| 摘要 |
PURPOSE:To reduce the loss within pass band and to increase the attenuation out of band, by constituting two stages of BPF through the arrangement of one wave length lines of rectangular shape parallelly by two lines, and providing the coupling line having open end between the input and output lines. CONSTITUTION:The rectangular one wave length closed lines 7, 8 are parallelly arranged, and the input line 5 is made adjacent to the input section 7a of the line 7, the output line 6 is made adjacent to the output section 8b of the line 8, and the coupling line 11 is placed in adjacency to the input section 8a of the output section 7b of the line 7 and the input section 8a of the line 8. The lines 7, 8 have the single tuning characteristics of the same resonant frequency and BPF is constituted with the stagger tuning circuit connection. Further, at the coupling between the input and output by the input line 5 and the coupling line 9, trap is caused at the almost symmetrical location to the center frequency. Accordingly, by changing the length l of the line 9' the location of trap frequency can be changed. Further, the effect on the pass band characteristics for the shift in resonant frequency can be finely tuned with the adjusting line 10 of the line 7. |
