A+ 광통신 1주차 과제 - 1. 주파수 대역

문서 내 토픽

1. ELF(Extremely low frequency)

ELF(Extremely low frequency) 주파수는 3~30Hz의 범위로, 지구 자기장의 번개와 자연적 교란에 의해 생성됩니다. 이러한 장파는 안테나 구축이 어려워 소수의 인공 통신 시스템에서만 사용되었습니다. ELF 파는 큰 장애물을 회절할 수 있고 지구 곡선을 따라 전파될 수 있어 잠수함 통신과 파이프라인 유지관리에 사용됩니다. 그러나 ELF 주파수 방송은 안테나 길이 문제로 어려움이 있습니다.
2. VF(Voice frequency)

음성 주파수(VF) 또는 음성 대역은 오디오 범위의 일부로, 전화에서 사용 가능한 주파수 대역은 약 300~3400Hz입니다. 이 대역은 베이스밴드에서의 음향에너지를 나타내는 전자기에너지로, 디지털 PSTN에 사용되는 펄스 코드 변조 시스템의 기초가 됩니다.
3. VLF(Very Low Frequency)

VLF 주파수는 3~30kHz, 파장은 100~10km로 초장파입니다. VLF 전파는 큰 장애물을 회절할 수 있고 지구의 곡률에 따라 전파될 수 있어 대양의 선박 위치 파악을 위한 오메가 항법에 사용됩니다. 또한 잠수함 통신, 지구 물리학 연구, 광산 통신 등에 활용됩니다.
4. LF(low frequency)

LF 주파수는 30~300kHz, 파장은 10~1km로 긴 편입니다. LF 전파는 신호 감쇠가 적어 장거리 통신에 적합하며, 유럽과 북아프리카 및 아시아 지역에서 AM 방송에 '장파' 대역으로 사용됩니다. 서반구에서는 항공기 비콘, 내비게이션, 정보 및 기상 시스템에 사용됩니다. LF 안테나는 전기적으로 짧아 복사 저항이 낮아 송신기 전력 소실이 적습니다.
5. MF(medium frequency)

MF 주파수는 300~3,000kHz, 파장은 1,000~100m의 중간 범위입니다. MF 전파는 지면 파와 전리층 반사를 통해 전파되며, 주로 AM 라디오 방송에 사용됩니다. 또한 해상 음성 통신, 국제 조난 주파수, 아마추어 라디오 등에도 활용됩니다.
6. HF(high frequency)

HF 주파수는 3~30MHz, 파장은 100~10m로 짧습니다. HF 전파는 전리층에서 반사되어 장거리로 전송될 수 있어 군사 및 정부 통신, 항공 대지 통신, 아마추어 라디오, 단파 국제 및 지역 방송, 해상 통신 등에 사용됩니다.
7. VHF(very high frequency)

VHF 주파수는 30~300MHz, 파장은 10~1m로 짧습니다. VHF 전파는 주로 가시선 및 ground-bounce 경로를 통해 전파되며, 항공기와 선박 통신, 양방향 육상 이동 무선 시스템 등에 활용됩니다.
8. UHF(ultra high frequency)

UHF 주파수는 300~3,000MHz, 파장은 1~0.1m입니다. UHF 전파는 거의 전적으로 LOS(line-of-sight) 및 지면 반사를 통해 이동하며, 이동무선, 지상파 TV 방송, 통신회선, 항공무선항행 등에 사용됩니다.
9. SHF(super high frequency)

SHF 주파수는 3~30GHz, 파장은 10~1cm입니다. SHF 전파는 가시선으로만 전파되며, 전화중계, TV 프로그램 송수신, 레이더, 위성통신 등에 사용됩니다. 높은 주파수와 낮은 대기 감쇠로 인해 레이더에 주로 사용됩니다.
10. EHF(extreme high frequency)

EHF 주파수는 30~300GHz, 파장은 10~1mm로 밀리미터파입니다. EHF 전파는 시야 경로로만 전파되며, 대기 가스 흡수와 강수에 의한 감쇠가 크지만 주파수 재사용이 가능해 개인 영역 네트워크에 유용합니다. 또한 보안 검색을 위한 밀리미터파 스캐너에 사용됩니다.

Easy AI와 토픽 톺아보기

1. VF (Voice Frequency)

VF (Voice Frequency) refers to the frequency range used for human speech and audio communication, typically between 300 Hz and 3,400 Hz. This frequency range is essential for the transmission of clear and intelligible speech, as it encompasses the fundamental frequencies and harmonics of the human voice. The VF range is widely used in various communication technologies, such as telephone systems, radio broadcasting, and voice over IP (VoIP) applications. Maintaining the integrity of the VF range is crucial for ensuring high-quality audio communication, as it allows for the accurate reproduction of the nuances and tones of the human voice. Additionally, the VF range is an important consideration in the design and development of audio equipment, such as microphones, speakers, and audio codecs, to ensure optimal performance and fidelity. Overall, the VF range is a fundamental aspect of audio communication and plays a vital role in our daily lives.
2. LF (Low Frequency)

LF (Low Frequency) refers to the electromagnetic spectrum range between 30 kHz and 300 kHz. This frequency range has several unique properties and applications. LF waves are capable of penetrating deep into the Earth's crust and the ocean, making them useful for communication with submerged submarines and other underwater applications. Additionally, LF waves can be used for long-distance communication, as they are able to propagate over vast distances with relatively low attenuation. This makes LF communication systems valuable for military and emergency communication networks, particularly in remote or isolated regions. However, the use of LF waves also has some limitations, such as the need for large antenna structures and the potential for interference from natural and man-made sources. Overall, LF is an important frequency range with significant practical applications, particularly in the fields of military and maritime communication.
3. HF (High Frequency)

HF (High Frequency) refers to the electromagnetic spectrum range between 3 MHz and 30 MHz. This frequency range is particularly useful for long-distance communication, as HF waves can propagate over vast distances by bouncing off the ionosphere, a layer of the Earth's atmosphere. HF communication is widely used in various applications, such as amateur radio, maritime communication, and military communication. The ability of HF waves to travel long distances and penetrate obstacles makes them valuable for communication in remote or isolated regions, where other communication methods may be limited. However, HF communication is also subject to various challenges, such as interference from solar activity, atmospheric conditions, and man-made sources. Despite these challenges, HF remains an essential frequency range for long-distance communication, particularly in situations where other communication methods are not feasible or reliable. The continued use of HF in various industries and applications underscores its importance in the field of telecommunications.
4. UHF (Ultra High Frequency)

UHF (Ultra High Frequency) refers to the electromagnetic spectrum range between 300 MHz and 3 GHz. This frequency range is widely used for various communication applications, including television broadcasting, mobile phones, and wireless data transmission. UHF waves have several advantages over lower frequency ranges, such as the ability to carry more information and the use of smaller antenna structures. This makes UHF an ideal choice for applications that require high-speed data transfer and compact equipment. Additionally, UHF waves are less affected by obstacles and interference compared to lower frequency ranges, allowing for more reliable communication in urban and indoor environments. The widespread adoption of UHF-based technologies, such as cellular networks and Wi-Fi, has been a driving force in the growth of modern communication systems. As the demand for high-speed and reliable communication continues to increase, the importance of the UHF frequency range will only continue to grow in the years to come.
5. EHF (Extreme High Frequency)

EHF (Extreme High Frequency) refers to the electromagnetic spectrum range between 30 GHz and 300 GHz. This frequency range is the highest of the commonly used radio frequency bands and has several unique properties and applications. EHF waves have very short wavelengths, which allows for the use of small and highly directional antennas. This makes EHF well-suited for applications that require high-speed data transmission, such as satellite communication, radar systems, and some types of wireless data networks. Additionally, EHF waves can be used for high-resolution imaging and sensing applications, as their short wavelengths allow for the detection of small objects and features. However, EHF waves are also highly susceptible to atmospheric absorption and interference, which can limit their range and reliability in certain environments. Despite these challenges, the unique properties of EHF waves make them an important and growing area of research and development in the field of telecommunications and sensing technologies. As the demand for high-speed and high-resolution communication and sensing continues to increase, the importance of the EHF frequency range is likely to grow in the coming years.