Determination of appropriate substrate for microstrip low-pass filter employing square designed tschebycheff distribution

In modern microwave design domain, Electromagnetic Band Gap (EBG) structures which is a unique innovation in consideration of high potential and low complication in designing with microwave integrated circuits. This article inspects the relationship between Tschebycheff polynomial distribution and operating behaviour of different substrates. A number of methods, Tschebycheff polynomial distribution for designing the conventional square pattern with constant volumetric ratio and method of moments (MOM) for numerical analysis are used. To begin with, the parametric comparison has been demonstrated reviewing the selectivity, 20-dB insertion loss bandwidth (20-dB IL BW) and 10-dB return loss bandwidth (10-dB RL BW). Consequently, two substrates RT/Duroid 5880 and FR4 prevail with negligible ripple less than 0.7 dB, well impedance matching in the passband and wider, deeper stopband upto 6-7.5 GHz. Moreover, the 10-dB RL BW fluctuates very slowly while frequency shifts 2-3% from resonant frequency. Miniaturization of the circuit has been improved along with high efficiency with the help of Tschebycheff polynomial distribution.