17.0 GHz Band
Understanding the 17.0 GHz Band
The Ku-Band stretches from 12 GHz to 18 GHz. As you climb toward the top of the band, crossing 17.0 GHz, the physical wavelength shrinks to roughly 1.7 centimeters. At this tiny wavelength, the signals become incredibly focused, but highly susceptible to atmospheric water absorption.
The DBS Feeder Uplink
If you have DirecTV or Dish Network, the satellite in space is beaming the TV shows down to your roof at 12.2 GHz. But how does the satellite get the video in the first place?
The television corporation uses massive 10-meter ground station dishes (Teleports) to blast the live video up to the satellite. To prevent this massive uplink blast from interfering with the delicate signals raining down on residential roofs, the FCC mandates the 17.3 to 17.8 GHz band specifically for these "Feeder Uplinks."
- The 17 GHz wave is highly susceptible to rain fade.
- To guarantee the TV broadcast never goes offline, these corporate ground stations utilize massive Klystron tube amplifiers, actively burning enormous amounts of electricity to brutally force the 17 GHz beam through the heaviest thunderstorms.
Airborne Ground-Mapping Radar
Because the 1.7-centimeter wavelength is so physically small, it provides phenomenal radar resolution. Military aircraft utilize the 17 GHz band for Synthetic Aperture Radar (SAR) to map the ground in high definition. The beam is narrow enough to detect the metallic chassis of individual tanks and missile launchers moving on the ground, even through dense cloud cover where optical cameras are completely blinded.
Key Equations
The 17.0 GHz Band (encompassing 17.3 to 17.8 GHz) sits at the extreme upper boundary of the Ku-Band spectrum, bordering the transition into the K-Band....
Key specifications:
17.0 GHz | 17.8 GHz | 12 GHz | 18 GHz
Power: P(dBm) = 10log(PmW), 0dBm = 1mW
Comparison
| Band | Range | Wavelength | Application | Standard |
|---|---|---|---|---|
| 17.0 GHz Band | 17 GHz region | 17.6 mm | Primary use | ITU allocation |
| Adjacent lower | 15.3 GHz | 19.6 mm | Related band | Shared spectrum |
| Adjacent upper | 18.7 GHz | 16.0 mm | Related band | Guard band |
| Harmonic 2f | 34.0 GHz | 8.8 mm | Spurious | Filter required |
| Sub-harmonic | 8.5 GHz | 35.3 mm | LO option | Mixer design |
Frequently Asked Questions
Can you use 17 GHz for Wi-Fi or Cellular?
No. The 17.0 GHz band is strictly licensed and heavily protected by the government. Blasting omni-directional cellular signals in this band would cause catastrophic interference to the massive satellite teleports attempting to "listen" to space.
What happens at 18.0 GHz?
At 18.0 GHz, the Ku-Band officially ends and the K-Band (Kurtz-Band) begins. The K-Band contains the notorious 22 GHz water vapor absorption spike, meaning signals traveling slightly above 18 GHz begin to face a massive, physical wall of atmospheric attenuation.
Do 17 GHz radars suffer from rain scatter?
Yes. While the 1.7cm wave is excellent for detecting solid metal objects, it is roughly the same physical size as large, heavy raindrops. If a 17 GHz radar hits a severe thunderstorm, the radar screen will 'white out' with massive amounts of chaotic reflection (Rain Clutter), entirely blinding the system to the targets hiding behind the storm.