Re: pole zero analysis
xulfee said:
poles and zeros decide the behaviour of circuits or transfer functions,on poles gain is decrease by -20db/dec per pole and zeros does oppossite to it mean gain is increased by 20db/dec for each zero
To make pole zero analysis manually for your ct. :
1.you should transform -or at least to imagine- the ct. into resistors, capacitors, inductors,dependant sources, & independant sources. [and you should know the s notation for each of all of these.]
2.you should know where is the out-put & the in-put [transfer fn is output/input ] , & try to divide the ct to cascaded stages if possible (in some cases some parts couldn't be divided) to get the transfer fn of each stage alone, & try to factorize the numerator & denominator of each T. Fn. into brakets each contain ( 1 +/- s/s° ) , in some cases you couldn't do this & you will get 2nd order factor (1 +/- s/ω°Q +/- s²/ω°²).
3.after geting the overall fn. : you could have:
i)in the numerator :LHP(complex or real) or RHP(complex or real) Zeros.
ii)in the denomenator :LHP(complex or real) or RHP(complex or real) Poles.
for ( 1 + s/s° )you have real LHP poles or zeros while for ( 1 - s/s° ) they are RHP.
for (1 +/- s/ω°Q +/- s²/ω°²) poles or zeros are complex conjugate or real depnding on the values of Q & ω°.
I want to add to xulfee post the phase variation:
poles make -20dB/dec for gain while if LHP they add +90 deg phase shift & -90 deg if RHP, while zeros are the opposite [all of these starts from basic complex no. calculation]
ashish_chauhan said:
if u need some thing regarding simulations... then probably ur simulation tools refenence manual will do... if u are talking about theoritical / paper-pencil analysis
then go for a good control systems book.
Ogata's book is a good ...