ETSI - TR 102 457
Fixed Radio Systems; Evaluation of the ElectroMagnetic Field (EMF) radiated by Line-of-Sight (LoS) fixed radio stations using parabolic dish directional antennas
|Publication Date:||1 September 2018|
The present document provides guidelines for assessing the compliance of human exposure to established RF exposure limits based on the evaluation of the electromagnetic fields in the main beam emission of fixed service radio (base) stations when operating in line-of-sight (LoS) using directional parabolic (dish) antennas (e.g. in Point to Point applications). The methodology may be applicable also to other fixed radio stations provided that they use similar directional parabolic antenna type (e.g. for some terminals in Point to Multipoint and Multipoint to Multipoint systems).
Fixed radio stations using sector and omni-directional antennas are not in the scope of the present document.
Fixed service radio stations in the scope of the present document may use integral/integrated antennas or dedicated antennas, supplied by the same manufacturer, or stand-alone antennas from different manufacturer, but compliant to radio equipment manufacturer specifications; detailed definition of those antenna types are found in ETSI EN 302 217-1 [i.10].
Article 3.1a of the 2014/53/EU Directive [i.1], provides essential requirement for health and safety. Council Recommendation 1999/519/EC [i.2] (for general public) and Directive 2013/35/EU (for workers) gives recommended limits for exposure to electromagnetic fields based on the ICNIRP guidelines [i.6]. Assessment of compliance to article 3.1a of the 2014/53/EU Directive [i.1] of equipment in the scope of the present document and to the requirements defined in the Directive 2013/35/EU [i.3] (for workers) and Council Recommendation 1999/519/EC [i.2] (for general public) may be carried on based on harmonised standards CENELEC EN 50385 [i.9] for placing equipment on the market and CENELEC EN 50401 [i.8] for putting them into service.
The present document considers these exposure limits for comparison; calculations and measurements are reported. The guidelines presented may be used for calculation of the compliance boundaries as required by CENELEC EN 50385 [i.9] and CENELEC EN 50401 [i.8].
The simplified assessment method described is derived from measurement and calculation techniques defined in clause 8 of CENELEC EN 62232 [i.7] (see note) and may help in the compliance assessment of the above mentioned fixed service radio stations.
Definitions from the above mentioned EN standards are used in the present document where appropriate.
NOTE: CENELEC EN 62232 [i.7] considers a very broad types of radio antennas used in Base Stations (including Fixed Radio Stations) and is presently limited to 100 GHz; however, in specific case of parabolic (dish) antennas, the electromagnetic field generation is dominated by purely geometrical factors (related to the D/λ ratio); therefore, the methodology in the present document is considered applicable also to fixed service stations operating at higher frequency up to 300 GHz.
The maximum electric field or power density evaluation is based on calculations and measurements performed with the most common configurations and the values are tabulated. The measurement and calculation results on real systems that have been used to establish the method are also provided to give an estimation on the accuracy of the method adopted.