百度
谷歌
图片
维基
百科
signal frequency
signal frequency multiplier
signal frequency shift
signal frequency side band
signal frequency sideband
signal frequency spectrum
signal function
signal gantry
signal generating device
signal generator
signal glass
signal glassware
signal grid
signal ground
signal group
signal gun
signal hair
signal halyard
signal handle
signal handling equipment
signal headway
signal horn
signal hose
signal hypothesis
signal identification
signal imitation
signal impulse
signal indication
signal indication checking
signal indication lamp
signal frequency multiplier
signal frequency shift
signal frequency side band
signal frequency sideband
signal frequency spectrum
signal function
signal gantry
signal generating device
signal generator
signal glass
signal glassware
signal grid
signal ground
signal group
signal gun
signal hair
signal halyard
signal handle
signal handling equipment
signal headway
signal horn
signal hose
signal hypothesis
signal identification
signal imitation
signal impulse
signal indication
signal indication checking
signal indication lamp
signal frequency
信号频率
在确定的时间间隔里出现的周期数
计 通信