WO2020192888A1

WO2020192888A1 - Means and method for antenna alignment

Info

Publication number: WO2020192888A1
Application number: PCT/EP2019/057461
Authority: WO
Inventors: Jan Sandberg; Stefan THÖRESSON; Martin Johansson
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2019-03-25
Filing date: 2019-03-25
Publication date: 2020-10-01

Abstract

The present disclosure relates to a removable film structure (208, 308) adapted to be at least partly attached on, or in front of, an antenna aperture (207) comprised in an antenna device (101). The film structure (208, 308) comprises one or more removable films (203; 303A, 303B, 303C, 303D), where each film (203; 303A, 303B, 303C, 303D) has a first microwave attenuation and comprises at least one electric aperture (204; 304A, 304B, 304C, 304D) adapted to be positioned at least partly on, or in front of, the antenna aperture (207) such that the film structure (208, 308) comprises at least one combined electric aperture (205, 305) adapted to be positioned at least partly on, or in front of, the antenna aperture (207, 307). Each electric aperture (204; 304A, 304B, 304C, 304D) has a second microwave attenuation that falls below the first microwave attenuation.

Description

TITLE

Means and method for antenna alignment TECHNICAL FIELD

The present disclosure relates to means for alleviating alignment of a first directive antenna in a direction towards a second antenna.

BACKGROUND

Microwave link communication is performed between microwave link nodes positioned at different sites, where two microwave link nodes that are adapted to communicate with each other constitute a microwave link hop. A microwave link node typically comprises a mast onto which a microwave radio transceiver and a link antenna are mounted.

Alignment of a microwave link hop between two sites is normally based on manual work where at least two persons should be located at each site, one person climbing the mast while the other person is remaining at the ground. The person that climbs the masts at each site has to carry antenna mount equipment including a mast bracket, the link antenna, the microwave radio transceiver and several tools. The link antenna with the antenna mount is assembled on the mast; a rough alignment is done before the bracket is fixed. The microwave radio transceiver is assembled onto and connected to the link antenna, and is then turned on.

A final alignment is done by one person at each mast by means of adjustment screws located in different positions on the antenna mount. When best Received Signal Strength Indication (RSSI) is found on each site, the persons in the masts tighten a number of locking screws and nuts on the respective antenna mount, and then the deployment is finished.

If re-alignment is needed, the alignment procedure is repeated for the already mounted equipment.

For all alignment procedures, the narrower the beam width, the more difficult the alignment procedure becomes. A large antenna can have a relatively narrow beam, for example in the order of 0.3 degrees 3 dB beamwidth, or smaller.

SUMMARY

It is an object of the present disclosure to provide enhanced means for alignment of an antenna device, for example a microwave link antenna or other directive antenna device, towards another antenna device. It is also an object of the present disclosure to provide an enhanced method for alignment of a directive antenna in a direction towards another antenna. This object is obtained by means of a removable film structure adapted to be at least partly attached on, or in front of, an antenna aperture comprised in an antenna device, where the film structure comprises one or more removable films. Each film has a first microwave attenuation and comprises at least one electric aperture adapted to be positioned at least partly on, or in front of, the antenna aperture such that the film structure comprises at least one combined electric aperture adapted to be positioned at least partly on, or in front of, the antenna aperture. Each electric aperture has a second microwave attenuation that falls below the first microwave attenuation.

This means that, installation time is reduced and installation is made easier. A wider beam and a distinct peak for accurate alignment is obtained with a film structure mounted, avoiding alignment towards a side lobe. Even if the antennas to be aligned are not optimized toward each other, transmitted power can be detected, and the antenna device can be adjusted to maximize power between the antennas to be aligned.

According to some aspects, the film structure is adapted to be attached to an antenna radome.

In this manner, the film structure can be used for re-alignment at an existing site.

According to some aspects, each film is made in a dielectric material, and where each electric aperture is constituted by air.

According to some aspects, each film comprises water, and where each electric aperture is constituted by air.

This means that the films can be made in many ways.

According to some aspects, each film has a thickness that corresponds to a quarter wavelength in the film material for a frequency in a frequency band for which the antenna device is intended.

In this manner, an efficient microwave attenuation is accomplished.

According to some aspects, the power reduction inferred by means the removable film structure is at least 4dB.

In this manner, a sufficient beam width is ensured.

According to some aspects, in the case of the film structure comprising two or more films, the electric apertures are of such size and corresponding alignment such that after one film has been removed, the present combined electric aperture is larger than the previous combined electric aperture.

In this manner, for each removed film, the beam becomes narrower for each removed film, enabling more accurate alignment.

According to some aspects, each electric aperture has a shape that is oval, square, or polygonal.

This enables beam shaping such that desired beam patterns and side lobe patterns can be obtained.

This object is also obtained by means of methods that are associated with the above advantages.

More in detail, this object is also obtained by means of a method for aligning a first directive antenna in a direction towards a second antenna, where the method comprises generating an alignment control signal. For each one of one or more removable films comprised in a removable film structure at least partly attached on, or in front of, an antenna aperture of the first antenna the method further comprises actuating alignment of the first directive antenna based on the alignment control signal, and removing an outer film. When the last film has been removed, the method comprises actuating alignment of the first directive antenna based on the alignment control signal. Each film has a first microwave attenuation and comprises at least one electric aperture east partly on, or in front of, the antenna aperture such that the film structure comprises at least one combined electric aperture at least partly on, or in front of, the antenna aperture. Each electric aperture has a second microwave attenuation that falls below the first microwave attenuation.

BRIEF DESCRIPTION OF THE DRAWINGS

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

Figure 1 schematically shows two microwave link nodes;

Figure 2A schematically shows an antenna device with one film attached; Figure 2B schematically shows an antenna device with one film removed;

Figure 3A schematically shows a film structure with four films attached to each other;

Figure 3B schematically shows a film structure with four films separated from each other;

Figure 4A-4E schematically show an example of how alignment can be performed; and Figure 5 shows flowcharts of methods according to embodiments.

DETAILED DESCRIPTION

Aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings. The different devices, systems, computer programs and methods disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein. Like numbers in the drawings refer to like elements throughout.

The terminology used herein is for describing aspects of the disclosure only and is not intended to limit the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

With reference to Figure 1, there is a first microwave link node 121 and a second microwave link node 122 comprised in a communication system 100. The first microwave link node 121 comprises a first directive antenna 101, a first microwave radio transceiver 129 that is attached to the first directive antenna 101, and a first alignment device 110 that also is attached to the first directive antenna 101. The first microwave link node 121 also comprises a first mast 131 onto which the first alignment device 110 is attached.

Correspondingly, the second microwave link node 122 comprises a second directive antenna 102, a second microwave radio transceiver 130 that is attached to the second directive antenna 102, and a second alignment device 120 that also is attached to the second directive antenna 102. The second microwave link node 122 also comprises a second mast 132 onto which the second alignment device 120 is attached. According to some aspects, each alignment device 110, 120 comprises mounting brackets and adjustment screws located in different positions. By rotating these screws, the alignment of the corresponding antenna is affected in a previously well-known manner. In the following the first directive antenna 101 will be used for the further discussions with reference to Figure 2A and Figure 2B showing a first example, and it should be understood that the following discussions also are applicable for the second directive antenna 102 as well.

The first directive antenna 101 comprises an antenna aperture 207 and an antenna radome 206 that covers the antenna aperture 207. According to the present disclosure, a removable film structure 208 is attached on the radome 206, in front of the antenna aperture 207, and comprises a removable film 203 that is made in a dielectric material. The film 203 has a first microwave attenuation and comprises an electric aperture 204 that generally constitutes a combined electric aperture 20 that is positioned in front of the antenna aperture 207. The electric aperture 204 has a second microwave attenuation that falls below the first microwave attenuation, and in this example, according to some aspects, the electric aperture is constituted by an air-filled opening in the film 203.

The removable film 203 is attached to the radome 206 by means of an adhesive that admits removing, for example by pulling a tab 209 comprised in the film 203. As shown in Figure 2B, the film 203 has been removed from the radome 206.

This means that the first directive antenna 101 is adapted for radiating a wider antenna beam when the film 203 is attached to the radome 206 than when the film 203 has been removed from the radome 206 since the efficient antenna aperture of the first directive antenna 101 is enlarged when the film 203 has been removed from the radome 206. The alignment of the first directive antenna 101 is thus made easier due to that the power can be detected although not the antennas 101, 102 have been centered. This means that even if the antennas 101, 102 are not optimized toward each other, transmitted power can be detected, and the first directive antenna 101 can be adjusted to maximize power between the antennas 101, 102.

When aligning first directive antenna 101, the film structure 308 with its single film 303 is first attached to the radome 206, resulting in a first antenna beam used for alignment. When alignment has been performed to satisfaction, the film 203 is removed from the radome 206, resulting is a second antenna beam that is narrower than the first antenna beam. In this manner, fine tuning of the alignment can be performed, until a satisfactory alignment result has been obtained. This will described more in detail for a following second example.

With reference to Figure 3A and Figure 3B, according to some aspects, the film structure 308 comprises two or more removable films 303A, 303B, 303C, 303D. In a second example that will be described more in detail below, four removable films 303A, 303B, 303C, 303D are shown. In Figure 3A there is a film structure 308 where the films 303A, 303B, 303C, 303D are shown mounted to each other, and in Figure 3B the films 303A, 303B, 303C, 303D are shown separated from each other. The films 303A, 303B, 303C, 303D are attached to each other by means of an adhesive that admits separating the from each other, for example by pulling a corresponding tab 309A, 309B, 309C, 309D comprised in each film 303A, 303B, 303C, 303D. Suitably, the tabs 309A, 309B, 309C, 309D lack any adhesive, making separation easier. Although not shown in Figure 3 A and Figure 3B. the film structure 308 is adapted to be adhered to an antenna radome, for example the radome 206 of the first directive antenna 101 as shown for the first example of a film structure 208 that comprises only a single film in Figure 2A.

Each film 303A, 303B, 303C, 303D is made in a dielectric material, has a first microwave attenuation and comprises a corresponding electric aperture 304A, 304B, 304C, 304D that together generally constitute a combined electric aperture 305 that is adapted to be positioned in front of an antenna aperture 207. Each electric aperture 304A, 304B, 304C, 304D has a second microwave attenuation that falls below the first microwave attenuation, in this example, according to some aspects, each electric aperture 304A, 304B, 304C, 304D is constituted by an air-filled opening in the corresponding film 303A, 303B, 303C, 303D.

The electric apertures 304A, 304B, 304C, 304D are of such size and corresponding alignment such that after one film has been removed, the present combined electric aperture is larger than the previous combined electric aperture, as is apparent from Figure 3B. In Figure 3B, the electric apertures 304A, 304B, 304C, 304D are shown aligned with each other, but this does not have to be the case. It is, however, desired that the present combined electric aperture is larger than the previous combined electric aperture.

In this way, when the film structure 308 is mounted to the radome 206 of the first directive antenna 101, the first directive antenna 101 is adapted for radiating a wider antenna beam when the film structure 308 is attached to the radome 206 than when the film structure 308 has been removed from the radome 206 since the efficient antenna aperture of the first directive antenna 101 is enlarged when the film structure 308 has been removed from the radome 206. For each film 303A, 303B, 303C, 303D that is removed from the film structure 308, the efficient antenna aperture of the first directive antenna 101 is enlarged since the electric apertures 304A, 304B, 304C, 304D become larger the closer they are poisoned to the radome 206.

With reference also to Figure 4A, when aligning first directive antenna 101, the film structure 308 is first attached to the radome 206, such that there is a first, outermost, film 303A with a first electric aperture 304 A, such that there is a first combined electric aperture 405 A resulting in a first antenna beam 410A used for a first alignment procedure. With reference also to Figure 4B, when the first alignment alignment has been performed to satisfaction, the first film 303A is removed from a second, next, film 303B with a second electric aperture 304B, such that a second combined electric aperture 405B is formed, resulting in a second antenna beam 41 OB that is narrower than the first antenna beam 410A. In this manner, a more accurate fine tuning of the alignment can be performed in a second alignment procedure.

Then, with reference also to Figure 4C, the second film 303B is removed from a third, next, film 303C with a third electric aperture 304C, such that a third combined electric aperture 405C is formed, resulting in a third antenna beam 4 IOC that is narrower than the second antenna beam 41 OB, allowing an even more accurate fine tuning of the alignment to be performed in a third alignment procedure. Then, with reference also to Figure 4D, the third film 303C is removed from a fourth, next, film 303D with a fourth electric aperture 304D, such that a fourth combined electric aperture 405 D is formed, resulting in a fourth antenna beam 410D that is narrower than the third antenna beam 4 IOC, allowing an even more accurate fine tuning of the alignment to be performed in a fourth alignment procedure. Finally, with reference also to Figure 4E, the fourth and last film 303D is removed from the radome 206 such that the original antenna aperture 207 is revealed, resulting in a fifth antenna beam 410E that is narrower than the fourth antenna beam 410D, allowing a final alignment that constitutes the most accurate fine tuning to be performed in a fifth alignment procedure. If considered redundant, the fifth alignment procedure can be omitted. All films 303A, 303B, 303C, 303D should, however, be removed such that the first directive antenna 101 can work according to its full efficiency.

Each alignment is performed until a satisfactory alignment result has been obtained. According to some aspects, the second antenna 102 is also a directive antenna, and a removable film structure 208, 308 is attached to the second antenna 102 as well. The alignment of the first directive antenna 101 is thus made easier due to that the power can be detected although not the antennas 101, 102 have been centered. This means that even if the antennas 101, 102 are not optimized toward each other, transmitted power can be detected, and the first directive antenna 101 can be adjusted to maximize power between the antennas 101, 102.

According to some aspects, with reference also to Figure 5, the present disclosure also relates to a method for aligning a first directive antenna 101 in a direction D1 towards a second antenna 102, where the method comprises generating S 1 an alignment control signal.

Furthermore, for each one of one or more removable films 203; 303A, 303B, 303C, 303D comprised in a removable film structure 208, 308 at least partly attached on, or in front of, an antenna aperture 207, 307 of the first antenna 101 the method comprises actuating alignment S2 of the first directive antenna 101 based on the alignment control signal; and removing S3 an outer film 203; 303A, 303B, 303C, 303D. When the last film has been removed, the method comprises actuating alignment S4 of the first directive antenna 101 based on the alignment control signal. Each film 203; 303A, 303B, 303C, 303D has a first microwave attenuation and comprises at least one electric aperture 204; 304A, 304B, 304C, 304D east partly on, or in front of, the antenna aperture 207, 307 such that the film structure 208, 308 comprises at least one combined electric aperture 205, 305 at least partly on, or in front of, the antenna aperture 207, 307. Each electric aperture 204; 304A, 304B, 304C, 304D has a second microwave attenuation that falls below the first microwave attenuation. In the case on only a single film being comprised in the removable film structure 208. this film constitutes an outer film when mounted.

According to some aspects, the method comprises obtaining S 11 an indicator signal configured to indicate a level of alignment of the first directive antenna 101 with respect to the second antenna 102, and generating S12 the control signal based on the indicator signal.

According to some aspects, the indicator signal comprises a received signal strength indication (RSSI) value.

According to some aspects, actuating alignment S2, S4 of the first directive antenna 101 comprises directing S51 the first directive antenna 101 towards the second antenna 102, measuring S52 signal strength between the antennas 101, 102, and adjusting S53 the first directive antenna 101 such that the signal strength is maximized.

According to some aspects, the method comprises at least partly attaching the removable film structure 208, 308 on, or in front of, the antenna aperture 207, 307 of the first antenna 101.

According to some aspects, the method comprises using a removable film structure 208, 308 where each film 203; 303A, 303B, 303C, 303D is made in a dielectric material, and where each electric aperture 204; 304A, 304B, 304C, 304D is constituted by air.

According to some aspects, the method comprises using a removable film structure 208, 308 where each film 203; 303A, 303B, 303C, 303D comprises water, and where each electric aperture 204; 304A, 304B, 304C, 304D is constituted by air.

According to some aspects, the method comprises using a removable film structure 208, 308 where each film 203; 303A, 303B, 303C, 303D has a thickness that corresponds to a quarter wavelength in the film material for a frequency in a frequency band for which the antenna device 101 is intended. According to some aspects, the method comprises using a removable film structure 208, 308 where the power reduction inferred by means the removable film structure 208, 308 is at least 4dB.

According to some aspects, the method comprises using a removable film structure 308 having two or more films 303 A, 303B, 303C, 303D, where the electric apertures 304A, 304B, 304C, 304D are of such size and corresponding alignment such that after one film has been removed, the present combined electric aperture is larger than the previous combined electric aperture.

According to some aspects, the method comprises using a removable film structure 208, 308 where each electric aperture 204; 304A, 304B, 304C, 304D has a shape that is oval, square, or polygonal.

The present disclosure is not limited to the above, but may vary freely within the scope the appended claims. For example, according to some aspects, each film 203; 303A, 303B, 303C, 303D comprises water, and each electric aperture 204; 304A, 304B, 304C, 304D is constituted by air. In this case, the water should be confined by means of enclosing dielectric layers.

According to some aspects, each film 203; 303A, 303B, 303C, 303D is made in a dielectric material, and where each electric aperture 204; 304A, 304B, 304C, 304D is constituted by air. Each film can be comprised by several dielectric layers having the same, or mutually different, material properties such as dielectric properties.

The term electric aperture relates to that it according to some aspects does not have to be constituted by a physical opening, but can be made in another material than the corresponding film, the material in an electric aperture having lower microwave attenuation than the dielectric material in the corresponding film 203; 303A, 303B, 303C, 303D. Each electric aperture 204; 304A, 304B, 304C, 304D is according to some aspects constituted by a dielectric material that has a lower microwave attenuation than the dielectric material in each corresponding film 203; 303 A, 303B, 303C, 303D.

According to some aspects, each film 203; 303A, 303B, 303C, 303D has a thickness that corresponds to a quarter wavelength in the film material for a frequency in a frequency band for which the antenna device 101 is intended.

According to some aspects, the power reduction inferred by means the removable film structure 208, 308 is at least 4dB.

According to some aspects, when there is not antenna radome, the film structure 208, 308 is generally adapted to be at least partly attached on, or in front of, an antenna aperture 207. This means that the film structure 208, 308 for example can be positioned directly on an antenna surface and/or antenna elements, such as for example microstrip patch antenna elements or slot antenna elements.

By means of the present disclosure, installation time is reduced and installation made easier. A wider beam and a distinct peak for accurate alignment is obtained with a film structure mounted, avoiding alignment towards a side lobe. Alignment can according to some aspects be regarded as accomplished when the last or only film is removed, but normally some fine tuning may be necessary when all films have been removed.

According to some aspects, an electric aperture 204; 304A, 304B, 304C, 304D does not have to be circular as shown in the Figures, but can have any suitable shape, where a certain shape enables beam shaping such that desired beam patterns and side lobe patterns can be obtained. Such shapes can for examples be oval, square, and polygonal.

The electric apertures 204; 304A, 304B, 304C, 304D in the examples have been shown to be more or less centered on the antenna aperture in the examples. This does not have to been the case, any suitable offset can of course be implemented. The electric apertures 204; 304A, 304B, 304C, 304D can thus have any suitable shape and position.

Generally, the present disclosure relates to a removable film structure 208, 308 adapted to be at least partly attached on, or in front of, an antenna aperture 207 comprised in an antenna device 101. The film structure 208, 308 comprises one or more removable films 203; 303A, 303B, 303C, 303D, where each film 203; 303A, 303B, 303C, 303D has a first microwave attenuation and comprises at least one electric aperture 204; 304A, 304B, 304C, 304D adapted to be positioned at least partly on, or in front of, the antenna aperture 207 such that the film structure 208, 308 comprises at least one combined electric aperture 205, 305 adapted to be positioned at least partly on, or in front of, the antenna aperture 207, 307. Each electric aperture 204; 304A, 304B, 304C, 304D has a second microwave attenuation that falls below the first microwave attenuation.

According to some aspects, the film structure 208, 308 is adapted to be attached to an antenna radome.

According to some aspects, in the case of the film structure 308 comprising two or more films 303A, 303B, 303C, 303D, the electric apertures 304A, 304B, 304C, 304D are of such size and corresponding alignment such that after one film has been removed, the present combined electric aperture is larger than the previous combined electric aperture. According to some aspects, each electric aperture 204; 304A, 304B, 304C, 304D has a shape that is oval, square, or polygonal.

Claims

1. A removable film structure (208, 308) adapted to be at least partly attached on, or in front of, an antenna aperture (207) comprised in an antenna device (101), where the film structure (208, 308) comprises one or more removable films (203; 303A, 303B, 303C, 303D), where each film (203; 303A, 303B, 303C, 303D) has a first microwave attenuation and comprises at least one electric aperture (204; 304A, 304B, 304C, 304D) adapted to be positioned at least partly on, or in front of, the antenna aperture (207) such that the film structure (208, 308) comprises at least one combined electric aperture (205, 305) adapted to be positioned at least partly on, or in front of, the antenna aperture (207, 307), where each electric aperture (204; 304A, 304B, 304C, 304D) has a second microwave attenuation that falls below the first microwave attenuation.

2. The film structure (208, 308) according to claim 1, wherein the film structure (208, 308) is adapted to be attached to an antenna radome.

3. The film structure (208, 308) according to any one of the claims 1 or 2, wherein each film (203; 303A, 303B, 303C, 303D) is made in a dielectric material, and where each electric aperture (204; 304A, 304B, 304C, 304D) is constituted by air.

4. The film structure (208, 308) according to any one of the claims 1 or 2, wherein each film (203; 303A, 303B, 303C, 303D) comprises water, and where each electric aperture (204; 304A, 304B, 304C, 304D) is constituted by air.

5. The film structure (208, 308) according to any one of the previous claims, wherein each film (203; 303 A, 303B, 303C, 303D) has a thickness that corresponds to a quarter wavelength in the film material for a frequency in a frequency band for which the antenna device (101) is intended.

6. The film structure (208, 308) according to any one of the previous claims, wherein the power reduction inferred by means the removable film structure (208, 308) is at least 4dB.

7. The film structure (208, 308) according to any one of the previous claims, wherein, in the case of the film structure (308) comprising two or more films (303A, 303B, 303C, 303D), the electric apertures (304A, 304B, 304C, 304D) are of such size and corresponding alignment such that after one film has been removed, the present combined electric aperture is larger than the previous combined electric aperture.

8. The film structure (208, 308) according to any one of the previous claims, wherein each electric aperture (204; 304A, 304B, 304C, 304D) has a shape that is oval, square, or polygonal.

9. A method for aligning a first directive antenna (101) in a direction D1 towards a second antenna (102), the method comprising:

generating (SI) an alignment control signal;

for each one of one or more removable films (203; 303A, 303B, 303C, 303D) comprised in a removable film structure (208, 308) at least partly attached on, or in front of, an antenna aperture (207, 307) of the first antenna (101) the method further comprises:

actuating alignment (S2) of the first directive antenna (101) based on the alignment control signal; and

removing (S3) an outer film (203; 303A, 303B, 303C, 303D);

and when the last film has been removed, the method comprises:

actuating alignment (S4) of the first directive antenna (101) based on the alignment control signal;

where each film (203; 303A, 303B, 303C, 303D) has a first microwave attenuation and comprises at least one electric aperture (204; 304A, 304B, 304C, 304D) east partly on, or in front of, the antenna aperture (207, 307) such that the film structure (208, 308) comprises at least one combined electric aperture (205, 305) at least partly on, or in front of, the antenna aperture (207, 307), where each electric aperture (204; 304A, 304B, 304C, 304D) has a second microwave attenuation that falls below the first microwave attenuation.

10. The method according to claim 9, wherein the method comprises:

obtaining (SI 1) an indicator signal configured to indicate a level of alignment of the first directive antenna (101) with respect to the second antenna (102), and

generating (SI 2) the control signal based on the indicator signal.

11. The method according to claim 10, wherein the indicator signal comprises a received signal strength indication, RSSI, value.

12. The method according to any one of the claims 9-11, wherein actuating alignment (S2, S4) of the first directive antenna (101) comprises:

directing (S51) the first directive antenna (101) towards the second antenna (102); measuring (S52) signal strength between the antennas (101, 102); and adjusting (S53) the first directive antenna (101) such that the signal strength is maximized.

13. The method according to any one of the claims 9-12, wherein the method comprises at least partly attaching the removable film structure (208, 308) on, or in front of, the antenna aperture (207, 307) of the first antenna (101).

14. The method according to any one of the claims 9-13, wherein the method comprises using a removable film structure (208, 308) where each film (203; 303A, 303B, 303C, 303D) is made in a dielectric material, and where each electric aperture (204; 304A, 304B, 304C, 304D) is constituted by air.

15. The method according to any one of the claims 9-13, wherein the method comprises using a removable film structure (208, 308) where each film (203; 303A, 303B, 303C, 303D) comprises water, and where each electric aperture (204; 304A, 304B, 304C, 304D) is constituted by air.

16. The method according to any one of the claims 9-15, wherein the method comprises using a removable film structure (208, 308) where each film (203; 303A, 303B, 303C, 303D) has a thickness that corresponds to a quarter wavelength in the film material for a frequency in a frequency band for which the antenna device (101) is intended.

17. The method according to any one of the claims 9-16, wherein the method comprises using a removable film structure (208, 308) where the power reduction inferred by means the removable film structure (208, 308) is at least 4dB.

18. The method according to any one of the claims 9-17, wherein the method comprises using a removable film structure (308) having two or more films (303A, 303B, 303C, 303D), where the electric apertures (304A, 304B, 304C, 304D) are of such size and corresponding alignment such that after one film has been removed, the present combined electric aperture is larger than the previous combined electric aperture.

19. The method according to any one of the claims 9-18, wherein the method comprises using a removable film structure (208, 308) where each electric aperture (204; 304A, 304B, 304C, 304D) has a shape that is oval, square, or polygonal.