus electromagnetic compatibility (CEM);

– the other is man, as a user, patient and human exposure to the electromagnetic fields induced by non-ionizing radiations (NIR). This last concern comes under the field of hygiene and safety.

This chapter dedicated to the measurement of the RF electromagnetic fields, in the frequency band concerned with non-ionizing radiations, relates to this last aspect exclusively. Even if it is a question of quantifying the same physical sizes, the differences of objectives, protocols, standardization and regulation and reference frame, measuring apparatus ensure that each concern preserves its own constraints and its characteristics and must be treated separately.

In order to bring ...