# US 2021/0242587 A1 · Multiband antenna feed

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- Number: US 2021/0242587 A1
- Document ID: US20210242587A1
- Status: Published application
- Kind: A1
- Application number: 17/050,651
- Filed: 2019-04-26
- Published: 2021-08-05
- Earliest claimed: 2018-04-27
- Assignees: Nokia Shanghai Bell Co., Ltd.
- Applicants: Nokia Shanghai Bell Co., Ltd.
- Inventors: Yoann Letestu; Denis Tuau
- Web page: https://patentgrep.com/patent/US20210242587A1

## CPC

- H01P 1/2131: {with combining or separating polarisations}
- H01P 1/16: for mode selection, e.g. mode suppression or mode promotion; for mode conversion
- H01P 1/2138: {using hollow waveguide filters (H01P1/2131 takes precedence)}
- H01P 5/20: Magic-T junctions
- H01Q 5/47: with a coaxial arrangement of the feeds
- H01Q 5/50: Feeding or matching arrangements for broad-band or multi-band operation
- H01P: WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE (operating at optical frequencies G02B)
- H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72)

## Abstract

A multiband antenna feed, an antenna incorporating the multiband antenna feed and a method are disclosed. An apparatus, comprises: a first port which may be configured to convey a first signal at a first frequency. A second port may configured to convey a second signal at a second frequency. The second frequency may be higher than the first frequency. A third port may be configured to convey the first signal and the second signal with a feed for a multiband antenna. The third port may have an inner waveguide and a coaxial waveguide. A first network may couple the first port with the coaxial waveguide and may be configured to propagate the first signal between the first port and the coaxial waveguide. A second network may couple the second port with the inner waveguide and may be configured to propagate the second signal between the second port and the inner waveguide.

## Claims

### Claim 1

An apparatus, comprising:
a first port configured to convey a first signal at a first frequency;
a second port configured to convey a second signal at a second frequency, said second frequency being higher than said first frequency;
a third port configured to convey said first signal and said second signal with a feed for a multiband antenna, said third port having an inner waveguide and an coaxial waveguide;
a first network coupling said first port with said coaxial waveguide and configured to propagate said first signal between said first port and said coaxial waveguide; and
a second network coupling said second port with said inner waveguide and configured to propagate said second signal between said second port and said inner waveguide.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein said coaxial waveguide at least partially surrounds said inner waveguide.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein an inner surface of said coaxial waveguide defines an outer surface of said inner waveguide.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein an inner diameter of said inner waveguide is selected to propagate a designated mode.

### Claim 5 (depends on 4)

The apparatus of claim 4, wherein an outer diameter of said inner waveguide together with said inner diameter of said coaxial waveguide is selected to propagate a designated mode.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein said inner waveguide is dimensioned to propagate a TE11 circular mode.

### Claim 7 (depends on 1)

The apparatus of claim 1, wherein said coaxial waveguide is dimensioned to propagate a TE11 coaxial mode.

### Claim 8 (depends on 1)

The apparatus of claim 1, wherein said first network comprises a junction configured to convert said first signal between a first mode in said first network and a coaxial mode in said coaxial waveguide.

### Claim 9 (depends on 1)

The apparatus of claim 1, wherein said first network comprises a first signal splitter configured to convert between said first signal and an in-phase first signal and an opposing phase first signal.

### Claim 10 (depends on 9)

The apparatus of claim 9, wherein said first signal splitter comprises a T-junction splitter having a splitter port configured to convey said first signal, an in-phase port configured to convey said in-phase first signal and an opposing phase port configured to convey said opposing phase first signal.

### Claim 11 (depends on 10)

The apparatus of claim 10, wherein said first network comprises a first pair of coupling waveguides, one of said coupling waveguides coupling said in-phase port with said junction and another of said coupling waveguides coupling said opposing phase port with said junction.

### Claim 12 (depends on 11)

The apparatus of claim 11, wherein said one of said coupling waveguides couples with one side of said junction and said another of said coupling waveguides couples with an opposing side of said junction.

### Claim 13 (depends on 1)

The apparatus of claim 1, comprising a fourth port configured to convey a third signal at a third frequency and with a differing polarization to said first signal, said third frequency being higher than said first frequency and wherein said first network couples said fourth port with said coaxial waveguide and is configured to propagate said third signal between said fourth port and said coaxial waveguide.

### Claim 14 (depends on 13)

The apparatus of claim 13, wherein said third frequency matches said first frequency.

### Claim 15 (depends on 13)

The apparatus of claim 13, wherein said first network comprises a second signal splitter configured to convert between said third signal and an in-phase third signal and an opposing phase third signal.

### Claim 16 (depends on 15)

The apparatus of claim 15, wherein said second signal splitter comprises a T-junction splitter having a splitter port configured to convey said third signal, an in-phase port configured to convey said in-phase third signal and an opposing phase port configured to convey said opposing phase third signal.

### Claim 17 (depends on 16)

The apparatus of claim 16, wherein said first network comprises a second pair of coupling waveguides, one of said coupling waveguides coupling said in-phase port with said junction and another of said coupling waveguides coupling said opposing phase port with said junction.

### Claim 18 (depends on 17)

The apparatus of claim 17, wherein said one of said coupling waveguides couples with one side of said junction and said another of said coupling waveguides couples with an opposing side of said junction.

### Claim 19 (depends on 17)

The apparatus of claim 17, wherein said second pair of coupling waveguides couple with said junction at positions intermediate said first pair of coupling waveguides.

### Claim 20 (depends on 8)

The apparatus of claim 8, wherein said junction has waveguides extending radially therefrom, each coupled with a corresponding coupling waveguide.

### Claim 21 (depends on 1)

The apparatus of claim 1, wherein said waveguides comprise tuning protrusions.

### Claim 22 (depends on 8)

The apparatus of claim 8, wherein said junction comprises tuning surface variations intermediate said waveguides.

### Claim 23 (depends on 8)

The apparatus of claim 8, wherein said junction comprises a coaxial turnstile junction.

### Claim 24 (depends on 13)

The apparatus of claim 13, wherein said first signal and third signal have a matching frequency and differing polarizations.

### Claim 25 (depends on 1)

The apparatus of claim 1 wherein, portions of said first network comprise waveguides of differing orientations.

### Claim 26 (depends on 1)

The apparatus of claim 1, wherein said first network comprises a rotator configured to change a polarization of a signal passing therethrough.

### Claim 27 (depends on 1)

The apparatus of claim 1, wherein said first network comprises rectangular waveguides.

### Claim 28 (depends on 1)

The apparatus of claim 1, wherein said inner waveguide comprise a circular waveguide.

### Claim 29 (depends on 1)

The apparatus of claim 1, wherein said second network comprises one of a rectangular-to-circular waveguide transition and a circular-to-circular waveguide transition.

### Claim 30 (depends on 1)

The apparatus of claim 1, defined by a series of stacked plates.

### Claim 31 (depends on 1)

The apparatus of claim 1, wherein said apparatus comprises a backfire dual band feed.

### Claim 32 (depends on 1)

The apparatus of claim 1, wherein said antenna comprises a parabolic antenna.

### Claim 33 (depends on 1)

An antenna comprising said apparatus as claimed in claim 1.

### Claim 34

A method, comprising:
conveying a first signal at a first frequency at a first port;
conveying a second signal at a second frequency at a second port, said second frequency being higher than said first frequency;
coupling said first port with a coaxial waveguide using a first network configured to propagate said first signal between said first port and said coaxial waveguide;
coupling said second port with an inner waveguide using a second network configured to propagate said second signal between said second port and said inner waveguide; and
conveying said first signal and said second signal with a third port having said inner waveguide and said coaxial waveguide and a feed for a multiband antenna.