thnaks for your advice , it is true that i am a begginer,i also see the enhancement , i will go on ;i just posted the first stage of an amp . i can easily get the bias "v9 N3 vss 3" , i think the other transistor suply a voltage rather than copy the current as the ransistor can be different .i will finish the current mirror ,and i have a question "have you ever simulated the circuit "
i use the book of analysis and design of analog integrated circuit by Paul R. Gray , i will follow your advice to read Cargo Cult Science by Richard Feynman , if you really happy to help a beginner , please give me a example that i can simulate , and understand it exactly . thanks a lot for your reply !
Added after 12 minutes:
"So I have just one wish for you -- the good luck to be somewhere where you
are free to maintain the kind of integrity I have described, and where you
do not feel forced by a need to maintain your position in the organization,
or financial support, or so on, to lose your integrity. May you have that freedom"
--by Richard Feynman
i will remember , thanks !