| 摘要 |
PURPOSE:To improve the cutoff performance at the high frequency side, by providing >=2 1/4-wavelength resonators and >=2 parallel resonators, insulating and drawing out an end of each of the parallel resonators to connect them to each other and opening the other end respectively. CONSTITUTION:A shielding case 8 contains 4 rooms 11 and 12, and the rooms 11 at both ends of the case 8 include the 1/4-wavelength resonators 13 and 13' with an end opened and the other end connected to the case 8, and the input windings 14 and 15 with an end connected to the case 8 and the other end insulated from the case 8 and then drawn outside. A coupling window 16 is provided to a partition wall 9 between the rooms 11 and 12, and the coils 17 and 17' are disposed in the room 12. In addition, the capacitors 18 and 18' are connected to both ends of the coils 17 and 17' to form the parallel resonators 19 and 19'. As no window is provided to a partition wall 10 of the room 12, the resonators 19 and 19' are separated from each other in terms of the electric field. Then an end of each of the resonators 19 and 19' is connected to each other to have an electromagnetic connection. The other end of each of the resonators 19 and 19' is opened, and a trap circuit is formed for connection of capacity by means of the capacity between the resonators 19/19' and the case 8. |
