Arrangement for dividing a filter output signal
View Patent ↗An arrangement for dividing the output signal of the antenna filter of a radio receiver to two different paths, such as two parallel low-noise amplifier branches of a base station. The divider circuit is physically integrated into a resonator-type antenna filter (RXF). This takes place by placing some conductors ( 332, 333 ) of the divider inside some conductive part of the filter structure or the resonator cavity and by using the coupling conductor ( 331 ) of the output resonator as part of the input line of the divider at the same time. As the divider is used a Wilkinson divider. Due to the arrangement, a transmission line between the antenna filter and the divider becomes unnecessary, and the dielectric losses of the divider are reduced as compared to the prior art, in which case correspondingly inferior noise qualities can be allowed for low-noise amplifiers.
1. An arrangement for guiding an output signal of antenna filter of a radio receiver into two parallel low-noise amplifier branches by means of a divider with division conductors connected to said branches, which antenna filter is of the resonator type, comprising a conductive filter housing, a space of which is divided by conductive partition walls into resonator cavities, in which case the filter has at least an input and output resonator, wherein the divider is located inside the outer surface of the filter housing.
2. An arrangement according to claim 1 , wherein there is a conductive element in the cavity of the output resonator for taking signal energy out from the filter, the conductive element being a part of said divider, at the same time.
3. An arrangement according to claim 2 , the coupling between the divider and the output resonator being electromagnetic.
4. An arrangement according to claim 2 , the coupling between the divider and the output resonator being galvanic.
5. An arrangement according to claim 1 , said division conductors being located for their substantial parts inside a conductive part of the filter.
6. An arrangement according to claim 5 , said conductive part of the filter being an outer wall of the output resonator.
7. An arrangement according to claim 6 , wherein it is a hole in said outer wall for each division conductor, in the middle of which hole the division conductor is as isolated from the surface of the hole.
8. An arrangement according to claim 5 , said conductive part of the filter being the inner conductor of the output resonator.
9. An arrangement according to claim 1 , said division conductors being located in the cavity of the output resonator.
10. An arrangement according to claim 9 , comprising a divider circuit board, the division conductors being strip conductors, which belong to that circuit board.
11. An arrangement according to claim 10 , said circuit board being fastened to inner surface of an outer wall of the output resonator.
12. An arrangement according to claim 10 , said circuit board being fastened to inner surface of a cover of the output resonator.
13. An arrangement according to claim 10 , said circuit board being fastened to the inner surface of a bottom of the output resonator.
14. An arrangement according to claim 1 , the divider being a Wilkinson divider.