ETSI EN 300 113 Guidance

Digital Radio Testing Standard

In 1996, the European standard for digital radio testing, ETSI EN 300 113, was first released to address radio’s movement away from analogue equipment into the emerging digital radio world. Since then, the RF environment has become more crowded, demanding higher performance from both transmitters and receivers inside smaller and smaller bandwidths. Over time, this has translated towards more testing and stricter limits. Today’s exacting standards reflect the past 30 years’ worth of tightening of these tolerances.

The Commission of the European Union publishes the list of radio testing standards in their Official Journal of the European Union (see the OJ here). EN 300 113 V3.1.1 is part of Europe’s newest revisions to the Radio Equipment Directive, and was fully adopted May 31st, 2022. It outlines compliance for the following:

• Radio Equipment: Transmitters, Receivers, and Transceivers
• Fixed (mounted), Mobile (vehicular & transportable systems), and Portable Radios
• Radios with a 50 Ohm antenna connector, or integral antenna
• Radios which operate between 30 MHz and 1 GHz
• Radios using 12.5 kHz, 20 kHz, or 25 kHz Channel Spacing
• Radios using digital modulation techniques to pass Data or Speech
• Radios which use either Constant Envelope or Non-Constant Envelope modulation
• Radios which operate continuously or non-continuously

There are some things to be aware of when preparing your product for radio testing against EN 300 113 V3.1.1.

Firstly, if your device is also capable of conventional radio, i.e., typically analog modulations (even when they are accomplished digitally), then you will also need to demonstrate compliance with EN 300 086, preferably first. This is because there are some tests within EN 300 113 from which you are exempt if their equivalent requirements have already been met within EN 300 086.

Secondly, radio products in their “off-the-shelf” state are typically un-ready for testing and need modification to prepare for the testing. In this regard, engineering-grade samples are acceptable for radio testing (although you might not use these samples in other types of testing). You’ll have to consult with your testing lab in order to prepare your sample correctly as many different situations exist for many different products, and sometimes the goal of each test is not as straightforward to reach.

Other considerations

One of the ways in which radio transmitters must be prepared for testing is to facilitate the several “test emission” types listed in EN 300 113. These are meant to be representative of the various modulation schemes used when loaded to max data throughput. Using these, all types of digital modulation in the system are meant to be evaluated, with the “worst-case” to be used for the complete testing.

One of the more unfamiliar modifications tends to be the incorporation of a Bit Error Rate (BER) output from the receiver; reporting a percentage of the number of bits flipped from what’s expected (in regard to the modulation being used). This becomes the basis of receiver degradation measurement in digital equipment; basically the digital equivalent to 12 dB SINAD in analogue systems.

In terms of hardware, there is often a need to supply a high-power attenuator or coupling to allow for measurement of high-power equipment. A rule of thumb is to regard anything greater than 5 W output as “high power”, but the lab usually has the necessary attenuation to measure VHF devices < 500 W, and UHF (up to 1 GHz) < 50 W.