Narrowband Bandpass Filter With Wide Stopband Using Front-Coupled Open Stubs
A narrowband bandpass filter with high rejection in the stopband and good passband performance is presented in this paper. This filter consists of three front-coupled sections that are connected in series form. The LC equivalent circuits of the resonators are derived to evaluate the behavior of different parts of the filter. The ElectroMagnetic (EM) and circuit simulations are performed and their agreement verifies the validity of the LC model. The proposed filter has a center frequency of 5 GHz that is compatible with IEEE 802.11a standard with 18 MHz bandwidth.