A TUNABLE WAVEGUIDE FILTER INPUT/OUTPUT COUPLING ARRANGEMENT

Abstract

The present disclosure relates to a tunable waveguide filter input/output coupling arrangement comprising a waveguide part, a coupling iris part and a tunable filter part. The waveguide part runs along a longitudinal extension and has a waveguide width extending perpendicular to the longitudinal extension, and is electrically connected to the tunable filter part by means of the coupling iris part which comprises an opening between the waveguide part and the tunable filter part. The opening is positioned at a certain position along the longitudinal extension. The waveguide part comprises a stub part that has a certain stub length along the longitudinal extension, between an electrical short-circuit end plate and an edge of the opening that is closest to the end plate, where the stub part also has a stub width extending perpendicular to the longitudinal extension.

Claims

1. A tunable waveguide filter input/output coupling arrangement comprising: a waveguide part, a coupling iris part and a tunable filter part, where the waveguide part runs along a longitudinal extension and has a waveguide width extending perpendicular to the longitudinal extension, and a waveguide height extending perpendicular to the waveguide width, where the waveguide part is electrically connected to the tunable filter part by the coupling iris part which comprises an opening between the waveguide part and the tunable filter part, where the opening is positioned at a certain position along the longitudinal extension, wherein the waveguide part comprises a stub part that has a certain stub length along the longitudinal extension, between an electrical short-circuit end plate and an edge of the opening that is closest to the end plate, where the stub part also has a stub width extending perpendicular to the longitudinal extension.

2. The tunable waveguide filter input/output coupling arrangement according to claim 1, wherein the tunable filter part comprises a tunable resonance cavity that is arranged to be electrically connected to further resonance cavities by a corresponding cavity iris part.

3. The tunable waveguide filter input/output coupling arrangement according to claim 1, wherein the stub part has a stub width that to the most part either: falls below the waveguide width; exceeds the waveguide width; or equals the waveguide width.

4. The tunable waveguide filter input/output coupling arrangement according to claim 1, wherein the stub length varies between /8 and /2, where denotes the wavelength in air that corresponds to the center frequency in a desired frequency band.

5. A microwave transceiver comprising: a tunable waveguide filter input/output coupling arrangement that in turn comprises a waveguide part, a coupling iris part and a tunable filter part, where the waveguide part runs along a longitudinal extension and has a waveguide width extending perpendicular to the longitudinal extension, and a waveguide height extending perpendicular to the waveguide width, where the waveguide part is electrically connected to the tunable filter part by the coupling iris part which comprises an opening between the waveguide part and the tunable filter part, where the opening is positioned at a certain position along the longitudinal extension, wherein the waveguide part comprises a stub part that has a certain stub length along the longitudinal extension, between an electrical short-circuit end plate and an edge of the opening that is closest to the end plate, where the stub part also has a stub width extending perpendicular to the longitudinal extension.

6. The microwave transceiver according to claim 5, wherein the tunable filter part comprises a tunable resonance cavity that is arranged to be electrically connected to further resonance cavities by a corresponding cavity iris part.

7. The microwave transceiver according to claim 5, wherein the stub part has a stub width that to the most part either: falls below the waveguide width; exceeds the waveguide width; or equals the waveguide width.

8. The microwave transceiver according to claim 5, wherein the stub length varies between /8 and /2, where denotes the wavelength in air that corresponds to the center frequency in a desired frequency band.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present disclosure will now be described more in detail with reference to the appended drawings, where:

[0016] FIG. 1 shows a schematic perspective view of a tunable waveguide filter input/output coupling arrangement;

[0017] FIG. 2 shows a schematic top cut-open view of a first example of a tunable waveguide filter input/output coupling arrangement;

[0018] FIG. 3 shows a schematic top cut-open view of a second example of a tunable waveguide filter input/output coupling arrangement;

[0019] FIG. 4 shows a schematic top cut-open view of a third example of a tunable waveguide filter input/output coupling arrangement; and

[0020] FIG. 5 shows a schematic view of a microwave transceiver.

DETAILED DESCRIPTION

[0021] With reference to FIG. 1, showing a schematic perspective view of a tunable waveguide filter input/output coupling arrangement, and FIG. 2, showing a corresponding top cut-open view, a first example of a tunable waveguide filter input/output coupling arrangement 1 will now be described.

[0022] The tunable waveguide filter input/output coupling arrangement 1 comprises a waveguide part 2, a coupling iris part 3 and a tunable filter part 4. The waveguide part 2 runs along a longitudinal extension L and has a waveguide width w.sub.w extending perpendicular to the longitudinal extension L, and a waveguide height w.sub.h extending perpendicular to the waveguide width w.sub.w. The waveguide part 2 is electrically connected to the tunable filter part 4 by means of the coupling iris part 3 which comprises an opening 5 between the waveguide part 2 and the tunable filter part 4, where the opening 5 is positioned at a certain position along the longitudinal extension L

[0023] According to the present disclosure, the waveguide part 2 comprises a stub part 6 that has a certain stub length L.sub.s along the longitudinal extension L, between an electrical short-circuit end plate 7 and an edge 8 of the opening 5 that is closest to the end plate 7, where the stub part 6 also has a certain stub width w.sub.s extending perpendicular to the longitudinal extension L. In this example, the stub part 6 has a stub width w.sub.s that is equal to the waveguide width w.sub.w.

[0024] According to some aspects, the tunable filter part 4 comprises at least one tunable resonance cavity 11. Generally, according to some further aspects, the tunable filter part 4 comprises a tunable resonance cavity 11 that is arranged to be electrically connected to further resonance cavities 9 by means of a corresponding cavity iris part 10. In FIG. 2, at least one further resonance cavity 9 is depicted with dashed lines; the tunable filter part 4 can according to some aspects comprise two or more further resonance cavities that are separated by a corresponding cavity iris parts in a previously well-known manner.

[0025] With reference to FIG. 3 that shows a schematic top cut-open view of a second example of a tunable waveguide filter input/output coupling arrangement 1, the stub part 6 has a stub width w's that falls below the waveguide width w.sub.w.

[0026] With reference to FIG. 4 that shows a schematic top cut-open view of a third example of a tunable waveguide filter input/output coupling arrangement 1, the stub part 6 has a stub width ws that to the most part exceeds the waveguide width w.sub.w.

[0027] According to some aspects, as shown in FIG. 2, FIG. 3 and FIG. 4, the stub width affects the design of other parts such as the coupling iris part 3, 3, 3, the opening 5, 5, 5 and the electrical short-circuit end plate 7, 7, 7.

[0028] By means of the present disclosure, with properly chosen dimensions of the stub width w.sub.s and stub length L.sub.s, it is possible to achieve control of dispersion properties of the input/output couplings at the coupling iris part 3, and nearly dispersion-free coupling in a relatively wide frequency band is practically obtainable. In practice, this control of the dispersion properties enables obtaining a nearly constant coupling, as well as a controllable increasing/decreasing coupling, in a relatively wide tuning range.

[0029] By means of the present disclosure, manufacturing is not made more complicated, the tunable waveguide filter input/output coupling arrangement 1 does in fact not require any particular changes into currently used production technology for short haul diplexers or other types of waveguide filters.

[0030] According to some aspects, the stub length L.sub.s varies between /8 and /2 where denotes the wavelength in air that corresponds to the center frequency in a desired frequency band.

[0031] With reference to FIG. 5, schematically showing a microwave transceiver 12, the microwave transceiver 12 comprises a waveguide filter device 13 that in turn comprises a tunable waveguide filter input/output coupling arrangement 1 according to the above. According to some aspects, the microwave transceiver 12 is used in a radio link device.

[0032] The present disclosure is not limited to the above, but may vary within the scope of the appended claims. For example, it is conceivable that the stub width varies in a continuous or stepped manner, at least along a part of the stub length L.sub.s.

[0033] The waveguide part 2 is shown to have a continuation with dashed lines in all the Figures. The waveguide part 2 can according to some aspects continue in a bend, such as a 90 bend, or continue by being connected to another waveguide part.

[0034] The waveguide parts may be made in any suitable metal such as aluminum, or as a metal plating on a non-conducting material such as plastics. A metal plating can also be used to cover another metal totally or partially.

[0035] Generally, the present disclosure relates to a tunable waveguide filter input/output coupling arrangement 1 comprising a waveguide part 2, a coupling iris part 3 and a tunable filter part 4, where the waveguide part 2 runs along a longitudinal extension L and has a waveguide width w.sub.w extending perpendicular to the longitudinal extension L, and a waveguide height w.sub.h extending perpendicular to the waveguide width w.sub.w, where the waveguide part 2 is electrically connected to the tunable filter part 4 by means of the coupling iris part 3 which comprises an opening 5 between the waveguide part 2 and the tunable filter part 4, where the opening 5 is positioned at a certain position along the longitudinal extension L. The waveguide part 2 comprises a stub part 6 that has a certain stub length L.sub.s along the longitudinal extension L, between an electrical short-circuit end plate 7 and an edge 8 of the opening 5 that is closest to the end plate 7, where the stub part 6 also has a stub width w.sub.s extending perpendicular to the longitudinal extension L.

[0036] According to some aspects, the tunable filter part 4 is constituted by a tunable resonance cavity that is arranged to be electrically connected to further resonance cavities 9 by means of a corresponding cavity iris part 10.

[0037] According to some aspects, the stub part 6, 6, 6 has a stub width w.sub.s w.sub.s w.sub.s that to the most part either:

[0038] falls below the waveguide width w.sub.w;

[0039] exceeds the waveguide width w.sub.w; or

[0040] equals the waveguide width w.sub.w.

[0041] According to some aspects, the stub length L.sub.s varies between /8 and /2 where denotes the wavelength in air that corresponds to the center frequency in a desired frequency band.

[0042] Generally, the present disclosure also relates to a microwave transceiver 12 comprising a tunable waveguide filter input/output coupling arrangement 1 that in turn comprises a waveguide part 2, a coupling iris part 3 and a tunable filter part 4, where the waveguide part 2 runs along a longitudinal extension L and has a waveguide width w.sub.w extending perpendicular to the longitudinal extension L, and a waveguide height w.sub.h extending perpendicular to the waveguide width w.sub.w, where the waveguide part 2 is electrically connected to the tunable filter part 4 by means of the coupling iris part 3 which comprises an opening 5 between the waveguide part 2 and the tunable filter part 4, where the opening 5 is positioned at a certain position along the longitudinal extension L. The waveguide part 2 comprises a stub part 6 that has a certain stub length L.sub.s along the longitudinal extension L, between an electrical short-circuit end plate 7 and an edge 8 of the opening 5 that is closest to the end plate 7, where the stub part 6 also has a stub width w.sub.s extending perpendicular to the longitudinal extension L.