Design of Dual-band Bandpass Filter With Novel Circuit Approach

This paper presents a novel method to design dual-band bandpass filters based on circuit values extraction approach. To employ the proposed technique, the examined circuit model's transfer function is first synthesized using specified transmission zeros (TZs) and reflection zeros (RZs). Based on the synthesized transfer function, the circuit elements are then removed one by one with the input admittance obtained. Furthermore, the coupling values of the suggested filters are derived using the standard filter synthesis approach. To demonstrate this novel approach, a third-order planar bandpass filter with a dual-band response is developed using microstrip technology. The theoretical study and simulation results were found to be in good agreement.