| 摘要 |
A Filter apparatus 2 is provided including a filter body 4 in which one or more resonating means are formed. A support member (e.g. lid) 6 is provided for location over at least a part of one face of the said filter body. At least one transmission line 14, 16 is located on or associated with the support member and is provided for transmitting one or more radio frequency signals therealong in use. Aspects of the invention include; the transmission line is connected with or to one or more of said resonating means; the support member (or lid) is formed of sheet material or non-electrically conductive material or PCB; the resonating means includes a cavity, channel and/or recess with an opening defined therein, wherein a resonating structure (combline resonators, one or more rods, ceramic rods/pucks) is formed or provided in said cavity; support member includes one or more tuning means. There is more space available on the upper surface of the support member for the locations of the transmission lines than is conventionally the case on the upper surface of the filter body. |
