仁寶登場美國臺灣形象展 展示可擴充AI伺服器方案 868MHz Antenna
Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA)
專家們長期以來一直警告睡前藍光的危害。(示意圖:shutterstock/達志)
以下內文出自: https://www.chinatimes.com/realtimenews/20250822002926-260408
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.
Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA)
想睡好別怕藍光?專家揭睡前看手機未必傷睡眠真相
專家警告睡前藍光會抑制褪黑激素,讓人更清醒、難以入睡,但研究顯示藍光本身未必是睡眠不佳的主因。
Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA)《紐約時報》報導,雖然藍光確實會降低褪黑激素,但影響程度取決於使用時間、距離與亮度,然而,目前仍無法確定這些褪黑激素的變化是否足以真正影響睡眠,干擾也可能來自咖啡因、壓力或打鼾等其他因素。
雖然還不確定螢幕究竟是透過什麼機制影響睡眠,但亞利桑那大學精神醫學助理教授哈特斯汀(Lauren E. Hartstein)指出,有些研究顯示,人們使用螢幕所作的事,可能扮演了重要角色。
以下內文出自: https://www.chinatimes.com/realtimenews/20250822002926-260408
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.