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W-band and propagation high up there - RF Cafe Forums

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Post subject: W-band and propagation high up there
Posted: Mon May 15, 2006 2:49 pm

Joined: Mon Sep 12, 2005 4:02 pm
Posts: 3
Location: Washington DC
Hi Folks,
I'm interested in O2/H2O/N2 absorption on W-band. Will atmospherics/water vapor knock out any communications with less than 1 watt amps? Think high-up -- above the water-barrier (say 50 Km altitude)
What is a pratical range for a 100 Gigs channel at this altiude (say 50 MHz BW)?
:?: 100 meters?,
:?: 1-10 Km?
:?: 1 AU?

Post subject: W Band Propagation
Posted: Tue May 23, 2006 7:44 am
User avatar

Joined: Fri Feb 17, 2006 12:07 pm
Posts: 218
Location: London UK
Sorry for long delay reply
The attenuation parameter which is the most important at 100GHz is the first oxygen line. The rate of attenuation is about 0.8 dB per kilometer according to data I have.
The max CW Tx power obtainable for commercial devices is about 50milliwatts.
The likely receiver sensitivity is about -67dBm for that bandwidth at 100GHz.
Antenna gain of course depends on size, and that depends on the platform geometry you have in mind.
Plug those figures into a one-way microwave path analysis programme and you have the answer.

Posted  11/12/2012