IEC 62037-8:2025

Overview

IEC 62037-8:2025 defines a standardized radiated passive intermodulation (PIM) test to measure passive intermodulation generated by any material or object when exposed to RF radiation. Applicable to near‑field or far‑field conditions, the test can be carried out in an outdoor test site or in an anechoic test chamber. This second edition (2025) is a technical revision of the 2022 edition and includes safety and reporting clarifications.

Key topics and technical requirements

• Test purpose: Determine PIM levels generated by a device under test (DUT) or surrounding objects illuminated by RF energy (radiated PIM).
• Test environments: Outdoor ranges (subject to regulatory RF limits) or low‑PIM anechoic chambers to reduce external interference and spurious PIM sources.
• Test configurations: Single‑antenna single‑band, dual‑antenna dual‑band, and dual‑antenna single‑band setups are specified to address different measurement needs.
• Antenna requirements:
  • Antennas should be directional panel or horn types.
  • Directivity requirement: ≈10.25 dBi ± 3.0 dBi at the transmit and IM product test frequencies. Directivity is calculated from the half‑power azimuth and elevation beamwidths per the standard’s formula (Dir = 41253 / (BW_az × BW_el)).
  • Antenna VSWR in the test environment (excluding DUT/support) shall be < 1.92:1 (10 dB return loss) at the test frequencies.
  • Linear polarization; Tx and Rx must be co‑polarized when separate antennas are used.
• Test system best practices:
  • Use low‑PIM components, minimize cable/waveguide lengths, and provide sufficient Tx/Rx isolation to prevent active intermodulation (AIM) inside the measurement system.
  • Perform residual PIM and VSWR verification prior to DUT measurements.
• Safety and reporting:
  • New safety warning: verify transmitters are switched off before connecting or disconnecting components.
  • Test reports must include maximum PIM and VSWR values.

Practical applications and users

• Useful for RF engineers, test labs, product developers, and installers assessing PIM risk from:
  • Infrastructure components, mounting hardware, signage, or unexpected metallic objects near antennas.
  • Passive materials or enclosures not intended for RF propagation but exposed to RF fields.
• Applies to acceptance testing, site surveys, product qualification, and troubleshooting of PIM sources affecting wireless networks (cellular, microwave links, etc.).

Related standards

• IEC 62037-1 - General requirements and measuring methods for PIM.
• IEC 62037-6:2021 - Guidance for PIM measurement in antennas (anechoic chamber construction and test considerations).

Keywords: IEC 62037-8:2025, radiated PIM, passive intermodulation, PIM test, anechoic chamber, near field, far field, DUT, VSWR, antenna directivity.