采用阶跃阻抗方环代替传统的均匀阻抗方环结构，设计一种基于阶跃阻抗谐振器的微带双模滤波器。为增强滤波器的带外抑制和谐渡抑制特性，将双模滤波器从单环结构扩展到双环，两环之间通过偏馈微带线耦合。通过一个中心频率为2．5GHz、带宽约300MHz的滤波器设计和仿真，证实了基于SIR的方环双模滤波器不但具有尺寸上的优势，而且能通过级联获得传输零点多、带外抑制高、谐波抑制好的优点。%A type of microstrip dual mode filter based on the step-impedance resonator is designed, which con- sists of the step-impedance square-loop instead of the conventional uniform impedence square-loop. To enhance the out-band and harmonic suppression, the structure of this filter is extended from single loop to double loop coupled by the bias-feeding microstrip. The design and simulation of a filter with a 2. 5 GHz operating frequency and 300 MHz passband shows that the double-loop dual mode filter with SIR shows superiority in size and has such advantages as multiple transmission zeros and good out-band and harmonic suppression.
展开▼
