双栅场效应管混频器在相位法激光测距中的应用

相位法激光测距机采用混频移相测相的方法来测量本地发射信号与接收的回波信号之间的相位差,通过相位差计算测量距离.由这个原理可知,当对测量精度要求较高时,对高频下的混频器的两路输入信号隔离度的要求也提高了.采用双栅场效应管作为相位法激光测距机的混频器,能达到很好的混频效果,可有效地克服由于混频器隔离度不够高造成的混频干扰,为高精度的距离测量提供了必要条件.试验验证了电压隔离度在27 dB（500倍）以上,适合做高精度相位法测距机的混频器.

Utilizing Dual-Gate MOSFET as mixer in phase laser range finder

Based on the theory of phase laser range finder,the measuring result was obtained through the phase-differences of the emitting signal and the returning signal that was measured by mixer and phase detection,so the high isolation of the mixer between input signals was required to obtain high precision.A Dual-Gate MOSFET mixer had been used for this purpose.The isolation ratio was analyzed,and experimental results show that the isolation ratio is more than 27 dB(500 times),and Dual-Gate MOSFET mixer is a kind of high performance mixer for high precision phase laser finder.