Professional ITU-R SM.1056 Spurious Emission Standards

International Telecommunication Union Radiocommunication Sector recommendation for spurious emission limits in radio frequency devices, including automotive and motorcycle key systems, transmitter specifications, and compliance requirements. Access comprehensive professional guidance for implementing industry-standard spurious emission compliance with advanced RF engineering excellence and regulatory conformance.

Standard Overview

Publication Date

2007 (Latest Revision)

Status

ITU-R Recommendation

Application

Spurious Emission Limits

Scope

Radio Frequency Devices

Spurious Emission Specifications

Frequency Range

9 kHz to 400 GHz

Comprehensive coverage for all radio frequency devices

Emission Limits

-36 dBm to -13 dBm

Varies by frequency band and transmitter power

Measurement Bandwidth

100 Hz to 1 MHz

Frequency-dependent measurement parameters

Automotive Applications

315/433/868/915 MHz

Key fob and immobilizer system frequencies

Protection Criteria

Interference Prevention

Safeguarding radio services from harmful interference

Test Methods

ITU-R SM.329

Standardized measurement procedures and equipment

Implementation Features

Filtering Requirements

Implementation of appropriate filtering techniques to suppress spurious emissions in transmitter designs.

  • Low-pass filters for harmonic suppression
  • Band-pass filters for out-of-band rejection
  • Cavity filters for high-power applications
  • Surface acoustic wave (SAW) filters

Design Considerations

Critical design elements for achieving compliance with spurious emission limits in RF devices.

  • Proper PCB layout and grounding techniques
  • Shielding of sensitive circuits
  • Component selection and placement
  • Power supply filtering and decoupling

Measurement Procedures

Standardized testing methods for verifying compliance with ITU-R SM.1056 requirements.

  • Spectrum analyzer configuration
  • Antenna factor corrections
  • Cable loss compensation
  • Environmental test conditions

Frequently Asked Questions

What is ITU-R SM.1056?

ITU-R SM.1056 is an International Telecommunication Union Radiocommunication Sector recommendation that specifies spurious emission limits for radio frequency devices, including automotive and motorcycle key systems. This standard complements ITU-R SM.329 measurement procedures and follows IEC 60068-2-6 environmental testing protocols for optimal RF performance and regulatory compliance.

What are spurious emissions?

Spurious emissions are unwanted radio frequency signals generated by transmitters outside their intended frequency band, which can cause interference to other radio services and must be limited according to ITU-R SM.1056 standards per FCC Part 15 regulations and ETSI EN 300 220 harmonized standards.

How does ITU-R SM.1056 apply to motorcycle key systems?

ITU-R SM.1056 applies to motorcycle key systems by setting limits on spurious emissions from key fob transmitters, immobilizer systems, and other RF devices to prevent interference with other radio services following SAE J2534 programming standards and ISO 14229 UDS protocols.

What are the key compliance requirements?

Key compliance requirements include measuring spurious emissions according to ITU-R SM.329 specified methods, ensuring emissions stay within defined limits per frequency band, and implementing proper filtering and shielding in RF transmitter designs according to CISPR 25 automotive EMC standards and IEC 61000-4-3 immunity testing requirements.