DD IEC/PAS 62437 is an international standard that discusses radio disturbances characteristics for the protection of receivers used on board vehicles, boats, and on devices.
DD IEC/PAS 62437 gives additional information for the use of active antennas for radiated emission measurement according to CISPR 25. Antennas with their active and passive parts inseparably combined within one housing are defined as category (II) antennas.
DD IEC/PAS 62437 defines test set-ups at the component level for the determination of noise floor. The current vehicle antenna technology provides two categories of active antennas. The first category (I) 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 tests (Antenna as EUT), the passive antenna part is normally replaced by an “artificial antenna network.”
DD IEC/PAS 62437 on specifications for active antennas is relevant to:
Active antennas used onboard vehicles are electronic components in the sense of CISPR 25. Therefore, the requirements regarding emissions apply to it in its function as EUT. In addition to this, vehicle active antennas are used as part of the measurement chain for the evaluation of emissions produced by any other component in the vehicle. With a passive antenna, no special considerations were necessary because it can neither generate emissions nor harmonics due to its linearity.
DD IEC/PAS 62437 lays out technical specifications for active antennas, as the use of active antennas, is today the state of the art in vehicles. The active antennas were handled like any other component/module used in vehicles. But now it has become essential to verify their performance since they have become a part of the test equipment while performing radiated emission tests, according to CISPR 25.
DD IEC/PAS 62437 gives a test method to determine the measurement of the emissions produced by the active antenna. It describes the knowledge of the noise floor which is strongly required for the assessment of emissions when the active antenna is part of the measurement chain.
Overall, DD IEC/PAS 62437 is useful as it provides guidance on the specifications for active antennas which contributes to checking the radio disturbance characteristics of receivers used on board vehicles, boats, and devices, for protecting the receivers.