Overview
IEC 62037-5:2013 - "Passive RF and microwave devices, intermodulation level measurement - Part 5: Measurement of passive intermodulation in filters" - defines recommended test fixtures and procedures for measuring passive intermodulation (PIM) generated by filters used in wireless communication systems. Its purpose is to provide qualification and acceptance test methods for filters intended for low intermodulation (low‑IM) applications.
Key topics and requirements
- Scope of measurement: Procedures for measuring PIM produced by filter assemblies in both transmit-band and receive-band configurations using recommended test schematics.
- Test setups: Example equipment schematics are provided for common scenarios:
- Two high‑power carriers (typical forward and reverse PIM tests).
- Single high‑power carrier with an injected interferer (receive‑band testing).
- N‑port DUT arrangements and receive‑port specific measurements.
- Calibration & procedure: Test set‑ups must be calibrated for carrier levels and IM receiver sensitivity (referenced to IEC 62037‑1:2012 procedures) before inserting the DUT; then measure and report IM performance in the forms referenced by the general part.
- Residual system PIM: The test system residual PIM should be verified (DUT removed) and is recommended to be at least 10 dB below the filter’s PIM requirement to avoid measurement errors.
- Sources of error: Guidance on common measurement pitfalls, such as:
- Back‑to‑back filters (diplexers) causing poor harmonic matching and standing waves that can re‑excite PIM sources and skew results.
- Electrical length sensitivity - standing wave patterns can change measured IM depending on DUT length.
- Environmental/dynamic testing: Thermal or vibrational stress testing while measuring PIM is not generally recommended because of repeatability and system isolation challenges; limited non‑destructive dynamic checks (e.g., light tapping) are suggested instead.
Applications and users
Who benefits from IEC 62037‑5:
- RF/microwave test engineers and labs performing qualification and acceptance testing of filters for base stations, repeaters and other wireless infrastructure.
- Design and manufacturing teams ensuring low PIM performance in filters for cellular, public safety, and broadcast systems.
- Test equipment vendors and calibration houses implementing compliant PIM measurement setups.
Practical uses:
- Establishing repeatable PIM test procedures for production acceptance.
- Selecting appropriate test fixtures and verifying system residual PIM before device evaluation.
- Comparing forward, reverse and receive‑port PIM behaviors of filter designs.
Related standards
- IEC 62037‑1:2012 - Passive r.f. and microwave devices, intermodulation level measurement - Part 1: General requirements and measuring methods (normative reference).
- Other parts of the IEC 62037 series covering PIM measurement for different passive components.
Open preview (PDF)Passive RF and microwave devices, intermodulation level measurement - Part 5: Measurement of passive intermodulation in filters
