BOOSTER

PROBLEM TO BE SOLVED: To provide a booster that can continue to output signals even when power is not supplied thereto.SOLUTION: A booster 3 comprises: a booster input terminal 30; an amplifier element 31; a branching tool 32 that branches amplified signals into a power supply-time output system and a continuous output system; a power supply-time output terminal 34; and a continuous output terminal 35. Further, the booster comprises a first switch 36a and a second switch 36b that when power is supplied, make the power supply-time output terminal 34 to output signals inputted into the booster input terminal 30, by connecting the booster input terminal 30 to the amplifier element 31, through the amplifier element 31 and the branching tool 32, and make the continuous output terminal 35 to output signals branched into the continuous output system by the branching tool 32, by connecting the continuous output terminal 35 to the branching tool 32; and when power is not supplied, make the continuous output terminal 35 to output the signals inputted into the booster input terminal 30, by connecting the booster input terminal 30 to the continuous output terminal 35, where gain of the amplifier element 31 is set to be approximately same as distribution loss of the branching tool 32. 【課題】無給電時でも信号の出力を継続できるブースタを提供する。【解決手段】ブースタ３は、ブースタ入力端子３０と、増幅素子３１と、増幅された信号を給電時出力系統と常時出力系統とに分配する分岐器３２と、給電時出力端子３４と、常時出力端子３５を備える。さらに、給電時には、ブースタ入力端子３０を増幅素子３１に接続して当該ブースタ入力端子３０に入力された信号を増幅素子３１及び分岐器３２を介して給電時出力端子３４から出力させると共に、常時出力端子３５を分岐器３２に接続して当該分岐器３２により常時出力系統に分配された信号を常時出力端子３５から出力させ、無給電時には、ブースタ入力端子３０を常時出力端子３５に接続して当該ブースタ入力端子３０に入力された信号を常時出力端子３５から出力させる、第１スイッチ３６ａ及び第２スイッチ３６ｂとを備え、増幅素子３１の利得を、分岐器３２の分配損失と略同一に設定した。【選択図】図２