MXPA06009049A - Slotted multiple band antenna - Google Patents

Abstract

A multiple band antenna has an RF coupling structure (110) and a resonant RF structure (102). The RF coupling structure (110) has an RF connection (116, 118) and an RF coupling end (112, 114). The resonant RF structure (102) is reactively coupled to the RF coupling end (112, 114). The resonant RF structure (102) has a first end (106) and a second end (108) and has a conductive perimeter (102) enclosing at least one slot area (104) configured to induce an additional resonant RF band for the resonant RF structure (102). The first end (106) and the second end (108) are reactively coupled to a ground plane (124, 120) to facilitate longer wavelength operation. Cellular phones (800) and wireless communications sections incorporating such antennas arealso provided.

Description

ANTENNA D? SLIMMED MULTIPLE BAND FIELD OF THE INVENTION The present invention generally relates to the field of radio frequency antennas and very particularly to compact multiple band antennas.

BACKGROUND OF THE INVENTION Many wireless devices, such as cell phones, pagers, remote control devices, and the like are required to operate in multiple RF bands. Examples of wireless devices that are required to operate in multiple RF bands include wireless devices that are for communication through the 802.11 b / g and 802.11a standards, which require communications in the 2.4 GHz band and the 5.2 and 5.8 GHz bands, respectively . Designers of wireless devices, particularly portable wireless devices such as cell phones, pagers, remote controllers and the like, desire and even require antennas operating in multiple RF bands and also minimizing physical size and manufacturing cost. Several types of antennas, including balanced and unbalanced antennas, are incorporated into the wireless communication devices. A typical balanced antenna, such as a dipole or a loop, generally requires a considerable size or volume within a wireless device. Said antennas can be incorporated in a printed circuit board (PCB) of the wireless device, but its size makes its use unattractive or even impractical. Unbalanced antennas, such as an inverted F antenna, are generally smaller than conventional balanced antenna structures. However, unbalanced antennas have an important component of their radiation currents that flow through the base plane of their wireless device, and are therefore sensitive to disturbances in the base plane of the wireless device. This effect is especially important for personal wireless devices, such as cell phones, that sometimes, but not always, the user holds them in one hand. A personal wireless device, such as a cell phone, has a very different base-plane characteristic when it is far from a person than when it is close to a person, such as the user. A further disadvantage in the use of unbalanced antennas is that many RF circuits used to activate antennas have a better performance than with balanced interfaces for the antenna. An example of such improved performance includes the suppression of even-order harmonics in power amplifiers that are activating a balanced load. Therefore, there is a need to develop an antenna that operates over multiple RF bands and that is particularly convenient for use with portable wireless devices.

SUMMARY OF THE INVENTION According to a preferred embodiment of the present invention, a multiple band antenna has an RF coupling structure with an RF driving end and an RF coupling end. The multiple band antenna also has a resonant RF structure coupled to the RF coupling end. The resonant RF structure has a first end and a second end and also has a conductive perimeter that encloses at least one area of a slot. The conductive perimeter and the area of at least one slot are configured to induce an additional resonant RF band for the resonant RF structure.

BRIEF DESCRIPTION OF THE FIGURES The accompanying figures, in which like reference numbers refer to functionally similar or identical elements in the various separate views and, where, together with the detailed description below are incorporated into and form part of the description, serve to better illustrate several embodiments and to explain various principles and advantages, all in accordance with the present invention. Figure 1 illustrates a multi-band inverted C-antenna with a slot, in accordance with an exemplary embodiment of the present invention. Figure 2 is a graph of lower-band reflected input power, as determined by the simulation for a multi-band inverted C-antenna with and without a slot, according to an exemplary embodiment of the present invention, as illustrated in Figure 1. Figure 3 is a graph of upper-band reflected input power, as determined by the simulation for a multi-band inverted C-antenna with and without a slot, according to an alternative exemplary embodiment of the present invention, as illustrated in Figure 1. Figure 4 illustrates a Smith diagram showing the reflected input power, as determined by the simulation for a multi-band inverted C-antenna with and without a slot, according to with the exemplary embodiment of the present invention, as illustrated in Figure 1. Figure 5 illustrates the dimensions of a multi-band inverted C-antenna with a slot, in accordance with the exemplary embodiment of the present invention, as illustrated in FIG. 1. FIG. 6 illustrates an alternate multi-band inverted C-antenna with a slot and loading tabs, in accordance with the alternative exemplary embodiment of the present invention. Figure 7 illustrates an alternative alternate multiple band inverted C-antenna with a central charging tab, in accordance with an additional exemplary alternative embodiment of the present invention. Figure 8 illustrates a wireless device, such as a cellular telephone, incorporating a multi-band inverted C-antenna, in accordance with an exemplary embodiment of the present invention. Figure 9 illustrates an alternative alternate multiple band inverted C-antenna with a central charging tab, in accordance with a further alternative exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION As required, the detailed embodiments of the present invention are described herein; however, it will be understood that the embodiments described are merely examples of the invention, which may be incorporated in various forms. Therefore, the specific functional and structural details disclosed herein will not be construed as a limitation, but simply as the basis for the claims and as a representative basis for showing those skilled in the art to variously employ the present invention virtually in any detailed structure appropriately. In addition, the terms and phrases used herein are not intended to be a limitation but rather to provide an understandable description of the invention. The terms "a" or "an", as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term other, as used herein, is defined at least as a second or more. The term that includes and / or has, as used herein, is defined as comprising (ie, open language). In Figure 1 there is illustrated a view of an exemplary antenna 100, comprising a multi-band inverted C-antenna with a slot, according to an exemplary embodiment of the present invention. The exemplary multi-band inverted C-antenna with the slot 100 is shown as being constructed on a double-sided printed circuit board 101. The dielectric substrate of this double-sided printed circuit board 101 is not shown in the following diagrams to improve the clarity and understanding of the diagrams. The exemplary multi-band inverted C-antenna with slot 100 shows the conductive areas of the double-sided printed circuit board 101 that forms the structure of the antenna. The exemplary multi-band inverted C-antenna with the slot 100 shows a rear base flat area 124. The rear base flat area 124 is the only conductive surface shown for the back, or inverse, side of the dual printed circuit board side 101. The rest of the conductive surfaces illustrated for the exemplary multi-band inverted C-antenna with the slot 100 in this diagram are on the front side of this double-sided printed circuit board 101. The printed circuit board 101, in this embodiment, is housed in a substantive non-conductive housing 130. The exemplary multi-band inverted C-antenna with the slot 100 includes a front-side base plane 120. The front-side base plane 120 and the base plane rear side 124 are relatively large areas of conductors placed on the dielectric substrate of the double-sided printed circuit board 101. The base planes provide a structure conductor base plane to support the desired operation of the exemplary multi-band inverted C-antenna with the slot 100. The front-side base plane 120 and the rear-side base plane 124 are connected by a number of aperture paths of step 122 that pass through the dielectric substrate of the dual-sided printed circuit board and provide an effective electrical connection between these two conductive sheets. It will be understood that additional embodiments of the present invention may incorporate base plane structures that are only in one layer of a printed circuit board, or that are in some or all of the layers of a multilayer printed circuit board. The exemplary multi-band inverted C-antenna with slot 100 includes a resonant RF structure 102 that is formed with a conductive outer perimeter. The resonant RF structure 102 of this exemplary embodiment has a first end 106 and a second end 108 that are formed near the upper edge of the base plane of the rear side 124 and the base plane of the front side 120. The proximity of the first end 106 and the second end 108 to these base planes, allows reactive coupling between the resonant RF structure 102, through the first end 106 and the second end 108 and the base planes. This reactive coupling supports resonance in the resonant RF structure 102 at wavelengths that are greater than would be supported by an isolated structure with the physical size of the resonant RF structure 102. The operation of the resonant RF structure 102, with its first end 106 and its second end 108 reactively coupled to the nearby base planes, conveniently allows a physically smaller antenna to be used with greater efficiency during longer wavelength operations. The resonant frequency, particularly in a lower frequency band, is modified by changing the placement of the ends 106 and 108 of the resonant RF structure 102 relative to the base plane 120 and 124. The multi-band inverted C-antenna exemplary with the slot 100 further includes an RF coupling structure 110 that includes a first feed conductor 140 and a second feed conductor 142. The first feed conductor 140 has an RF drive connection 116 at one end and a first coupling arm RF 112 at its opposite end. The second feed conductor 142 has a base plane connection 118 at one end and a second coupling arm RF 114 at its opposite end. The RF drive connection 116 and the base plane connection 118 form an unbalanced RF drive connection (i.e., a first RF coupling end) for the exemplary multiple band inverted C-antenna with the slot of this exemplary embodiment. The RF drive connection 116 and the base plane connection can alternatively be connected as balanced terminals for a balanced RF signal. The first coupling arm RF 112 and the second coupling arm RF 114 form an RF coupling end (i.e., a second RF coupling end) for the RF coupling structure 110. The first feed conductor 140 and the second conductor of power supply 142 transform the RF drive into a substantially symmetrical RF coupling which is coupled to the resonant radiation structure 102. This conveniently allows the balanced and unbalanced drive of the resonant RF structure 102 in this exemplary embodiment. Additional embodiments of the present invention operate with asymmetric RF couplings or electrical conductive connections of the RF drive to a resonant RF structure. The resonant RF structure 102 of this exemplary embodiment is reactively coupled to the RF coupling end of the RF coupling structure 110. The first RF coupling arm 112, in the exemplary embodiment, is capacitively coupled to the resonant RF structure 102 a through a first drive space 144. The second coupling arm RF 114 is capacitively coupled in a manner similar to the resonant RF structure 102 through a second drive space 146. The capacitive coupling of the RF coupling structure 110 with the resonant RF structure 102 conveniently allows controlling the impedance of the RF circuit shown by the exemplary multiple band reversed C-antenna to the slot 100 and reduces fluctuations in this interface impedance. The resonant impedance of the exemplary multi-band inverted C-antenna with the slot 100 can be changed by modifying the width and / or length of the first drive space 144 and the second drive space 146. The width of these spaces is modified by the positioning of the first coupling arm RF 112 and the second coupling arm RF 114. The length of these spaces is adjusted by modifying the length of these RF coupling arms. Additional embodiments of the present invention include direct coupling of the resonant RF structure with the RF interface, as described below. It will be appreciated that this exemplary embodiment of the present invention utilizes a substantially symmetrical deployment for the antenna components. In an example of additional embodiments, the different parts, such as the first coupling arm RF 112, the second coupling arm RF 114, the coupling end RF 116, the base plane connection 118, the first feed conductor 140 and the second supply conductor 142 of the RF coupling structure 110 may be on planes that are different from the resonant RF structure 102 and the base planes 120 and 124. In another embodiment still, the parts of the RF coupling structure, i.e. , the first coupling arm RF 112, the second coupling arm RF 116, and the first feed conductor 140 may be in a plane that is different from the plane or planes containing the second coupling arm RF 114, the plane connection base 118 and the second feed conductor 142 of the RF coupling structure 110. The design of said variation of the RF coupling structure 110 can be executed by practically in the relevant techniques using, for example, antenna design tools that include computer simulation of electromagnetic structures at RF frequencies. The conductive perimeter of the resonant RF structure 102 of this exemplary embodiment encloses a slot 104. It has been observed that the presence of the slot 104 in the resonant RF structure 102 induces additional resonant frequencies for the exemplary multiple band inverted C-antenna with the slot 100. This results in the exemplary multiple band inverted C-antenna with slot 100 showing useful radiation patterns in multiple RF bands. The frequency characteristics of these multiple bands are affected by the dimensions of the slot 104. The structure described above, which includes the first end 106 and the second end 108 reactively coupled to the base planes, additionally results in convenient, a multiple band antenna structure with compact dimensions relative to the longer wavelengths where the antenna structure radiates efficiently. The results of the computer simulation for the exemplary multi-band inverted C-antenna previously described with the slot 100 indicate the characteristics of this antenna structure over multiple bands. Figure 2 shows a lower band frequency response 200 for the exemplary multiple band inverted C-antenna with the slot 100, as generated by a computer simulation. The lower band frequency response 200 illustrates the reflected power with respect to the characteristics of the input power for the RF input on two antennas, a non-slotted Inverted C Antenna (ICA) and an Inverted C-slot Antenna (ICAWS). ) between the RF frequencies of 2200 MHz and 2700 MHz. The magnitude of the reflected power, in relation to the input power, is illustrated in the vertical scale 204 as the decibel value of the magnitude Su. The frequency for a particular point in this graph is shown on the horizontal scale 202, which extends linearly from 2200 MHz to 2700 MHz. Two frequency response curves are illustrated in the lower band frequency response 200. A first curve is an Antenna C curve in Inverted non-slotted (ICA) 208 and a second curve is an Antenna C curve in Inverted with Slot (ICAWS) 206. ICA curve 208 is provided as a reference to allow comparison with the ICAWS curve 206 to better illustrate the effect of the slot 104 on the exemplary multiple band inverted C-antenna with slot 100. Both the ICA curve 208 and the ICAWS curve 206 show a first local minimum of reflected input power 210 in the vicinity of 2400. MHz. The reduced reflected input power in the vicinity of this RF frequency indicates that the rest of the power delivered to the antenna is being radiated. ICA curve 208 indicates that above 2400 MHz, the reflected input power increases, indicating that less power is radiated. In contrast, the ICAWS curve 206 shows a second local reflected power minimum 212 in the vicinity of 2600 MHz. This indicates an improved irradiation efficiency for the exemplary multi-band inverted C-antenna with slot 100 in the vicinity of 2600 MHz in comparison with a non-slotted inverted C-antenna with similar dimensions. As understood in the relevant techniques, the reception and transmission characteristics of the RF antennas are essentially identical. Therefore, it is understood that references to, or descriptions of, any of the reception or transmission characteristics of an antenna, apply to the characteristics of both reception and transmission of that antenna. Figure 3 illustrates a higher band frequency response 300 for the exemplary multiple band inverted C-antenna with slot 100, as generated by a computer simulation. The upper band frequency response 300 illustrates the reflected power in relation to the input power for the input to the same two antennas previously analyzed, an Inverted C Non-Slotted Antenna (ICA) and an Inverted C Antenna With Slot (ICAWS ) between the RF frequencies of 5000 MHz and 6200 MHz. The magnitude of the reflected power, in relation to the input power, is illustrated in the vertical scale 304 as the decibel value of the magnitude Su. The frequency for a particular point in this graph is shown on the horizontal scale 302, which extends linearly from 5000 MHz to 6200 MHz. Two frequency response curves are also illustrated in the upper band frequency response 300. The first curve is an Inverted C not-slotted Antenna (ICA) curve 308 and a second curve is an Inverted C-band upper slot antenna curve (ICAWS) 306. ICA curve 208 illustrates a high level of reflected input power through this RF band, indicating a deficient irradiation characteristic for this antenna in this band. In contrast, the high band ICAWS curve 306 shows a third local minimum of reflected input power 316 in the vicinity of 5600 MHz.

This indicates an improved irradiation efficiency for the exemplary multi-band inverted C-antenna with slot 100 in the vicinity of 5600 MHz compared to a non-slotted inverted C-antenna with similar dimensions. This demonstrates the advantageous performance of the exemplary multi-band inverted C-slot antenna 100 that provides effective transmission and reception of RF signals in the multiple bands, as illustrated.

Figure 4 illustrates a Smith 400 diagram of an Inverted C Antenna and an Inverted C Slotted Antenna, as generated by a computer simulation. Two traces are shown in this Smith diagram, an ungrooved ICA curve 402 and an ICAWS curve 404. The normalized values in the ICAWS curve for the points corresponding to the local minimum values that were illustrated in the previous reflected power diagrams. they are indicated in a particular way in this diagram. A first value Its normalized 406 is displayed for an input RF frequency of 2400 MHz, a second value Its normalized 408 is displayed for an input RF frequency of 2600 MHz and a third value Its normalized 410 is displayed for an input RF frequency 5650 MHz. These three normalized Su values are shown with magnitudes very close to zero for these traces in their respective RF frequency bands, further illustrating the effectiveness of the exemplary multiple band inverted C antenna with slot 100 within these bands Multiple RF As illustrated above, the exemplary multiple band inverted C-antenna with slot 100 can operate effectively in the RF bands required by the 802.11b / g and 802.11a standards of 2.4 GHz and 5.2, 5.8 GHz, respectively. This multi-band operation is conveniently provided in these exemplary embodiments with a balanced antenna having a compact size. Figure 5 illustrates the dimensions of the exemplary multiple band inverted C-antenna with the slot 100 corresponding to the structure used in the simulations described above. For this exemplary embodiment, a general resonant RF structure width 502 is 27mm, an upper length of resonant RF structure 504 is 16mm, a falling distance of resonant RF structure 506 that follows the contour of the PCB is 3.5mm, and a height of vertical arm of resonant RF structure 508 is 7. Omm, a slot width 510 is 2. Omm, an end length of RF coupling 512 is 4. Omm, a coupling end clearance RF 514 is 8mm, a coupling end RF to the resonant RF structure space 516 is 0.375mm, an RF coupling end extension length 518, which is the difference between the RF coupling end length 512 and the feed conductor width 142, is 3mm, a RF coupling end at the bottom base plane distance 520 is 3.75mm, an RF drive space 522 is lmm, a base plane width 524 is 3.2mm, a bottom base plane extension 526, i.e. the distance that is extend the lower base plane 124 passing the upper base plane 120, is 2. Omm, and a second end at the bottom base plane distance 530 is 0.5mm. It will be appreciated that those skilled in the art will be able to use RF antenna design techniques, particularly those that incorporate magnetic simulation of antenna structures, to adjust these dimensions and thus produce a similar multi-band inverted C-antenna with slot operating with a variety of desired parameters. It will also be understood that this exemplary embodiment of this multi-band inverted C-antenna with slot 100 is a substantially symmetrical structure so that the dimensions described above are shown for elements on one side of the inverted multi-band C-antenna with slot 100 , the corresponding elements on the opposite side of the exemplary multi-band inverted C-antenna with slot 100 have the same dimension. Figure 6 illustrates a slotted inverted C-shaped antenna with load tabs 600, according to another exemplary embodiment of the present invention. The slotted inverted C-shaped antenna with load tabs 600 shows a first loading tab 602 and a second loading tab 604, which are located within the slot 104 of the alternating resonant RF structure 622. The adjustment of the various dimensions of the alternating resonant RF structure 622, including the size, number and position of the load tabs, can be modified to optimize the RF performance of the slotted inverted C-antenna with load tabs 600 to meet various requirements and / or operational criteria. The design of a variation of the slotted inverted C antenna with load tabs 600 can be executed by those skilled in the art using, for example, tools for the design of antennas including, computer simulation of electromagnetic structures at RF frequencies. Furthermore, it is clear that the variations of the slotted inverted C antenna with load tabs 600 can include any of any number of load tabs within the slot 104. It will further be appreciated that these load tabs can be conductively isolated, for example , without conductive or ohmic contact with the conductive perimeter of the alternating resonant RF structure 622, as shown in Figure 6. Alternatively, some or even all of the loading tabs within the slot 104 may be conductively connected to the perimeter conductor of the alternating resonant RF structure 622. The loading tabs induce a reactive component in the slot, which allows the slot to resonate at a frequency that is less than would otherwise be possible. Therefore, they can be used to control the resonant frequency of the slot, particularly in a high band. In addition, by using the tabs of different sizes and different connections to the conductive perimeter, multiple resonances can be created that can be independently controlled to tune the antenna to the required frequency bands, for example, the 5.2 GHz and 5.8 GHz bands for 802.11a protocols. The alternating resonant RF structure 622 of the slotted inverted C antenna with load tabs 600 further illustrates an alternative design for that element. In contrast to the resonant RF structure 102 of the slotted inverted C-antenna 100, which has a drop 506, the alternating resonant RF structure 622 has a first vertical end 610 and a second vertical end 612 that are at right angles to the top of the alternating resonant RF structure 622. This alternative design for the perimeter of the alternating resonant RF structure 622 is not related to the presence of loading tabs within the slot 104. The loading tabs can be incorporated with equal effectiveness in any structure of inverted C antenna, including, without limitation, the exemplary inverted C-antenna 100 and the slotted inverted C-antenna with load tabs 600. The resonant RF structures may incorporate said vertical ends, such as vertical ends that are substantially perpendicular to the antenna. a central portion of the resonant RF structure, whether or not the resonant RF structure includes load as. An exemplary slotted inverted C-shaped antenna with a central loading tab 700 is illustrated in FIG. 7, in accordance with another exemplary embodiment of the present invention. The exemplary slotted inverted C-antenna with the central loading tab 700 includes a central loading tab 702 which is conductively connected to two opposite sides of the conductive perimeter forming the resonant RF structure 700 of the inverted C-slotted antenna with the reed tab. central load 700. The inverted C-shaped antenna slotted with the central loading tab 700 of this exemplary embodiment has two additional loading tabs, a first additional loading tab 704 and a second additional loading tab 706. These additional loading tabs are in conductive or ohmic contact with one side of the conductive perimeter of the resonant RF structure 722, and are positioned to improve the operation of the slotted inverted C-antenna with the central loading tab 700 in the bands of interest. Figure 8 illustrates an exemplary cell phone 800 incorporating a multi-band inverted C-slot antenna. The exemplary cell phone 800 includes a box 804 and a resonant RF structure 102 and RF coupling structure 110 which are similar to those of the exemplary inverted C-antenna with the slot 100 described above. The front side base plane 120 is also shown. A printed circuit board 802 is shown as mounted for the conductive elements of the antenna structure and other electronic components contained in the exemplary cell phone 800. A back side base plane is also present. , but it is not shown. The exemplary cell phone 800 is shown to include an RF receiver 806 and an RF transmitter 808. The RF receiver 806 and the RF transmitter 808 include a multi-coupler RF circuit (not shown) that allows simultaneous transmission and reception. The RF receiver 806 and the RF transmitter 808 are connected to an RF power line 810 which is guided in a lower layer of the multiple layer printed circuit board 802. The RF receiver 805, the RF transmitter 808, the base plane 120 and The associated antenna structure forms a wireless communication section in this exemplary embodiment. The exemplary cell phone 800 further includes a baseband circuit 812 which processes data, audio, image and video data, as communicated with the user interface circuit, such as speakers, cameras and other interface circuits (not shown). show all), in a manner well known to those skilled in the art to interface this information with the RF receiver 806 and the RF transmitter 808. Other circuits are included within the wireless device 800, as is well known to those skilled in the art. the technique, but they are not shown to improve the clarity and understanding of this diagram. In exemplary cell phone 800, a wireless device, and many other embodiments of the present invention, it is often desired to have an antenna structure, including resonant RF structure 102, with a maximum size. The configuration illustrated for the exemplary cell phone 800 shows the resonant RF structure 102 located along the upper edge of the box 804. This allows a maximum antenna area for a given box design. The shape of the resonant RF structure 102, according to various embodiments of the present invention, can be adjusted to suit the shape of the boxes or other physical components that house the antenna structure. Design techniques known to those skilled in the art, including the use of computer simulation software to model the electromagnetic characteristics of antenna structures, can design such antenna structures to fit a wide variety of profiles and shapes of box. Wireless devices, such as cell phones, may incorporate a number of multiple band antennas, as described in the present invention. Some multi-band antennas can be used to receive operations only, some are used to transmit operations only, and some are used to both transmit and receive operations. Said multiple band antenna arrangements, as described in the present invention, can conveniently reduce the complexity of multi-link circuits. Multiband antennas can be accommodated within, or even outside of, a wireless device to provide spatial diversity for either wireless reception, wireless transmission, or both RF operations. These multiple band antennas can also be selectively coupled to receiver circuits and / or transmitter circuits to allow the use of the antenna for reception and transmission functions, respectively. The selective coupling may include, for example, RF switching circuits that are selectively enabled to couple receiver circuits and / or transmit circuits with at least one multiband antenna, in accordance with alternative embodiments of the present invention.

Exemplary embodiments of the present invention conveniently provide a compact multiple band antenna structure that can be easily incorporated into portable wireless devices. These exemplary embodiments further provide a balanced radiator antenna structure that is less susceptible to variations of the base plane, such as in the case where a user holds the portable wireless device. In Figure 9 there is illustrated a directly coupled multiple band inverted C-antenna 900, in accordance with an alternate mode. The directly coupled multiple band inverted C antenna 900 includes a base plane 900 and a directly coupled resonant RF structure 902 that encloses a slot 904. The directly coupled resonant RF structure 902 of this alternate mode is directly connected to an RF input by means of of a direct coupling structure 910. A first coupling arm 940 and a second coupling arm 942 provide a connection, from an RF drive input / output connection in the lower part of the illustrated structure of direct coupling 910 to the structure Directly coupled resonant RF 902. The direct coupled structure 910 is designed to induce resonance for the directly coupled multiple band inverted C antenna 900 within one or more RF bands. Those skilled in the art will be able to easily realize such designs by virtue of the present disclosure. The directly coupled resonant RF structure 902 further has a first end 906 and a second end 908. The first end 806 and the second end 908 of the directly coupled resonant RF structure 902 have a reactive coupling to the base plane 920 to support the resonance in the resonant RF structure directly coupled 902 at wavelengths that are greater than would be supported by an isolated structure with the physical size of the directly coupled resonant RF structure 902. Although specific embodiments of the invention have been described, those skilled in the art will appreciate that changes can be made to the specific modalities without departing from the spirit and scope of the invention. The scope of the invention will not be restricted, therefore, to the specific embodiments, and it is intended that the appended claims encompass any and all applications, modifications and embodiments within the scope of the present invention.

Claims (10)

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as a priority: CLAIMS

1. - A multiple band antenna, comprising: an RF coupling structure with an RF driving end and an RF coupling end; and a resonant RF structure coupled to the RF coupling end, the resonant RF structure has a first end and a second end, the resonant RF structure comprises a conductive perimeter enclosing at least the area of a slot configured to induce a resonant RF band additional for the resonant RF structure.

2. - The multiple band antenna according to claim 1, characterized in that the coupling end RF is substantially symmetrical.

3. - The multiple band antenna according to claim 1, characterized in that the RF coupling structure is conductively coupled to the resonant RF structure to induce resonance within a preselected RF band.

4. - The multiple band antenna according to claim 1, characterized in that the RF coupling structure is on a plane that is different from the plane of the resonant RF structure, and in addition, the parts of the RF coupling structure are not in the same planes.

5. - The multiple band antenna according to claim 1, characterized in that the resonant RF structure is formed of conductors on a printed circuit board.

6. The multiple band antenna according to claim 1, further comprising a reactive loading tab that substantially cuts into two parts one of at least one slot area, the reactive loading tab connected conductively to the perimeter conductor in two physical points, the two points on opposite sides of the resonant RF structure.

7. The multiple band antenna according to claim 1, characterized in that the RF coupling structure is reactively coupled to the resonant RF structure to induce resonance within a preselected RF band.

8. - The multiple band antenna according to claim 7, characterized in that the RF coupling end is capacitively coupled to the resonant RF structure to induce resonance within a preselected RF band.

9. - The multiple band antenna according to claim 1, further comprising at least one reactive load tongue which is located within one of at least one slot area and positioned to improve irradiation in one of the additional RF band and an additional RF band still.

10. The multiple band antenna according to claim 9, characterized in that at least one reactive load tongue is conductively connected at least at one point to the conductive perimeter.