resonant filter design

i want to design a resonant filter or narrow bandpass filter of 15.92 kHz frequency.
i want the working method of it.

That sounds roughly like the horizontal deflection frequency of old fashioned TVs.

In any case, at this low frequency there are a few options. The simplest, which works at higher frequencies too is a L-C filter. This can be configured two ways. In parallel the L-C has zero impedance at the resonant frequency and in series it has infinite impedance. This means you use the parallel as a shunt or the series as a pass element. What specifically are you stuck on?

Another option at such a low frequency is to do it all digitally. Even with a low end DSP you can sample at 160 KHz or more, which is 10x the frequency of interest. The digital solution will be more complicated, but is easily tunable, much more precise, and doesn't suffer from part tolerance problems.

What kind of filter are you looking to design:

* Passive LCs
* Active (Opamp)
* Digital (DSP)

Also you need to identify some specs like bandwidth of the passband, roll off slope, etc. I have found that starting with a bode plot of the filter response you are looking for answers many of the questions. It all comes down to poles and zeros.

i want to design narrow bandpass filter using active op-amp. i want the working method of it.......

What are you trying to accomplish overall? Previously you said you wanted a resonant filter. Now you say it has to use a opamp. These are all implementation details and pre-suppose particular solutions.

As Cody said, you need to provide some real specs. There is not much anyone can help until you answer all the questions that have been asked.

Try "Analog Devices Filter Wizard":http://www.analog.com/Wizard/filter/filterUserEntry.asp

I believe you can build a bandpass filter out of an appropriate combination of a highpass and lowpass filter cascaded together. The tool will do various types of lowpass and highpass filters so you may have to experiment to get the "narrowness" you desire without excess attenuation at your chosen frequency.

I'm assuming you are a student, so unless your professor had a specific all-in-one active bandpass filter circuit topology in mind you should be able to use the tool to get something that works. If he had a specific topology in mind then you may need to review your class text/notes.

Read about the various types of filters the tool can help you design and take note of the response for each. Pay special attention to how steep the slope is at the cutoff frequency since this will determine the "narrowness" you will ultimately end up with.