Lesson plan
Array factor
In the study of antennas, the array factor is a mathematical function that describes the signal of an antenna array as a combination of the signals of its individual antennas. More precisely, the array factor is multiplied by the radiation pattern of an individual antenna to produce the pattern of the entire array. This difference in the patterns is due to the constructive and destructive interference properties of radio waves. The array factor depends on * the positions of the individual antennas in the array, * the complex weights (amplitudes and phases) being used to combine (or excite) the signals of the antennas, and * the direction of signal arrival (or transmission). When the antenna weights are chosen appropriately, then the array factor has large magnitude for signals in the desired direction(s) and small in the direction(s) that the array operator wants to ignore. This is how the beam of a phased array is steered.
Article summary
In the study of antennas, the array factor is a mathematical function that describes the signal of an antenna array as a combination of the signals of its individual antennas. More precisely, the array factor is multiplied by the radiation pattern of an individual antenna to produce the pattern of the entire array. This difference in the patterns is due to the constructive and destructive interference properties of radio waves. The array factor depends on * the positions of the individual antennas in the array, * the complex weights (amplitudes and phases) being used to combine (or excite) the signals of the antennas, and * the direction of signal arrival (or transmission). When the antenna weights are chosen appropriately, then the array factor has large magnitude for signals in the desired direction(s) and small in the direction(s) that the array operator wants to ignore. This is how the beam of a phased array is steered.
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Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
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Key claims and bibliography are generated from the same tracked claims and sources as the article page.