Abstract:
System and methods for modifying an electrical parameter of an electrical component are described. The system includes an electrical component disposed on a circuit board and a dielectric material. The electrical component has an electrical parameter that is sensitive to a dielectric constant of a substance proximate to the electrical component. The dielectric material is attached to the circuit board proximate to the electrical component and modifies the electrical parameter of the electrical component.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to systems and methods that modify electrical characteristics. 
     BACKGROUND OF THE INVENTION 
     Handheld wireless communications devices often employ, for example, quarter-wave transformers for cellular, personal communications services (PCS) or global positioning system (GPS) frequency bands. Such quarter-wave transformers, when not adapted, are typically much longer than can be easily accommodated by most handheld wireless communications devices. 
     In order to reduce the length of such quarter-wave transformers, a block  20  of dielectric material is used as shown in  FIG. 3 .  FIG. 3  shows a trace  10  that has been printed on a circuit board  50 . The trace  10  is not continuous as a space was provided onto which the dielectric block  20  could be mounted. The dielectric block  20  already has a trace  40  printed on its surface across three faces of the block  20 . The dielectric block  20  must be carefully aligned when it is mounted to avoid any discontinuities at point  30  between trace  10  of the board  50  and trace  40  of the block  20 . If successful, the dielectric block  20  modifies the electrical properties of the trace  10 ,  40  such that a shorter trace can be used for a quarter-wave transformer, for example. 
     As is evident from  FIG. 3 , there is very little room for error concerning the proper alignment of the traces  10 ,  40 . Not only must the traces  10 ,  40  be connected, but they must be well aligned since misaligned (albeit connected) traces  10 ,  40  provide variances from the expected electrical characteristics of the trace  10 ,  40  which can have deleterious effects on the handheld wireless communications device, especially during mass production. 
     In addition, since the block can only be mounted in one way, that is, with the traces  10 ,  40  aligned and connected, there is no easy way in which to modify the electrical characteristics of the trace  10 ,  40  in situ. Thus, a degree of flexibility is lost especially in light of the variability of the electrical characteristics of the traces  10 ,  40 . 
     Accordingly, there exists a need for a method and a system of modifying the electrical characteristics of a trace that provide robust, well-aligned trace connections and also provides flexibility to change electrical properties in situ. 
     SUMMARY OF THE INVENTION 
     The present invention alleviates to a great extent the disadvantages of conventional apparatus and methods for providing a multiband antenna. 
     In a preferred embodiment, the present invention provides an electrical component disposed on a circuit board and a dielectric material. The electrical component has an electrical parameter that is sensitive to a dielectric constant of a substance proximate to the electrical component. The dielectric material is attached to the circuit board proximate to the electrical component and modifies the electrical parameter of the electrical component. 
     The present invention has an advantage in that the dielectric material is not required to complete the electrical component. Accordingly, problems such as alignment and continuity of the electrical component are reduced, if not eliminated. 
     The present invention also has an advantage in that the electrical properties of the electrical component can be modified, in situ, by placing the dielectric material in a different position or a different orientation relative to the electrical component. 
     These and other features and advantages of the present invention will be appreciated from review of the following detailed description of the present invention, along with the accompanying figures in which like reference numerals refer to like parts throughout. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  shows a perspective view of a dielectric block mounted on top of a trace according to the present invention; 
         FIG. 1B  shows a top view of the dielectric block mounted on top of a trace according to the present invention; 
         FIG. 2A  shows a top view of the dielectric block mounted at a particular displacement from the trace according to the present invention; 
         FIG. 2B  shows a top view of the dielectric block attached to a circuit board via adhesive dots according to the present invention; and 
         FIG. 3  shows a conventional arrangement between a dielectric block and a trace. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1A and 1B  illustrate an exemplary embodiment of a dielectric material  70  disposed on top of a trace  60  according to the present invention. The trace  60  may be printed or deposited on the circuit board  50 . Subsequently, the dielectric material is mounted or deposited on top of trace  60 . 
     Such a system may find application in wireless communications devices, for example, for use in a quarter-wave transformer. However, the present invention is not so limited and contemplates uses in any application in which the electrical properties may be modified or optimized. For example, the trace may be part of an antenna, an inductor, a capacitor, a resonating structure, transmission lines, wave-guides, etc. In addition, although illustrated as using a trace, the present invention contemplates using other electrical components known to one of ordinary skill in the art. 
     Since there is only the one trace  60 , there are no trace-to-trace continuity and alignment problems which might affect the electrical characteristics of the trace. In addition, since the disposition of the dielectric material  70  with respect to the trace  60  affects the electrical properties of the trace  60 , the dielectric material  70  can be mounted in different orientations and positions with respect to the trace  60  to optimize the expected electrical properties of the trace  60 . 
     For example,  FIG. 2A  shows the dielectric material  70  that has been displaced, for example, along a direction that is perpendicular to the axis of the trace  60 . The trace  60  illustrated in  FIG. 2A  has different electrical properties than the trace  60  illustrated in  FIG. 1B . Furthermore, although  FIG. 2A  illustrates a particular displacement and orientation of the dielectric material  70  with respect to the trace  60 , it is understood that there are a wide variety of displacements and orientations of the dielectric material  70  from which to choose to provide additional degrees of freedom in optimizing or achieving particular electrical properties of the trace  60 . 
       FIG. 2B  illustrates that adhesive dots  80  mounted on the circuit board  50  may be used to hold the dielectric material  70  to the circuit board  50 . Accordingly, the dielectric material  70  can easily be attached and detached from circuit board  50 . Thus, in attempting to achieve an optimized or particular electrical property of the trace  60 , the dielectric material  70  can be displaced or reoriented and easily mounted or dismounted from the circuit board  50 . With each mounting of the dielectric material  70 , the trace  60  could be tested to see if the particular electrical property had been achieved or optimized. Thus, for example, the trace  60  can be optimized for cellular band frequencies when the dielectric material  70  is in a first orientation and position, while the trace  60  can be optimized for PCS band frequencies when the dielectric material  70  is in a second orientation and position. 
     Although illustrated as adhesive dots  80  mounted on the circuit board  50 , other types and shapes of adherents may be used to attach and to detach the dielectric material  70 . For example, physical hooks or receptors could be mounted on the circuit board  50  in order to hold the dielectric material  70  on the circuit board  50 . In addition, the adhesive dots  80  may be disposed on the dielectric material  70  instead or in addition to the adhesive dots  80  on the circuit board  50 .  FIG. 2B  also illustrates an example of adhesive pads  90  on the dielectric material that can be used to attach the dielectric material to the circuit board  50 . 
     In addition, although the dielectric material  70  has been illustrated as a block, the dielectric material  70  can take on any number of shapes and forms. Moreover, although the trace  60  has been illustrated as a line trace, other shapes and forms of the trace  60  known in the art are also contemplated. In addition, the particular choices available for materials for use in the dielectric material  70  and the trace  60  are well known in the art. 
     Although the dielectric material  70  has been illustrated as being on top of the trace  60 , the dielectric material  70  could equally be mounted under the trace  60 . For example, the trace  60  could be disposed on a first side of the circuit board  50  and the dielectric material  70  could be disposed on the second (opposite) side of the circuit board  50 . 
     Finally, although the dielectric material  70  has been illustrated in contact with the trace  60 , the dielectric material  70  may be in contactless proximity of the trace  60 . Such contactless proximity can still affect the electrical properties of the trace  60 . 
     Thus, it is seen that systems and methods for modifying electrical properties have been described. One skilled in the art will appreciate that the present invention can be practiced by other than the preferred embodiments which are presented in this description for purposes of illustration and not of limitation, and the present invention is limited only by the claims that follow. It is noted that equivalents for the particular embodiments discussed in this description may practice the present invention as well.