How Is Radio Communication Used In Aviation?

Radio communication is intrinsic to air traffic control (ATC) within the aviation sector. When operating an aircraft several miles above sea level, having an effective communication channel between pilots onboard other airplanes and aviation personnel on the ground is paramount to avoid collisions. However, before the advent of radio communication, pilots and controllers used to depend on flags and other outdated signals to transmit messages until rudimentary radio communication systems emerged. Now, modern aircraft rely on far more advanced communication systems such as satellite and radio transmitters, enabling more effective flight operations and exchange of information.

The History of Radio Communication in Aviation

The US passed the “Air Commerce Act” in 1926 which enabled the Department of Commerce to devise rules for streamlining air traffic through the coordination of their protection, marking, and navigation. Though this act worked well initially, the rise in volume of air traffic created the need for inventing a better management system. This led to an increase of aircraft control towers equipped with rudimentary radio control set-ups which were exemplified by the establishment of the Cleveland Municipal Airport tower in 1930. Subsequently, by 1932, almost all aircraft towers across the United States had been equipped with radio-telecommunication systems, while nearly 20 operated on radio waves alone.

The Backbone of Radio Communication - Radio Waves

Radio waves are a constituent of the invisible electromagnetic spectrum, where they fall within a specific range of frequency and wavelength characteristic. When it comes to modern radio communication, many radio frequencies, such as those ranging between 100 kHz to 10 GHz, are used. The Federal Communications Commission (FCC) is entrusted with allocating portions of the radio frequency spectrum to different entities for commercial purposes.

Radio waves can be manually generated by placing an AC source in the center of an antenna, wherein the wavelength is generally half the wavelength of the input AC signal. As the current flowing through the source fluctuates, a corresponding magnetic and electric field is also established around the antenna. Eventually, a manually generated radio wave emerges which can be outsourced to space at an upwards of 186,000 miles per second. This process continues as long as the AC source generates the input signal.

Types of Radio Waves

James Clerk Maxwell is credited with predicting radio waves’ existence, which proved to be the backbone of communication in aviation. As previously discussed, radio waves are separated into different categories depending on their differences in frequency and wavelength. Radio waves constitute a small portion of the electromagnetic spectrum, but they feature the longest wavelengths that range from 1 mm to 100 km, and the lowest frequencies, between 3000 Hz to 300 billion Hz. The National Telecommunications and Information Administration has categorized radio waves into the following bands:

The aviation sector uses both low frequency and medium frequency radio bands, alongside more commercially available amplitude modulation (AM) radio waves.

Devices Aiding Radio Communication: Transmitters and Receivers

Both transmitters and receivers are electronic devices used for the successful transmission of information-carrying signals through space by manipulating electricity. Their detailed definition is as follows:

Transmitters: Modern transmitters are devices used to transmit electronic signals from one place to another; they allow signals to be sufficiently bolstered to prevent their loss of strength while effectively covering their distance of transmission. A typical transmitter consists of an oscillator that generates an AC carrier wave and an amplifier for the amplification of the input wave. They may also contain additional circuits for processing input signals for their effective loading onto carrier waves. Based on their design specifications, transmitters are further categorized into AM, FM, and SSB transmitters, where each can work with low or high power inputs.

Receivers: Like transmitters, receivers use antennas to decode signals they receive while using amplifiers to generate a desired output. Depending on the architectural specifications of such devices, receivers can be further categorized into AM, FM, or SSB receivers. 

How Is Information Loaded Onto Radio Waves 

The generation of a radio wave alone is insufficient as a resource unless it is equipped with some transmissible information. This activity usually depends on the carrier wave being either altered or modulated by an information signal. This modulated signal then gets transmitted from a transmitting station to a receiving station with the help of their antennas. Moreover, while conducting such operations, radio modulation can cause the development of sidebands. Two standard methods of radio wave modulation are:

Frequency Modulation

Frequency modulation involves the alteration of the frequency of carrier waves and is considered the optimal form of wave alteration. The degree of carrier wave alteration occurs in tandem with the strength of the signal wave, wherein the amplitude remains constant, but the frequency is slightly altered. The observable changes in frequency are recorded as varied crests and troughs by an oscilloscope.

Amplitude Modulation

Like in the case of frequency modulation, amplitude modulation can be achieved to carry useful information. Here, an AC carrier wave signal can be modified by a DC wave generated from a DC source, such as a microphone. With the amplification of a fluctuating DC signal, the output signal also gets amplified, allowing the oscillator bearing the carrier wave to amplify the output proportionally.

In Conclusion

To ensure an aircraft's safety at all times, pilots cannot afford to compromise any form of radio communication. Therefore, only top-quality radio communication components should be sourced from reliable suppliers such as Aviation Parts Distributor. Through our extensive supply chain network and in collaboration with the best manufacturers in the aviation industry, we offer expedited shipping services on select in-stock items, complete with 24/7x365 customer service assistance. Get started on your parts procurement journey with us and receive a quote for your comparisons within 15 minutes or less, today!

1. sandra diaz
2. Posted on May 9, 2022
aviation

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