Design and development of quarter-wavelength bandpass microstrip filter

Abstract

This thesis presents a quarter-wavelength bandpass microtrip filter. The proposed bandpass filter structure using five short-circuited stubs is designed based on Chebyshev lowpass filter response for ultra wideband (UWB) applications. The dimension parameter of bandpass filter is calculated by using J/K inverters formula. Bandpass filter is designed on Roger 4003C and simulated in Advanced Design System (ADS) for both schematic and layout. Simulation results of both schematic and layout is analyzed and compared for optimum values. Five poles of quarter-wavelength bandpass microstrip filter with 73% fractional bandwidth is designed and simulated. From simulation results, return loss for both schematic and layout is less than -10dB. Hence, the simulation results in schematic and layout show good equal ripple performance in the passband as well as low losses. Bandwidth of simulated filter for schematic and layout are 5.42GHz and 4.75GHz respectively. Simulation results from both schematic and layout is slightly difference to each other but theoretical requirement is fulfill for both design. Hence, results of both schematic and layout design are agreed each other in term of S-parameter of filter performance.