| 摘要 |
The filter comprises a plurality of coupled resonators, preferably cavity resonators operating in the microwave region. The filter has a common structure 6 comprising at least one common coupling or resonator 7; an upper loop 8 comprising first and second end resonators 9, 10 coupled together by a signal path 11 and to the common resonator 7, the upper loop further comprises a plurality of further resonators 12-15 in a cross-coupled ladder configuration; and a lower loop 18 constructed similarly to the upper loop. The filter topology is such that an equivalent circuit (fig 3) splits the resonators into high- and low-pass sub-filters with one sub-filter receiving the output of the other. A number of alternative arrangements are disclosed (figs 5-9). |
