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Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)巴黎奧運》旅遊必讀「安全8訣」 最後1項很多人不知
2024巴黎夏季奧運會已於26日揭幕，身為國際級觀光重鎮的花都因而湧入更多來自世界各地的遊客。支援奧運旅遊服務的遊客服務中心「我愛巴黎」（Paris je t'aime - Tourist Office）官網特地撰文條列8大基本安全準則，提醒觀光客在探索巴黎萬象的同時別忘了維護自身安全與旅遊品質。
一、謹防扒手：尤其注意繁華地帶與觀光景點，這些都是扒手行竊的熱區。務必保持警覺，個人物品妥善收於隨身行囊，而且要經常檢查包包開口是否完全關閉，而且務必佩掛在身體正面，不要後揹。
二、消費時盡量使用信用卡或行動支付：盡可能避免隨身攜帶大筆現金。如果非不得已，務必留意財物安全。付款食，優先使用信用卡或手機行動支付。
三、保持警惕：對於任何不尋常的行為都要三思留意。例如，有人上前要求加入連署請願，或有人突然當街表演雜耍或魔術，有可能是詐騙或分散遊客注意力的「聲東擊西」手法。
四、行李不離身：所有行李與個人物品，最好都放在自己身旁。
本文引用自: https://www.chinatimes.com/realtimenews/20240727003673-260408
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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