Null fill

Null fillinradio engineeringis used inradioantennasystems which are located onmountainsor talltowers,to prevent too much of thesignalfrom overshooting the nearest part of intended coverage area.Phasingis used between antenna elements to takepoweraway from themain lobeand electrically direct more of it at a more downward angle in thevertical plane.This requires aphased array.Changing the relative power supplied to each element also changes theradiation patternin this manner, and often both methods are used in combination.

See also

• Null (radio)
• Beam tilt

References

• "Analysis of Antenna Null-fill and Broadcast Coverage." Myron D. Fanton.ERI Technical Series,vol. 6, April 2006.[1]
• "The Tide is Turning." Charles Rhodes.[2]
• "A Study on Null-Fill Array Antenna for Service Coverage Expansion in PCS Band" Youngseok Ko