短語詞組短語amplitude e spectrum 振幅譜amplitude frequency spectrum analysis 幅頻分析amplitude density spectrum [電子]振幅密度譜;廣闊和局面頻譜amplitude sound spectrum 聲幅度譜amplitude e spectrum shaping 振幅譜整形multi -amplitude spread spectrum technology 多幅擴頻技術(shù)pulse amplitude spectrum [電子]脈沖振幅譜FFT amplitude spectrum FFT 幅值譜amplitude spectrum integral 振幅譜積分 返回 amplitude spectrum