A balanced bandpass filter with open stubs centrally loaded

This paper presents a compact balanced bandpass filter (BPF) with wide stopband. Firstly, it presents the equivalent circuits of the balanced BPF. By utilizing merits of the used resonator and open stubs centrally loaded, a balanced BPF with wide stopband and miniaturization can be achieved. Finally, a microstrip balanced BPF working at 2 GHz is designed and fabricated. Measured results accord well with the simulated results.