Antenna for uniform radiation for ultra-wideband

Abstract

An antenna element (120) for ultra-wideband (UWB) comprising an outer conductor (122) forming a periphery of the antenna element (120) and an inner conductor (124) physically and electrically connected to the outer conductor (122) only at a middle connection (123) of an inner portion of the outer conductor (122), wherein the outer conductor (122) and the inner conductor (124) are arranged to form a slot (125) between them and the slot (125) extends around the inner conductor (124) such that each end of the slot (125) is adjacent to the middle connection (123).

Description

Technical Field

[0001] This disclosure generally relates to antennas. More specifically, this disclosure relates to systems and methods for antennas with uniform radiation patterns for ultra-wideband (UWB). Background Technology

[0002] Ultra-wideband (UWB) technology can be effectively used to determine the distance between two devices by measuring the time it takes for a pulse to travel directly between them; this is commonly referred to as "distance measurement." Since the speed of the pulse is known, the distance can be calculated by multiplying the speed by the measured time.

[0003] However, UWB ranging has limitations. First, UWB ranging requires a direct path of pulses transmitted between the two devices because the distance calculated for an indirect path gives the length of that indirect path, not the distance between the devices. Second, the angular position between the two devices is often unknown (although this can be determined using multiple antennas).

[0004] Due to the aforementioned limitations of UWB ranging, the non-uniform radiation pattern of the antenna used for UWB can significantly affect the efficiency of UWB devices. Figure 1 This is a schematic diagram of the first UWB device 10 positioned relative to the second UWB device 20 and the third UWB device 40, wherein the polar coordinate graph 50 shows a typical radiation pattern 51 of the first antenna 11 relative to the first UWB device 10.

[0005] like Figure 1 As shown, the typical radiation pattern 51 of the first antenna is non-uniform at different angular positions relative to the first UWB device 10. In typical wireless products, a low-profile, small, and integrated antenna is desired. Inverted-F antennas (IFAs) and planar inverted-F antennas (PIFAs) are commonly used and positioned in wireless products / devices. The shape and positioning of the IFA / PIFA can reduce the uniformity of the radiation pattern 51, resulting in a significant variation between the maximum radiation 52 at the first angular position and the minimum radiation 53 at the second angular position. Figure 1 In the example shown, there is a difference of approximately 20 dB between the maximum radiation 52 and the minimum radiation 53. Since antennas are inherently reciprocal, the same applies to the maximum and minimum values ​​in the receiver sensitivity pattern.

[0006] Because of this unevenness in antenna signal strength at certain angular positions, some devices (located at similar distances to the first UWB device 10) will effectively communicate with the first device 10, while others will not. For example, the UWB device 20 is at an angular position where the maximum radiation 52 of the first antenna 11 occurs or near it, while the UWB device 30 is at an angular position where the minimum radiation 53 of the first antenna 11 occurs or near it. Thus, the pulses 22 transmitted by the second antenna 21 are easily received by the first antenna 11, while the pulses 32 of the third antenna 31 can not be received by the first antenna 11, because the minimum radiation 53 can be below the reception sensitivity of the first device 10.

[0007] While, as mentioned above, the unevenness does not severely affect other wireless technologies, such as cellular networks and Wi-Fi, UWB ranging requires a direct path to accurately determine the distance between two devices. Figure 2 is a schematic illustration of the first UWB device 10 positioned relative to the second UWB device 20 and the third UWB device 40, wherein a polar plot 60 illustrates an optimal radiation pattern 61 of the first antenna 11 relative to the first UWB device 10. Thus, it is desirable that antennas, in particular for UWB applications, have a more uniform radiation pattern. As shown in Figure 2 by maintaining the uniformity of the radiation pattern of the antenna 11 of the first UWB device 10, the angular position of the second UWB device 20 and the third UWB device 30 is independent of whether the pulses 22 and 32 will be received by the first UWB device 10. SUMMARY

[0008] In one embodiment, an antenna element is disclosed. The antenna element includes an outer conductor and an inner conductor. The outer conductor forms a perimeter of the antenna element. The inner conductor is physically and electrically connected to the outer conductor only at a middle connection portion of an inner portion of the outer conductor. The outer conductor and the inner conductor are arranged to form a slot therebetween. The slot extends around the inner conductor such that each end of the slot is adjacent to the middle connection portion.

[0009] In embodiments, the inner conductor includes a feed point adapted to receive an electrical connection and located distal relative to the middle connection portion. In some embodiments, the perimeter of the outer conductor includes a cylindrical shape. In some embodiments, a length of the cylindrical perimeter differs from one-half of a wavelength that the antenna element is adapted to receive by less than ten percent of the wavelength. In some embodiments, the slot is curved on each side of the inner conductor such that the slot includes a length that differs from one-half of a wavelength that the antenna element is adapted to receive by less than ten percent of the wavelength.

[0010] In an embodiment, the antenna element further comprises a planar portion forming at least a perimeter of the antenna element and a protrusion protruding from the planar portion. Optionally, the protrusion comprises an arcuate shape, the inner conductor comprises a feed point adapted to receive an electrical connection and located distally with respect to the intermediate connection, and the intermediate portion is adapted to tilt towards the ground plane due to the arcuate shape of the protrusion.

[0011] In another embodiment, a slotted patch antenna is disclosed. The slotted patch antenna comprises an antenna element and short walls. The antenna element comprises an outer conductor and an inner conductor. The outer conductor forms a perimeter of the antenna element. The inner conductor is physically and electrically connected to the outer conductor only at an intermediate connection of an inner portion of the outer conductor. The inner conductor is adapted to approximate an electrical monopole. The outer conductor and the inner conductor are arranged to form a slot therebetween. The outer conductor and the inner conductor are adapted to produce a voltage across the slot that approximates a magnetic dipole orthogonal to the electrical monopole. The short walls are adapted to physically and electrically connect the antenna element to a ground plane. Each short wall is connected to an end of the outer conductor on a side of the antenna element opposite the intermediate connection.

[0012] In an embodiment, the inner conductor comprises a feed point adapted to receive an electrical connection and located distally with respect to the intermediate connection, the feed point is located between the ends of the outer conductor, and the electrical monopole is approximated by a current flowing from the feed point to the intermediate connection. Optionally, the electrical monopole is further approximated by a current flowing along the perimeter of the outer conductor from the short walls to the intermediate connector. Optionally, the magnetic dipole is approximated by a voltage across the slot caused by a current flowing along the perimeter of the outer conductor from the short walls to the intermediate connector (which also flows along the slot) and a current flowing through the intermediate connector and along the slot on the inner conductor to the feed point.

[0013] In an embodiment, the perimeter length of the cylindrical shape differs from half of a wavelength that the antenna element is adapted to receive by less than ten percent of the wavelength, and the slot is curved on each side of the inner conductor such that the slot comprises a length that differs from half of the wavelength that the antenna element is adapted to receive by less than ten percent of the wavelength.

[0014] In an embodiment, the antenna element further comprises a planar portion forming at least a perimeter of the antenna element and a protrusion protruding from the planar portion. Optionally, the protrusion comprises an arcuate shape, the inner conductor comprises a feed point adapted to receive an electrical connection and located distally with respect to the intermediate connection, and the intermediate portion is adapted to tilt towards the ground plane due to the arcuate shape of the protrusion.

[0015] In another embodiment, an antenna system is disclosed. The antenna system comprises an antenna element, a mounting bracket, and a short wall. The antenna element comprises an outer conductor and an inner conductor. The outer conductor forms a perimeter of the antenna element. The inner conductor is physically and electrically connected to the outer conductor only at a middle connection at an inner portion of the outer conductor. The inner conductor extends from the middle connection to a feed point adapted to receive an electrical connection and located distally with respect to the middle connection. The outer conductor and the inner conductor are arranged to form a slot therebetween. The slot extends around the inner conductor such that each end of the slot is adjacent to the middle connection. The mounting bracket is adapted to serve as a ground plane. The short wall physically and electrically connects the outer conductor to the mounting bracket. Each short wall is connected to an end of the outer conductor adjacent to the feed point.

[0016] In an embodiment, the inner conductor is adapted to approximate an electric monopole, and the outer conductor and the inner conductor are adapted to generate a voltage across the slot that approximates a magnetic dipole orthogonal to the electric monopole.

[0017] In an embodiment, the antenna element comprising the outer conductor and the inner conductor, the short wall, and the mounting bracket are formed from a unitary structure by one of stamping and casting.

[0018] In an embodiment, the antenna system further comprises a second antenna element physically and electrically connected to the mounting bracket by a second short wall. Optionally, wherein the antenna element, the short wall, the mounting bracket, and the second antenna element form a unitary structure by one of stamping and casting.

[0019] In an embodiment, the antenna element further comprises a planar portion and a protrusion. The planar portion forms at least a perimeter of the antenna element. The protrusion protrudes from the planar portion. The feed point is adapted to be tilted towards the ground plane due to a shape of the protrusion.

[0020] In an embodiment, the antenna element is planar and printed on a printed circuit board (PCB). Optionally, the slot and the perimeter are defined by printed shapes on a surface of the PCB. Optionally, the short wall is a through-hole extending through the PCB to the ground.

[0021] In an embodiment, the antenna system comprises a plurality of antenna elements arranged within a device with known distances and angles between the antenna elements for finding relative phases and angles of incoming signals from other devices.

[0022] In an embodiment, the antenna element is printed on a carrier using metallized plastic, and wherein the antenna element and the carrier are mounted as a unit to the device. BRIEF DESCRIPTION OF DRAWINGS

[0023] In this document, the disclosure is explained and described in relation to the enclosed drawings, in which similar reference signs are used to indicate similar system components / method steps, and in which:

[0024] Figure 1is a schematic illustration of a first UWB device positioned relative to a second UWB device and a third UWB device, where a polar plot illustrates a typical radiation pattern relative to a first antenna of the first UWB device;

[0025] Figure 2 is a schematic illustration of a first UWB device positioned relative to a second UWB device and a third UWB device, where a polar plot illustrates an optimal radiation pattern relative to a first antenna of the first UWB device;

[0026] Figure 3 is a perspective view of a slotted patch antenna;

[0027] Figure 4 is Figure 3 a perspective view of the slotted patch antenna of

[0028] Figure 5 is Figures 3 to 4 a side perspective view of the slotted patch antenna of

[0029] Figure 6 is Figures 3 to 5 a top perspective view of the slotted patch antenna of

[0030] Figure 7 is a perspective view of an embodiment of a single slotted patch antenna of Figures 3 to 6 connected to a mounting bracket;

[0031] Figure 8 is a perspective view of an embodiment of two slotted patch antennas of Figures 3 to 6 connected to a mounting bracket;

[0032] Figure 9 is a schematic illustration and representation of the current flowing in the slotted patch antenna of Figures 3 to 6 ;

[0033] Figure 10 is a schematic illustration and representation of the voltage of the slotted patch antenna of Figures 3 to 6 ;

[0034] Figure 11 is a schematic illustration and representation of the flowing current, voltage across the slot, and equivalent magnetic current of the slotted patch antenna of Figures 3 to 6 ;

[0035] Figure 12 is a schematic illustration and representation of the radiation pattern resulting from the current and voltage of the slotted patch antenna of Figures 3 to 6 ;

[0036] Figure 13 is a polar plot showing a comparison of the radiation pattern of one embodiment of a slotted patch antenna to the radiation pattern of a conventional IFA antenna; and

[0037] Figure 14 is Figure 13 a comparative Cartesian plot of the gain. DETAILED DESCRIPTION

[0038] In various embodiments, the present disclosure relates to systems and methods for producing a uniform radiation pattern with a slotted patch antenna. The slotted patch antenna includes a vertical short wall that positions the slotted patch antenna above a ground plane and mechanically supports the antenna element. The antenna element includes a long slot that separates an outer conductive element from an inner conductive element except at an intermediate connection between the outer conductive element and the inner conductive element distal from a feed point on the inner conductor. The outer conductive element, the inner conductive element, and the slot therebetween are adapted to produce two complementary sources of radiation that are orthogonal to each other such that the two sources of radiation compensate for a decrease in the radiation pattern of the other, which results in a more uniform overall radiation pattern for the slotted patch antenna.

[0039] Figure 3 is a perspective view of the slotted patch antenna 100. Figure 4 is Figure 3 a perspective view of the slotted patch antenna 100 from another angle of Figure 5 is Figures 3 to 4 a side perspective view of the slotted patch antenna 100. Figure 6 is Figures 3 to 5 a top perspective view of the slotted patch antenna 100. Referring to Figures 3 to 6 , the slotted patch antenna 100 includes a short wall 110 and an antenna element 120. The short wall 110 is adapted to physically and electrically connect the antenna element 120 to a ground plane 105 and to act as a vertical ground wall / leg. The short wall 110 provides a through hole that increases the matching of the shunt inductance to ground. As shown in Figure 4 , the short wall 110 is adapted to maintain a gap 115 between the antenna element 120 and the ground plane 105. In embodiments, the short wall 110 is adapted such that the gap 115 is smaller than at least one of the length, width, and height of the antenna element 120, such that the slotted patch antenna 100 has a low profile with respect to the ground plane 105. In the illustrated embodiment, the slotted patch antenna 100 includes two short walls 110 on the same side of the antenna element 120 and spaced apart. In some embodiments, the gap 115 is 1-2 millimeters.

[0040] In some embodiments, the short wall 110 is a through hole that extends through a printed circuit board (PCB) to the ground plane 105 at the bottom of the PCB, allowing the antenna element 120 to be placed on a dielectric material.

[0041] Antenna element 120 includes an outer conductor 122, an inner conductor 124, and a slot 125. Outer conductor 122 is adapted to form a perimeter of antenna element 120 (this length is the fully enclosed perimeter between short walls 110 including both ends of slot 125). In embodiments, this perimeter has a length of approximately one-half the wavelength that antenna element 120 is configured to receive.

[0042] In some embodiments, the perimeter length of antenna element 120 differs from one-half the wavelength by less than ten percent of the wavelength, e.g., the perimeter length of the antenna element is between 40% and 60% of the wavelength. For example, a UWB channel is centered at 6.5 GHz, where the wavelength in free space is approximately 46 mm. In these embodiments, the perimeter length differs from one-half of 46 mm by less than ten percent of 46 mm, in other words, within plus or minus 4.6 mm of 23 mm. In one embodiment, the perimeter length is 27 mm.

[0043] In some embodiments, the perimeter length differs from one-half the wavelength by less than 5 mm. In the illustrated embodiment, the perimeter includes a circular shape, e.g., a cylindrical shape. In some embodiments, the cylindrical shape includes a radius of 3 mm to 4.5 mm.

[0044] Outer conductor 122 is connected to short walls 110. In embodiments, outer conductor 122 includes two adjacent ends on the same side of antenna element 120, each of which is connected to a short wall 110. Outer conductor 122 then extends around inner conductor 124, forming the perimeter of the antenna element while maintaining a gap directly between the two adjacent ends. In embodiments having a circular / cylindrical shape, the circular / cylindrical shape is formed to have an opening opposite intermediate connection 123.

[0045] Inner conductor 124 is physically and electrically connected to outer conductor 122 at intermediate connection 123, which is located on an interior portion of outer conductor 122 and on a side of antenna element 120 opposite short walls 110. Inner conductor 124 extends generally toward the short walls from intermediate connection 123 to a feed point 126 located near short walls 110 and distal from intermediate connection 123. In embodiments, feed point 126 is located between the ends of outer conductor 122 that are connected to short walls 110. In embodiments having a circular / cylindrical shape, feed point 126 is located between the ends that define the opening.

[0046] Inner conductor 124 and outer conductor 122 are adapted to form slot 125 between them. Referring to FIG. 2, slot 125 is formed between inner conductor 124 and outer conductor 122. In embodiments, slot 125 is formed between the perimeter of outer conductor 122 and inner conductor 124. In some embodiments, slot 125 is formed between the perimeter of outer conductor 122 and the outer surface of inner conductor 124. In some embodiments, slot 125 is formed between the perimeter of outer conductor 122 and the inner surface of inner conductor 124. Figure 6The ends of the slots 125 are adjacent the middle connection 123, and the slots 125 extend from one end of the slots 125 around the inner conductor 124 past the feed point 126 and back along the inner conductor 124 to the other end of the slots 125. Although the slots 125 appear to be open between the ends of the outer conductor 122 and the short wall 110, the slots 125 can be considered to be closed by the short wall 110 and the ground plane 105 at the ends of the antenna element 120, which provides continuity of conductive material (e.g., metal) around the entire slot structure.

[0047] In embodiments, the slots 125 are curved to increase the length of the slots 125 so that the length of each half of the slots extending along each side of the inner conductor 124 is longer than at least one of the length and width of the antenna element 120. In the illustrated embodiment, each half of the slots 125 is longer than the diameter of the cylindrical perimeter of the outer conductor 122. In some embodiments, the length of the slots 125 measured from the end of the slots 125 adjacent the middle connection to the other end of the slots 125 adjacent the middle connection 123 is approximately one-half of the wavelength of the configuration received by the antenna element 120.

[0048] In some embodiments, the length of the slots 125 of the antenna element 120 differs from one-half of the wavelength by less than ten percent of the wavelength, e.g., 40% to 60% of the wavelength. For example, the UWB channel is centered at 6.5 GHz, where the wavelength in free space is approximately 46 mm. In these embodiments, the slots 125 differ from one-half of 46 mm by less than ten percent of 46 mm, in other words, within plus or minus 4.6 mm of 23 mm. In one embodiment, the length of the slots is 20 mm. In some embodiments, the length of the slots 125 differs from one-half of the wavelength by less than 5 mm.

[0049] In embodiments, the curved path is in the form of one or more curves that are advantageous for the radiation pattern. In the illustrated embodiment, the slots 125 are symmetrical, where each half of the slots 125 diverges circumferentially from the middle connection 123, then converges toward the other half of the slots 125, after which each half of the slots 125 extends parallel to the other half toward the feed point 126 and the short wall 110. This curvature results in the inner conductor having a thicker, semi-circular / wedge-like shape adjacent the middle connection, and a rod-like shape extending therefrom to the feed point 126. As discussed in more detail below, the curved slots 125 result in an approximation of an electrically single-stage sub-orthogonal magnetic dipole produced by the antenna element 120.

[0050] The width of the slot 125 is selected to control the voltage across the slot 125. In embodiments, the width of the slot 125 is less than the width of the portion of the inner conductor 124 having a rod-like shape. In embodiments, the slot 125 is narrow relative to the length and width of the antenna element 120. In some embodiments, the slot is approximately 1 millimeter, e.g., within a predetermined tolerance of 1 millimeter. However, other widths are also contemplated. Because the slot 125 is relatively narrow, the resulting bandwidth is sufficient, the mechanical integrity of the antenna element 120 is maintained, and the final volume of the antenna element 120 is minimized.

[0051] The antenna element 120 includes a plate-like shape. In embodiments, the plate-like shape is one of a flat plate and a planar portion 128 having a protrusion 129 therein. In some embodiments, the protrusion 129 is elevated away from the ground plane 105, while in other embodiments, the protrusion 129 is lowered toward the ground plane 105. In embodiments, the protrusion 129 is elevated away from the ground plane 105 by a maximum height 127 of 3 millimeters to 5 millimeters, e.g., 1 / 15 to 1 / 10 of a wavelength. Figures 3 to 6 In the embodiment shown in FIG. 1, the protrusion 129 includes an arched shape, e.g., a hollow spherical cap and a hollow hemisphere, having a planar portion 128 at its base, where the planar portion 128 includes a ring-like shape, e.g., a hollow right circular cylindrical shape. The direction in which the protrusion 129 extends can be selected based on the direction in which the protrusion 129 extending away from or toward the ground plane 105 results in the least portion of the radiation pattern.

[0052] In some embodiments, the maximum height 127 of the protrusion 129 relative to the planar portion 128 is 1 / 15 to 1 / 10 of a wavelength, e.g., 3 millimeters to 5 millimeters.

[0053] In embodiments, the slot 125 extends primarily within the protrusion 129, such that the outer conductor 122 includes the planar portion 128 and an outer portion of the protrusion 129, and the inner conductor 124 includes primarily an inner portion of the protrusion 129.

[0054] In Figures 3 to 6 In the embodiment shown in FIG. 1, the slotted patch antenna 100, including the short wall 110 and the antenna element 120, is a unitary structure, which is a single structure formed as a unit. In embodiments, the slotted patch antenna 100 is stamped sheet metal. In other embodiments, the slotted patch antenna 100 is cast.

[0055] In other embodiments, the slotted patch antenna 100 is integrated in a PCB. In particular, the antenna element 120 is planar and printed on the PCB. In some embodiments, the antenna element 120 is formed using traces on the top of the PCB. The short wall 110 is a via extending through the PCB to ground due to the ground on the back side of the PCB. In some embodiments, the slot 125 and the perimeter are defined by printed shapes on the surface of the PCB. In some embodiments, multiple antenna elements 120 are printed on the PCB, each connected to ground through a short wall 110 as a via.

[0056] In yet other embodiments, the slotted patch antenna 100 is printed on a carrier with metallized plastic (e.g. LDS), metal printed on plastic, and metal patterns on flexible materials. The antenna element 120 and the carrier are mounted as a unit to the device.

[0057] Figure 7 is a single Figures 3 to 6 embodiment of a slotted patch antenna 100 connected to a mounting bracket. The mounting bracket is a ground plane 105. Figure 8 is a two Figures 3 to 6 embodiment of a slotted patch antenna 100 connected to a mounting bracket. Refer to Figure 7 and Figure 8 , one or more single slotted patch antennas 100 can be connected to a mounting bracket, where the mounting bracket is a ground plane 105.

[0058] In the embodiments shown in Figure 7 and Figure 8 , the mounting bracket includes a bracket arm 104 that connects the short wall 110 to the mounting bracket. The mounting bracket also includes a first hole 106 and a second hole 108 for securing the mounting bracket within the electronic device. The first hole 106 and the second hole 108 can be formed in the body of the mounting bracket, a separate bracket support 107, etc. In some embodiments, the mounting bracket also includes a clamp 109 for securing the slotted patch antenna 100 in place within the electronic device.

[0059] In embodiments with two or more slotted patch antennas 100, the angle of arrival and relative phase can be determined, and in embodiments with at least three slotted patch antennas 100, the location of the electronic device sending the signal can be determined using triangulation. The spacing between the multiple slotted patch antennas 100 is chosen to operate over the entire range of UWB frequencies. In some embodiments, the spacing between the multiple slotted patch antennas 100 is different, such that good spacing is achieved for varying UWB frequencies. In embodiments with multiple slotted patch antennas 100, the antenna elements 120 are located within the device with known distances and angles between them for finding the relative phase and angle of incoming signals from other devices.

[0060] Similarly, the slotted patch antenna 100 is structured to generate two complementary radiation sources. The two complementary radiation sources are orthogonal to each other, such that the two radiation sources compensate for the reduction in the radiation pattern of the other, thereby producing a more uniform overall radiation pattern for the slotted patch antenna 100. Figure 9 Is Figures 3 to 6 A schematic diagram and representation of the currents 93 and 94 flowing in the slotted patch antenna 100. Figure 9 The current in the image is indicated by arrows, where the larger the arrow, the stronger the current. (See reference...) Figure 9 Most and the strongest current flows from the feed 91 and ground 92 to opposite ends of the slotted patch antenna, which includes an intermediate connection 123. The strong current flowing through the inner conductor 124 and around the edge of the outer conductor 122 is the first radiation source. Figure 9 As shown, the first radiation source flowing from the direction of feed 91 and ground 92 has a flow similar to that of the electric monopole 80. Furthermore, in embodiments with a protrusion 129 (e.g., an arched shape), the current at the end of the inner conductor 124 and through the intermediate connection 123 moves at least partially toward the ground plane 105. Since the radiation patterns of the monopoles and dipoles can be weaker along the current flow direction, the current bends toward ground, causing the weaker portions of the radiation to tilt toward ground, resulting in a more uniform pattern of the overall radiation pattern.

[0061] Figure 10 yes Figures 3 to 6 Schematic diagrams and representations of voltages 95, 96, and 97 for slotted patch antennas. Figure 11 yes Figures 3 to 6 A schematic diagram and representation of the currents 93 and 94 flowing through the slotted patch antenna 100, the voltages 95 and 96 at both ends of the slot, and the equivalent magnetic current 98. (Refer to...) Figure 10 and Figure 11 The currents 93 and 94 flowing around the slot 125 generate voltages 95 and 96, respectively. The maximum voltage 95 is adjacent to the feed point 126, while the minimum voltage 96 is adjacent to the intermediate connection 123, which generates a second radiation source. It should be noted that an edge field voltage 97 is also generated between the ground plane 105 and the periphery of the antenna element 120, which contributes to the radiation.

[0062] As currents 93 and 94 flow around slot 125, an equivalent magnetic current 98 is generated, which is equivalent to magnetic dipole 83. Figure 12 It is by Figures 3 to 6 A schematic diagram and representation of the approximate electric field obtained from the electric monopole 80 and magnetic dipole 83 generated by the currents 93, 94 and voltages 95, 96, 97 of the slotted patch antenna 100. (See attached diagram.) Figure 12As shown, the approximate electric monopole 80 resulting from the current flowing through the slotted patch antenna 100 has a minimum electric field 82 in the direction of the approximate electric monopole 80 and a maximum electric field orthogonal to the minimum electric field. Complementarily, the approximate magnetic dipole 83 is orthogonal to the approximate electric monopole 80 and has a minimum electric field 85 in the direction of the magnetic dipole and a maximum electric field 86 orthogonal to the minimum electric field. Thus, the radiation pattern resulting from the combined electric field due to the orthogonal nature of the maximum electric fields 81 and 84, the two sources are complementary, which results in a more uniform combined electric field in all angular directions.

[0063] Thus, since the inner conductor 124, the edge of the outer conductor 122, and the slot 125 each radiate, and the resulting patterns are orthogonal, the edge of the inner conductor 124 and the outer conductor 122 compensate for the decrease in the radiation pattern created by the slot 125, and vice versa.

[0064] Figure 13 is a polar plot 70 comparing the radiation pattern 72 of an embodiment of the slotted patch antenna 100 to the radiation pattern 73 of a conventional IFA antenna. Figure 14 is a polar plot 70 comparing the radiation pattern 72 of an embodiment of the slotted patch antenna 100 to the radiation pattern 73 of a conventional IFA antenna. Figure 13 is a Cartesian plot 71 comparing the radiation pattern 72 of an embodiment of the slotted patch antenna 100 to the radiation pattern 73 of a conventional IFA antenna. As Figure 13 and Figure 14 shown, the radiation pattern 72 of an embodiment of the slotted patch antenna 100 has a generally uniform radiation pattern, with a variation of only about 6 dB. In contrast, the conventional IFA antenna has a non-uniform radiation pattern, with a significantly greater variation, of about 20 dB.

[0065] With the generally uniform pattern in all angular directions, as shown in the radiation pattern 72 in Figure 13 and Figure 14 , it is possible to more accurately determine the distance of a device from an electronic device having one or more slotted patch antennas, and more accurately determine whether the device (and thus the user) is moving toward or away from the electronic device including one or more slotted patch antennas 100, regardless of the angular direction. Moreover, with multiple slotted patch antennas 100, it is possible to use triangulation to track devices within its range. Such tracking can be used to track the location of a device, movement of a device, identify a device from or to a location, etc. In fact, the more uniform the radiation pattern, the more accurate each of the above can be determined. Such tracking can be used for: health, such as ensuring that an elderly person is moving, not lying on the floor (e.g., detecting a device on the floor) and remaining at that location; energy management (based on the number of devices detected and the location of those devices); and security, such as initiating / shutting off alarms, detecting whether unknown persons are approaching, identifying approaching persons, from which direction a person is approaching, etc.

[0066] While the present disclosure has been illustrated and described with reference to the preferred embodiments and specific examples thereof, it will be clear to those skilled in the art that other embodiments and examples can practice the present disclosure. All such equivalent embodiments and examples are within the spirit and scope of the present disclosure and are intended to be covered thereby.

Claims

1. An antenna element (120), comprising: An outer conductor (122) forms the periphery of the antenna element (120); The inner conductor (124) is physically and electrically connected to the outer conductor (122) only at the intermediate connection (123) of the inner portion of the outer conductor (122); and At least a planar portion (128) is formed around the periphery of the antenna element (120), and a protrusion (129) protrudes from the planar portion (128); wherein The outer conductor (122) and the inner conductor (124) are configured to form a groove (125) between them. The groove (125) is curved and symmetrical, and, The groove (125) extends around the inner conductor (124) such that each end of the groove (125) is adjacent to the intermediate connection portion (123), and The protrusion (129) has an arched shape, the inner conductor (124) includes a feed point (126) adapted to receive an electrical connection and located at a distal end relative to the intermediate connection (123), and due to the arched shape of the protrusion (129), the intermediate connection (123) is adapted to be inclined toward the ground plane (105).

2. The antenna element (120) according to claim 1, wherein, The periphery of the outer conductor (122) includes a cylindrical shape.

3. The antenna element (120) according to claim 1 or 2, wherein, The perimeter length of the antenna element (120) differs from half the wavelength that the antenna element (120) is adapted to receive by within 10 percent of the wavelength.

4. The antenna element (120) according to claim 1 or 2, wherein, The slot (125) bends on each side of the inner conductor (124) such that the slot (125) includes a length that differs from half the wavelength that the antenna element (120) is adapted to receive by within ten percent of the wavelength.

5. A slotted patch antenna (100), comprising: The antenna element (120) according to any one of claims 1 to 4, wherein the inner conductor (124) is adapted to approximate an electric monopole, the slot (125) is adapted to approximate a magnetic dipole, the outer conductor (122) and the inner conductor (124) are adapted to generate a voltage across the slot (125), and the magnetic dipole is orthogonal to the approximate electric monopole; and Short walls (110) are adapted to physically and electrically connect the antenna element (120) to the ground plane (105), and each short wall is connected to the end of the outer conductor (122) on the side of the antenna element (120) opposite to the intermediate connection (123).

6. An antenna system, comprising: Antenna element (120) according to any one of claims 1 to 4; Suitable as a mounting bracket for ground contact surfaces; as well as Short walls (110) that physically and electrically connect the outer conductor (122) to the mounting bracket, each short wall being connected to the end of the outer conductor (122) adjacent to the feed point.

7. An ultra-wideband (UWB) device (10, 20, 40) comprising any one of the following: an antenna element (120) according to any one of claims 1 to 4, a slotted patch antenna (100) according to claim 5, and an antenna system according to claim 6.

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