Active Bandpass Filter Design to Attenuate Harmonic Distortions in MPI Scanner
This paper describes the design and simulation of Fourth order Butterworth and Chebyshev active bandpass filter designed for one of many applications like magnetic particle imaging (MPI) scanner. It can be simulated and compared as to which filter will be best choice for MPI scanner module for attenuation of harmonic distortions by power amplifier. By using coefficient matching method the values of passive components are calculated and the BPF is designed for Butterworth and Chebyshev response for excitation frequency of 22.8kHz using high-pass and low-pass filters of variable orders cascaded together.Results are compared by simulation on NI Multisim software. The resultant output shows maximally flat magnitude response using Butterworth filter and ripples in passband of Chebyshev filter magnitude response at orders N=2,3,4 and 5. So it can be selected as to which filter will be best for desired magnitude response according to the specific application. Fourth Order Active BPF is concluded to be suitable for desired output in this application. Keywords - Bandpass Filter; NI Multisim; Butterworth; Chebyshev; Passband; Stopband; Magnitude Response; Magnetic Particle Imaging.