Background Technology

W band and V band are proposed nowadays as a valuable alternative to Ku and Ka bands for high-speed transmission over satellite networks. The W band has range from 75 to 110 GHz. It has higher frequency than the V band (50–75 GHz), and overlaps the NATO designated M band (60–100 GHz). The W/V band can be used for satellite communications, millimeter-wave radar research, military radar targeting and tracking applications, and some non-military applications. Because of increasing spectrum and orbit congestion at lower frequencies, W/V band satellite allocations are of increasing interest to commercial satellite operators [2].
The higher operating frequency has some advantages respect to traditional ranges (Ka, Ku and lower). It has no crowding in frequency and hence reduced interference, large bandwidth availability, reduced antenna and electronic components size, and more security in point-to-point links due to smaller beamwidth [1]. W/V band offers high data rate throughput when used at high altitudes and in space.
In the last years an increasing interest for such a range has been demonstrated in some fields due to its advantageous intrinsic characteristics such as higher bandwidth availability, minimum oxygen attenuation around 95 GHz, reduced interference and smaller dimensions of antennas [1]. Actually, the transmitted signal is more affected as frequency increases (above 10 GHz) by atmosphere (absorption) and by weather conditions (rain, clouds, fog, snow, etc.).
These effects do not only depend on frequency, but also on location, path elevation angle, and season (time). It is not possible to make observations at every locations, the region of interest can be divided into several rain or atmospheric climate zones. A climate zone is an area on the ground that has certain statistical attribute. For example, Global rain patterns characterized over many years.  Figure 2 shows the ITU rain data for North America.

The atmosphere and weather effects are:
• Gaseous Attenuation – When radio waves pass through the troposphere, they undergo interactions with the gas molecules that are present in the atmosphere. Each gas molecule interacts with the radio wave, the interaction may or may not cause loss of energy and hence attenuation. The total, dry air and water-vapour zenith attenuation from sea level are shown in Figure 1. In W/V band, the loss is around 0.8 dB.


Figure 1. Total, Dry Air and Water-vapour Zenith Attenuation from Sea Level with Surface pressure: 1013 hPa, Surface temperature: 15° C, and Surface water-vapour density: 7.5 g/m3

• Cloud Attenuation – Attenuation due to cloud depends on cloud thickness and frequency. At W/V-bands, it can contribute more than 10 dB loss for total path attenuation, which is much more significant than observed at typical Ka-band frequencies [4].
• Rain Attenuation – Rain attenuation is a key limiting factor in the introduction of higher frequency bands into satellite systems. The estimation can be done by looking at Figure 2 and Figure 3. The rain statistics is shown in Figure 2. The loss/km can be found by rain level and frequency in Figure 3.

Figure 2. ITU rain statistics for North America [6].

Figure 3. Rain attenuation at microwave and millimeter-wave frequencies [6]

• Wet or Snow-Covered Antenna – Condensation and snow on the antenna cause signal losses. These losses can be as large as several dB [4].

[1] M. Lucente, “Analysis and Design of a Point-to-Point Radio-Link at W Band for Future Satellite Telecommunication Experiments” IEEEAC paper #1345, Version 6, Updated January 11, 2011
[2] W band. (2012, August 24). Retrieved from
[3] R.K. Crane, "Propagation phenomena affecting satellite communication systems operating in the centimeter and millimeter wavelength bands," Proceedings of the IEEE, vol.59, no.2, pp. 173-188, Feb. 1971
[4] R. Acosta, “W/V-Band RF Propagation Experiment Design”, Glenn Research Center, September 24, 2012
[5] R. Acosta, S. Johnson, and L. Blackman, "Ka-Band Wideband Dispersion Technology Verification Experiment," 6th Ka-Band Utilization Conference, Cleveland, Ohio, May 31, 2000.
[6] E-band technology. (2012). Retrieved from