Glossary

Radiowaves Glossary

 
Axial Force:
Force applied to the face of the antenna due to wind at specified wind speed
Beamwidth
The total width of the main beam measured in degrees between the 3-dB (half-power) points on either side of the peak of the main beam
Cross Polarization Discrimination (XPD)
The dB difference between maximum received co-polarized signal at electrical boresight and maximum received cross-polarized signal
Front to Back Ratio (F/B)
The dB difference between maximum received signal at electrical boresight to maximum received signal behind the antenna (180 +/- 40 degrees)
Gain
A measure of how well the antenna focuses available energy into a single beam. Larger antennas typically have higher gains and smaller beamwidths.
Gross Weight
Shipping weight, includes weight of antenna plus packaging materials
Net Weight
Weight of antenna only as mounted on tower.
Operating Frequency Band
The frequency limits between which the antenna meets declared specifications. Antennas may operate outside the frequency band with mild performance degradation.
Return Loss
A measure of how much rf energy incident upon the antenna is reflected back from whence it came, expressed as a negative dB value.
Side Force (FS)
Force applied to the side of the antenna due to wind at specified wind speed
Twisting Moment (MT)
The torsional (twisting) moment (force x distance) applied to the mounting pipe due to wind at the specified wind speed.
VSWR
A measure of how much rf energy incident upon the antenna is reflected back from whence it came, expressed as a ratio
Wind Velocity Operational
Wind speed where the antenna deflection is less than or equal to 0.1 degrees
Wind Velocity Survival Rating
Wind speed where the antenna will not suffer permanent damage, but may require re-pointing.