DD IEC PAS 62437:2005 pdf download Radio disturbance characteristics for the protection of receivers used on board vehicles, boats, and on devices — Limits and methods of measurement — Specifications for active antennas
Scope
Active antennas used on board vehicles are electronic components in the sense of CISPR 25Therefore, the requirements regarding emissions apply to it in its function as EUT. In additionto this, vehicle active antennas are used as part of the measurement chain for the evaluationof emissions produced by any other component in the vehicle. With a passive antenna nospecial considerations were necessary because it can neither generate emissions norharmonics due to its linearity
This Publicly Available Specification (PAS) gives additional information for the use of activeantennas for radiated emission measurement according to CISPR 25. Test set-ups atcomponent level are defined for the determination of noise floor.
The current vehicle antenna technology provides two categories of active antennas. The firstcategory () consists of an active part (electronic part) and a passive part (antenna structure)These parts can be considered as two separate “black boxes”. During the emission testsantenna as EUT), the passive antenna part is normally replaced by an “artificial antennanetwork”
Antennas with their active and passive parts inseparably combined within one housing aredefined as category (ll) antennas.
2 Normative references
The following referenced documents are indispensable for the application of this documentFor dated references, only the edition cited applies. For undated references, the latest editionof the referenced document (including any amendments) applies.
CISPR 25, Radio disturbance characteristics for the protection of receivers used on boardvehicles, boats, and on devices – Limits and methods of measurement
3Terms and definitions
For the purposes of this document, the following definitions apply
3.1
antenna matching unitunit for matching the impedance of an antenna output to that of the 50 2 measuringinstrument over the antenna measuring-frequency range
3.2
antenna noise floorvoltage measured at the output of an active antenna via an original coaxial cable in theabsence of a reception field strength (category ll) or when the passive part of the antenna isreplaced by a terminated artificial antenna network (category l)
3.3
artificial antenna network (AAN)
electrical circuit consisting of lumped inductors, capacitors and resistors giving the samecomplex scattering parameter Soo as the passive part of the antenna installed in the vehicle.boat or device
3.4
artificial network(AN)
line impedance stabilization network (LISN1))network inserted in the supply lead or signal/load lead of apparatus to be tested whichprovides, in a given frequency range, a specified load impedance for the measurement ofdisturbance voltages and which may isolate the apparatus from the supply or signalsources/loads in that frequency range
IIEV 161-04-05,modified]
3.5
r.f.-amplifier
electronic part of the antenna system
3.6
shielded enclosure
screened room
mesh or sheet metallic housing designed expressly for the purpose of separating electromagnetically the internal and the external environment
TIEV 161-04-371
3.7
vehicle active antenna
antenna consisting of the passive part, the active part (r.f.-electronic) and the whole vehiclebody including the cable harnesses acting as counterpoise
Set-up for noise-floor measurement
Knowledge of the noise floor s strongly required for assessment of emissions when the activeantenna is part of the measurement chain. lt is not useful to define limits for the noise floor.However, it shall be measured according to the following method and shall be recorded toallow interpretation of measurement results. Noise-floor measurements are required only inthe frequency bands for which the antenna is designed. lt applies to both category l and lantennas. The measurements shall be performed with the active antenna mounted in ashielded enclosure (see Figures 1 and 2). In the case of a category l antenna, an artificiaantenna network (see Annex A) shall be used. The intended coaxial cable shall be used forthe connection between the antenna and the measurement receiver or the antenna matchingunit (usually applicable for AM bands), Bandwidths and detectors shall be chosen in order tocover all emission measurement necessities described in CISPR 25 for which the antenna willbe used.
DD IEC PAS 62437:2005 pdf download
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