Design of a finite attenuation pole miniaturized S-band lowpass filter using elliptic function

A miniaturized microstrip lowpass filter design using elliptic function is presented in this paper. The proposed filter has a cut-off frequency of 2.5 GHz with passband ripple 0.1dB and stopband insertion loss greater than 20dB at 2.85 GHz. It provides two finite attenuation poles at 2.945 GHz and 4.015 GHz in the stopband having attenuation of the order of 35dB and 50dB respectively. Different types of design characterization have been investigated of the proposed filter and a comparative study based on design parameters and dimensions has been provided.