Co/Au multilayered magnetic nanowires with a diameter of 200 nm were electrodeposited into nanoporous anodic aluminum oxide (AAO) templates. Coplanar waveguide transmission lines were patterned on the AAO templates that were filled with the Co/Au nanowires. Noise suppressors based on pure Co and Au nanowires were also fabricated as references. The transmission coefficient S21 of the device based on Co nanowires showed an absorption peak due to the loss of ferromagnetic resonance; S21 of the device based on Au nanowires decreased linearly with increasing frequency due to the loss of eddy current. S21 of the noise suppressors based on Co/Au multilayered nanowires showed a dual-band absorption phenomenon, because of the ferromagnetic resonance of the nanowires and the periodicity of the magnetic/nonmagnetic nanostructure. The frequencies of the two absorption peaks were 24-25 GHz and 36-38 GHz, which indicated that the working frequency of the microwave devices could be beyond 20 GHz.