What is the atmospheric attenuation at D-band frequencies and how does it limit link distance?
Atmospheric attenuation at D-band (110-170 GHz) ranges from 0.4 dB/km at 140 GHz in dry conditions to approximately 2-4 dB/km at the water vapor line near 183 GHz. The frequency 140 GHz sits in a favorable propagation window between the oxygen complex near 118 GHz and the strong water vapor line at 183 GHz. Rain adds significantly: moderate rain (10 mm/hr) adds approximately 8-12 dB/km. For 99.99% availability in a moderate rain climate, practical D-band links are limited to approximately 1-3 km.
Atmospheric Propagation Limits for D-Band Communication
Atmospheric attenuation profile across D-band varies significantly due to several absorption mechanisms.
Common Questions
Frequently Asked Questions
Is D-band propagation significantly worse than E-band?
Clear-air attenuation is about 2x higher and rain attenuation is 2-3x higher. D-band links are typically 30-50% shorter than E-band links for the same availability.
Can D-band work in tropical climates?
Yes but at reduced distances. 99.99% availability limits links to 300-800 meters in tropical rain zones.
How does humidity affect D-band propagation?
Going from 20% to 80% relative humidity increases attenuation by approximately 0.5-1.0 dB/km at 140 GHz.
Keep Reading
Related Questions
Glossary