Compact UWB Micro Strip Band Pass Filter with Open Circuited Stubs

A filter is a key and critical component for all types of wireless communication receivers, which are used to reject the noises (unwanted frequencies) in accordance with the applications. Band pass filters enable operation of any given module in a particular frequency range. In this paper, a compact microstrip band pass filter is proposed with operating range from 2.7 to 10.7 GHz for Ultra-Wide band (3.1 to 10.6 GHz) applications. The Chebychev elliptic function filtering method is employed. Two open circuited stubs are used to achieve the upper transmission loss and coupled micro strip structure is used to reduce transmission loss. The designed filter has insertion loss greater than -1 dB and return loss lower than -10 dB in pass band. The filter is designed with dimensions of 10mm x 9mm x 1.6mm on FR4 (εr = 4.3) substrate. The sharp cut-off at lower and upper stop bands has been achieved by proper tuning of the widths and lengths of the open circuited stubs. Bandwidth of about 8 GHz and a flat group delay in the pass band have been achieved. In view of its compactness, this filter can be easily integrated with all communication devices. The designed band pass filter has potential and promising application in UWB (Wi-Fi, Wi-Max, WLAN and ITU) applications.