The present application relates generally to a communication device and in particular to a communication device containing a multi/broadband antenna of reduced size.
With the ever-increasing demand for portable communication devices, coupled with the advent of disparate technologies, it has been desirable to provide communication devices that operate in different frequency bands. The ability to use multiple frequency bands has many advantages, for example, permitting communications in different locations around the world in which one or more of the different bands are used, providing a backup so that the same information can be provided through the different bands, or permitting different information to be provided to the device using the different frequencies and permitting the device to determine the manner in which to respond to the different information.
While the introduction of an additional frequency band provides additional functionality, the design and incorporation of a single antenna that operates satisfactorily in all of these bands may not be feasible for certain structures from a cost or efficiency standpoint or may be unwieldy from the standpoint of user. In many instances it is more desirable to provide a separate antenna for the new frequency band. However, the use of two or more external antennas may not be desirable, both for reasons above as well as problems such as cost and manufacturing inherent in altering the external structure of an already-existing communication device (e.g., there may be a lack of dedicated volume/space for the additional antenna element).
Accordingly, it would be desirable to provide a separate antenna that can be readily integrated into an existing communication device without necessitating excessive external changes to the communication device.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate embodiments of concepts that include the claimed invention, and explain various principles and advantages of those embodiments.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of the embodiments of shown.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments shown so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Other elements, such as those known to one of skill in the art, may thus be present.
Before describing in detail the various embodiments, it should be observed that such embodiments reside primarily in combinations of apparatus components related to a radio having antennas designed for short and long range communications. The short-range antenna is a PIFA and is contained internally in the radio chassis in a non-conductive speaker bracket. The speaker bracket also contains a speaker. The PIFA is part of a flexible structure that also contains a contact area, a flexible cable and an extension portion. Feed/ground contact for the PIFA is made in the contact area, as is contact for audio components including a speaker and microphone of the radio. The flexible cable and extension portion of the flexible structure route the audio signals to the audio components. The flexible cable and extension portion are far enough away from the PIFA so that the amount of crosstalk is insignificant. The launch pad where feed/ground contact for the PIFA is made is disposed at a surface of the speaker bracket, while the PIFA is bent such that the PIFA extends into the speaker bracket, with the free end of the PIFA leveling out and being disposed in a corner of the speaker bracket. The free end and launch pad are thus non-planar. The free end of the PIFA is disposed such that the distance between the free end of the PIFA and various metallic components of the radio including the chassis and speaker is maximized.
One embodiment of a portable communication device is shown in
Turning to the electronics within the portable communication device, one embodiment is shown in the block diagram of
The processor 202 includes one or more microprocessors, microcontrollers, DSPs, state machines, logic circuitry, or any other device or devices that process information based on operational or programming instructions. Such operational or programming instructions are preferably stored in the program memory 214. The program memory 214 may be an IC memory chip containing any form of random access memory (RAM) or read only memory (ROM), a floppy disk, a compact disk (CD) ROM, a hard disk drive, a digital video disk (DVD), a flash memory card or any other medium for storing digital information. One of ordinary skill in the art will recognize that when the processor 202 has one or more of its functions performed by a state machine or logic circuitry, the program memory 214 containing the corresponding operational instructions may be embedded within the state machine or logic circuitry. The operations performed by the processor 202 and the rest of the communication device 200 are described in detail below.
The transmitter circuitry 206 and the receiver circuitry 208 enable the communication device 200 to respectively transmit and receive communication signals. In this regard, the transmitter circuitry 206 and the receiver circuitry 208 include appropriate circuitry to enable wireless transmissions. The implementations of the transmitter circuitry 206 and the receiver circuitry 208 depend on the implementation of the communication device 200 and the devices with which it is to communicate. For example, the transmitter and receiver circuitry 206, 208 may be implemented as part of the communication device hardware and software architecture in accordance with known techniques. One of ordinary skill in the art will recognize that most, if not all, of the functions of the transmitter or receiver circuitry 206, 208 may be implemented in a processor, such as the processor 202. However, the processor 202, the transmitter circuitry 206, and the receiver circuitry 208 have been artificially partitioned herein to facilitate a better understanding. The buffer memory 216 may be any form of volatile memory, such as RAM, and is used for temporarily storing received information.
In many instances, portable communication devices such as the radios shown in
As above, incorporating an additional external antenna into the physical structure of a pre-existing portable radio is often not feasible due to the manufacturing changes required (e.g., molds, cost). Accordingly, it is desirable to add an internal antenna. However, it is often difficult to insert additional components such as an antenna in a structure already dense with physical and electronic objects. The design and incorporation of an antenna into such a structure is extremely challenging, especially in structures such as the Motorola APX™ 6000 and 7000 in which tolerances are tight.
Moreover, a large amount of metal parts including at least part of the chassis, shielding flex cables and more may be in close proximity (e.g., <about 5 mm) with the antenna, thereby significantly affecting the performance of the antenna due to the coupling with the nearby metal. While optimization of the resonance response of the antenna at the required frequency in tightly coupled conditions may be designed without an extraordinary amount of difficulty, simultaneous optimization for maximum radiation efficiency taking into account effects such as PCB layout limitations, geometry and electrical properties of all nearby objects, and interconnects between different parts of the communication device is non-trivial to say the least. Thus, both the antenna structure and the placement of the antenna within the communication device represent significant challenges.
One such embodiment of an antenna able to be placed into the radio is shown in
Contact portions 314 are formed in a contact area 304 of the flexible structure 300. The elements of the flexible structure 300 are connected with external components in the radio, such as a PCB (which may contain the processor, memory and/or other components shown in
The distal portion 306 of the flexible structure 300 is connected to the contact area 304 through a winding, distended S-shaped portion 310 and flexible cable 308. The distal portion 306 contains a contact pad to be connected with a microphone of the radio. The distal portion 306 and distended S-shaped portion 310 form an extension portion of the flexible structure 300. The flexible cable 308 extends perpendicularly from middle of one side of the contact area 304. The distended S-shaped portion 310 and the flexible cable 308 provide sufficient flexibility to enable the flexible structure 300 to be bent through the area between the speaker and speaker bracket, as described in more detail below, thereby enabling the flexible structure 300 to be employed in the limited space available.
One section of the distended S-shaped portion 310 contains a wider, gradual “C,” while the remaining section of the distended S-shaped portion 310 has a smaller, less wide, “C” formed by straight portions. The lengths of the top and bottom legs of the “C” of the remaining section are different sizes, so that the connection between the legs is angled, forming a triangle. The distended S-shaped portion 310 contains a connection pad to be connected to the speaker so that signals can be supplied from/to the speaker through the flexible cable 308. The distended S-shaped portion 310 is shaped to allow alignment to the speaker for assembly and contains a plurality of (e.g., two) through hole connection pads at the edges of the distend portions (right and left). The through hole connection pads allow electrical connection to the speaker. The left portion (as shown in
Many PIFA designs are typically based on antenna structures not constrained by the limiting conditions similar to those present in the current radios, e.g., small available volume, substantial shielding of the available volume by metal (speaker, chassis, PCB). Thus, as above, design of the antenna is only one part of the solution to the above problems and is inseparable from finding a portion of the communication device relatively free of metal parts and redesigning the surrounding area if necessary. To this end, in one embodiment the flexible structure 300 containing the PIFA 302 was designed to be incorporated in the speaker bracket of the radio and takes into account both frequency of operation and loading of the antenna by the surrounding metal and plastic components of the radio, which, as mentioned above, affects the antenna efficiency. The speaker bracket is formed primarily from a non-conductive material such as a low-loss plastic, thereby maximizing the separation of the PIFA 300 from the surrounding metal chassis.
One embodiment of a front view of a radio in which the flexible structure 300 containing the PIFA 302 is disposed is shown in
The contact area, containing the launch pad and contact portions, of the flexible structure 502 is disposed at one face of the speaker bracket 504, 604, hereinafter referred to as the bottom of the speaker bracket 504, 604 (as illustrated in
As shown in the figures, both the speaker bracket 504, 604 and the flexible structure 502 have been designed so that the flexible structure 502 is integrated in the speaker bracket 504, 604 between the speaker 506, 606 and the chassis 620. In addition to carrying the signals to/from the PIFA 510, 610, the flexible structure 502 conveys audio signals such as the signal lines between the speaker and microphone and the PCB using conductive traces on the flexible. These traces on the flexible cable 508, 608 are separated sufficiently from the PIFA 510, 610 (as shown, a few mm) such that there is sufficient decoupling of the PIFA 510, 610 signals from the audio signals and thus the amount of crosstalk is insubstantial. The audio signals are supplied to the flexible structure 502 through spring contacts such as those used for the feed and ground of the PIFA 510, 610.
The launch pad shown in the figures is designed to maximize the length available for the PIFA 510, 610 while simultaneously maximizing the distance between the high charge point of the PIFA 510, 610 and the various metal components in the radio such as the PCB ground, speaker metal and chassis. The high charge point of the PIFA 510, 610 is the free end of the PIFA 510, 610, and thus excessive coupling between the charge at this location and the rest of the metallic structure, which degrades performance, is minimized. The launch pad is relatively close to the area where the flexible cable contacts are disposed and therefore the contacts are coupled with the PIFA 510, 610. Thus, when the PIFA 510, 610 is tuned and optimized, this process occurs with those elements in place. Examples of these distances are, for example about 1 mm between the free end of the PIFA 510, 610 and the speaker 606 (shown as t1 in
As shown in
Measurements of the return loss (S11) of the PIFA of
It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “a” or “an” does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
The Abstract of the Disclosure and Summary section are provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that neither will be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.
Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention and that such modifications, alterations, and combinations are to be viewed as being within the scope of the inventive concept. Thus, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims issuing from this application. The invention is defined solely by any claims issuing from this application and all equivalents of those issued claims.
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