close
Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA)
俄國貨運船飄出「異味」 太空人關閉俄羅斯太空站模組
美國太空總署NASA週日表示，國際太空站上的俄羅斯太空人發現，從俄羅斯的「進步 90」(Progress 90 )的貨運船發出「不尋常怪味」，只能暫時封鎖了軌道實驗室的俄羅斯模組區。
CNN報導，美國太空總署的聲明表示，據俄羅斯太空人所說，怪味道可能與他們觀察到的「水滴」有關，或許是「俄羅斯進步號太空船內部材料釋放的氣體」。
美國太空總署擔任通訊的休士頓詹森中心新聞主管漢福萊斯 (Kelly O. Humphries) 表示「太空人不用太擔心。」
本文出自: https://www.chinatimes.com/realtimenews/20241126003710-260408
The Log Periodic Antenna as known as LPDA is a wideband directional antenna that provides gain and directivity combined over a wide band of frequencies.
Both Log-Periodic Antennas and Yagi antennas are high gain directional antennas. The main difference between these antennas is that Log-Periodic Antennas support wider frequency bandwidths and are physically much larger than Yagi antennas.
The log-periodic dipole array typical VSWR is 2:1 and operates over a much wider bandwidth and will have a lower gain for an equivalent number of elements.
With this level of performance, it is ideal for many applications, although a log-periodic antenna will be much larger than a Yagi of an equivalent gain.
Horn Antenna
文章標籤
全站熱搜
留言列表
