Antennas and Communication Modules

Abstract

This antenna comprises a substrate, a plurality of power supply elements, and a plurality of non-power supply elements. The substrate is configured from a dielectric. The plurality of power supply elements are lined up and arranged in a matrix along the surface of the substrate. The plurality of non-power supply elements are lined up and arranged so as to surround the periphery of a power supply element group configured from the plurality of power supply elements. Furthermore, the pitch in a steering direction between non-power supply elements that are adjacent along the steering direction is narrower than the pitch in the steering direction between power supply elements that are adjacent along the steering direction. This communication module has an antenna of the abovementioned configuration and an RF element.

Description

[Technical field]

[0001] The disclosed embodiments relate to an antenna and a communication module. [Background technology]

[0002] 2. Description of the Related Art Conventionally, an array antenna has been disclosed in which a plurality of feed elements and a plurality of parasitic elements are arranged side by side on a substrate (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-121406 A Summary of the Invention

[0004] The antenna of the present disclosure includes a substrate, a plurality of feed elements, and a plurality of parasitic elements. The substrate is made of a dielectric material. The plurality of feed elements are arranged in a matrix along a surface of the substrate. The plurality of parasitic elements are arranged so as to surround a periphery of a feed element group constituted by the plurality of feed elements. In addition, the pitch in the steering direction between the parasitic elements adjacent along the steering direction is narrower than the pitch in the steering direction between the feed elements adjacent along the steering direction. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a front view showing an example of the configuration of an array antenna according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing an example of the configuration of a feed element according to the embodiment. [Diagram 3] FIG. 3 is a front view showing an example of the configuration of a feed element according to an embodiment. [Figure 4] FIG. 4 is a diagram showing beam steering characteristics in the E-plane of the array antenna of the embodiment and the reference example. [Diagram 5] FIG. 5 is a diagram showing beam steering characteristics in the E-plane of the array antenna of the embodiment and the reference example. [Figure 6] FIG. 6 is a diagram showing beam steering characteristics in the E-plane of the array antenna of the embodiment and the reference example. [Figure 7] FIG. 7 is a diagram showing beam steering characteristics in the −60° direction and the +60° direction of the array antenna of the embodiment and the reference example. [Figure 8] FIG. 8 is a diagram showing the transition of gain in the E-plane direction when the pitch ratio of the array antenna is changed. [Figure 9] FIG. 9 is a diagram showing the beam steering characteristics when the size of the parasitic element is changed. [Figure 10] FIG. 10 is a front view illustrating an example of a configuration of an array antenna according to another embodiment. [Figure 11] FIG. 11 is a diagram showing beam steering characteristics in the E-plane of the array antenna of another embodiment and a reference example. [Figure 12] FIG. 12 is a diagram showing beam steering characteristics in the E-plane of the array antenna of another embodiment and a reference example. [Figure 13] FIG. 13 is a diagram showing beam steering characteristics in the E-plane of the array antenna of another embodiment and a reference example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Hereinafter, embodiments of an antenna and a communication module disclosed in the present application will be described with reference to the accompanying drawings. Note that the present disclosure is not limited to the embodiments described below.

[0007] In addition, in the embodiments described below, expressions such as "constant", "orthogonal", "vertical" and "parallel" may be used, but these expressions do not necessarily mean "constant", "orthogonal", "vertical" and "parallel" strictly. In other words, each of the above expressions allows for deviations due to, for example, manufacturing accuracy and installation accuracy.

[0008] Conventionally, array antennas have been disclosed in which a number of feed elements and a number of parasitic elements are arranged side by side on a substrate. However, in the above conventional technology, the radiation pattern may be distorted in a direction significantly tilted from the front direction of the antenna (for example, in a direction of ±60°).

[0009] For example, in a phased array antenna module (PAAM), when an antenna and a control circuit are arranged on the same board, if the size of the ground layer is larger than the size of the array antenna, the radiation pattern may be significantly distorted.

[0010] Therefore, there is a need to develop technology that enables wide-angle beam steering in array antennas.

[0011] <Embodiment> First, the configuration and characteristics of an array antenna 1 according to an embodiment will be described with reference to Fig. 1 to Fig. 9. Fig. 1 is a front view showing an example of the configuration of an array antenna 1 according to an embodiment. The array antenna 1 is an example of an antenna.

[0012] As shown in FIG. 1, an array antenna 1 according to the embodiment includes a substrate 2, a plurality of feed elements 3, and a plurality of parasitic elements 4.

[0013] In addition, in the accompanying drawings of this disclosure, in order to clarify the positional relationships, mutually perpendicular X-axis, Y-axis, and Z-axis are defined, with the Z-axis direction being the thickness direction of the substrate 2, the X-axis direction being the E-plane direction of the array antenna 1, and the Y-axis direction being the H-plane direction of the array antenna 1.

[0014] The substrate 2 is made of a dielectric material and has, for example, a flat plate shape. The substrate 2 may be made of a ceramic material such as an aluminum oxide sintered body, a glass ceramic sintered body, a mullite sintered body, or an aluminum nitride sintered body, or may be made of an organic material.

[0015] A plurality of feed elements 3 are arranged along the front surface 2a of the substrate 2, and one feed element group 3A is configured by the plurality of feed elements 3. For example, 8×8 feed elements 3 are arranged in a matrix along the front surface 2a of the substrate 2. Note that in the present disclosure, the number and arrangement of feed elements 3 provided in the array antenna 1 are not limited to the example in FIG.

[0016] Fig. 2 is a cross-sectional view showing an example of the configuration of the feed element 3 according to the embodiment, and Fig. 3 is a front view showing an example of the configuration of the feed element 3 according to the embodiment. As shown in Fig. 2 and other figures, the feed element 3 according to the embodiment is a patch antenna (microstrip antenna) configured by arranging a plurality of metal layers on the surface 2a of the substrate 2 and inside the substrate 2.

[0017] The feed element 3 includes a feed layer 11, a ground layer 12, a feed patch layer 13, and a parasitic patch layer 14 as metal layers arranged parallel to the front surface 2a of the substrate 2. The feed element 3 also includes a feed via 21 and a short-circuit via 22 as via conductors arranged perpendicular to the front surface 2a of the substrate 2.

[0018] These metal layers and via conductors are made of metal materials such as copper, silver, palladium, gold, platinum tungsten, molybdenum, or manganese, or alloy materials or mixed materials containing these metal materials as main components.

[0019] Of the above-mentioned metal layers, the power supply layer 11 is disposed farthest from the surface 2a of the substrate 2. The power supply layer 11 is electrically connected to a control IC (not shown).

[0020] The control IC outputs, for example, a modulated electrical signal as an electrical signal corresponding to the radio waves to be transmitted to the power feed patch layer 13 via the power feed layer 11, the power feed vias 21, etc. Also, the control IC collects an electrical signal corresponding to the radio waves received by the power feed element 3 from the power feed patch layer 13 via the power feed vias 21, the power feed layer 11, etc.

[0021] The ground layer 12 is disposed inside the substrate 2, closer to the front surface 2a than the power supply layer 11. The ground layer 12 is connected to a ground potential (not shown).

[0022] The power supply patch layer 13 is disposed inside the substrate 2, closer to the front surface 2a than the ground layer 12. The power supply patch layer 13 is electrically connected to the power supply layer 11 through a power supply via 21, and receives an electrical signal from the control IC described above.

[0023] The power supply patch layer 13 is, for example, a square shape with sides having lengths according to the frequency of radio waves to be transmitted and received, as shown in Fig. 3. Note that in the present disclosure, the power supply patch layer 13 is not limited to a square shape and may have various shapes.

[0024] The parasitic patch layer 14 is disposed on the surface 2a of the substrate 2. For example, as shown in Fig. 3, the parasitic patch layer 14 is square and has approximately the same size and shape as the fed patch layer 13. The parasitic patch layer 14 is disposed so as to overlap with the fed patch layer 13 in a plan view.

[0025] The power feed via 21 electrically connects the power feed layer 11 and the power feed patch layer 13. Since a dielectric constituting the substrate 2 is disposed between the power feed via 21 and the ground layer 12, the power feed via 21 and the ground layer 12 are electrically insulated from each other.

[0026] In the feed element 3 according to the embodiment, two feed vias 21 (hereinafter also referred to as feed vias 21A and 21B) are connected to one feed patch layer 13, as shown in FIG.

[0027] Furthermore, the feed vias 21 are connected to positions away from the center of the feed patch layer 13, for example, based on the input impedance (reflection characteristics) requirements of the feed element 3, and are located at positions differing by 90(°) so as to accommodate polarization characteristics in two orthogonal directions. For example, the feed via 21A is connected to a position away from the center of the feed patch layer 13 in the -Y direction, and the feed via 21B is connected to a position away from the center of the feed patch layer 13 in the -X direction.

[0028] The short-circuiting vias 22 electrically connect the power supply patch layer 13 and the ground layer 12. In the power supply element 3 according to the embodiment, two short-circuiting vias 22 (hereinafter also referred to as short-circuiting vias 22A and 22B) are connected to one power supply patch layer 13, as shown in FIG.

[0029] Moreover, the short-circuiting via 22 is connected, for example, to a position away from the center of the power feed patch layer 13 and closer to the center of the power feed patch layer 13 than the power feed via 21. For example, the short-circuiting via 22A is connected to a position away from the center of the power feed patch layer 13 in the +Y direction, and the short-circuiting via 22B is connected to a position away from the center of the power feed patch layer 13 in the +X direction.

[0030] Returning to the explanation of Fig. 1, the multiple parasitic elements 4 are arranged side by side so as to surround the periphery of a feed element group 3A composed of the multiple feed elements 3. For example, the multiple parasitic elements 4 may be arranged so as to surround the periphery of the feed element group 3A in a double layer.

[0031] Moreover, the parasitic elements 4 may be arranged so that their rows or columns align with the plurality of feed elements 3 arranged in a matrix. Furthermore, adjacent parasitic elements 4 may also be arranged so that their rows or columns align with each other.

[0032] The parasitic element 4 is an element that is not fed by the feed layer 11. The configuration of the parasitic element 4 is, for example, a configuration in which the feed patch layer 13, the feed vias 21, and the short-circuit vias 22 are removed from the configuration of the feed element 3 shown in Figures 2 and 3. This allows the parasitic element 4 to function as a parasitic element.

[0033] Here, in the embodiment, as shown in FIG. 1, the pitch in the steering direction between adjacent parasitic elements 4 along the steering direction is narrower than the pitch in the steering direction between adjacent fed elements 3 along the steering direction.

[0034] Specifically, in the embodiment, the pitch PE2 in the E-plane direction between adjacent parasitic elements 4 along the E-plane direction (X-axis direction) is narrower than the pitch PE1 in the E-plane direction between adjacent fed elements 3 along the E-plane direction.

[0035] Similarly, in the embodiment, the pitch PH2 in the H plane direction between adjacent parasitic elements 4 along the H plane direction (Y-axis direction) is narrower than the pitch PH1 in the H plane direction between adjacent fed elements 3 along the H plane direction.

[0036] This reduces the distortion of the radiation pattern in a direction significantly tilted from the front direction of the antenna, compared to when the pitches PE2, PH2 between adjacent parasitic elements 4 and the pitches PE1, PH1 between adjacent feed elements 3 are equal.

[0037] 4 to 6 are diagrams showing beam steering characteristics in the E-plane of the array antenna 1 of the embodiment and the reference example. In this disclosure, the array antenna 1 of the reference example is an array antenna in which the pitches PE2, PH2 between adjacent parasitic elements 4 and the pitches PE1, PH1 between adjacent feed elements 3 are equal to each other in the array antenna 1 according to the embodiment shown in FIG. 1 etc.

[0038] In addition, in the present disclosure, the array antenna 1 of the embodiment and the reference example has a ground layer 12 having an area larger than the area in which the multiple feed elements 3 and the multiple parasitic elements 4 are arranged. Specifically, in the present disclosure, the length of one side of the ground layer 12 is approximately twice the length of one side of the feed element group 3A. Note that the results shown in Figs. 4 to 6 correspond to E-plane steering in the feed via 21A (see Fig. 3).

[0039] Also, FIG. 4 shows the beam steering characteristics at a frequency of 26.5 (GHz), FIG. 5 shows the beam steering characteristics at a frequency of 28 (GHz), and FIG. 6 shows the beam steering characteristics at a frequency of 29.5 (GHz).

[0040] As shown in Figures 4 to 6, it can be seen that the array antenna 1 of the embodiment has reduced distortion of the radiation pattern in directions significantly tilted from the front direction (here, the -60° and +60° directions) compared to the reference example, and has improved gain in such directions.

[0041] In this manner, in the embodiment, narrowing the pitches PE2 and PH2 can reduce the collapse of the radiation pattern, which occurs significantly when the area of ​​the ground layer 12 is larger than that of the array antenna 1. This is presumably because narrowing the pitches PE2 and PH2 can enhance the shielding effect for the ground layer 12.

[0042] Therefore, according to the embodiment, wide-angle beam steering is possible in the array antenna 1.

[0043] In the above embodiment, the area of ​​the ground layer 12 is larger than the area in which the multiple feed elements 3 and the multiple parasitic elements 4 are arranged, but the present disclosure is not limited to this example.

[0044] For example, in the present disclosure, the area in which the multiple feed elements 3 and the multiple parasitic elements 4 are arranged may be approximately equal to the area of ​​the ground layer 12, or the area of ​​the ground layer 12 may be smaller than the area in which the multiple feed elements 3 and the multiple parasitic elements 4 are arranged.

[0045] 7 is a diagram showing beam steering characteristics in the -60(°) and +60(°) directions of the array antenna 1 of the embodiment and the reference example. As shown in FIG. 7, the array antenna 1 of the embodiment can reduce the second lobe in a direction significantly tilted from the front direction of the antenna compared to the reference example.

[0046] Therefore, according to the embodiment, noise due to interference can be reduced, and the communication quality of the array antenna 1 can be improved.

[0047] 8 is a diagram showing the transition of gain in the E-plane direction when changing the pitch ratio of the array antenna 1. In this disclosure, the "pitch ratio" refers to the ratio of the pitch PE2 (or pitch PH2) between the parasitic elements 4 to the pitch PE1 (or pitch PH1) between the feed elements 3.

[0048] As shown in FIG. 8, in the E-plane direction, by setting the pitch ratio to 100% or more, the gain in the −60° direction at 29.5 GHz is significantly reduced.

[0049] Furthermore, as shown in FIG. 8, in the E-plane direction, by setting the pitch ratio to 60% or less, the gain in the −60° direction at 26.5 GHz and 28 GHz is significantly reduced.

[0050] That is, in the embodiment, the pitch in the steering direction between adjacent parasitic elements 4 along the steering direction may be 70(%) to 90(%) of the pitch in the steering direction between adjacent fed elements 3 along the steering direction.

[0051] This makes it possible to improve the beam steering characteristics of the array antenna 1 in a wide band in the embodiment. Note that the examples of Figs. 4 to 6 described above show the results when the pitch ratio is 80(%).

[0052] Fig. 9 is a diagram showing the beam steering characteristics when changing the size of the parasitic element 4. Note that the example in Fig. 9 shows the beam steering characteristics of 26.5 (GHz) in the H-plane direction in the -60(°) direction, the front direction, and the +60(°) direction of the array antenna 1 when the size of the parasitic element 3 is 2.57(mm) square.

[0053] As shown in Fig. 9, by making the parasitic element 4 larger than the feed element 3, the gain in the -60(°) direction and the +60(°) direction can be improved. Therefore, according to the embodiment, wider angle beam steering is possible in the array antenna 1. Note that the examples in Figs. 4 to 6 described above show the results when the feed element 3 and the parasitic element 4 are the same size.

[0054] 1, the parasitic elements 4 may surround the feed element group 3A in two layers. The parasitic elements 4 may surround the feed element group 3A in three or more layers. In this case, the two-layer configuration is preferable in terms of the shielding effect for the ground layer 12 and the suppression of an increase in the area of ​​the array antenna 1.

[0055] In other words, in the embodiment, by doubly surrounding the periphery of the feed element group 3A with multiple parasitic elements 4, it is possible to reduce the distortion of the radiation pattern in a direction significantly tilted from the front direction of the antenna and also to reduce the area of ​​the array antenna 1.

[0056] In addition, in an embodiment, as shown in FIG. 1, the steering direction pitch between adjacent feed elements 3 and parasitic elements 4 along the steering direction may be narrower than the steering direction pitch between adjacent feed elements 3 along the steering direction.

[0057] Specifically, in an embodiment, the pitch PE3 in the E-plane direction between adjacent feed elements 3 and parasitic elements 4 along the E-plane direction may be narrower than the pitch PE1 in the E-plane direction between adjacent feed elements 3 along the E-plane direction.

[0058] Similarly, in the embodiment, the pitch PH3 in the H-plane direction between adjacent feed elements 3 and parasitic elements 4 along the H-plane direction may be narrower than the pitch PH1 in the H-plane direction between adjacent feed elements 3 along the H-plane direction.

[0059] This further enhances the shielding effect for the ground layer 12, thereby further reducing the distortion of the radiation pattern in a direction significantly tilted from the front direction of the antenna. Therefore, according to the embodiment, wider angle beam steering is possible in the array antenna 1.

[0060] In the present disclosure, the pitch PE1 in the E-plane direction between adjacent power supply elements 3 along the E-plane direction and the pitch PH1 in the H-plane direction between adjacent power supply elements 3 along the H-plane direction may be equal to or different from each other.

[0061] <Another embodiment> Next, an array antenna 1 according to another embodiment of the present invention will be described with reference to Fig. 10 to Fig. 13. Fig. 10 is a front view showing an example of the configuration of the array antenna 1 according to another embodiment of the present invention. As shown in Fig. 10, the array antenna 1 according to the other embodiment differs from the above-mentioned embodiment in the arrangement of the parasitic elements 4.

[0062] Specifically, in another embodiment, a plurality of parasitic elements 4 arranged to surround the periphery of the feed element group 3A are arranged in a staggered manner with respect to the plurality of feed elements 3. That is, in another embodiment, the parasitic elements 4 are arranged so as to be shifted in rows or columns with respect to the plurality of feed elements 3 arranged in a matrix.

[0063] In another embodiment, similar to the above embodiment, the pitch in the steering direction between adjacent parasitic elements 4 along the steering direction is narrower than the pitch in the steering direction between adjacent feed elements 3 along the steering direction.

[0064] Specifically, in another embodiment, the pitch PE2 in the E-plane direction between adjacent parasitic elements 4 along the E-plane direction (X-axis direction) is narrower than the pitch PE1 in the E-plane direction between adjacent fed elements 3 along the E-plane direction.

[0065] Similarly, in another embodiment, the pitch PH2 in the H-plane direction between adjacent parasitic elements 4 along the H-plane direction (Y-axis direction) is narrower than the pitch PH1 in the H-plane direction between adjacent fed elements 3 along the H-plane direction.

[0066] As a result, in this other embodiment, similarly to the above-mentioned embodiment, it is possible to reduce the distortion of the radiation pattern in a direction significantly tilted from the front direction of the antenna. The details of the results will be described below.

[0067] 11 to 13 are diagrams showing beam steering characteristics in the E-plane of the array antenna 1 according to another embodiment and a reference example of the embodiment. Note that the results shown in Figs. 11 to 13 correspond to the E-plane steering in the power feed via 21A (see Fig. 3).

[0068] Also, FIG. 11 shows the beam steering characteristics at a frequency of 26.5 (GHz), FIG. 12 shows the beam steering characteristics at a frequency of 28 (GHz), and FIG. 13 shows the beam steering characteristics at a frequency of 29.5 (GHz).

[0069] As shown in Figures 11 to 13, it can be seen that the array antenna 1 of another embodiment further reduces the distortion of the radiation pattern in directions significantly tilted from the front direction (here, the -60° and +60° directions) compared to the reference example, and further improves the gain in such directions.

[0070] In this way, in this other embodiment, narrowing the pitches PE2 and PH2 can effectively reduce the disruption of the radiation pattern that occurs significantly when the area of ​​the ground layer 12 is larger than that of the array antenna 1. Therefore, according to this other embodiment, wider angle beam steering is possible in the array antenna 1.

[0071] The above-described array antenna 1 can be combined with an RF element to form a communication module, which can also perform wide-angle beam steering.

[0072] The array antenna 1 according to the embodiment includes a substrate 2, a plurality of feed elements 3, and a plurality of parasitic elements 4. The substrate 2 is made of a dielectric material. The plurality of feed elements 3 are arranged in a matrix along a surface 2a of the substrate 2. The plurality of parasitic elements 4 are arranged so as to surround a periphery of a feed element group 3A composed of the plurality of feed elements 3. In addition, the pitches PE2, PH2 in the steering direction between adjacent parasitic elements 4 in the steering direction are narrower than the pitches PE1, PH1 in the steering direction between adjacent feed elements 3 in the steering direction. This enables wide-angle beam steering in the array antenna 1.

[0073] In the array antenna 1 according to the embodiment, the pitches PE2, PH2 in the steering direction between adjacent parasitic elements 4 in the steering direction are 70(%) to 90(%) of the pitches PE1, PH1 in the steering direction between adjacent feed elements 3 in the steering direction. This makes it possible to improve the beam steering characteristics of the array antenna 1 in a wide band.

[0074] In the array antenna 1 according to the embodiment, the parasitic elements 4 surround the feed element group 3A in a doubly fashion, which reduces the distortion of the radiation pattern in a direction significantly tilted from the front direction of the antenna and reduces the area of ​​the array antenna 1.

[0075] Moreover, in the array antenna 1 according to the embodiment, the multiple parasitic elements 4 are arranged in a staggered manner with respect to the multiple feed elements 3. This enables the array antenna 1 to perform beam steering over a wider angle.

[0076] Moreover, in the array antenna 1 according to the embodiment, the parasitic elements 4 are larger than the fed elements 3. This enables the array antenna 1 to perform beam steering over a wider angle.

[0077] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present disclosure. For example, in the above embodiments, an example is shown in which the feed element 3 and the parasitic element 4 are arranged by stacking the feed patch layer 13 and the parasitic patch layer 14, but the present disclosure is not limited to such an example, and the feed element 3 and the parasitic element 4 having various configurations may be used.

[0078] In addition, in the above embodiment, an example is shown in which a short-circuit via 22 is provided in the power supply element 3 to connect the ground layer 12 and the power supply patch layer 13, but the present disclosure is not limited to such an example, and such a short-circuit via 22 does not have to be provided in the power supply element 3.

[0079] Further advantages and other aspects may readily occur to those skilled in the art. Thus, the disclosure in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0080] 1 Array antenna (an example of an antenna) 2. Board 2a surface 3. Feed element 3A power supply element group 4 Parasitic elements PE1~PE3, PH1~PH3 pitch

Claims

1. A substrate made of a dielectric material; A plurality of feeding elements arranged in a matrix along a surface of the substrate; a plurality of parasitic elements arranged side by side so as to surround a periphery of a group of feed elements constituted by the plurality of feed elements; Equipped with a pitch in the steering direction between the parasitic elements adjacent to each other along the steering direction is narrower than a pitch in the steering direction between the feed elements adjacent to each other along the steering direction, The pitch in the steering direction between the parasitic elements adjacent along the steering direction is 70(%) to 80(%) of the pitch in the steering direction between the feed elements adjacent along the steering direction. An antenna used in the frequency range of 26.5 (GHz) to 29.5 (GHz).

2. A substrate made of a dielectric material; A plurality of feeding elements arranged in a matrix along a surface of the substrate; a plurality of parasitic elements arranged side by side so as to surround a periphery of a group of feed elements constituted by the plurality of feed elements; Equipped with a pitch in the steering direction between the parasitic elements adjacent to each other along the steering direction is narrower than a pitch in the steering direction between the feed elements adjacent to each other along the steering direction, The pitch in the steering direction between the parasitic elements adjacent along the steering direction is 70(%) to 90(%) of the pitch in the steering direction between the feed elements adjacent along the steering direction. An antenna used in the frequency range of 26.5 (GHz) to 28 (GHz).

3. The plurality of parasitic elements surround the group of feed elements in a double layer.

3. An antenna as claimed in claim 1 or 2.

4. The parasitic elements are arranged in a staggered manner with respect to the feed elements.

3. An antenna as claimed in claim 1 or 2.

5. The parasitic element is larger than the feed element.

3. An antenna as claimed in claim 1 or 2.

6. An antenna according to claim 1 or 2; An RF element; A communication module comprising:

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