Filter combiner

• US 7,623,005 B2
• Filed: 05/04/2006
• Issued: 11/24/2009
• Est. Priority Date: 05/11/2005
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Kallberg, Daniel, Johansson, Rune
• Primary Examiner(s): Takaoka; Dean O
• Application Number:
  US11/914,016
• Publication Number:
  US 20080174385A1
• Time in Patent Office: 1,300 Days
• Field of Search: 333/109, 333/110, 333/126, 333/129, 333/132
• US Class Current: 333/110
• CPC Class Codes: H01P 1/2138 using hollow waveguide filters H01P1/2131 takes precedence
• CPC Class Codes: H03H 2007/013 Notch or bandstop filters
• CPC Class Codes: H03H 7/46 Networks for connecting several sources or loads, working on different frequencies or frequency bands, to a common load or source for use in multiplex transmission systems H04J1/00
• CPC Class Codes: H04J 1/08 Arrangements for combining channels branching filters H01P1/213, H03H7/46

Abstract

The invention presents a filter combiner, in particular for mobile communications applications, adapted to be connected to an antenna (12), comprising a first directional coupler (13), connected to at least one first filter (15, 15a, 15b), to an antenna branch (12a), to at least one second filter (17, 17a, 17b), and to a first signal branch (20), the combiner also comprising a second directional coupler (21), connected to the at least one first filter (15, 15a, 15b), to a second signal branch (25), and to the at least one second filter (17, 17a, 17b). Further, the first directional coupler (13) is adapted to be connected to the first signal branch (20) via at least one third filter (29, 29a, 29b).

Claims

1. A filter combiner, for mobile communications applications, adapted to be connected directly or via other components to an antenna, comprising:

a first directional coupler, connected to at least one first filter and at least one second filter, and adapted to be connected to an antenna branch, and to a first signal branch via at least one third filter;

a second directional coupler, connected to the at least one first filter and the at least one second filter, and adapted to be connected to a second signal branch

wherein each of the filters is one of a band pass filter type or a band reject filter type;

wherein the at least one first filter and the at least one second filter are of the same type whereas the at least one third filter is of the other type; and

,

wherein the at least one first, second and third filters are all tuned to a band between substantially the same frequencies.

2. The filter combiner according to claim 1, wherein the first directional coupler and the second directional coupler are hybrids.

3. The filter combiner according to claim 1, comprising a fourth filter at the second directional coupler.

4. The filter combiner according to claim 3, wherein the first signal branch is connected to a first radio base station, which in turn is connected to the fourth filter, the second signal branch being connected to a second radio base station.

5. The filter combiner according to claim 1, wherein the first directional coupler, the first filter, the second filter, the second directional coupler, and the third filter, are included in a first combiner assembly, the filter combiner further comprising a second combiner assembly comprising:

a first directional coupler connected to at least one first filter, at least one second filter, and at least one third filter, and adapted to be connected to the antenna branch;

a second directional coupler connected to the at least one first filter and the at least one second filter, and adapted to be connected to a third signal branch,

the first directional coupler of the first combiner assembly being connected to the at least one third filter of the second combiner assembly.

6. The filter combiner according to claim 5, further comprising:

a fourth filter at the second directional coupler of the first combiner assembly; and

,

a fourth filter at the second directional coupler of the second combiner assembly;

wherein the first signal branch is connected to a first radio base station, which in turn is connected to the fourth filter of the first combiner assembly, and the second signal branch being connected to a second radio base station; and

,

wherein the first radio base station is connected to the fourth filter of the second combiner assembly, the third signal branch being connected to a third radio base station.

7. The filter combiner according to claim 1, wherein the first filter is implemented as a combination of two first filters, the second filter is implemented as a combination of two second filters, and the third filter is implemented as a combination of two third filters.

8. The filter combiner according to claim 7, wherein the two first filters and the two second filters are bandpass filters, and the two third filters are bandreject filters, one of the first filters, one of the second filters, and one of the third filters being tuned to a band between two RX frequencies, and another of the first filters, another of the second filters, and another of the third filters being tuned to a band between two TX frequencies.

9. The filter combiner according to claim 7, wherein the two first filters and the two second filters are bandreject filters, and the two third filters are bandpass filters, one of the first filters, one of the second filters, and one of the third filters being tuned to a band between two RX frequencies, and another of the first filters, another of the second filters, and another of the third filters being tuned to a band between two TX frequencies.

10. The filter combiner according to claim 7, wherein one of the first filters and one of the second filters are band reject filters tuned to a band between two TX frequencies, and another of the first filters and another of the second filters are bandpass filters tuned to a TX fullband, in addition to which one of the third filters is a bandpass filter tuned to a band between the two TX frequencies, and another of the third filters is a bandpass filter tuned to the RX fullband.

11. The filter combiner according to claim 7, wherein the first filters and the second filters are bandpass filters, one of the first filters and one of the second filters being tuned to a band between a first and a second TX frequency, and another of the first filters and another of the second filters being tuned to a band between a third and a fourth TX frequency, the interval between the first and the second TX frequency and the interval between the third and the fourth TX frequency overlapping each other at least partially,

the third filters being band reject filters, one of the third filters being tuned to a band between the third frequency and a fifth frequency, and another of the band reject filters being tuned to a band between a sixth frequency and the second frequency, the interval between the third frequency and the fifth frequency, and the interval between the sixth frequency and the second frequency overlapping each other at least partially.

12. The filter combiner according to claim 7, wherein

the first filters and the second filters are band reject filters, one of the first filters and one of the second filters being tuned to a band between a first and a second TX frequency, and another of the first filters and another of the second filters being tuned to a band between a third and a fourth TX frequency, the interval between the first and the second TX frequency and the interval between the third and the fourth TX frequency overlapping each other at least partially,

the third filters being bandpass filters, one of the third filters being tuned to a band between a fifth frequency and the fourth frequency, and another one of the band reject filters being tuned to a band between the first frequency and a sixth frequency, the interval between the fifth frequency and the fourth frequency, and the interval between the first frequency and the sixth frequency overlapping each other at least partially.

13. A splitter assembly comprising:

a first directional coupler and a second directional coupler, both connected to at least one first filter and at least one second filter, the first directional coupler being adapted to be connected to a first antenna branch via a third filter, and the second directional coupler being adapted to be connected to a second antenna branch, each of the filters being one of a band pass filter type or a band reject filter type, the at least one first filter and the at least one second filter being of the same type whereas the at least one third filter is of the other type, the at least one first, second and third filters all being tuned to a band between substantially the same frequencies.