Problem with bandwidth function()

[Samiran]

Dear all,

I have a situation where I have to measure the bandwidth of a low-pass
transfer function. So, I am using the bandwidth( ) function as
follows:

bw=bandwidth( dB20(VF("/net18") / VF("/net15")) 3 "low")

net18 is the output net and net15 is the input net. And I want to get
the frequency value at gain=3dB lower than the dc gain.

But the value of bw is coming as 825KHz, whereas I can see the
frequency value at gain = (dcgain-3db) point as 1MHz. Is there any
problem with the bandwidth function or am I doing any fundamental
mistake or the function is required to be used in other way?

Please help!

Regards
Sam

 

[Gunnar]

Hi Sam:
try
bw=bandwidth( VF("/net18") / VF("/net15") 3 "low")

the bandwidth function works with the frequency response but without
dB20.
Cheers
Gunnar

 

[Samiran]

On May 4, 2:07 pm, Gunnar <gunnar.mun...@web.de> wrote:

Hi Sam:
try
bw=bandwidth( VF("/net18") / VF("/net15") 3 "low")

the bandwidth function works with the frequency response but without
dB20.
Cheers
Gunnar

Hi Gunnar,

Bingo!!!!!!!!! It worked perfectly. Thanks for the suggestion.

Cheers
Sam.