Eugen_E
Full Member level 6
Hello,
To transform a LPF to BPF, the following frequency transform is made:
ω=(1/w) ( (f/f0) - (f0/f) )
ω is related to the generic LPF prototype filter, so ωc = 1.
For the BPF with a bandwidth f1...f2:
w is the fractional bandwidth: w=(f2-f1)/f0.
Suposing a zero is added at ωz, what is the corect resulting fz for the BPF?
Solving the transform equation gives two fz values, negative and positive.
E.g.:
w=0.05
f0=2GHz
ωz=2
Gives: fz= -1902MHz or fz=2102MHz
Which one is correct?
In an EM simulation of the filter I got fz=2106MHz, and in a lumped component linear circuit simulation I have fz=1904MHz.
Thanks
To transform a LPF to BPF, the following frequency transform is made:
ω=(1/w) ( (f/f0) - (f0/f) )
ω is related to the generic LPF prototype filter, so ωc = 1.
For the BPF with a bandwidth f1...f2:
w is the fractional bandwidth: w=(f2-f1)/f0.
Suposing a zero is added at ωz, what is the corect resulting fz for the BPF?
Solving the transform equation gives two fz values, negative and positive.
E.g.:
w=0.05
f0=2GHz
ωz=2
Gives: fz= -1902MHz or fz=2102MHz
Which one is correct?
In an EM simulation of the filter I got fz=2106MHz, and in a lumped component linear circuit simulation I have fz=1904MHz.
Thanks
