# determinant of transfer function

Discussion in 'Electronics Homework Help' started by bhuvanesh, Jan 29, 2015.

1. ### bhuvanesh

201
0
Aug 29, 2013
i am studying control system i crossed this transfer function

H(jw)=(1-jw/1+jw)

now taking determinant of this

|H(jw)|=1

My question in what way the determinant is usefull to learn about the systrem.Here the determinant of transfer function is 1,so the 1 saying anything about the system

2. ### LvW

604
146
Apr 12, 2014
|H(jw)|=1 and phi(jw)=-2arctan(w).
It is an alppass with a phase between 0 and -Pi.

Arouse1973 and bhuvanesh like this.
3. ### bhuvanesh

201
0
Aug 29, 2013
sir,This is what i really need but i am not clear yet

|H(jw)|=1 .so does it mean that high pass ?

does phi(jw) mean phase of transfer function ?

how do you say its all pass with phase between 0 to -pi?

Last edited: Jan 29, 2015
4. ### LvW

604
146
Apr 12, 2014
N0 - it`s not a highpass;
Yes - phi(jw) is the phase function;
The name is "allpass" because this filter lets pass all frequencies with the same amplitude, only the phase goes from zero to -Pi (continuously).

bhuvanesh likes this.
5. ### bhuvanesh

201
0
Aug 29, 2013
if suppose the determinant gives decreasing amplitude value for giving increasing frequency value .is that low pass?
if suppose the determinant gives increasing amplitude value for giving increasing frequency value .is that high pass?