43.0 GHz Band
Understanding the 43.0 GHz Band
The 43.0 GHz Band operates entirely within the lower V-Band. Like its neighboring 42 GHz band, it is characterized by massive available bandwidth and brutal environmental physics.
The Atmospheric Wall
As you push higher into the millimeter-wave spectrum, the Earth's atmosphere becomes increasingly hostile to radio waves. The 43 GHz band sits dangerously close to the infamous "60 GHz Oxygen Absorption Peak."
- Even on a perfectly clear, sunny day, the physical oxygen molecules in the air absorb the 43 GHz radio wave.
- If a heavy rainstorm rolls in, the liquid raindrops violently scatter the microscopic 6.9mm wave.
- To guarantee "Five Nines" (99.999%) reliability (meaning the network only drops for 5 minutes a year), a 43 GHz link must be incredibly short. A telecom operator will not typically design a 43 GHz link longer than 1.5 to 2.5 miles.
Urban Backhaul Deployments
Despite the range limitations, 43 GHz is highly valued in dense urban environments.
If an enterprise requires a 2 Gigabit connection between two skyscrapers, running a fiber-optic cable under the streets of Manhattan is impossible. An engineer simply mounts a 1-foot 43 GHz parabolic dish on each roof. Because the beam is so incredibly narrow (less than 1 degree wide), it cuts perfectly through the cluttered urban skyline without causing any interference to other microwave links operating on nearby buildings.
Key Equations
The 43.0 GHz Band (encompassing the 42.5 to 43.5 GHz spectrum block) is a specialized segment of the millimeter-wave V-Band allocated primarily for aeronautical radionavigation,...
Key specifications:
43.0 GHz | 43.5 GHz | 2 m | 42 GHz
Power: P(dBm) = 10log(PmW), 0dBm = 1mW
Comparison
| Band | Range | Wavelength | Application | Standard |
|---|---|---|---|---|
| 43.0 GHz Band | 43 GHz region | 7.0 mm | Primary use | ITU allocation |
| Adjacent lower | 38.7 GHz | 7.8 mm | Related band | Shared spectrum |
| Adjacent upper | 47.3 GHz | 6.3 mm | Related band | Guard band |
| Harmonic 2f | 86.0 GHz | 3.5 mm | Spurious | Filter required |
| Sub-harmonic | 21.5 GHz | 14.0 mm | LO option | Mixer design |
Frequently Asked Questions
How does Radio Astronomy use the 43 GHz band?
Astronomers use massive dish arrays (like the Very Long Baseline Array) to listen to the specific 43 GHz frequency to study the formation of massive stars and the emission of Silicon Monoxide (SiO) masers occurring naturally in deep space. Because these cosmic signals are incredibly faint, the ITU heavily protects specific blocks of the 43 GHz band from commercial interference.
What is Aeronautical Radionavigation?
It is the use of radio waves to safely navigate aircraft. Certain segments of the 43 GHz band are allocated for experimental and military radar systems capable of scanning runways or detecting microscopic debris on the tarmac, utilizing the massive resolution provided by the tiny 6.9mm wavelength.
Is 43 GHz related to WiGig?
No. WiGig (802.11ad/ay) is an indoor Wi-Fi technology that operates much higher in the spectrum, specifically in the unlicensed 60 GHz V-Band. The 43 GHz band is strictly licensed, meaning a telecom company must formally register the specific GPS coordinates of their microwave dishes with the government to legally operate.