Spurious Emission: Causes, Effects and Prevention

Spurious emission, also known as out-of-band emission, refers to any radio frequency emission that is outside of the frequency range of the intended signal. These emissions can cause interference with other radio signals and devices, leading to poor performance and even equipment failure. In this article, we will discuss the causes, effects, and prevention of spurious emission.

Causes of Spurious Emission

Spurious emission can be caused by a variety of factors, including poor design, faulty components, and inadequate shielding. One of the most common causes of spurious emission is harmonics, which occur when the frequency of the signal is a multiple of the intended frequency. Other causes include intermodulation distortion, cross-modulation, and frequency mixing.

Effects of Spurious Emission

The effects of spurious emission can be significant, particularly in sensitive radio applications such as aviation and military communication. Interference from spurious emissions can cause signal degradation, reduced range, and even complete loss of communication. In addition, spurious emissions can interfere with other electronic devices, such as computers and medical equipment, leading to malfunctions and potential safety hazards.

Prevention of Spurious Emission

Preventing spurious emission requires careful design and testing of radio equipment. This includes using high-quality components, proper shielding, and effective filtering to eliminate unwanted frequencies. In addition, regular maintenance and calibration of equipment can help prevent spurious emissions from occurring.

Regulatory Requirements for Spurious Emission

Many countries have regulations in place to limit the amount of spurious emission that can be emitted by radio equipment. These regulations typically specify maximum emission levels for different frequency ranges and require equipment to be tested and certified before it can be sold or used.

Measurement and Testing of Spurious Emission

Measuring and testing spurious emission requires specialized equipment and expertise. This typically involves using spectrum analyzers and other test equipment to measure the frequency and amplitude of emissions at different frequencies. Testing must be performed in a controlled environment to ensure accurate results.

Conclusion

Spurious emission can have significant effects on radio communication and electronic devices. Preventing spurious emission requires careful design, testing, and maintenance of radio equipment. Regulatory requirements and testing procedures can help ensure that equipment meets acceptable emission levels and does not cause interference with other devices. By understanding the causes and effects of spurious emission, engineers and technicians can work to minimize its impact and improve the performance and reliability of radio communication systems.