What Are the Compliance Certifications for VHF Products?

VHF stands for Very High Frequency, referring to radio waves with a frequency range between 30 MHz and 300 MHz. A detailed explanation of VHF is provided below:

Key Characteristics

1. Propagation Mode

①　Primarily line-of-sight propagation, with signals transmitted in a straight line, typically covering a range of several dozen to over a hundred kilometers.

②　Susceptible to obstruction by terrain (e.g., mountains, buildings), yet possesses slightly stronger diffraction capability than UHF (Ultra High Frequency).

③　Does not rely on ionospheric reflection, resulting in high signal stability, although long-distance transmission requires support from relay stations.

2. Application Fields

①　Aviation Communication: Voice communication between aircraft and air traffic control towers (utilizing AM modulation).

②　Maritime Communication: Ship-to-ship communication and distress calls (e.g., International Maritime Channel 16).

③　FM Broadcasting: Operating within the frequency range of 88–108 MHz.

④　Television Broadcasting: Selected traditional television channels (e.g., low VHF band channels 2–6, high VHF band channels 7–13).

⑤　Public Safety: Emergency communication for police, fire departments, and other relevant services.

⑥　Amateur Radio: Commonly used frequency bands for walkie-talkies among radio enthusiasts.

3. Advantages and Limitations

①　Advantages: Stable signal, strong anti-interference performance, suitable for scenarios requiring high reliability.

②　Limitations: Relatively short coverage distance, vulnerable to the impact of obstacles.

Comparison with Other Frequency Bands

①　HF (High Frequency, 3–30 MHz): Capable of global communication via ionospheric reflection, but susceptible to interference from weather conditions and solar activity.

②　UHF (Ultra High Frequency, 300 MHz–3 GHz): Features stronger penetration, making it suitable for urban environments, and is widely applied in mobile phones, Wi-Fi, and digital television.

Typical Application Examples

①　Aviation: The 118–137 MHz frequency band is used for communication between air traffic control towers and pilots.

②　Maritime: VHF Channel 16 (156.8 MHz) serves as the international distress calling channel.

③　FM Radio: FM broadcasting is concentrated within the 88–108 MHz frequency range.

Certification Requirements for VHF Products

It is recommended to plan the certification route in advance according to the target market, and cooperate with JJR professional laboratories or certification agencies to ensure efficient compliance.