Antenna apparatus for improved polarization purity

Abstract

The present disclosure relates to an antenna apparatus comprising an array of antenna elements and a dielectric element. The dielectric element is arranged on an outer surface of the antenna. The antenna apparatus further comprises one or more polarizer elements arranged in front of the antenna. At least one polarizer element within the one or more polarizer elements is arranged with respect to the array of antenna elements, e.g., in front of one or some of the antenna elements within the array of antenna elements.

Description

[0001] ANTENNA APPARATUS FOR IMPROVED POLARIZATION PURITY

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to the field of antennas that radiate radio waves. Some example embodiments relate to an antenna apparatus comprising one or more polarizer elements.

[0004] BACKGROUND

[0005] Millimeter-wave end-fire antennas are an essential part of future 5G compatible mobile devices. Thin mobile devices such as foldable phones present a challenge for antenna performance. Traditionally, in order to radiate to an edge (end-fire) direction of the device a window opening is carved into a metal frame of the device and filled with, e.g., plastic or glass. Since the thickness of the metal frame of the mobile device may be reduced to 5 mm or even less, the dimensions of the window must also be very reduced, such as less than 3 mm, to ensure mechanical strength and robustness of the device. In order to avoid an imbalance between polarizations and to electrically enlarge the window opening two linear slanted polarizations may be used.

[0006] Due to the constrained dimensions of the filled window and its effects on horizontal and vertical components of radiation waves propagating from the antenna, polarization purity radiated by the antenna volume may be degraded. Therefore, there is a need for a solution recovering or improving the polarization purity of the antenna apparatus.

[0007] SUMMARY

[0008] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0009] Example embodiments of the present disclosure provide an antenna apparatus that is designed to be integrated in an electronic device of limited thickness such as, e.g., a handheld electronic device (a smartphone, a tablet, or a laptop), and configured to operate efficiently in different frequency bands of radio spectrum. This benefit may be achieved by the features of the independent claims. Further example embodiments are provided in the dependent claims, the detailed description, and the drawings.

[0010] According to a first aspect, an antenna apparatus is disclosed. The apparatus may comprise: An antenna comprising an array of antenna elements. A dielectric element arranged on an outer surface of the antenna. One or more polarizer elements arranged in front of the antenna. At least one polarizer element within the one or more polarizer elements is arranged with respect to the array of antenna elements.

[0011] Such an apparatus may improve or recover polarization purity. The polarizer elements may introduce a phase delay by generating an inductance in order to recover polarization purity.

[0012] According to an example embodiment of the first aspect, the antenna may comprise an array of first frequency band antenna elements. The one or more polarizer elements may be arranged in a symmetric structure with respect to the array of first frequency band antenna elements. Such an apparatus may provide an improved polarization purity for first frequency band radiation waves. By arranging the polarizer elements in a symmetric structure, an unequal beam-steering may be avoided.

[0013] According to an example embodiment of the first aspect, the antenna may comprise an array of second frequency band antenna elements. The one or more polarizer elements may be arranged in a symmetric structure with respect to the array of second frequency band antenna elements. Such an apparatus may provide an improved polarization purity for second frequency band radiation waves. By arranging the polarizer elements in a symmetric structure, an unequal beam-steering may be avoided.

[0014] According to an example embodiment of the first aspect, the antenna may comprise an array of second frequency band antenna elements. At least one polarizer element within the one or more polarizer elements may be arranged in front of a second frequency band antenna element within the array of second frequency band antenna elements. Such an apparatus may provide an improved polarization purity for second frequency band radiation waves.

[0015] According to an example embodiment of the first aspect, each of the one or more polarizer elements may be arranged in front of a second frequency band antenna element within the array of second frequency band antenna elements. Such an apparatus may provide an improved polarization purity for second frequency band radiation waves.

[0016] According to an example embodiment of the first aspect, the antenna may comprise an array of first frequency band antenna elements. At least one polarizer element within the one or more polarizer elements may be arranged in front of a first frequency band antenna element within the array of first frequency band antenna elements. Such an apparatus may provide an improved polarization purity for first frequency band radiation waves.

[0017] According to an example embodiment of the first aspect, each of the one or more polarizer elements may be arranged in front of a first frequency band antenna element within the array of first frequency band antenna elements. Such an apparatus may provide an improved polarization purity for first frequency band radiation waves.

[0018] According to an example embodiment of the first aspect, the antenna may comprise an array of second frequency band antenna elements and an array of first frequency band antenna elements. The first frequency band may be lower than the second frequency band. Each of the one or more polarizer elements may be arranged in front of a second frequency band antenna element within the array of second frequency band antenna elements or each of the one or more polarizer elements may be arranged in front of a first frequency band antenna element within the array of first frequency band antenna elements. Such an apparatus may provide an improved polarization purity for first frequency band radiation waves while maintaining the polarization purity for second frequency band radiation waves, or provide an improved purity for second frequency band radiation waves while maintaining the polarization purity for first frequency band radiation waves.

[0019] According to an example embodiment of the first aspect, the one or more polarizer elements may have a length between 4 and , wherein is a wavelength in a medium.

[0020] According to an example embodiment of the first aspect, the one or more polarizer elements may have a length of 2.

[0021] According to an example embodiment of the first aspect, at least one polarizer element within the one or more polarizer elements may be arranged on an outer surface of the dielectric element.

[0022] According to an example embodiment of the first aspect, at least one polarizer element within the one or more polarizer elements may be arranged on an inner surface of the dielectric element.

[0023] According to an example embodiment of the first aspect, the dielectric element may comprise a first dielectric element and a second dielectric element arranged on an outer surface of the first dielectric element. At least one polarizer element within the one or more polarizer elements may be arranged between the first dielectric element and the second dielectric element. According to an example embodiment of the first aspect, the one or more polarizer elements may be implemented as silver paint, silver paste, conductive paint, conductive surface, or conductive structure.

[0024] According to an example embodiment of the first aspect, the one or more polarizer elements may be implemented as a conductive mesh that may be visually transparent.

[0025] According to an example embodiment of the first aspect, the dielectric element may comprise plastic, glass, or a ceramic composite.

[0026] According to an example embodiment of the first aspect, the antenna may be arranged to produce a slant-polarized electromagnetic wave.

[0027] According to an example embodiment of the first aspect, the slant-polarized electromagnetic wave may be slanted by 45 degrees.

[0028] According to an example embodiment of the first aspect, the apparatus may comprise: A first number of polarizer elements and a second number of antenna elements within the antenna. The first number may be equal to the second number or the first number may be equal to the second number plus one.

[0029] According to an example embodiment of the first aspect, the apparatus may further comprise a metal frame surrounding the dielectric element. Such an apparatus may recover polarization purity degraded by the phase delay introduced by a parallel capacitance generated by the metal frame to the electric field.

[0030] According to an example embodiment of the first aspect, the antenna and the one or more polarizer elements may be oriented to radiate towards an edge of the metal frame.

[0031] According to an example embodiment of the first aspect, the apparatus may further comprise a window in the metal frame. The antenna and the one or more polarizer elements may be oriented to radiate towards an edge of the window.

[0032] According to an example embodiment of the first aspect, the antenna may comprise a one-dimensional antenna array or a two- dimensional antenna array.

[0033] According to an example embodiment of the first aspect, the array of first frequency band antenna elements and the array of second frequency band antenna elements may be interleaved.

[0034] According to an example embodiment of the first aspect, the array of first frequency band elements and the array of second frequency band elements may be provided in a staggered arrangement.

[0035] According to an example embodiment of the first aspect, the array of first frequency band antenna elements and the array of second frequency band antenna elements may be co-located.

[0036] According to an example embodiment of the first aspect, the array of first frequency band antenna elements may be operable in a frequency range of 24.25 GHz to 29.5 GHz. The array of second frequency band antenna elements may be operable in a frequency range of 37 GHz to 43.5 GHz. According to an example embodiment of the first aspect, at least one polarizer element within the one or more polarizer elements may be shaped as a horizontal rectangle, a vertical rectangle, two crossed rectangles, a rectangle with end beams, a bow tie, a plurality of rectangles in a row, or a plurality of rectangle interleaved.

[0037] According to a second aspect, a wireless communication apparatus may comprise: An antenna apparatus according to any of the preceding claims and a transceiver connected to the antenna apparatus.

[0038] According to an example embodiment of the second aspect, the wireless communication apparatus may further comprise a camera housing. The antenna apparatus may be arranged within the camera housing.

[0039] Any example embodiment may be combined with one or more other example embodiments. Many of the attendant features will be more readily appreciated as they become better understood by reference to the following detailed description considered in connection with the accompanying drawings.

[0040] DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which are included to provide a further understanding of the example embodiments and constitute a part of this specification, illustrate example embodiments and together with the description help to understand the example embodiments. In the drawings:

[0042] FIG. 1A and IB illustrate schematic block diagrams of different views of an antenna apparatus according to an example embodiment, namely: FIG. 1 A illustrates an isometric view of the antenna apparatus and FIG. IB illustrates a cross-sectional view of the antenna apparatus.

[0043] FIG. 2 illustrates a schematic block diagram of an antenna apparatus according to an example embodiment;

[0044] FIG. 3 illustrates schematic block diagrams of a polarizer element according to various example embodiments;

[0045] FIG. 4 illustrates a schematic block diagram of an antenna apparatus according to an example embodiment;

[0046] FIG. 5 illustrates a schematic block diagram of an antenna apparatus according to an example embodiment;

[0047] FIG. 6 illustrates a schematic block diagram of an antenna apparatus according to an example embodiment;

[0048] FIG. 7 illustrates a schematic block diagram of an antenna apparatus according to an example embodiment;

[0049] FIG. 8 illustrates a schematic block diagram of an antenna apparatus according to an example embodiment;

[0050] FIG. 9 illustrates a schematic block diagram of an antenna apparatus according to an example embodiment;

[0051] FIG. lOA and 10B illustrate experimental results obtained for the antenna apparatus of FIG. 6, namely: FIG. 10A illustrates a dependence of a Cross-Polarization Ratio (XPR) on frequency for first frequency band frequencies, and FIG. 10B illustrates a dependence of the XPR on frequency for second frequency band frequencies;

[0052] FIG. 11 illustrates a schematic block diagram of a wireless communication apparatus according to an example embodiment; and

[0053] FIG. 12 illustrates a schematic block diagram of a wireless communication apparatus according to an example embodiment.

[0054] DETAILED DESCRIPTION

[0055] Reference will now be made in detail to example embodiments, examples of which are illustrated in the accompanying drawings. The detailed description provided below in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present example may be constructed or utilized. The description sets forth the functions of the example and the sequence of steps for constructing and operating the example. However, the same or equivalent functions and sequences may be accomplished by different examples.

[0056] Although the specification may refer to “an”, “one”, or “some” embodiment(s) in several locations, this does not necessarily mean that each such reference is to the same embodiment(s), or that the feature may not apply to other embodiments. Single features of different embodiments may also be combined to provide other embodiments. Furthermore, words “comprising” and “including” should be understood as not limiting the described cmbodimcnts / cxamplc. and the embodiments / examples may contain also features / structures that have not been specifically mentioned.

[0057] Furthermore, although the numerative terminology, such as “first”, “second”, etc., may be used herein to describe various embodiments, elements, orfeatures, it should be understood that these embodiments, elements, orfeatures should not be limited by this numerative terminology. This numerative terminology is used herein only to distinguish one embodiment, element, or feature from another embodiment, element, or feature. For example, a first number discussed below could be called a second number, and vice versa, without departing from the teachings of the present disclosure.

[0058] Any positioning terminology, such as “in front of’, “outer”, “inner”, “vertical”, “horizontal”, etc., may be used herein for convenience to describe an element’s or feature’s relationship to one or more other elements orfeatures in accordance with the drawings. It should be apparent that the positioning terminology is intended to encompass different orientations of the apparatus disclosed here, in addition to the orientation(s) depicted in the drawings. Therefore, the positioning terminology used herein should not be construed as any limitation of the invention.

[0059] As used in the example embodiments disclosed herein, an antenna apparatus may refer to an apparatus configured to radiate and receive radio waves. The radio waves may refer to a type of electromagnetic radiation that occurs in different frequency bands of the radio spectrum (e.g., in the so-called centimeter-wave (cm-wave) and millimeter-wave (mm-wave) bands). The radio waves are used, for example, in wireless communications, such as point-to-point communications, intersatellite links, and point-to-multipoint communications, etc. However, application of the radio waves is not limited to wireless communications only, and they may be also used, for example, for (air, ground or marine) vehicle navigation and control, road obstacle detection, etc. For this reason, the antenna apparatus according to the example embodiments disclosed herein may be used in the same use scenarios as the radio waves. More specifically, the antenna apparatus may be implemented as part of a user equipment (UE) that may refer to a wireless customer premises equipment (CPE) (e.g., a wireless router, switch, etc.), a mobile device, a mobile station, a terminal, a subscriber unit, a mobile phone, a cellular phone, a smart phone, a cordless phone, a personal digital assistant (PDA), a wireless communication device, a desktop computer, a laptop computer, a tablet computer, a singleboard computer (SBC) (e.g., a Raspberry Pi device), a gaming device, a netbook, a smartbook, an ultrabook, a medical device or medical equipment, a biometric sensor, a wearable device (e.g., a smart watch, smart glasses, a smart wrist band, etc.), an entertainment device (e.g., an audio player, a video player, etc.), a vehicular component or sensor (e.g., a driver-assistance system), a smart meter / sensor, an unmanned vehicle (e.g., an industrial robot, a quadcopter, etc.) and its component (e.g., a self-driving car computer), industrial manufacturing equipment, a global positioning system (GPS) device, an Intemet-of- Things (loT) device, an Industrial loT (IIoT) device, a machine-type communication (MTC) device, a group of Massive loT (MIoT) or Massive MTC (mMTC) devices / sensors, or any other suitable device that uses the radio waves for operation. In some example embodiments, the UE may refer to at least two collocated and inter-connected UEs thus defined.

[0060] According to an example embodiment, an antenna apparatus comprises an array of antenna elements and a dielectric element (block, component). The dielectric element may be understood as an element or a medium that has insulating or poorly conducting properties. The dielectric element is arranged on an outer surface of the antenna. The antenna apparatus further comprises one or more polarizer elements arranged in front of the antenna. At least one polarizer element within the one or more polarizer elements is arranged with respect to the array of antenna elements, e.g., in front of one or some of the antenna elements within the array of antenna elements.

[0061] According to the example embodiment, horizontal and vertical components of the radiation waves propagating from the antenna may be affected differently by to the dielectric element which it may be understood to be behaving as an anisotropic material. This may lead to a change in polarization due to a phase imbalance between the components of the radiation waves. Polarization purity may be recovered by introducing a phase delay to one of the components. A phase delay in electronic circuits may be generated, e.g., by introducing an inductance, a capacitance, or both. By adding the one or more polarization elements to the antenna apparatus an inductance or a capacitance may be generated. Thus, the phase delay may be introduced to the horizontal or the vertical component, which may improve or recover the slanted polarization.

[0062] FIG. 1A and FIG. IB illustrate schematic block diagrams of different views of an antenna apparatus 100 according to an example embodiment. More specifically, FIG. 1 A shows an isometric view of the antenna apparatus 100, while FIG. IB shows a cross-sectional view of the antenna apparatus 100.

[0063] Referring to FIG. 1 A and IB, the antenna apparatus 100 comprises an antenna 102 comprising an array of antenna elements. In an example embodiment, the antenna may comprise a one-dimensional antenna array. In an example embodiment, the antenna may comprise a two-dimensional antenna array. In an example embodiment, the antenna is arranged to produce a slant- polarized electromagnetic wave. In an example embodiment, the slant-polarized electromagnetic wave is slanted by 45 degrees.

[0064] Referring to FIG. 1 A and IB, the antenna apparatus 100 further comprises a dielectric element 104. The dielectric element 104 is arranged on an outer surface of the antenna 102. In an example embodiment, the dielectric element 104 may comprise, e.g., plastic, glass, or a ceramic composite. Horizontal and vertical components of the electromagnetic wave produced by the antenna may be affected differently by the dielectric component 104 and thus cause a degradation in polarization purity.

[0065] Referring to FIG. 1A and FIG. IB, the antenna apparatus 100 further comprises one or more polarizer elements 106a, 106b, 106c. The one or more polarizer elements 106a, 106b, 106c are arranged with respect to the array of antenna elements. This may be understood in such a way that the polarizer elements 106a, 106b, 106c are positioned, e.g., symmetrically with respect to the antenna elements, in front of at least one or some of the antenna elements, or shifted with respect to at least one or some of the antenna elements. In an example embodiment, at least one polarizer element within the one or more polarizer elements 106a, 106b, 106c may be arranged on an outer surface of the dielectric element 104. In an example embodiment, each of the one or more polarizer elements 106a, 106b, 106c may be arranged on the outer surface of the dielectric element 104.

[0066] In an example embodiment, the one or more polarizer elements may have a length between 4 and , wherein is a wavelength in a medium. In an example embodiment, the one or more polarizer elements may have a length of 2. In an example embodiment, the one or more polarizer elements 106a, 106b, 106c may be implemented as silver paint, silver paste, conductive paint, conductive surface, or conductive structure. In another example embodiment, the one or more polarizer elements 106a, 106b, 106c may be implemented as a conductive mesh, such as, e.g., a metal mesh. The antenna apparatus 100 may be used for end-fire radiation.

[0067] FIG. 2 illustrates a schematic block diagram of an isometric view of an antenna apparatus 200 according to an example embodiment. The antenna apparatus 200 comprises an antenna (not shown in FIG. 2), a dielectric element 204 arranged on an outer surface of the antenna, and one or more polarizer elements 206a, 206b, 206c. The antenna apparatus 200 further comprises a metal frame 208 arranged surrounding the dielectric element 204 and a window 210 in the metal frame 208. In an example embodiment, the antenna and at least one polarizer element within the one or more polarizer elements 206a, 206b, 206c may be oriented to radiate towards an edge of the metal frame 208. Horizontal and vertical components of the electromagnetic wave produced by the antenna may be affected differently by the metal frame 208 and thus cause a degradation in polarization purity. In an example embodiment, the antenna and at least one polarizer element within the one or more polarizer elements 206a, 206b, 206c may be oriented to radiate towards an edge of the window 210. FIG. 3 illustrates schematic block diagrams of a polarizer element within the one or more polarizer elements according to various example embodiments. In an example embodiment, the polarizer element may be shaped as a horizontal rectangle 321. In an example embodiment, the polarizer element may be shaped as a vertical rectangle 322. In an example embodiment, the polarizer element may be shaped as two crossed rectangles 323. In an example embodiment, the rectangles may be perpendicularly crossed. In an example embodiment, the polarizer element may be shaped as a rectangle with end beams 324. In an example embodiment, the polarizer element may be shaped as a bow tie 325. In an example embodiment, the polarizer element may be shaped as a plurality of rectangles in a row 326. In an example embodiment, the row may be horizontal. In an example embodiment, the row may be vertical. In an example embodiment, the polarizer element may be shaped as a plurality of interleaved rectangles 327.

[0068] FIG. 4 illustrates a schematic block diagram of a front view of an antenna apparatus 400 according to an example embodiment. The antenna apparatus 400 comprises an antenna comprising an array of antenna elements 412a, 412b, 412c, 412d. The antenna apparatus 400 further comprises a dielectric element arranged on an outer surface of the antenna (not shown in FIG. 4) and one or more polarizer elements 406a, 406b, 406c, 406d. In an example embodiment, the antenna apparatus 400 may comprise a first number of polarizer elements 406a, 406b, 406c, 406d and a second number of antenna elements 412a, 412b, 412c, 412d within the array of antenna elements, wherein the first number is equal to the second number.

[0069] Referring to FIG. 4, at least one polarizer element within the one or more polarizer elements 406a, 406b, 406c, 406d is arranged in front of an antenna element within the array of antenna elements 412a, 412b, 412c, 412d. In an example embodiment, each of the one or more polarizer elements 406a, 406b, 406c, 406d may be arranged in front of an antenna element within the array of antenna elements 412a, 412b, 412c, 412d.

[0070] In an example embodiment, the array of antenna elements 412a, 412b, 412c, 412d, may be an array of first frequency band antenna elements. In an example embodiment, the first frequency band may correspond to a frequency range of 24.25 GHz to

[0071] 29.5 GHz, which may be called the low-band of radio spectrum. The first frequency band antenna elements may be designed for operation in the first frequency band of radio spectrum. The one or more polarizer elements 406a, 406b, 406c, 406d are arranged in a symmetric structure with respect to the first frequency band antenna elements. In an example embodiment, at least one polarizer element within the one or more polarizer elements 406a, 406b, 406c, 406d is arranged in front of a first frequency band antenna element within the array of first frequency band antenna elements. In an example embodiment, each polarizer element within the one or more polarizer elements 406a, 406b, 406c, 406d is arranged in front of a first frequency band antenna element within the array of first frequency band antenna elements.

[0072] In an example embodiment, the array of antenna elements 412a, 412b, 412c, 412d, may be an array of second frequency band antenna elements. In an example embodiment, the second frequency band may correspond to a frequency range of 37 GHz to

[0073] 43.5 GHz, which may be called the high-band of radio spectrum. The second frequency band antenna elements may be designed for operation in the second frequency band of radio spectrum. The one or more polarizer elements 406a, 406b, 406c, 406d are arranged in a symmetric structure with respect to the second frequency band antenna elements. In an example embodiment, at least one polarizer element within the one or more polarizer elements 406a, 406b, 406c, 406d is arranged in front of a second frequency band antenna element within the array of second frequency band antenna elements. In an example embodiment, each polarizer element within the one or more polarizer elements 406a, 406b, 406c, 406d is arranged in front of a second frequency band antenna element within the array of second frequency band antenna elements.

[0074] FIG. 5 illustrates a schematic block diagram of a front view of an antenna apparatus 500 according to an example embodiment. The antenna apparatus 500 comprises an array of antenna elements 512a, 512b, 512c, 512d. The antenna apparatus 500 further comprises a dielectric element arranged on an outer surface of the antenna (not shown in FIG. 5) and one or more polarizer elements 506a, 506b, 506c, 506d, 506e. In an example embodiment, the antenna apparatus 500 may comprise a first number of polarizer elements 506a, 506b, 506c, 506d, 506e and a second number of antenna elements 512a, 512b, 512c, 512d within the array of antenna elements, wherein the first number is equal to the second number plus one.

[0075] In an example embodiment, the array of antenna elements 512a, 512b, 512c, 512d may be an array of second frequency band antenna elements. The one or more polarizer elements 506a, 506b, 506c, 506d are arranged in front of the antenna in a symmetric structure with respect to the array of second frequency band antenna elements and not in front of any second frequency band antenna elements within the array of second frequency band antenna elements.

[0076] In an example embodiment, the array of antenna elements 512a, 512b, 512c, 512d may be an array of first frequency band antenna elements. The one or more polarizer elements 506a, 506b, 506c, 506d are arranged in front of the antenna in a symmetric structure with respect to the array of first frequency band antenna elements and not in front of any first frequency band antenna elements within the array of first frequency band antenna elements.

[0077] FIG. 6 illustrates a schematic block diagram of a front view of an antenna apparatus 600 according to an example embodiment. The antenna apparatus comprises an array of second frequency band antenna elements 612a, 612b, 612c and an array of first frequency band antenna elements 614a, 614b, 614c. In an example embodiment, the array of second frequency band antenna elements 612a, 612b, 612c and the array of first frequency band antenna elements 614a, 614b, 614c may be interleaved. In an example embodiment, the array of second frequency band antenna elements 612a, 612b, 612c and the array of first frequency band antenna elements 614a, 614b, 614c may be provided in a staggered arrangement. In another example embodiment, the array of second frequency band antenna elements 612a, 612b, 612c and the array of first frequency band antenna elements 614a, 614b, 614c may be co-located.

[0078] Referring to FIG. 6, the antenna apparatus 600 further comprises one or more polarizer elements 606a, 606b, 606c. At least one polarizer element within the one or more polarizer elements 606a, 606b, 606c is arranged in front of a second frequency band antenna element within the array of second frequency band antenna elements 612a, 612b, 612c. In an example embodiment, each of the one or more polarizer elements 606a, 606b, 606c may be arranged in front of a second frequency band antenna element within the array of second frequency band antenna elements 612a, 612b, 612c.

[0079] FIG. 7 illustrates a schematic block diagram of a front view of an antenna apparatus 700 according to an example embodiment. The antenna apparatus comprises an array of second frequency band antenna elements 712a, 712b, 712c and an array of first frequency band antenna elements 714a, 714b, 714c. In an example embodiment, the array of second frequency band antenna elements 712a, 712b, 712c and the array of first frequency band antenna elements 714a, 714b, 714c may be interleaved. In an example embodiment, the array of second frequency band antenna elements 712a, 712b, 712c and the array of first frequency band antenna elements 714a, 714b, 714c may be provided in a staggered arrangement. In another example embodiment, the array of second frequency band antenna elements 712a, 712b, 712c and the array of first frequency band antenna elements 714a, 714b, 714c may be co-located.

[0080] Referring to FIG. 7, the antenna apparatus further comprises one or more polarizer elements 706a, 706b, 706c At least one polarizer element within the one or more polarizer elements 706a, 706b, 706c is arranged in front of a first frequency band antenna element within the array of first frequency band antenna elements 714a, 714b, 714c. In an example embodiment, each of the one or more polarizer elements 706a, 706b, 706c is arranged in front of a first frequency band antenna element within the array of first frequency band antenna elements 714a, 714b, 714c. FIG. 8 illustrates a schematic block diagram of a cross-sectional view of an antenna apparatus 800 according to an example embodiment. The antenna apparatus 800 comprises an antenna 802, a dielectric element 804, and one or more polarizer elements 806a, 806b, 806c. At least one polarizer element within the one or more polarizer elements 806a, 806b, 806c is arranged on an inner surface of the dielectric element 804. In an example embodiment, each of the one or more polarizer elements 806a, 806b, 806c may be arranged on the inner surface of the dielectric element 804.

[0081] FIG. 9 illustrates a schematic block diagram of a cross-sectional view of an antenna apparatus 900 according to an example embodiment. The antenna apparatus 900 comprises an antenna 902, a dielectric element comprising a first dielectric element 904a and a second dielectric element 904b, and one or more polarizer elements 906a, 906b, 906c. The second dielectric element 904b is arranged on an outer surface of the first dielectric element 904a. At least one polarizer element within the one or more polarizer elements 906a, 906b, 906c is arranged between the first dielectric element 904a and the second dielectric element 904b. This may be understood as the at least one polarizer element being arranged on the outer surface of the first dielectric element 904a and / or on an inner surface of the second dielectric element 904b. In an example embodiment, each of the one or more polarizer elements 906a, 906b, 906c may be arranged between the first dielectric element 904a and the second dielectric element 904b.

[0082] FIG. 10A and 10B illustrate experimental results obtained for the antenna apparatus 600. More specifically, FIG. 10A illustrates a dependence of a Cross-Polarization Ratio (XPR) on frequency for first frequency band frequencies whereas FIG. 10B illustrates a dependence of the XPR on frequency for second frequency band frequencies. The XPR may be understood as a measure for the polarization purity. To obtain these experimental results, a 45 degrees slant-polarized electromagnetic wave was produced by the antenna and polarizer elements of 2 mm length were arranged in front of the second frequency band antenna elements. FIG. 10A shows how by using the polarizer elements the XPR for first frequency band frequencies is improved by 7 dB on average with respect to the antenna apparatus without the polarizer elements. At some frequencies the XPR is improved up to 10 dB and an average XPR with polarizer elements is 11 dB for first frequency band frequencies. FIG. 10B shows how the XPR for second frequency band frequencies is degraded only by 1 dB on average with respect to the antenna apparatus without the polarizer elements. An average XPR with polarizer elements is 12.5 dB for second frequency band polarizer elements. In this experiment, there is a phase difference of 83 degrees between horizontal and vertical components of the signal if no polarizer elements are used. With polarizer elements in front of the second frequency band antenna elements phase delays may be introduced to the signal. Thus, the phase difference between the horizontal and vertical components of the signal is only 2 degrees.

[0083] FIG. 11 illustrates a schematic block diagram of a wireless communication apparatus 1100 according to an example embodiment. The wireless communication apparatus 1100 may be implemented as part of a user equipment such as, e.g., a smartphone, or implemented as an individual device. As shown in FIG. 11, the wireless communication apparatus 1100 comprises a transceiver 1102 and an antenna apparatus 1104. The antenna apparatus 1104 may be implemented as any of the antenna apparatuses 100, 200, 400, 500, 600, 700, 800, 900. The transceiver 1102 is configured to perform wireless communications, e.g., with another user equipment by using the antenna apparatus 1104.

[0084] In an example embodiment, the wireless communication apparatus 1100 further comprises a metal frame or a metal structure surrounding or partially covering the antenna apparatus 1104. In an example embodiment, the antenna and / or the one or more parasitic polarizer elements within the antenna apparatus 1104 are arranged to radiate towards an edge of the metal frame.

[0085] In an example embodiment, the wireless communication apparatus 1100 further comprises a display. In an example embodiment, the antenna and / or the one or more parasitic polarizer elements within the antenna apparatus 1104 are arranged to radiate towards the display. In an example embodiment, the wireless communication apparatus 1100 further comprises a back cover. In an example embodiment, the antenna and / or the one or more parasitic polarizer elements within the antenna apparatus 1104 are arranged to radiate towards a side of the back cover.

[0086] FIG. 12 illustrates a schematic block diagram of a wireless communication apparatus 1200 according to an example embodiment. The wireless communication apparatus 1200 may be implemented as part of a user equipment such as, e.g., a smartphone, or implemented as an individual device. As shown in FIG. 12, the wireless communications apparatus 1200 comprises a transceiver (not shown in FIG. 12) and an antenna apparatus comprising an antenna 1202, a dielectric element 1204, and one or more polarizer elements 1206 (only one shown in FIG. 12). The wireless communication apparatus 1200 further comprises a chassis 1210 and a camera housing 1208 comprising a glass element 1212. The camera housing may be of a shape convenient or appropriate for one or more cameras, such as, e.g., a circular shape, an oval shape, a curved shape, or a rectangular shape. The antenna apparatus is arranged within the camera housing 1208 such that the one or more polarizer elements 1206 are arranged, e.g., on a side of the camera housing 1208. The antenna apparatus may be implemented as any of the antenna apparatuses 100, 200, 400, 500, 600, 700, 800, 900.

[0087] Although the subject matter has been described in language specific to structural features and / or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example embodiments of implementing the claims and other equivalent features and acts are intended to be within the scope of the claims.

[0088] It will be understood that the benefits and advantages described above may relate to one example embodiment or may relate to several example embodiments. The example embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will further be understood that reference to 'an' item may refer to one or more of those items.

[0089] Aspects of any of the example embodiments described above may be combined with aspects of any of the other example embodiments described to form further example embodiments without losing the effect sought.

[0090] It will be understood that the above description is given by way of example embodiments only and that various modifications may be made by those skilled in the art. The above specification, example embodiments, and data provide a complete description of the structure and use of exemplary embodiments. Although various example embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed example embodiments without departing from the scope of this specification.

Claims

CLAIMS1. An antenna apparatus comprising: an antenna comprising an array of antenna elements; a dielectric element arranged on an outer surface of the antenna; and one or more polarizer elements arranged in front of the antenna, wherein at least one polarizer element within the one or more polarizer elements is arranged with respect to the array of antenna elements.

2. An antenna apparatus according to claim 1, wherein the antenna comprises an array of first frequency band antenna elements, and wherein the one or more polarizer elements are arranged in a symmetric structure with respect to the array of first frequency band antenna elements.

3. An antenna apparatus according to claim 1, wherein the antenna comprises an array of second frequency band antenna elements, and wherein the one or more polarizer elements are arranged in a symmetric structure with respect to the array of second frequency band antenna elements.

4. An antenna apparatus according to claim 1, wherein the antenna comprises an array of second frequency band antenna elements, and wherein at least one polarizer element within the one or more polarizer elements is arranged in front of a second frequency band antenna element within the array of second frequency band antenna elements.

5. An antenna apparatus according to claim 4, wherein each of the one or more polarizer elements is arranged in front of a second frequency band antenna element within the array of second frequency band antenna elements.

6. An antenna apparatus according to claim 1, wherein the antenna comprises an array of first frequency band antenna elements, and wherein at least one polarizer element within the one or more polarizer elements is arranged in front of a first frequency band antenna element within the array of first frequency band antenna elements.

7. An antenna apparatus according to claim 6, wherein each of the one or more polarizer elements is arranged in front of a first frequency band antenna element within the array of first frequency band antenna elements.

8. An antenna apparatus according to claim 1, wherein the antenna comprises an array of second frequency band antenna elements and an array of first frequency band antenna elements, wherein the first frequency band is lower than the second frequency band, and wherein each of the one or more polarizer elements is arranged in front of a second frequency band antenna element within the array of second frequency band antenna elements or each of the one or more polarizer elements is arranged in front of a first frequency band antenna element within the array of first frequency band antenna elements.

9. An antenna apparatus according to any of the preceding claims, wherein the one or more polarizer elements have a length between 4 and , wherein is a wavelength in a medium.

10. An antenna apparatus according to claim 9, wherein the one or more polarizer elements have a length of 2.

11. An antenna apparatus according to any of the preceding claims, wherein at least one polarizer element within the one or more polarizer elements is arranged on an outer surface of the dielectric element.

12. An antenna apparatus according to any of the preceding claims, wherein at least one polarizer element within the one or more polarizer elements is arranged on an inner surface of the dielectric element.

13. An antenna apparatus according to any of the preceding claims, wherein the dielectric element comprises a first dielectric element and a second dielectric element arranged on an outer surface of the first dielectric element, and wherein at least one polarizer element within the one or more polarizer elements is arranged between the first dielectric element and the second dielectric element.

14. An antenna apparatus according to any of the preceding claims, wherein the one or more polarizer elements are implemented as silver paint, silver paste, conductive paint, conductive surface, or conductive structure.

15. An antenna apparatus according to any of claims 1 to 13, wherein the one or more polarizer elements are implemented as a conductive mesh.

16. An antenna apparatus according to any of the preceding claims, wherein the dielectric element comprises plastic, glass, or a ceramic composite.

17. An antenna apparatus according to any of the preceding claims, wherein the antenna is arranged to produce a slant-polarized electromagnetic wave.

18. An antenna apparatus according to claim 17, wherein the slant-polarized electromagnetic wave is slanted by 45 degrees.

19. An antenna apparatus according to any of the preceding claims, comprising a first number of polarizer elements and a second number of antenna elements within the antenna, wherein the first number is equal to the second number or the first number is equal to the second number plus one.

20. An antenna apparatus according to any of the preceding claims, further comprising a metal frame surrounding the dielectric element.

21. An antenna apparatus according to claim 20, wherein the antenna and the one or more polarizer elements are oriented to radiate towards an edge of the metal frame.

22. An antenna apparatus according to claim 20, further comprising a window in the metal frame, wherein the antenna and the one or more polarizer elements are oriented to radiate towards an edge of the window.

23. An antenna apparatus according to any of the preceding claims, wherein the antenna comprises a one-dimensional antenna array or a two-dimensional antenna array.

24. An antenna apparatus according to any of claims 8 to 23, wherein the array of first frequency band antenna elements and the array of second frequency band antenna elements are interleaved.

25. An antenna apparatus according to claim 24, wherein the array of first frequency band elements and the array of second frequency band elements are provided in a staggered arrangement.

26. An antenna apparatus according to any of claims 8 to 23, wherein the array of first frequency band antenna elements and the array of second frequency band antenna elements are co-located.

27. An antenna apparatus according to any of claims 8 to 26, wherein the array of first frequency band antenna elements is operable in a frequency range of 24.25 GHz to 29.5 GHz, and the array of second frequency band antenna elements is operable in a frequency range of 37 GHz to 43.5 GHz.

28. An antenna apparatus according to any of the preceding claims, wherein at least one polarizer element within the one or more polarizer elements is shaped as a horizontal rectangle, a vertical rectangle, two crossed rectangles, a rectangle with end beams, a bow tie, a plurality of rectangles in a row, or a plurality of rectangle interleaved.

29. A wireless communication apparatus, comprising: an antenna apparatus according to any of the preceding claims; and a transceiver connected to the antenna apparatus.

30. A wireless communication apparatus according to claim 29, further comprising a camera housing, wherein the antenna apparatus is arranged within the camera housing.

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