Design of Concurrent Dual-Band Filters for GSM Application

Abstract

In this paper, concurrent dual band filters are designed and stimulated using CST software. This system has Notch filter with an operating range 720MHz to 920MHz and Dual-band Band pass filter with an operating range of 700MHz to 1.8GHz. Dual bands are obtained between 0.98-1.02 GHz and 1.47-1.57GHz. The Notch and the Band pass filter are both designed with the help of microstrip structure with a material called FR4 with relative dielectric constant 4.4 and order 2. Band pass filter is designed using two step impedance resonator. And Notch filter structure is designed by placing a single stub between the load of the microstrip and its source. The change in the filter output with the change in the length as well as width if the stub is noted. The band of the filters changes according to the dimensions of the stub. Thus, the range of the filters can be adjusted accordingly by changing the stub dimensions.

Keywords: Band Pass Filter, Dual-Band, Microstrip, Notch Filter, Resonator

JEL Classification: Y60