Null fill in radio engineering is used in radio

antenna Antenna ( antennas or antennae) may refer to: Science and engineering * Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves * Antennae Galaxies, the name of two collid ...

systems which are located on mountains or tall towers, to prevent too much of the signal from overshooting the nearest part of intended coverage area. Phasing is used between antenna elements to take power away from the main lobe and electrically direct more of it at a more downward angle in the vertical plane. This requires a

phased array In antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving th ...

. Changing the relative power supplied to each element also changes the radiation pattern in this manner, and often both methods are used in combination.

References

* "Analysis of Antenna Null-fill and Broadcast Coverage." Myron D. Fanton. ''ERI Technical Series'', vol. 6, April 200

* "The Tide is Turning." Charles Rhodes

* "A Study on Null-Fill Array Antenna for Service Coverage Expansion in PCS Band" Youngseok Ko

References

See also