For electronic devices, miniaturization can provide significant advantages such as, for example, improved portability and/or reduced costs for storage, packaging, and/or transportation. However, miniaturization of an electronic device can be hindered by various physical constraints.
For example, in an electronic device, a gap having a sufficient width between two conductive units may be required to enable the electronic device to satisfy one or more performance requirements. The performance requirements can include one or more of electromagnetic wave transmission efficiency, radio signal reception efficiency, heat dissipation efficiency, etc. If the gap is narrowed for miniaturizing the electronic device, the performance of the electronic device can be compromised. If the gap is enlarged to improve the performance of the electronic device, the form factor of the electronic device can become undesirably large.
Techniques have been developed to physically widen the gap without enlarging the electronic device. However, the performance of the electronic device can be unacceptable in some situations when such prior art techniques are employed. A gap in a prior-art electronic device and a prior-art gap-widening arrangement are discussed with reference to
As well known in the art, gap 104 with a sufficient width, as illustrated by width 114, may be required so that transmission and/or reception of electromagnetic waves can satisfy one or more requirements such as efficiency, pattern shape, interference, mismatch, etc. Physically increasing width 114 of gap 104 can reduce the capacitance in gap 104, thereby freeing antenna 102 to radiate. Given the limited dimensions of board 100 (and required dimensions of ground 108), width 114 can be increased by, for example, physically reducing width 112 of antenna 102. However, reducing width 112 can have a significant impact on the radiation characteristics of antenna 102. As a result, the transmission and/or reception efficiency can be reduced, for example. Further, reducing width 112 can change the resonance frequency of antenna 102 as well as reducing the bandwidth of antenna 102. An example of a conventional technique for physically reducing the dimensions of an antenna is dielectric loading. This approach is discussed with reference to
The invention relates, in an embodiment, to an electronic device comprising a first conductive unit and a second conductive unit disposed such that a gap exists between the first component and the second component. The electronic device further includes one or more components disposed along the gap and configured to counteract one or more capacitance effects in the gap, wherein at least one of the first conductive unit and the second conductive unit represents a part of an antenna.
In another embodiment, the invention relates to an electronic device comprising a conductive unit including a slot and one or more components disposed along the slot and configured to counter one or more capacitance effects in the slot.
The above summary relates to only one of the many embodiments of the invention disclosed herein and is not intended to limit the scope of the invention, which is set forth is the claims herein. These and other features of the present invention will be described in more detail below in the detailed description of the invention and in conjunction with the following figures.
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
The present invention will now be described in detail with reference to a few embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention.
In one or more embodiments, the invention can relate to an electronic device. The electronic device can include a first conductive unit and a second conductive unit. The first and second conductive units can be disposed such that a gap exists between the first component and the second component. The electronic device can further include one or more components disposed along the gap and configured to counteract one or more capacitance effects in the gap. In one or more embodiments, at least one of the first and second conductive units can be an antenna or part of an antenna.
The term “counteract” as employed herein has the meaning of alter, reduce, minimize or eliminate. Analogously, the term “counteracting” as employed herein has the meaning of altering, reducing, minimizing or eliminating. For example, in an embodiment, the components disposed along the gap has the effect of eliminating the capacitance effects in the gap. As another example, in an embodiment, the components disposed along the gap has the effect of minimizing the capacitance effects in the gap. As another example, in an embodiment, the components disposed along the gap has the effect of reducing the capacitance effects in the gap. As another example, in an embodiment, the components disposed along the gap has the effect of altering the capacitance effects in the gap.
In one or more embodiments, the one or more components can be configured to provide inductive reactance to counteract the effects of the capacitive reactance generated in the gap. In one or more embodiments, the one or more components can include one or more inductive components, magnetic components, inductor equivalent magnetic energy storing components. These components may have any suitable form factor, including for example surface-mount devices (SMDs) and/or inductor-capacitor networks.
In one or more embodiments, at least one inductance value of the one or more components can correspond to at least one of an operating frequency, an operating power level, and an operating duration of the electronic device. The at least one inductance value of the one or more components can be determined based on at least one of one or more widths of the gap and one or more intervals (or spaces) between the one or more components.
In one or more embodiments, the number of components in the one or more components can be at least twelve (12) multiplied by a length of the gap and divided by the wavelength.
One or more embodiments of the present invention can relate to an electronic device that can include a conductive unit with a slot. The electronic device can further include one or more components disposed along the slot and configured to counter, alter, minimize or reduce the capacitance effect in the slot.
The features and advantages of the present invention may be better understood with reference to the figures and discussions that follow.
In one or more embodiments, capacitance value C can represent a capacitance value per unit length between conductive line 208 and the line represented by series inductors 202 (shown in the example of
In one or more embodiments, mathematical relationships of ZC//L′, C, and L′ can be represented for a LC parallel circuit model 401:
Z
C//L′=((1/jωC)·jωL′)/(1/jωC+jωL′) (401)
Z
C//L′ can approach infinity, if 1/jωC+jωL′ approaches 0 (402)
Therefore, for ZC//L′ to approach infinity, tank circuit 344 (of equivalent circuit 304 shown in the example of
L′=1/ω2C (403)
From the foregoing, ω=SQRT(1/L′C) (404)
As can be appreciated from the foregoing, inductance value L′ can be determined by configuring or measuring operating frequency f and measuring capacitance value C, in order to make ZC//L′ sufficiently large to result in a virtually expanded gap. This aspect will be discussed in details later herein. In one or more embodiments, multiple components 324 with inductance value L′ can be deployed at an equal interval of the aforementioned unit length along the gap. On the other hand, if L′ is predetermined, operating frequency f can be configured to virtually expand the gap.
Alternatively or additionally, L′ can be determined experimentally. For example, components with relatively high inductance values can be disposed initially along the gap, and then the inductance values can be gradually reduced (for example, by adjusting the inductance values or replacing the components) until tank circuits (e.g. tank circuit 344) in equivalent circuit 304 (shown in
In one or more embodiments, the inductance values can be further reduced to provide one or more attenuation effects for facilitating transmission line termination.
In one or more embodiments, first conductive unit 502 can represent an antenna or part of an antenna. The antenna can be coupled to generator 106 and configured to transmit electromagnetic waves. Alternatively or additionally, first conductive unit 502 can be configured to receive electromagnetic waves (or signals). In one or more embodiments, second conductive unit 508 can represent the ground. Conductive units 502 and 508 can be disposed on board 500 of an electronic device, for example.
In one or more embodiments, the one or more components 524 are configured according to one or more of equations 401-404 such that gap 504 is virtually expanded with capacitance effects reduced or canceled. As a result, the efficiency for the radiative transmission and/or reception can be enhanced without gap width w or first conductive unit width W being physically modified. Preserving the dimensions w and W can advantageously save redesign and/or manufacturing costs in many situations.
On the other hand, the gap width w can be physically reduced without unduly compromising the radiative transmission and/or reception efficiency or the bandwidth. As a result, the form factor of the electronic device can be reduced without compromising the device's performance.
Alternatively or additionally, the gap width w can be physically reduced with the first conductive unit width W being physically increased. As a result, the resonance of first conductive unit 502 can be improved, and therefore the radiative transmission and/or reception efficiency and/or bandwidth of the electronic device can be advantageously enhanced. Since the gap width w is physically reduced concomitantly with the enlargement of the first conductive width W, the performance increase can be achieved without having to enlarge the overall form factor of the electronic device.
One or more embodiments of the present invention also relate to the determination of the number (or quantity) of the one or more components 524. In one or more embodiments, based on experimental results, the number of the one or more components 524 (added components) for effectively canceling the one or more capacitance effects can be determined. In some cases, the number of the one or more components 524 may depend on length D of gap 504 and wavelength λ of the electromagnetic waves:
Number of added components 3/(λ/(4D)), i.e.,
Number of added components 12D/λ (501)
Wavelength λ is related to operating frequency of the electromagnetic waves:
λ=c/f (502)
In one or more embodiments, the number of the one or more components 524 is at least 12D/λ in order for the one or more capacitance effects to be effectively canceled. For example, if gap 504 length D is half of the wavelength λ, i.e., λ/2, at least six (6) of components 524 can be deployed along gap 504, as illustrated in the example of
One or more embodiments of the present invention also relate to positioning the one or more components 524 in order to effectively cancel, alter, reduce, or minimize the one or more capacitance effects. In one or more embodiments, based on experimental results, a first component among the one or more components 524 can be disposed at most one twenty-fourth ( 1/24) of wavelength λ from at least one end of first conductive unit 502. For example, in the example of
Alternatively or additionally, in one or more embodiments, based on experimental results, a first component among the one or more components 524 can be disposed at most one twelfth ( 1/12) of wavelength λ from at least one end of first conductive unit 502. For example, in the example of
In one or more embodiments, the one or more components 524 can have the same inductance value. Alternatively, some components among the one or more components 524 can have different inductance values. Further, one or more components 524 can be distributed along gap 504 at different intervals, for example, for optimal layout of parts of the electronic device.
As illustrated in the example of
In one or more embodiments, inductance values of components 621-624 and/or intervals of components 621-624 (e.g., intervals d1 and d2) can be determined utilizing equations such as, for example, those characterizing the following LC parallel circuit model 601, equivalence capacitance models 602-603, and capacitance models 604-605.
From equations 601-602, Ce=C−1/(ω2L′) (603)
Capacitance models provide relationships of parameters including one or more of inductance values, gap widths, and intervals. To simplify the expression, conductor thicknesses are made unity, and fringe capacitance is neglected.
d
1
=w
1
·C
el/ε=(w1/ε) (C1−1/(ω2L1′)) (604)
d
2
=w
2
·C
e2/ε=(w2/ε) (C2−1/(ω2L2′)) (605)
One or more parameters in equations 604-605 can be configured, for example, for meeting certain design and/or performance requirements. For example, if w1<w2, components 621-624 can be configured such that d1<d2. Alternatively or additionally, components 621-624 can be configured from equation 603 so that L1′<L2′. For example, if w1=w2 and d1<d2, components 621-624 can be configured such that L2′<L1′.
Components 621-624 can be disposed along gap 650 according various cost-saving and/or efficiency-improving considerations. In one or more embodiments, nonconductive medium 680 can be provided to carry components 621-624, for example, for facilitating alignment in manufacturing an electronic device that include conductive units 611-612 and components 621-624. Components 621-624 can be pre-attached to nonconductive medium 680 before being applied to gap 650. In one or more embodiments, nonconductive medium 680 can be formed of epoxy or a similarly suitable medium. Alternatively or additionally, one or more of components 621-624 can be soldered to at least one of conductive units 611-612. Alternatively or additionally, one or more of components 621-624 can be pre-printed on board 600 before conductive units 611-612 are installed on board 600. One or more of components 621-624 can contact both of conductive units 611-612.
In one or more embodiments, conductive unit 712 can form an exterior part of an electronic device, and width ws of slot 704 can be physically reduced such slot 704 can be inconspicuous to users and/or substantially resistant to contaminants (i.e., foreign matters). As a result, for the electronic device, aesthetics can be enhanced and/or contamination can be reduced. Further, the structural integrity of the electronic device also can be reinforced.
As can be appreciated from the foregoing, embodiments of the present invention can virtually expand gaps between conductive units and/or for slots in conductive units. As discussed, this approach effectively cancels, alters, reduces or minimizes the capacitance effects in the gaps and/or slots, thereby advantageously improving performance without physically altering dimensions of existing elements of the electronic device. Further, embodiments of the present invention can physically minimize gaps and/or slots of an electronic device thereby enabling a reduction in the form factor of the electronic device, without compromising performance. Physically minimizing the gaps and/or slots also can advantageously provide room for accommodating different designs and/or components (such as higher performance designs and/or higher performance parts). An example of a higher performance part that may be accommodated is an antenna with a larger surface area and bandwidth. Further, physically minimizing the gaps and/or slots also can advantageously improve aesthetics, contamination resistance, and/or structural robustness of the electronic device.
While this invention has been described in terms of several embodiments, there are alterations, permutations, and equivalents, which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. Furthermore, embodiments of the present invention may find utility in other applications. The abstract section is provided herein for convenience and, due to word count limitation, is accordingly written for reading convenience and should not be employed to limit the scope of the claims. It is therefore intended that the following appended claims be interpreted as including all such alternations, permutations, and equivalents as fall within the true spirit and scope of the present invention.
The present invention claims priority under 35 USC 119(e) to a commonly owned provisionally filed patent application entitled “ELECTRONIC DEVICE WITH A VIRTUALLY EXPANDED GAP,” U.S. Application No. 60/878,936, Attorney Docket No. APPL-P023P1, filed Jan. 5, 2007 by inventor Bing Chiang.
Number | Date | Country | |
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60878936 | Jan 2007 | US |