Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
來自: https://www.chinatimes.com/realtimenews/20240709004846-260408
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.
秘魯5000年前祭祀神廟出土 含活祭遺骸
考古學家在秘魯發掘出一座五千年歷史的祭祀用神廟及人類骨骸。這座神廟位於秘魯西北部蘭巴耶克省(Lambayeque)的薩納區(Zaña)區,根據秘魯文化部的新聞聲明,這個遺跡也屬於洛斯帕雷多內斯-拉斯阿尼馬斯考古遺址(Los Paredones de la Otra Banda-Las Ánimas)的一部分。
由秘魯蘭巴耶克文化部(DDC)主導了本次烏庫佩文化(Úcupe)第一階段考古進展,今年6月初展開的挖掘工作中,研究人員發現了多層神廟的遺跡,並在牆壁之間發現了3具成人遺骸。這些墓葬中包含包裹在布料中的祭品,證明這裡可能曾是祭祀儀式的場所。
烏庫佩文化考古計畫主任穆羅・伊諾南(Luis Armando Muro Ynoñán)指出:「我們可能發現一個五千年歷史的宗教遺址,考古區域由泥土建造的牆壁界定,」 、「我們發現了可能是一個中央階梯,從這裡可以通往中央的舞台。」
聲明中還談到,這些牆壁裝飾著複雜的浮雕,描繪了鳥頭人身、貓科動物特徵和爬行動物爪子的圖像。牆壁的上部覆有「帶有圖案設計的細膩灰泥」。
研究人員還發掘出另一座比較新的紀念碑遺跡,可追溯至公元600年至700年之間,這段時期屬於秘魯的莫切文化(Moche)時期。莫切人會進行人類活祭,並以大型神廟和精美藝術作品著稱,包括模仿人頭形狀的陶瓷酒杯。團隊還發現了一名約5、6歲孩童的墓葬,但該墓葬跟相關遺跡年代不同,是比較近代的墓葬。
來自: https://www.chinatimes.com/realtimenews/20240709004846-260408
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.
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