Flying things in THz communication

Abstract

Our study examines THz channel applications and THz band characteristics. Factors affecting capacity in air-to-ground and air-to-air communication in the THz band, such as antenna power, distance, and environment-dependent absorption loss, have been analyzed. Since the molecular structure of each material varies, some electromagnetic waves pass easily through certain substances at specific frequencies, while others are blocked. The frequency range with minimal absorption for a material is called the transmission window. In our study, absorption coefficients, dependent on the environment and frequency, were obtained using SSRAM (Step-by-Step Radiative Transfer Model). These coefficients illustrate transmission windows. Variations in transmission windows across atmospheric layers with changing material density are explained. It is shown that noise is low in narrow bandwidths, improving the signal-to-noise ratio (SNR). THz waves are sensitive to absorption, and this is emphasized through calculations. Capacities from six weather models, each containing varying material quantities, are evaluated to demonstrate the climatic effect on capacity.

Keywords

• THz bands
• THz absorption coefficients
• Signal-to-Noise Ratio (SNR)

Uçan nesnelerin THz haberleşmesi

Öz

Çalışmamızda THz kanalı uygulamaları ve THz bandı özellikleri incelenmiştir. THz bandında havadan yere, havadan havaya iletişimde kapasiteyi etkileyen, anten gücü, mesafe, ortama bağlı emilim kaybı gibi faktörler incelenmiştir. Her maddenin moleküler yapısı farklı olduğu için madde molekül yapısına bağlı olarak belli frekanstaki elektromanyetik dalgayı (EM) rahat geçirirken bazılarının geçişine izin vermez. Maddeye özgü olarak emilimin az olduğu frekans aralığına iletim penceresi adı verilir. Çalışmamızda pratik sonuçlar veren SSRAM (Satır Satır Radyatif Aktarım Modeli)’den ortama ve frekansa bağlı emilim katsayıları elde edilmiştir. Bu katsayılar kullanılarak iletim pencereleri gösterilmiştir. Madde yoğunluğunun değiştiği atmosfer katmanlarında iletim pencerelerinin de buna bağlı olarak değiştiği ayrıntılı olarak açıklanmıştır. Gürültünün dar bant genişliğinde düşük olduğu ve bunun sinyal gürültü oranını (SGO) yükselttiği gösterilmiştir. THz dalgalarının emilim duyarlı olduğu gösterilmiş buna bağlı hesaplamalarla bu durum vurgulanmıştır. İçerisinde farklı oranda madde bulunan altı farklı hava modelinden elde edilen kapasiteler, kapasitenin iklimsel etkisini göstermesi açısından değerlendirilmiştir.

Anahtar Kelimeler

• THz bantları
• THz emilim katsayısı
• Sinyal Gürültü Oranı

Kaynakça

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