DESIGN OF PARALLEL COUPLED MICROSTRIP BAND PASS FILTER FOR WIRELESS APPLICATION

Abstract

Radio frequency (RF) filters operating in the microwave frequency range are needed for applications including wireless and satellite communications as well as military applications. Most communication system contains an RF front end which performs signal processing with RF filters. Planar or printed circuit board (PCB) based filters are popular and relatively practical to design. Band pass filters play a significant role in wireless communication systems. Transmitted and received signals have to be filtered at a certain center frequency with a specific bandwidth. Parallel coupled line microstrip filter are very common for implementation of bandpass and band-stop filters with required bandwidth up to a 20% of fractional bandwidth. Because of weak coupling these type of filter has narrow fractional bandwidth (FBW) but has certain advantages such as low cost fabrication, easy integration and simple design procedure. This thesis describes the design of low cost L-band Parallel coupled microstrip Band pass filter (BPF) for GPS system by using micro strip layout at center frequency 1.575 GHz with a fractional bandwidth of 20%. The simulation of this filter has been done using ADS (Advanced design system) design software by Agilent Technology. And also for calculation of the physical parameter of the coupled line CAD tool LineCalc built in ADS is used.