Deflection criteria for microwave antenna support structures

The dynamic behavior of microwave towers and the consequent loss of signal are analyzed using the statistical methods of modern wind engineering. These signal losses are then compared with those allowed for radio paths according to CCIR recommendations for analogue systems, and it is found that the extreme 0.01-percent duration criterion is most likely to be exceeded due to deflections. Significant losses of signal under the 0.01-percent criterion are confined to major storms above a certain threshold. It is pointed out that further work is needed to establish deflection criteria appropriate to digital systems.