Devices with radiating systems proximate to conductive bodies

Abstract

A device includes a radiating system comprising: at least one of a radiation booster or a radiating element; a ground plane layer having at least two connecting points; a radiofrequency system electrically connected to the radiation booster and/or the radiating element and comprising at least one matching network; at least one external port electrically connected to the radiofrequency system; and at least first and second electrically conductive elements each comprising one or more components and being adapted to electrically connect first and second connecting points, respectively, of the at least two connecting points to an electrically conductive body of an apparatus at a distance from the ground plane layer, the distance being less than λ/15, wherein λ is a free-space wavelength at a lowest frequency of operation of the radiating system.

Claims

1. A device including a radiating system, the radiating system comprising: at least one of a radiation booster or a radiating element; a ground plane layer having at least first and second connecting points; a radiofrequency system electrically connected to the at least one of a radiation booster or a radiating element and comprising at least one matching network; at least one external port electrically connected to the radiofrequency system; and at least first and second electrically conductive elements, each comprising one or more components and being adapted to electrically connect the first and second connecting points, respectively, to an electrically conductive body of an apparatus other than the at least one of a radiation booster or a radiating element at a distance from the ground plane layer, the distance being less than λ/15, wherein λ, is a free-space wavelength at a lowest frequency of operation of the radiating system, wherein the electrically conductive body has a first surface that is larger than a second surface of the ground plane layer such that a projection of the radiation booster or radiating element onto a printed circuit board housing the ground plane layer intersects the electrically conductive body in plan view.

2. The device of claim 1, wherein the at least one of a radiation booster or a radiating element comprises: a single radiation booster element; or two or three radiation booster elements electrically connected.

3. The device of claim 1, wherein the radiating system further comprises a feeding system that electrically connects the at least one external port to the radiofrequency system.

4. The device of claim 1, wherein: the ground plane layer includes a third connecting point; the first connecting point is within a first third of the ground plane layer in a lengthwise dimension thereof, the second connecting point is within a second third of the ground plane layer in the lengthwise dimension thereof, and the third connecting point is within a third of the ground plane layer in the lengthwise dimension thereof; and the radiating system further includes a third electrically conductive element adapted to electrically connect the third connecting point to the electrically conductive body.

5. The device of claim 4, wherein: the first connecting point is at a first distance in a width direction of the ground plane layer and at a second distance in the lengthwise dimension of the ground plane layer, the first distance being between ⅓ and ⅔ of a width of the ground plane layer, the second distance being between 0 and ⅙ of a length of the ground plane layer; the second connecting point is at the first distance in the width direction of the ground plane layer and at a third distance in the lengthwise dimension of the ground plane layer, the third distance being between 5/12 and 7/12 of the length of the ground plane layer; and the third connecting point is at the first distance in the width direction of the ground plane layer and at a fourth distance in the lengthwise dimension of the ground plane layer, the fourth distance being between ⅚ and 6/6 of the length of the ground plane layer.

6. The device of claim 4, wherein: the ground plane layer further includes four or more connecting points; and the radiating system includes as many electrically conductive elements as there are connecting points, each of the electrically conductive elements being adapted to electrically connect one of the connecting points to the electrically conductive body.

7. The device of claim 1, wherein each of the at least first and second electrically conductive elements comprises one or more of: a switch, a capacitor, an inductor, a resistor, a filter, or a via.

8. The device of claim 1, wherein the device is a wireless device and the radiating system operates from 824 MHz to 960 MHz or from 1710 MHz to 2690 MHz or from both 824 MHz to 960 MHz and 1710 MHz to 2690 MHz.

9. A system comprising: the device of claim 1; and the apparatus comprising the electrically conductive body.

10. The system of claim 9, wherein: a width of the electrically conductive body is greater than a width of the ground plane layer; a length of the electrically conductive body is greater than a length of the ground plane layer; and the apparatus is one of: a smart TV, a refrigerator, a washing machine, a drying machine, a gas-meter, a water-meter, an electricity meter, a motor vehicle, a train, an airplane, a rocket, and a ship.

11. A device including a radiating system, the radiating system comprising: at least one of a radiation booster or a radiating element; a ground plane layer comprising at least first and second connecting points; a radiofrequency system electrically connected to the at least one of a radiation booster or a radiating element and comprising at least one matching network; at least one external port electrically connected to the radiofrequency system; at least first and second electrically conductive elements, each comprising one or more components and adapted to electrically connect the first and second connecting points, respectively, to an electrically conductive body of an apparatus other than the at least one of a radiation booster or a radiating element at a distance from the ground plane layer, the distance being less than λ/15, wherein λ, is a free-space wavelength at a lowest frequency of operation of the radiating system, wherein: each of the at least first and second electrically conductive elements is further adapted to induce electric currents in the ground plane layer that are in-phase with respect to at least some electric currents induced in the ground plane layer by the at least one of a radiation booster or a radiating element, and the electrically conductive body has a first surface that is larger than a second surface of the ground plane layer such that a projection of the radiation booster or radiating element onto a printed circuit board housing the ground plane layer intersects the electrically conductive body in plan view.

12. The device of claim 11, wherein the at least one of a radiation booster or a radiating element comprises: a single radiation booster element; or two or three radiation booster elements electrically connected.

13. The device of claim 11, wherein the radiating system further comprises a feeding system that electrically connects the at least one external port to the radiofrequency system.

14. The device of claim 11, wherein: the ground plane layer includes a third connecting point; the first connecting point is within a first third of the ground plane layer in a lengthwise dimension thereof, the second connecting point is within a second third of the ground plane layer in the lengthwise dimension thereof, and the third connecting point is within a third of the ground plane layer in the lengthwise dimension thereof; and the radiating system further includes a third conductive element adapted to electrically connect the third connecting point to the electrically conductive body.

15. The device of claim 14, wherein: the first connecting point is at a first distance in a width direction of the ground plane layer and at a second distance in the lengthwise dimension of the ground plane layer, the first distance being between ⅓ and ⅔ of a width of the ground plane layer, the second distance being between 0 and ⅙ of a length of the ground plane layer; the second connecting point is at the first distance in the width direction of the ground plane layer and at a third distance in the lengthwise dimension of the ground plane layer, the third distance being between 5/12 and 7/12 of the length of the ground plane layer; and the third connecting point is at the first distance in the width direction of the ground plane layer and at a fourth distance in the lengthwise dimension of the ground plane layer, the fourth distance being between ⅚ and 6/6 of the length of the ground plane layer.

16. The device of claim 14, wherein: the ground plane layer further includes four or more connecting points; and the radiating system includes as many electrically conductive elements as there are connecting points, each of the electrically conductive elements being adapted to electrically connect one of the connecting points to the electrically conductive body.

17. The device of claim 11, wherein each of the at least first and second electrically conductive elements comprises one or more of: a switch, a capacitor, an inductor, a resistor, a filter, or a via.

18. The device of claim 11, wherein the device is a wireless device and the radiating system operates from 824 MHz to 960 MHz or from 1710 MHz to 2690 MHz or from both 824 MHz to 960 MHz and 1710 MHz to 2690 MHz.

19. A system comprising: the device of claim 11; and the apparatus comprising the electrically conductive body.

20. A method comprising: providing a device including a radiating system, the radiating system comprising: at least one of a radiation booster or a radiating element; a ground plane layer including at least first and second connecting points; a radiofrequency system electrically connected to the at least one of a radiation booster or a radiating element and comprising at least one matching network; and at least one external port electrically connected to the radiofrequency system; providing an apparatus other than the at least one of a radiation booster or a radiating element comprising an electrically conductive body such that the ground plane layer is at a distance from the electrically conductive body, the distance being smaller than λ/15, wherein λ, is a free-space wavelength at a lowest frequency of operation of the radiating system, and wherein the electrically conductive body has a first surface that is larger than a second surface of the ground plane layer such that a projection of the radiation booster or radiating element onto a printed circuit board housing the ground plane layer intersects the electrically conductive body in plan view; and providing at least first and second electrically conductive elements each comprising one or more components.

21. The method of claim 20, further comprising: altering at least some electric currents on the surface of the electrically conductive body by connecting the ground plane layer to the electrically conductive body with the at least first and second electrically conductive elements, the at least some electric currents being altered such that they are in-phase with respect to at least some electric currents induced in the ground plane layer by the at least one of a radiation booster or a radiating element.

22. The method of claim 21, wherein connecting the ground plane layer to the electrically conductive body with the at least first and second electrically conductive elements comprises: connecting the first connecting point to the electrically conductive body with the first electrically conductive element, and connecting the second connecting point to the electrically conductive body with the second electrically conductive element.

23. The method of claim 22, wherein: connecting the ground plane layer to the electrically conductive body further comprises: connecting a third connecting point of the ground plane layer to the electrically conductive body with a third electrically conductive element.

24. The method of claim 23, wherein the first connecting point is within a first third of the ground plane layer in a lengthwise dimension thereof, the second connecting point is within a second third of the ground plane layer in the lengthwise dimension thereof, and the third connecting point is within a third of the ground plane layer in the lengthwise dimension thereof.

25. The method of claim 24, wherein: the first connecting point is at a first distance in a width direction of the ground plane layer and at a second distance in the lengthwise dimension of the ground plane layer, the first distance being between ⅓ and ⅔ of a width of the ground plane layer, the second distance being between 0 and ⅙ of a length of the ground plane layer; the second connecting point is at the first distance in the width direction of the ground plane layer and at a third distance in the lengthwise dimension of the ground plane layer, the third distance being between 5/12 and 7/12 of the length of the ground plane layer; and the third connecting point is at the first distance in the width direction of the ground plane layer and at a fourth distance in the lengthwise dimension of the ground plane layer, the fourth distance being between ⅚ and 6/6 of the length of the ground plane layer.

26. The method of claim 23, wherein: the at least two connecting points comprise four or more connecting points; the at least first and second electrically conductive elements comprise as many electrically conductive elements as there are connecting points; and electrically connecting the ground plane layer to the electrically conductive body comprises electrically connecting each of the connecting points of the ground plane layer to the electrically conductive body with a respective one of the electrically conductive elements.

27. The method of claim 20, wherein the at least one of a radiation booster or a radiating element comprises: a single radiation booster element; or two or three radiation booster elements electrically connected.

28. The method of claim 20, wherein the radiating system further comprises a feeding system that electrically connects the at least one external port to the radiofrequency system.

29. The method of claim 20, wherein each of the at least two electrically conductive elements comprises one or more of: a switch, a capacitor, an inductor, a resistor, a filter, or a via.

30. The method of claim 20, further comprising providing the at least one matching network such that the radiating system operates from 824 MHz to 960 MHz or from 1710 MHz to 2690 MHz or from both 824 MHz to 960 MHz and 1710 MHz to 2690 MHz; and wherein the device is a wireless device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The mentioned and further features and advantages of the invention become apparent in view of the detailed description which follows with some examples of the invention, referenced by means of the accompanying drawings, given for purposes of illustration only and in no way meant as a definition of the limits of the invention.

(2) FIGS. 1A-1B show, from two different views, a radiating system of a device in accordance with an embodiment

(3) FIGS. 2-6 diagrammatically show portions of ground plane layers where connecting points may be provided in accordance with embodiments.

(4) FIGS. 7A-7C show different graphs in which radiation and antenna efficiencies of a device in free-space conditions, a device in close proximity to an electrically conductive body and a device in accordance with an embodiment are compared.

(5) FIG. 8 shows an exemplary matching network.

(6) FIG. 9 diagrammatically shows an exemplary arrangement of an electrically conductive element in accordance with the present disclosure.

(7) FIG. 10 diagrammatically shows exemplary paths followed by electric currents in a device in accordance with an embodiment.

(8) FIGS. 11A-11B diagrammatically show a test platform for the electromagnetic characterization of radiation booster elements.

(9) FIG. 12 shows a graph with the radiation efficiency and antenna efficiency of a radiation booster element measured with the test platform of FIGS. 11A-11B.

DETAILED DESCRIPTION

(10) FIGS. 1A-1B show a device 5 in accordance with an embodiment of the invention; FIG. 1A shows the device 5 from a top view whereas FIG. 1B shows the device 5 from a side view.

(11) The device 5 includes a radiating system that comprises a printed circuit board 10, i.e. PCB, with a ground plane layer 15 (shown with a striped pattern for illustrative purposes only). The ground plane layer 15 may be on one side of the printed circuit board 10 only or on both sides of the printed circuit board 10, and in some cases even have one or more ground plane layers within the printed circuit board 10; in any of these cases, the different ground plane layers provided in the PCB 10 are connected one to each other by means of via holes. The device 5 further comprises at least one radiation booster or radiating element 11. In this example, the device 5 comprises a single radiation booster element 11 mounted on the PCB 10, particularly in a portion thereof free from ground plane layer 15, and features dimensions of 12.0 mm×3.0 mm×2.4 mm.

(12) The radiation booster element 11 excites radiation modes in the ground plane layer 15. Since the radiation booster element 11 is mainly reactive across the frequencies of operation, it is mismatched to an impedance of e.g. a signal transmitter or receiver, a modem or the like for effecting communications by means of the radiating system, which is usually 50 ohms. The device 5 further comprises a radiofrequency system, which comprises a matching network 30 (in FIG. 1A only several pads are shown where components of the matching network are installed for the sake of clarity only) for matching purposes. The radiofrequency system is electrically connected to both the radiation booster element 11 (by means of a feeding line 12, that is, for example a metallic strip or a conductive trace) and at least one external port 32. In this example, the matching network 30 comprises seven electrical components and is illustrated in FIG. 8. Said radiation booster element 11, in combination with said radiofrequency system and the ground plane layer 15, enables the operation of the radiating system in two frequency bands: from 824 MHz to 960 MHz, and from 1710 MHz to 2690 MHz.

(13) The device 5 may also comprise a feeding system 34 that connects the radiofrequency system to the at least one external port 32, such as in this example, but in other embodiments the radiofrequency system is electrically connected to the at least one external port 32 without a feeding system 34, for example with a direct electrical connection from an end terminal of the at least one matching network 30 to the at least one external port 32.

(14) Beneath the device 5 is an apparatus having an electrically conductive body 50. Such electrically conductive body 50, when it is proximate to the radiating system of the device 5, influences the capability of the radiating system of radiating and/or capturing electromagnetic waves. The electrically conductive body 50 has electric currents flowing therein that are coupled to the ground plane layer 15 of the radiating system when the distance between the two is small. Normally, an average distance between the electrically conductive body 50 and the ground plane layer 15 must be small, meaning that the two are substantially parallel and one above or below the other so that there is at least some superposition between the two, as in FIGS. 1A-1B where there is complete superposition: beneath the entire ground plane layer 15 is the electrically conductive body 50. The distance is small when it is less than λ/10; by way of example the distance may also be smaller than any one of the following values: λ/15, λ/20 and λ/30; wherein λ is a free-space wavelength at a lowest frequency of operation of the radiating system.

(15) The device 5 is provided with two nylon spacers 37, 38 that maintain the device 5 attached to the electrically conductive body 50 such that there is the distance D (shown in FIG. 1B) between the two. The electric currents that are coupled from the electrically conductive body 50 to the ground plane layer 15 worsen the performance of the radiating system by decreasing the efficiency thereof and increasing the impedance mismatch thereof.

(16) In this example, the distance D is set to 10 mm. The radiating system of the device 5 operates from 824 MHz to 960 MHz and from 1710 MHz to 2690 MHz, and thus the distance D is less than λ/10 and even less than λ/30 for the free-space wavelength at 824 MHz.

(17) A plurality of connecting points, in this example three connecting points 20-22, is provided in the ground plane layer 15. A plurality of electrically conductive elements, in this example three electrically conductive elements 25-27 that comprise vias in the form of wire-made vias, is provided between the ground plane layer 15 and the electrically conductive body 50 such that a plurality of electrical connections is made between the two. The vias have a length equal to the distance D and a diameter of 1 mm.

(18) The electrically conductive elements 25-27 alter the electric currents induced on the surface of the electrically conductive body 50, which are coupled to the ground plane layer 15. The electric currents are preferably altered so that at least some electric currents in the electrically conductive body 50 are in-phase with at least some electric currents induced in the ground plane layer 15 owing to the excitation of radiating modes by the radiation booster element 11. As the electric currents flowing in the electrically conductive body 50 are coupled to the ground plane layer 50, the altered electric currents are also coupled thereto, thereby improving the operation of the radiating system.

(19) In some examples, one or more of the electrically conductive elements 25-27 comprise different components and/or even two or more components; for example, switches, inductors, capacitors, filters, etc. The provision of such electrically conductive elements makes possible to further improve the operation of the radiating system by adjusting how the electric currents flowing in the electrically conductive body 50 are altered. Accordingly, by providing switches, inductors, capacitors, filters, etc. it is possible to adjust when the electric currents are altered and for which frequencies the electric currents are altered.

(20) The device 5 is an electronic device such as e.g. a mobile phone, a smartphone, a router, a communications module, a transceiver, a laptop computer, a tablet, a GPS system, a sensor, or generally a multifunction wireless device which combines the functionality of multiple devices).

(21) The radiation booster element 11 may be a radiation booster as described in patent document WO-2016012507-A1, which is hereby incorporated by reference in its entirety. For instance, as described in lines 25-33 of page 9 and lines 1-10 of page 10 of said patent document, the radiation booster element 11 includes a dielectric material and in some embodiments, a single standard layer of dielectric material spacing two or more conductive elements. A single standard layer of dielectric material refers to dielectric material with a standard thickness, which is available off-the-shelf. For example, 0.025″ (0.635 mm), 0.047″ (1.2 mm), 0.093″ (2.36 mm) or 0.125″ (3.175 mm) are common/standard thicknesses for dielectric materials which are available in the market. Examples of dielectric materials include fiber-glass FR4, Cuclad, Alumina, Kapton, Ceramic and for instance commercial laminates and substrates from Rogers® Corporation (R03000® and R04000® laminates, Duroid substrates and alike) or other suitable non-conductive materials. The radiation booster element 11 may be formed by printing or depositing conductive material in a first and a second surface of the dielectric material (e.g. top and bottom) and adding several vias to electrically connect the conductive material in the first surface with the conductive material in the second surface. The conductive material in the first and second surfaces may have a substantially polygonal shape. Some possible polygonal shapes are for instance, but not limited to, squares, rectangles, and trapezoids. When the conductive material in said first and second surfaces has an elongated shape, for instance a rectangular shape, the radiation booster element takes the form of a booster bar; a booster bar may also include vias that electrically connect the conductive material in the first surface with the conductive material in the second surface.

(22) In some embodiments, the radiation booster element 11 has a size as described in lines 24-34 of page 12, lines 1-34 of page 13, and lines 1-6 of page 14 of said patent document, thus the maximum size is at least smaller than 1/15 of the free-space wavelength corresponding to the lowest frequency of operation. In some cases, said maximum size may also be smaller than any one of the following values: 1/20, 1/25, 1/30, 1/50, and/or 1/100 of the free-space wavelength corresponding to the lowest frequency of operation. Additionally, in some of these examples the radiation booster element 11 has a maximum size larger than any one of the following values: 1/1400, 1/700, 1/350, 1/250, 1/180, 1/140, and/or 1/120 times the free-space wavelength corresponding to the lowest frequency of operation. The maximum size of the radiation booster element 11 is preferably defined by the largest dimension of a booster box that completely encloses said radiation booster element 11, and in which the radiation booster element 11 is inscribed. More specifically, a booster box for a radiation booster element 11 is defined as being the minimum-sized parallelepiped of square or rectangular faces that completely encloses the radiation booster element 11 and wherein each one of the faces of said minimum-sized parallelepiped is tangent to at least a point of said radiation booster element 11. Moreover, each possible pair of faces of said minimum-size parallelepiped sharing an edge forms an inner angle of 90°.

(23) Different matching networks 30 are possible within the scope of the present disclosure, for example but not limited to, those described in patent document WO-2016012507-A1.

(24) FIGS. 2-4 diagrammatically show portions of a ground plane layer 100 where connecting points may be provided in accordance with embodiments. The ground plane layer 100 of a device is provided on a PCB thereof and has a rectangular shape. The ground plane layer 100 has a lengthwise dimension defining a length L, and a width dimension defining a width W. By way of example, the length L is 120 mm and the width W is 60 mm, but other lengths and widths are also possible within the scope of the present disclosure.

(25) In FIG. 2, the ground plane layer 100 has first, second and third portions 101-103 (shown with a striped pattern for illustrative purposes only, but it is readily apparent that they are part of the ground plane layer 100) in which connecting points may be provided.

(26) The first portion 101 is at a first end of the ground plane layer 100, and coincides with a first edge thereof that extends in a direction corresponding to the width dimension; the first portion 101 extends a length L/6 along the lengthwise dimension of the ground plane layer 100 and has a width W. The second portion 102 is at a central part (at a length of L/2) of the ground plane layer 100 and extends a length L/6 along the lengthwise dimension of the ground plane layer 100 and has a width W. The third portion 103 is at a second end of the ground plane layer 100, and coincides with a second edge thereof that extends in a direction corresponding to the width dimension; the third portion 101 extends a length L/6 along the lengthwise dimension of the ground plane layer 100 and has a width W.

(27) Each of the connecting points (not illustrated) may be provided in any part of one of the three portions 101-103 so that the connecting points are spaced apart one relative to each other. In some examples, the connecting points are each provided in one of the three portions 101-103 such that they are on or proximate to a central axis 150 (shown with a dashed line for illustrative purposes only) of the ground plane layer 100, which goes along the lengthwise dimension thereof.

(28) In FIG. 3, the ground plane layer 100 has first, second and third portions 111-113 (shown with a striped pattern for illustrative purposes only, but it is readily apparent that they are part of the ground plane layer 100) in which connecting points may be provided.

(29) Each of the first, the second and the third portions 111-113 extend a same length as the three portions 101-103 of FIG. 2, but the width thereof is different. The first, the second and the third portions 111-113 have a width W/3 (which in this example coincides with L/6 owing to the dimensions of the ground plane layer 100). In this example, half of the width thereof extends from one side of the central axis 150 and the other half of the width thereof extends from the other side of the central axis 150. In some examples, the width of the first, the second and the third portions 111-113 is between 0.05λ and 0.06λ, and in some examples between 0.0535λ and 0.0545λ, where λ is a free-space wavelength corresponding to a lowest frequency of operation of the radiating system.

(30) In FIG. 4, the same portions 111-113 of the example of FIG. 3 are shown, but also illustrated herein are first, second and third connecting points 201-203. The connecting points 201-203 are provided at the center of the portions 111-113 such that they coincide with the central axis 150. The distances between the first and the second connecting points 201-202, and between the second and the third connecting points 202-203 are the same, which is 5L/12. In some examples, the distance between the first and the second connecting points 201-202 and the distance between the second and the third connecting points 202-203 are between 0.1λ and 0.4λ, for example between 0.11λ and 0.324λ, and in some examples between 0.135λ and 0.145λ along the central axis 150.

(31) FIG. 5 diagrammatically shows portions of a ground plane layer 130 where connecting points may be provided in accordance with embodiments. The ground plane layer 130 of a device is provided on a PCB thereof and has an irregular shape. The ground plane layer 130 has a lengthwise dimension defining a length L, and a width dimension defining a width W. By way of example, the length L is 110 mm and the width W is 55 mm, but other lengths and widths are also possible within the scope of the present disclosure.

(32) The ground plane layer 130 has first, second and third portions 131-133 (the first and the third portions 131, 133 are shown with a striped pattern for illustrative purposes only, but it is readily apparent that they are part of the ground plane layer 130) in which connecting points may be provided.

(33) Each of the three portions 131-133 corresponds to a third of the ground plane layer 130 along the lengthwise dimension thereof, thus each portion 131-133 has a length of L/3. The first portion 131 is at a first end of the ground plane layer 130, and coincides with a first edge thereof that extends in a direction corresponding to the width dimension; the first portion 131 has a width that is less than W. The second portion 132 is at a center of the ground plane layer 130 and has a width that is less than W, but is greater than the width of the first portion 131. The third portion 133 is at a second end of the ground plane layer 130, and coincides with a second edge thereof that extends in a direction corresponding to the width dimension; the third portion 133 has a same width as the second portion 132.

(34) Each of the connecting points (not illustrated) may be provided in any part of one of the three portions 131-133 such that they are spaced apart one relative to each other. In some examples, the connecting points are each provided in one of the three portions 131-133 such that they are on or proximate to the central axis 150 of the ground plane layer 130.

(35) FIG. 6 diagrammatically shows portions of a ground plane layer 140 where connecting points may be provided in accordance with embodiments.

(36) The ground plane layer 140 of a device comprises first and second ground plane layers 141, 142 that are provided on a same PCB of the device or on different PCBs of the device. The first and the second ground plane layers 141, 142 have an irregular shape and are electrically connected with at least one electrically conductive element 143. The ground plane layer 140 has a lengthwise dimension defining a length L, and a width dimension defining a width W when both the first and the second ground plane layers 141, 142 are fixedly attached to the device. The placement of the ground plane layers 141, 142 inside the device is important for the location of the connecting points because it establishes the location where the electric currents will be altered on the surface of an electrically conductive body of an apparatus. By way of example, the length L is 100 mm and the width W is 50 mm, but other lengths and widths are also possible within the scope of the present disclosure.

(37) The ground plane layer 140 has first, second, third and fourth portions 145-148 (the first and the third portions 145, 147 are shown with a striped pattern for illustrative purposes only, but it is readily apparent that they are part of the ground plane layer 140) in which connecting points may be provided. In this example, the first and the second portions 145, 146 are in the first ground plane layer 141, a first part of the third portion 147 is in the first ground plane layer 141 and a second part of the third portion 147 is in the second ground plane layer 142, and the fourth portion 148 is in the second ground plane layer 142.

(38) Each of the four portions 145-148 corresponds to a fourth of the ground plane layer 140 along the lengthwise dimension thereof, thus each portion 145-148 has a length of L/4. The first portion 145 is at a first end of the ground plane layer 140, and coincides with a first edge thereof that extends in a direction corresponding to the width dimension; the first portion 145 has a width that is less than W. The second portion 146 is between the first portion 145 and the third portion 147 (i.e. it extends between L/4 and L/2 of the lengthwise dimension of the ground plane layer 140) and has a width that is less than the width of the first portion 145. The third portion 147 is at a part of the first ground plane layer 141 having a second end thereof and also at a part of the second ground plane layer 142 having a first end thereof; the third portion 147 has a width that is less than W but greater than the widths of the first and the second portions 145, 146. The fourth portion 148 is at a part of the second ground plane layer 142 having a second end thereof and coincides with a second edge of the ground plane layer 140 that extends in a direction corresponding to the width dimension; the fourth portion 148 has a width that is less than W.

(39) The connecting points 201-204 are in one of the four portions 145-148 such that they are spaced apart one relative to each other. In this example, the connecting points 201-204 are on or proximate to the central axis 150 of the ground plane layer 140. In some other embodiments, several connecting points are arranged on a same portion of the four portions 145-148, for example when six connecting points are provided, two may be in the first portion 145, two other points in the second portion 146, one other point in the third portion 147 and a last point in the fourth portion 148. Different combinations are possible within the scope of the present disclosure.

(40) FIGS. 7A-7C show different graphs in which radiation and antenna efficiencies of a device in free-space conditions, a device in close proximity to an electrically conductive body and a device in accordance with an embodiment are compared.

(41) In FIG. 7A is shown the radiation and antenna efficiencies 250, 251 (shown with dashed and solid lines, respectively) of a device such as the device 5 of FIGS. 1A-1B in free-space conditions, that is to say, not in close proximity to the electrically conductive body 50 and without any electrically conductive elements connected thereto. The device features a radiation efficiency 250 ranging from 70% up to 85% and an antenna efficiency 251 ranging from 55% up to 80% in the 824 MHz to 960 MHz band whereas, whereas the radiation efficiency 250 ranges from 75% up to 90% and the antenna efficiency 251 ranges from 65% up to 85% in the 1710 MHz to 2690 MHz band.

(42) In FIG. 7B, there is shown the radiation and antenna efficiencies in the lower frequency band of the same device when it is in close proximity to the electrically conductive body, particularly when provided with connecting points and electrically conductive elements connecting it to the electrically conductive body and when it is not provided with such connecting points and electrically conductive elements. In the latter case, the radiation efficiency 260 (shown with a dashed line) ranges from 18% up to 60% and the antenna efficiency 261 (shown with a solid line) ranges from 10% up to 24% in the 824 MHz to 960 MHz band, whereas in the former case the radiation efficiency 265 (shown with a dashed line with dashes shorter than those of the dashed line of the radiation efficiency 260) ranges from 50% up to 75% and the antenna efficiency 266 (shown with a dotted line) ranges from 40% up to 73% in the same band. In this particular example, there is an improvement of up to 6 dB in radiation efficiency 265 (an improvement over 1:4) at frequencies in the band up to around 900 MHz, raising the efficiency from around 10-15% to over 60% at the lower frequencies of the band, for instance at 824 MHz; at higher frequencies in the band, the improvement is smaller. In this example, the efficiency at the higher frequency band (1710 MHz to 2690 MHz) is preserved compared to a free-space case, i.e. in absence of a conductive body, this is because the device and the electrically conductive body are not proximate in terms of the free-space wavelength at said frequencies. In some examples, the efficiency of the radiating system is improved in the same bands of operation or in other part(s) of the electromagnetic spectrum where the improve in efficiency enables the use of further bandwidth(s); for example the efficiency may be improved 0.5 dB or more, such as 1 dB, 2 dB, 3 dB, 6 dB or even more. This is illustrated in FIG. 7C, where the radiation and antenna efficiencies 270, 271 (shown with dashed and solid lines, respectively) of the device 5 of FIGS. 1A-1B are shown. In comparison with the free-space case of FIG. 7A, the radiating system has improved both the radiation and antenna efficiency 270, 271 in a frequency range at about 1400 MHz, thereby enabling the radiating system to operate in one more band of operation.

(43) FIG. 8 shows an exemplary matching network 80 that is to be installed in the pads of the printed circuit board 10 corresponding to the location of the matching network 30 of the device 5.

(44) The matching network 80 is connected to the at least one radiation booster 11 of the device 5 of FIGS. 1A-1B from one side, and to the at least one external port 32 from the other side. The matching network 80 comprises: a first inductor 81 with an inductance of 4.3 nH: a second inductor 82 with an inductance of 18 nH; a first capacitor 83 with a capacitance of 0.9 pF; a second capacitor 84 and a third inductor 85 with a capacitance of 1.0 pF and an inductance of 13 nH, respectively; a third capacitor with a capacitance of 2.0 pF; and a fourth inductor with an inductance of 4.5 nH.

(45) It is readily apparent that, in other embodiments, different matching networks are possible within the scope of the present disclosure.

(46) FIG. 9 diagrammatically shows an exemplary arrangement of an electrically conductive element in accordance with the present disclosure. In FIG. 9 there is partially represented a device with a printed circuit board 10, which comprises a ground plane layer 15 that is in close proximity (in terms of the operating free-space wavelength) to an electrically conductive body 50 of an apparatus (partially represented in FIG. 9 for the sake of clarity only).

(47) An electrically conductive element for connecting a connecting point of the ground plane layer 15 to the electrically conductive body 50 comprises first and second components 41, 27. The first component 41 is an inductor, which is arranged on a same plane of the ground plane layer 15 such that a first terminal thereof is connected to the connecting point and a second terminal thereof is connected to a soldering pad 16. The second component 27 is a wire-made via having a first terminal thereof connected to the soldering pad 16 and a second terminal thereof connected to the electrically conductive body 50. The first and the second components 41, 27 are arranged in series and adapted to alter the electric currents flowing in the electrically conductive body 50. In other embodiments, other components are provided in the electrically conductive element and may be arranged differently, for example connected in shunt and/or not coplanar with the ground plane layer 15.

(48) In some other embodiments, one or more components are provided in the electrically conductive body 50, said one or more components being electrically connected to the ground plane of the electrically conductive body 50. The electrically conductive element is thus formed by both the component or components in the device and the one or more components in the electrically conductive body 50. The component or components of the device establish the electrical connection between the ground plane layer 15 thereof and the ground plane layer of the electrically conductive body 50, the electrical connection being established through the one or more components in the electrically conductive body 50.

(49) FIG. 10 diagrammatically shows exemplary paths followed by electric currents in a device in accordance with an embodiment of the present invention.

(50) A side view of a device is represented in which only the ground plane layer 15 and five electrically conductive elements 25-29 are shown for the sake of clarity. The electrically conductive elements 25-29 connect five different connecting points of the ground plane layer to an electrically conductive body 50 of an apparatus.

(51) Depending on the distribution of the connecting points and the components of the electrically conductive elements 25-29, the different connections between the ground plane layer 15 and the electrically conductive body 50 are established for different ranges of frequencies, thereby providing different paths for the electric currents flowing therein. For example, shown with a dashed line is a first path 91 followed by electric currents of a first wavelength or frequency; the first path 91 goes through two different connections of the electrically conductive elements 28, 29. Further, shown with a dashed line is a second path 92 followed by electric currents of a second wavelength or frequency; the second path 92 goes through three different connections of the electrically conductive elements 25-27 and has a length longer than the first path 91. Also, shown with a solid line is a third path 93 followed by electric currents of a third wavelength or frequency; the third path 93 goes through four different connections of the electrically conductive elements 25-28 and has a length longer than the second path 92.

(52) By adjusting how the induced electric currents flowing on the conductive body are altered and the paths followed by electric currents of different frequencies or wavelengths, the radioelectric performance of the radiating system is improved, not only in terms of reducing the decrease of performance owing to the close proximity of the electrically conductive body 50 but also in terms of further bandwidth provided, such an improvement evidenced by an increase in efficiency in one or more bands.

(53) The behavior of the device of the embodiment of FIG. 10 is also applicable to devices in accordance with other embodiments in which the ground plane layer has two or more connecting points. There is a greater flexibility in the configuration of the different paths for electric currents of different frequencies or wavelengths as more connecting points are provided; in this sense, devices in which the ground plane layer has four or more connecting points are more suitable for providing different paths for the electric currents and, thus, improve even further the bandwidth of operation of the radiating system.

(54) FIG. 11A diagrammatically shows, in a 3D perspective, a test platform for the characterization of radiation booster elements.

(55) Radiation booster elements such as the radiation booster element 301 of the device 5 have an electromagnetic behavior that may be characterized by means of a test platform for electromagnetically characterizing radiation boosters, as described in lines 9-34 of page 20 of said document. Said platform comprises a substantially square conductive surface 300 on top of which, and substantially close to the central point, the element to be characterized is mounted perpendicular to said surface in a monopole configuration, said conductive surface acting as the ground plane. The substantially square conductive surface 300 comprises sides with a dimension larger than a reference operating wavelength. In the context of the present invention, said reference operating wavelength is the free-space wavelength equivalent to a frequency of 900 MHz. A substantially square conductive surface according to the present invention is made of copper with sides measuring 60 centimeters, and a thickness of 0.5 millimeters.

(56) In the test configuration as set forth above, a radiation booster element 11 may be characterized by a ratio between the first resonance frequency and the reference frequency (900 MHz) being larger than a minimum ratio of 3.0. In some cases, said ratio may be even larger than a minimum ratio such as any one of the following values: 3.4, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.6 or 7.0.

(57) A radiation booster element 11 may also be characterized by a radiation efficiency measured in said platform, at a frequency equal to 900 MHz, being less than 50%, preferably being less than 40%, 30%, 20%, or 10%, and in some cases being less than 7.5%, 5%, or 2.5%. All those are quite remarkably low efficiency values.

(58) The platform comprises the substantially square conductive surface 300 and a connector 305 (for instance an SMA connector) electrically connected to the device or element 301 to be characterized. The conductive surface 300 has sides with a length greater than the reference operating wavelength corresponding to the reference frequency. For instance, at 900 MHz, said sides are at least 60 centimeters long. The conductive surface may be a sheet or plate made of copper, for example. The connector 305 is placed substantially in the center of conductive surface 300.

(59) In FIG. 11B the same test platform is diagrammatically represented in a 2D perspective wherein the conductive surface 300 is partially drawn. In this example, the element that is to be characterized is a radiating booster element 301, which is arranged so that its largest dimension is perpendicular to the conductive surface 300, and one of the first or second conductive surfaces of the radiating booster element 301 is in direct electrical contact with the connector 305 (for clearer interpretation of the orientation of the radiation booster element 301, via holes 302 connecting the first and second conductive surfaces of the radiation booster element 301 are also drawn in FIG. 11B). The radiation booster element 301 lies on a dielectric material (not shown) attached to the conductive surface 300 so as to minimize the distance between radiation booster element 301 and the surface 300. Said dielectric material may be a dielectric tape or coating, for example.

(60) FIG. 12 shows a graph of the radiation efficiency and antenna efficiency measured in a test platform like the one shown in FIGS. 11A-11B, when the element 301 to be characterized is a radiation booster element 301. In this particular example, the radiation efficiency measured 310 (shown with a solid line) at 900 MHz is less than 5%, and the antenna efficiency measured 311 (shown with a dashed line) at 900 MHz is less than 1%.

(61) Even though the terms first, second, third, etc. have been used herein to describe several devices, elements or magnitudes, it will be understood that the devices, elements or magnitudes should not be limited by these terms since the terms are only used to distinguish one device, element or magnitude from another. For example, the first connecting point could as well be named second connecting point and the second connecting point could be named first connecting point without departing from the scope of this disclosure.

(62) In this text, the term “comprises” and its derivations (such as “comprising”, etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc.

(63) On the other hand, the invention is obviously not limited to the specific embodiment(s) described herein, but also encompasses any variations that may be considered by any person skilled in the art (for example, as regards the choice of materials, dimensions, components, configuration, etc.), within the general scope of the invention as defined in the claims.