Antenna desensitization system and design method thereof

Abstract

Disclosed is an antenna desensitization system and a method for designing an antenna desensitization system. The system and method are operative to provide a configuration and positioning of an antenna desensitizer element, with respect to an antenna, to overcome a frequency detuning experienced during operation of such antenna. The antenna desensitizer element comprises one or a combination of more than one decoupling components selected from the group of a frequency selective surface, an electromagnetic band gap structure, a ferromagnetic material, an anisotropic material, a nanomaterial, a dielectric material, and a conductive material. The system and method are particularly suitable for reducing the antenna frequency detuning effects caused by an external agent, such as a user or operator of a mobile electronics device, during operation of such device.

Claims

1. An antenna desensitization case for at least partly enclosing an electronic device, said device comprising an antenna element, and said case comprising: a shell having an inner surface and an outer surface; at least one peripheral sidewall; and a desensitizer element; wherein said at least one peripheral sidewall is physically attached to at least one of said inner and outer surfaces; wherein said case is disposed on said electronic device, such that said desensitizer element at least partly overlaps said antenna element; wherein said antenna element operates at a frequency band susceptible to a detuning effect caused by an external agent during operation of said antenna element; and wherein said desensitizer element is positioned on said case such that said detuning effect is reduced.

2. The antenna desensitization case of claim 1, wherein said electronic device at least partly encloses said antenna element.

3. The antenna desensitization case of claim 1, wherein said desensitizer element electromagnetically couples to said antenna element.

4. The antenna desensitization case of claim 1, wherein said desensitizer element is structurally integrated with said case.

5. The antenna desensitization case of claim 4, wherein said desensitizer element is embedded in said case.

6. The antenna desensitization case of claim 1, wherein said desensitizer element is at least partly disposed on at least one of said inner surface, said outer surface, and said at least one peripheral sidewall of said case.

7. The antenna desensitization case of claim 1, wherein said desensitizer element thickens a cross-section profile of said case.

8. The antenna desensitization case of claim 1, further comprising a decorative element.

9. The antenna desensitization case of claim 8, wherein said decorative element comprises an item selected from the group of a label, logo, word, name, symbol, picture, photo, text, animal representation, geographical region, and map.

10. The antenna desensitization case of claim 1, wherein said desensitizer element comprises one or a combination of more than one decoupling components selected from the group of a frequency selective surface, an electromagnetic band gap structure, a ferromagnetic material, an anisotropic material, a nanomaterial, a dielectric material, and a conductive material.

11. A method for designing an antenna desensitization system, comprising: a. providing a first electronic device comprising: an antenna element and a desensitizer element; wherein said desensitizer element is disposed at least partly overlapping said antenna element; and wherein said desensitizer element at least partly prevents a condition selected from the group of: a frequency detuning of said antenna element caused by an external agent during operation of said first electronic device, a radiofrequency interference received by said antenna element and caused by an external agent during operation of said first electronic device, and a radiofrequency interference transmitted by said antenna element affecting an external second electronic device during operation of said first electronic device; b. identifying a location of said antenna element; c. determining said condition during operation of said first electronic device; d. designing and implementing a desensitizer element to at least partly reduce said condition during operation of said first electronic device; and e. selecting a most suitable configuration of said desensitizer element, in terms of performance or other predetermined criteria of said first electronic device under said condition.

12. The method of claim 11, wherein designing said desensitizer element further comprises at least one of the following steps: a. designing a structure, including a dielectric material disposed adjacent to and at least partly overlapping said antenna element, in order to increase a spacing between said antenna element and said external agent, b. designing a structure, including a dielectric material and at least a portion of a case to at least partly enclose said first electronic device, said dielectric material disposed adjacent to and at least partly overlapping said antenna element, in order to increase a spacing between said antenna element and said external agent; c. designing a structure, including a dielectric material and an insert, said dielectric material disposed adjacent to and at least partly overlapping said antenna element, in order to increase a spacing between said antenna element and said external agent; and d. designing a structure, including a decoupling material disposed adjacent to and at least partly overlapping said antenna element, in order to reduce an electromagnetic coupling between said antenna element and said external agent.

13. The method of claim 11, wherein said antenna desensitization system further comprises a case for at least partly enclosing said first electronic device, said case comprising a shell having an inner surface and an outer surface and at least one peripheral sidewall, wherein said at least one peripheral sidewall is physically attached to at least one of said inner and outer surfaces.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying drawings in which:

(2) FIG. 1 shows a cross-sectional side view of a wireless device using an antenna desensitization dielectric material in accordance with an exemplary embodiment.

(3) FIG. 2 shows a cross-sectional side view of a wireless device with a surrounding case using an antenna desensitization dielectric material in accordance with another exemplary embodiment.

(4) FIGS. 3A to 3P show various aspects of different shapes of an antenna desensitizer element.

(5) FIGS. 4A to 4C show various aspects of a wireless device with a surrounding antenna desensitization case in accordance with different exemplary embodiments.

(6) FIGS. 5A to 5B show various aspects of a cross-sectional side view of a wireless device with an antenna desensitization case in accordance with another exemplary embodiment.

(7) FIGS. 6A and 6B show various aspects of a wireless device with a plurality of antenna desensitization elements in accordance with another exemplary embodiment.

(8) FIG. 7 shows a cross-sectional side view of a wireless device using an antenna desensitization decoupling material in accordance with another exemplary embodiment.

(9) FIGS. 8A and 8B show various aspects of a cross-sectional side view of wireless device surrounded by a case using an antenna desensitization decoupling material in accordance with different exemplary embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(10) The following description of particular embodiments of invention is set out to enable one to practice an implementation of the invention and is not intended to limit the invention to any specific embodiment, but to serve as a particular example thereof. Those skilled in the art should appreciate that they may readily use the conception and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent assemblies do not depart from the spirit and scope of the invention in its broadest form.

(11) In accordance with certain aspects of a configuration of the invention, a side view of a wireless device 10, using an antenna desensitization dielectric material 14, is shown in FIG. 1. Wireless device 10 is represented by a cell phone, comprising an antenna 16 enclosed within an outer surface 12 of cell phone 10 and adjacent to a side of outer surface 12 of cell phone 10. Under certain operational conditions, the performance of antenna 16 may be degraded by frequency detuning caused by the electromagnetic coupling effects caused by external agents or factors.

(12) These agents include the presence of any combination of human user body parts (e.g. hands, fingers, head or other parts of the body as when such device is placed in a pocket or hung on clothing), conductive materials, or dielectric materials located within a radius of two wavelengths at the lowest frequency of operation in the medium where said antenna element is operating. In particular, the degradation of performance of antenna 16 results more significant where such external agents influence an area of outer surface 12 closer to antenna 16. In other words, a largest impact on the degradation of the performance of antenna 16 occurs where an affecting agent is in the vicinity of antenna 16. Specifically, antenna 16 is more sensitive to an affecting agent located around the area of outer surface 12 that is adjacent to antenna 16. More specifically, antenna 16 will be most susceptible to an agent positioned within 5 mm of antenna 16.

(13) In some cases, the degradation of the performance of antenna 16 may reach up to levels in which cell phone 10 may no longer operate. In certain instances, the reduction in the performance of antenna 16 may be overcome by an automatic increase of the power transmitted by cell phone 10. However, more power would be consumed and the battery charge of cell phone 10 would be more rapidly depleted. Additionally, a performance degradation of antenna 16 may result in a compromised signal integrity of device 10 with increased adverse effects caused by noise signals and interference signals transmitted or received by antenna 16.

(14) In particular, for cell phone 10, during normal operation the hand of a user may certainly be placed in the vicinity of outer surface 12 of cell phone 10, causing a severe impact on the performance of cell phone 10. Thus, in the configuration shown in FIG. 1, dielectric material 14 is disposed on the area of outer surface 12 that is adjacent to antenna 16, such that dielectric material 14 overlaps an area defined by antenna 16. As a result, a spacing between antenna 16 and an external agent that may electromagnetically couple to antenna 16 is increased, reducing the impact that said external agent may have on antenna 16. Preferably, dielectric material 14 has a relative dielectric permittivity close to the relative dielectric permittivity of air to minimize the impact on antenna 16. However, a design of antenna 16 may be optimized to operate with dielectric material 14.

(15) Typically, dielectric material 14 is disposed on an area of outer surface 12 of cell phone 10 that is larger than the area of antenna 16 adjacent to outer surface 12 of cell phone 10. Preferably, dielectric material 14 has a thickness ranging between 1 mm and 10 mm. More preferably, dielectric material 14 has a thickness not larger than 5 mm. In this particular configuration, dielectric material 14 has a hemispherical shape with a maximum separation of approximately 5 mm from outer surface 12 of cell phone 10. Dielectric material may be affixed to outer surface 12 of cell phone 10, by means that include glue, adhesive, or resin as well known to those skilled in the art.

(16) According to another configuration, FIG. 2 shows a cross-sectional side view of device 10 surrounded by a case 20. In this embodiment, dielectric material 14 is disposed on the area of outer surface 22 of case 20, such that dielectric material 14 overlaps an area defined by antenna 16. As a result, a spacing between antenna 16 and an external agent that may electromagnetically couple to antenna 16 is increased, reducing the impact that said external agent may have on antenna 16. Preferably, dielectric material 14 has a relative dielectric permittivity close to the relative dielectric permittivity of air to minimize the impact on antenna 16. However, a design of antenna 16 may be optimized to operate with dielectric material 14.

(17) In this configuration, case 20 is representative of a protective case against scratches, dents, or minor bumps that device 10 may suffer during normal use. However, other uses of case 20 include decorative, convenience, personalized preference or other purposes, as known in the prior art. Preferably, dielectric material 14 is disposed on an area of outer surface 22 of case 20 that is larger than the area of antenna 16 adjacent to outer surface 22 of case 20. Preferably, dielectric material 14 has a thickness ranging between 1 mm and 10 mm. More preferably, dielectric material 14 has a thickness not larger than 5 mm. In this particular configuration, dielectric material 14 has a hemispherical shape with a maximum separation of approximately 5 mm from outer surface 22 of case 20. Dielectric material may be affixed to outer surface 22 of case 20, by means that include glue, adhesive, or resin as well known to those skilled in the art.

(18) FIGS. 3A to 3P show various aspects of different shapes that an antenna desensitizer element formed by dielectric material 14 may take to be attached to device 10 or case 20 for desensitization of antenna 16 of device 10. More specifically, FIGS. 3A to 3E show a top view of a solid design of dielectric material 14, having a circular, elliptical, rectangular, trapezoidal, and pentagonal cross-section, respectively. Likewise, FIGS. 3F to 3J show a corresponding side view of the solid design of dielectric material 14. Thus, FIG. 3A is the top view of a design of dielectric material 14 for which FIG. 3F is its corresponding side view. Similarly, FIGS. 3B, 3C, 3D, and 3E correspond to FIGS. 3G, 3H, 3I, and 3J, respectively. In particular, FIGS. 3K to 3P show a top view of a patterned design of dielectric material 14, having a circular, elliptical, rectangular, trapezoidal, and pentagonal cross-section, respectively.

(19) Those skilled in the art will realize that other designs of dielectric material 14 may be created, including a label, logo, word, name, symbol, picture, photo, text, map, or any combination thereof for use not only in a case for a cellphone, but also including uses on a laptop computer, tablet, cellphone, touch-screen display device, or different type of handheld devices.

(20) In accordance with another configuration, FIGS. 4A to 4C show various aspects of device 10 surrounded by case 20, wherein the spacing between antenna 16 and outer surface 22 of case 20 is larger than the minimum spacing required to provide the benefits of case 20. Although a larger spacing results in a larger size of case 20, antenna 16 becomes less sensitive to an external agent that may otherwise electromagnetically couple stronger to antenna 16, which may cause a degradation of performance of antenna 16. Preferably, case 20 has a thickness such that the spacing between device 10 and outer surface 22 of case 20 ranges between 1 mm and 10 mm on the region adjacent to antenna 16. More preferably, such spacing is not larger than 5 mm. In this configuration, air is filling the spacing between antenna 16 and outer surface 22 of case 20 to reduce the weight of case 20. However, those skilled in the art will realize that one or more layers of dielectric material other than air may be disposed in between antenna 16 and outer surface 22 of case 20.

(21) Particularly, FIG. 4A shows a cross-sectional side view of device 10 surrounded by case 20, wherein outer section 22 of case 20 has a rectangular cross-section. More specifically, FIG. 4B shows a cross-sectional side view of device 10 surrounded by case 20, wherein the spacing between antenna 16 and outer surface 22 of case 20 is larger than the minimum spacing required only in a section 22a of outer surface 22 of case 20. Section 22a defines a largest uniform spacing between device 10 and outer surface 22 on the area where antenna 16 is disposed. In other words, the spacing between device 10 and outer surface 22 is smaller, in all regions between device 10 and case 22, than the spacing between device 10 and section 22a of case 20. The spacing between device 10 and outer surface 22 of case 20 transitions from the largest to the smallest values at section 22b, which has a curved concave cross-section from an external view of case 20.

(22) Likewise, FIG. 4C shows a cross-sectional side view of device 10 surrounded by case 20, wherein a section 22c of outer surface 22 of case 20 defines a region having a hemispherical shape. Preferably, the region of outer surface 22 of case 20 defined by section 22c has an area that overlaps and is larger than the area of antenna 16 adjacent to outer surface 22 of case 20.

(23) In yet another configuration, FIGS. 5A and 5B show various aspects of a cross-sectional side view of device 10, represented by a cell phone comprising a front side 10a, wherein a user interfaces for normal operation of cell phone 10, and a back side 10b opposite front side 10a. Cell phone 10 also comprises a first antenna 16a, positioned adjacent to back side 10b towards a first end 23a of cell phone 10, and a second antenna 16b positioned adjacent to back side 10b towards a second end 23b of cell phone 10 opposite first end 23a of cell phone 10.

(24) A case comprising a first section 24a, a second section 24b, and a third section 24c attaches to cell phone 10 overlapping an area defined by back side 10b, an area defined by first end 23a, and an area defined by second end 23b of cell phone 10. Section 24a is positioned contiguous to and in between sections 24b and 24c, whereas a part of section 24b and a part of section 24c protrudes away from cell phone 10 in the areas adjacent to antennas 16a and 16b. A protrusion of a part of sections 24b and 24c desensitizes antennas 16a and 16b by increasing the spacing between antennas 16a and 16b and an external agent that may otherwise electromagnetically couple to and degrade the performance of antenna 16a or antenna 16b.

(25) In this specific configuration, sections 24b and 24c create air gaps 26a and 26b in between cell phone 10 and sections 24b and 24c, respectively. Preferably, sections 24b and 24c protrude away from cell phone 10 such that the spacing between back side 10b and the outer surface of sections 24b and 24c ranges between 1 mm and 10 mm on the region adjacent to antennas 16a and 16b. More preferably, such spacing is not larger than 5 mm. However, those skilled in the art will realize that one or more layers of dielectric material other than air may be used to create the protrusion of sections 24b and 24c.

(26) In addition, sections 24b and 24c extend contiguously to cell phone 10 to attach to cell phone 10 at ends 23a and 23b by means of a lip at the edge of each section 24b and 24c towards front end 10a of cell phone 10, as well known in the prior art.

(27) In particular, FIG. 5A shows a side view of cell phone 10, wherein antennas 16a and 16b of cell phone 10, and correspondingly sections 24b and 24c, are located adjacent to ends 23a and 23b of cell phone 10, respectively. FIG. 5B specifically shows a side view of cell phone 10, wherein antennas 16a and 16b of cell phone 10, and correspondingly sections 24b and 24c, are spaced from ends 23a and 23b of cell phone 10, respectively.

(28) FIGS. 6A and 6B show various aspects of a wireless device with a plurality of antenna desensitization elements in accordance with another exemplary embodiment. In this configuration, device 10 is represented by a cell phone comprising a front side 10a, wherein a user interfaces for normal operation of cell phone 10, and a back side 10b opposite front side 10a. Cell phone 10 also comprises a first antenna 16a, positioned adjacent to back side 10b towards a first end 23a of cell phone 10, and a second antenna 16b positioned adjacent to back side 10b towards a second end 23b of cell phone 10 opposite first end 23a of cell phone 10.

(29) A first insert or cap 30a and a second insert or cap 30b attach contiguously to cell phone 10 overlapping an area defined by antennas 16a and 16b of cell phone 10, respectively. Each of inserts 30a and 30b comprises a section 28a and a section 28b that protrudes away from cell phone 10 in the areas adjacent to antennas 16a and 16b. Sections 28a and 28b desensitizes antennas 16a and 16b by increasing the spacing between antennas 16a and 16b and an external agent that may otherwise electromagnetically couple to and degrade the performance of antenna 16a or antenna 16b. In addition, sections 28a and 28b attach to cell phone 10 at ends 23a and 23b by means of a lip at one or more edges of front side 10a of cell phone 10, as well known in the prior art.

(30) In this specific configuration, sections 28a and 28b create air gaps 32a and 32b in between cell phone 10 and sections 28a and 28b, respectively. Preferably, sections 28a and 28b protrude away from cell phone 10 such that the spacing between back side 10b and the outer surface of sections 28a and 28b ranges between 1 mm and 10 mm on the region adjacent to antennas 16a and 16b. More preferably, such spacing is not larger than 5 mm. However, those skilled in the art will realize that one or more layers of dielectric material other than air may be used to create the protrusion of sections 28a and 28b.

(31) Specifically, FIG. 6A shows a side view of cell phone 10, wherein antennas 16a and 16b of cell phone 10, and correspondingly inserts 30a and 30b, are located adjacent to ends 23a and 23b of cell phone 10, respectively. In particular, FIG. 6B shows a side view of cell phone 10, wherein antennas 16a and 16b of cell phone 10, and correspondingly inserts 34a and 34b, are spaced from ends 23a and 23b of cell phone 10, respectively.

(32) In accordance with certain aspects of another configuration, a cross-sectional side view of a wireless device 10, using an antenna desensitization decoupling material 40, is shown in FIG. 7. Wireless device 10 is represented by a cell phone, comprising an antenna 16 enclosed within an outer surface 12 of cell phone 10 and adjacent to a side of outer surface 12 of cell phone 10.

(33) In the configuration shown in FIG. 7, decoupling material 40 is disposed on the area of outer surface 12 of cell phone 10 that is adjacent to antenna 16, such that decoupling material 40 overlaps an area defined by antenna 16. Preferably, a thickness of decoupling material 40 is not larger than 3 mm. As a result, a spacing between antenna 16 and an external agent that may electromagnetically couple to antenna 16 is usually not increased enough to reduce the impact, due to spacing, that said external agent may have on antenna 16. However, and more importantly, decoupling material 40 has electrical and magnetic properties that minimize an effect between antenna 16 and an external agent that may electromagnetically couple to antenna 16 causing a degradation of the performance of antenna 16, even at such small spacing.

(34) Decoupling material 40 may comprise one or a combination of more than one layer of a frequency selective surface, electromagnetic band gap structure, ferromagnetic material, anisotropic material, nanomaterial, dielectric material, or conductive material. A design of antenna 16 may be optimized to operate with decoupling material 40. Those skilled in the art will realize that decoupling material 40 may be also used as part of a means for including a label, logo, word, name, symbol, picture, photo, text, map, or any combination thereof. Preferably, decoupling material 40 is disposed on an area of outer surface 12 of cell phone 10 that is larger than the area of antenna 16 adjacent to outer surface 12 of cell phone 10. Also, decoupling material may be affixed to outer surface 12 of cell phone 10, by means that include glue, adhesive, or resin as well known to those skilled in the art.

(35) According to another configuration, FIGS. 8A and 8B show various aspects of a cross-sectional side view of device 10 surrounded by case 20. In this embodiment, decoupling material 40 is disposed on an area of an outer surface 22 of case 20, such that decoupling material 40 overlaps an area defined by antenna 16 adjacent to outer surface 22 of case 20. As a result, decoupling material 40 desensitizes antenna 16 by reducing an effect of an external agent that may electromagnetically couple to antenna 16 causing a degradation of the performance of antenna 16.

(36) In particular, FIG. 8A shows a cross-sectional side view of device 10 surrounded by case 20, wherein decoupling material 40 is disposed on outer surface 22 of case 20. Specifically, FIG. 8B shows a cross-sectional side view of device 10 surrounded by case 20, wherein decoupling material 40 is disposed within outer surface 22 of case 20.

(37) Alternatively, and in reference to FIGS. 1 to 2 and 4 to 8, antenna 16 may be disposed partly enclosed or not enclosed at all within the outer surface of wireless device 10.

(38) In reference to each of the above-described configurations, a method for designing an antenna desensitization system to mitigate adverse effects when operating in a potentially antenna-detuning environment or under conditions that may interfere with other systems or be susceptible to interference from other sources may be performed according to the following:

(39) 1. At step 10, identifying the location of an antenna operating in an environment capable of detuning the operational frequency range of said antenna or under conditions in which said antenna may interfere with the operation of other systems or may be susceptible to noise or interference from other sources.

(40) 2. Next, at step 20, determining the operational conditions wherein the antenna, whose location was identified in step 1, might be susceptible to either a unique or significant detuning or performance degradation. These operational conditions may include, but are not limited to, the presence of any combination of human user body parts (e.g. hands, fingers, head or other parts of the body as when such device is placed in a pocket or hung on clothing), conductive materials, or dielectric materials located within a radius of two wavelengths at the lowest frequency of operation in the medium where said antenna element is operating, corresponding to an intended application (e.g. antennas on a laptop computer, tablet, cellphone, touch-screen display device, or different type of handheld devices.

(41) 3. Next, at step 30, designing and implementing one or more desensitizer elements for each of the operational conditions identified in step 2, to mitigate or eliminate the adverse effects of each of these conditions, by implementing at least one of the following steps: 3.1. Designing a structure, including a dielectric material, disposed adjacent to and at least partly overlapping such antenna, in order to increase the spacing between the antenna and an external agent creating each operational condition; 3.2. Designing a structure, including a dielectric material and an insert or at least a portion of a case at least partly enclosing an electronic device operating in association with the antenna identified in step 1, wherein said dielectric material is disposed adjacent to and at least partly overlapping said antenna element, in order to increase the spacing between the antenna and an external agent creating each operational condition; and 3.3. Designing a structure, including a decoupling material disposed adjacent to and at least partly overlapping such antenna, in order to reduce the electromagnetic coupling between the antenna and an external agent creating each operational condition;

(42) 4. Last, at step 40, selecting the most suitable configuration of each desensitizer element, in terms of performance or other predetermined criteria, corresponding to a specific antenna or a device which operates using such antenna.

(43) The method determines dimensional and operational parameters of the elements of the antenna desensitization system, such as the relative positioning of each element and the use of dielectric materials or other types of decoupling materials that may prevent adverse electromagnetic coupling that may detune or degrade the performance of such antenna or a device which operates using such antenna.

(44) Those skilled in the art will recognize that the steps above indicated can be correspondingly adjusted for specific antenna element configurations and other constraints such as antenna dimensions, conformality, obtrusiveness, operating frequency, bandwidth, operational conditions, number of antennas, and surrounding environment as well as available area and location for implementation of each antenna in a particular device for a specific application.

(45) The method and different configurations of the antenna desensitization system and design method thereof have been described herein in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in a descriptive rather than in a limiting nature. Any embodiment herein disclosed may include one or more aspects of the other embodiments. The exemplary embodiments were described to explain some of the principles of the present invention so that others skilled in the art may practice the invention. Those skilled in the art will recognize that many modifications and variations of the invention are possible in light of the above teachings. The present invention may be practiced otherwise than as specifically described within the scope of the appended claims and their legal equivalents.