Abstract:

A novel dualmode microstrip filter with a slowwave openloop resonator has been designed. It uses a perturbation arrangement of length change and includes open stubs as capacitive loads, leading to size reduction of the filter. Compared with the traditional dualmode filter at the same design frequency, the proposed filter can significantly reduce the circuit size of 19%, and possesses a quasielliptic response. A bandpass filter with a 4% bandwidth centered at 2.4 GHz has been achieved. The measured results agree well with simulations.

Key words:  双模滤波器；微扰方式；开路枝节；小型化；高选择性