俄羅斯與烏克蘭交戰已3年6個月有餘。就在美俄領導人即將於周五（15日）於美國阿拉斯加州舉行峰會之前，靠近烏克蘭的2座俄羅斯城市周四（14日）發生爆炸，當地官員聲稱是烏克蘭的無人機攻擊所致，至少16人喪生。俄羅斯國防部稍早宣稱，防空系統在午夜攔截並摧毀44架烏克蘭無人機。

綜合路透社、《莫斯科時報》、烏克蘭媒體UNN報導，俄羅斯西南部羅斯托夫州代理州長表示，首府頓河畔羅斯托夫（Rostov-on-Don）有一棟公寓大樓遭烏蘭無人機擊中，13人受傷，其中2人重傷。目擊居民稱，轟擊聲震耳欲聾，好幾個街區以外都聽得見，事發前不久，當地才宣布進入飛彈威脅預警狀態，爆炸現場已封鎖。羅斯托夫州位於歐俄西南端，距離與烏克蘭東南部邊境70公里，靠近黑海東北方的亞速海。

社群平台一段影片顯示，一架疑似無人機的飛行物體緩緩下降到頓河畔羅斯托夫市區上空，接著撞上一棟建物引發大爆炸。其他影片顯示，無人機墜毀後引發大量煙霧。俄羅斯官媒「今日俄羅斯」（RT）稱逾10棟大樓毀損。

以下文章來自: https://www.chinatimes.com/realtimenews/20250814004008-260408
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.