Low-loss fourth-order coupled resonator filter using artificial magnetic conductor

The design of a fourth-order coupled resonant filter based on artificial magnetic conductor(AMC) is presented in this paper. This new technology has the characteristics of low insertion loss and self-packaged. A coupler resonator filter based on artificial magnetic conductor is designed. For this microstrip line filter, the band gap characteristic of artificial magnetic conductor is used. A mushroom-shaped artificial magnetic conductor structure is designed. The band gap of this structure is from 26GHz to 57GHz, in which the propagation of electromagnetic wave is restrained. A virtual magnetic wall is formed between the artificial magnetic conductor and the microstrip interface, and the propagation of electromagnetic wave in the upper air is realized. It realized low-loss and 3dB bandwidth of the fourth-order resonator filter in 29GHz to 32GHz, the central frequency is 31.5GHz, and the relative bandwidth is 9.5%. In the pass band of the filter, the insertion loss is less than 0.96 dB. Measured results show good agreement with analyses.