Design Analysis of UWB Bandpass Filter Using Suspended Microstrip Technology

This paper presents a suspended microstrip technology to enhance the bandwidth of proposed ultra-wideband (UWB) bandpass filter. The earlier proposed filter suffer with the problem of low bandwidth, to eliminate this the concept of suspended microstrip technology is introduced to enhance the bandwidth. The proposed filter is designed by combining the step impedance lowpass filter (LPF) and the optimum distributed highpass filter (HPF). For designing of the structure FR-4 substrate of thickness h = 1 mm with Dielectric constant = 4.05 is used and the filter occupies 22.8mm x 12mm die of area. This filter is operating in the whole UWB passband of 3.1 GHz to 10.6 GHz. Further, the bandwidth is enhanced from 2 to 6 percent from the earlier UWB filters. CST microwave studio software is used for the simulation of the designed structures.