The influences of the disturbance of the parameters,such as L,R 1,R 2 ,on the output coupling and on the far field intensity of positive branch unstable confocal resonator are studied.

To troubleshoot the broken clutch transmission apparatus,a detailed modification was made,a bearing gland with oil sealing box was designed to replace the oil sealing parts on the YLC-700I Frac Trucks.

Then the hardware and software design of the middle voltage distribution power line carrier modulate demodulator is described in detail ,and the design principle of the coupling device described briefly in follow.