Tuesday, December 4, 2012

Radio module integration and R&TTE compliance, EMC evaluation

radio module

radio module (Photo credit: ckhamken)

Building on a previous post focusing on radio module integration and the Radio and telecommunications terminal equipment (R&TTE) directive compliance, this article will focus on compliance of the combined apparatus with section 3.1(b) of the R&TTE directive, namely the essential requirements of Electromagnetic Compatibility or EMC.

As a basic primer, the R&TTE directive’s essential requirements are detailed within the directive under article 3, to paraphrase;

3.1 Essential requirements applicable to all apparatus;

       a. Safety requirements of the Low Voltage Directive, with lower limits removed

       b. Electromagnetic compatibility as per EMC directive

3.2 Effective use of radio spectrum

3.3 Construction, protection and accessibility requirements (with a number of specified items)

As posited in a previous post “Radio module integration and R&TTE compliance”, compliant radio modules installed in accordance with a manufacturer’s installation instruction require no further evaluation to article 3.2 of the R&TTE directive. However, an assessment, in most cases, will be necessary for article 3.1(a) and 3.1(b). The combined product will essentially form a new apparatus.

Given that the combined product should be assessed as a new apparatus, a couple questions may arise. What EU directive and standards apply? How do you make an assessment for EMC on the combined product?

When adding a radio to an apparatus, the new combined apparatus now falls within the scope of the R&TTE directive. ETSI EN 301 489-1 annex C gives guidance regarding this combined equipment EMC assessment, and it is based on the ETSI TR 102 070-1 technical report. In accordance with the guidance, for a combined apparatus where all products can operate independently of each other, an evaluation may be made by review of existing assessment of the individual apparatus, and if it is concluded that the combined configuration has been assessed and is representative of the combined apparatus, and, is used in according to its manufacturer’s instructions, it is not necessary to re-assess the apparatus. If there is insufficient information to make an evaluation, or the results of the evaluation are unclear, then an additional assessment shall be performed. Most of the time an assessment for EMC of the combined apparatus will not have been performed, or there is insufficient data to support a declaration of conformity.

Although under the scope of the R&TTE directive, the selection of applicable standards for EMC will be based on the primary function of the newly combined apparatus. The manufacturer shall declare the primary function and identify applicable standards from the EMC directive and/or R&TTE directive. The assessment should be supplemented with test levels and extended frequency ranges to cover both radio and non-radio aspects of the newly combined apparatus (i.e. a worst case representation of applicable levels and limits). See this flow chart from Compatible Electronics for a simplification of the assessment process based on the ETSI guidance.

The declaration of conformity will need to declare compliance with the R&TTE directive, and the party responsible for the completed combined apparatus is the party responsible for ensuring that the final configuration, when used properly, and in accordance with the provided instructions, fulfills ALL essential requirements of the R&TTE directive.



ETSI TR 102 070-1

ETSI EN 301 489-1 annex C

R&TTE CA TGN 01 Rev 5