景文科大帶弱勢童職探藍莓乳酪塔與蘋果橙茶製作 Open Boundary Quad-Ridged Horn Antenna
Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA) Log Periodic Antenna (LPDA)
以色列國營航太IAI 的箭式高層防禦飛彈，與美國的THAAD性能相當。(圖/IAI)
Log Periodic Antenna (LPDA)
Log Periodic Antenna (LPDA)
本文出自: https://www.chinatimes.com/realtimenews/20241201002889-260408
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)
葉門再對以色列發射彈道飛彈 防空系統成功攔截
以色列國防軍週日表示，一枚從葉門向以色列發射的彈道飛彈，在中途被以色列的高層防空系統成功攔截，雖然攔截後的彈片落在以色列境內，卻並無造成額外的損害。
以色列時報(Times of Israel)報導，紅大衛盾會(MDA, Magen David Adom,國際紅十字會的以色列分部)緊急服務部門表示，彈道飛彈沒有造成直接傷害，但是有4人在警報響起時，跑向避難所的途中受到輕傷；另有1人因警報引發急性焦慮症而感到身心不適，同樣進醫院接受治療。
以色列國防軍表示，這枚地對地的彈道飛彈是被「箭式」防禦系統(Arrow defense system)擊落的，該系統可消滅仍在大氣層外的彈道飛彈。據以色列空軍消息人士稱，這枚飛彈就是在「高空」被擊落的。
本文出自: https://www.chinatimes.com/realtimenews/20241201002889-260408
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.