Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
（示意圖／路透社）
本篇文章引用自此: https://www.chinatimes.com/realtimenews/20250213004374-260408
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.
AI回答時事錯誤百出？BBC調查結果出爐
英國廣播公司（BBC）最新研究顯示，當前市場上領先的人工智慧（AI）工具在回應時事問題時，經常出現錯誤資訊、扭曲事實及誤導性內容，可能對公眾的新聞信任度構成威脅。
BBC的研究對象涵蓋四款知名AI工具——ChatGPT、Copilot、Gemini與Perplexity。研究人員以BBC文章為來源，向上述AI工具詢問100個與新聞時事相關的問題，並由BBC專業記者評估回應。結果顯示，超過半數回答存在「重大問題」，約20％回答在數字、日期或陳述上存在事實性錯誤，13％回答中引述的報導內文遭到竄改或純粹由AI杜撰。
BBC研究指出，AI提供的錯誤資訊面向涵蓋廣泛，可能向使用者提供錯誤的時事資訊。例如ChatGPT與其他AI聲稱蘇納克（Rishi Sunak）仍為英國首相，而施特金（Nicola Sturgeon）仍為蘇格蘭首席大臣，但事實上，兩人已分別於2024年和2023年卸任。
本篇文章引用自此: https://www.chinatimes.com/realtimenews/20250213004374-260408
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.