# How to Find Phase Lead/Lag

I have the transfer function $$H(s) = \frac{s+1}{0.1s+1}$$ I apply the Bilinear Rule with a sampling time T =.25 sec to the transfer function and get a z-domain representation of

$$H(z) = \frac{2.25z - 1.75}{.45z + .05}$$

I found the pole to be at -.1111 and the zero to be at .7778

How can I compute the amount of phase lead at $$z_{1} = e^{jw_{1}T}$$ where w1 = 3 rad.

I guess I am confused about what phase lag/lead is and how to find it.

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Since [homework] is not a stand alone tag in our community, I have added two other tags. Please check if they are relevant. –  user21436 Feb 3 '12 at 7:59
@Kanna: Perhaps the tag should be (signal-analysis) instead? –  anon Feb 3 '12 at 8:06
@anon Done, Thanks. –  user21436 Feb 3 '12 at 11:13