Patent Application
20080150830
Recent developments in a number of different digital technologies have greatly increased the need to transfer large amounts of data from one device to another or across a network to another system. Technological developments permit digitization and compression of large amounts of voice, video, imaging, and data information, which may be rapidly transmitted from computers and other digital equipment to other devices within the network. Computers have faster central processing units and substantially increased memory capabilities, which have increased the demand for devices that can more quickly store and transfer larger amounts of data.
To transfer data, mobile wireless devices incorporate Radio Frequency (RF) subsystems to support the multiple frequency ranges that may be needed. The radio subsystems may include a single band antenna, multi-band antenna or broadband antenna. Single band antenna may increase the platform space as more radios are integrated into the platform. Multi-band antenna may limit operation to three or four bands to maintain desirable antenna performance in those bands. The broadband antenna may introduce undesired out of band noise that necessitates RF front end band pass filters. Clearly, the developments in digital technology have stimulated a need to deliver data and improvements in multi-radio subsystems in the same platform are needed.
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
It will be appreciated that for simplicity and clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding or analogous elements.
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention.
The embodiment illustrated in
It should be noted that communications device 10 may have applications in a variety of products. For instance, the claimed subject matter may be incorporated into desktop computers, laptops, smart phones, MP3 players, cameras, communicators and Personal Digital Assistants (PDAs), medical or biotech equipment, automotive safety and protective equipment, automotive infotainment products, etc. However, it should be understood that the scope of the present invention is not limited to these examples.
Switches 220 and 230 may be placed either on the top or on the bottom of the flexible substrate. Whereas prior art devices typically use switches on the top of the substrate, in accordance with the present invention the switches may also be placed on the bottom of the flexible substrate in order to reduce the height of the switch package. By placing switches 220 and 230 underneath the flexible substrate, the flexible substrate may be placed or embedded inside the mechanical casing of the laptop lid, i.e., the area around the Liquid Crystal Display (LCD) screen. In some embodiments selected areas on the mechanical casing edge may be cut to provide places for the switches. Thus, excess switch package height may be eliminated from the top of the antenna pattern. Note that the switches on the bottom of the antenna substrate may be connected to the antenna metal patterns on the top side of the flexible substrate using vias filled with a metal.
Antenna 200 may be designed to operate in the lowest frequency band and switch to higher frequency operation using RF switches such as, for example, Micro-Electrical-Mechanical (MEM) switches, Field Effect Transistor (FET) switches and PIN diode switches. Antenna 200 may adaptively reconfigure to operate in different frequency bands by using the switches to achieve different electrical lengths and current distributions.
In operation, both switch 220 and switch 230 may be closed to allow antenna 220 to communicate in the five cellular bands listed as GSM 850, PCS 1900, GSM 900, DCS 1800 and IMT 2000. In another switch setting, switches 220 and 230 may both be open to allow antenna 200 to communicate in the WLAN bands denoted by band 6 and band 7. Note that switches 220 and 230 may both turn on or turn off at approximately the same time so that one DC switch control line is able to tune reconfigurable antenna 200 to the different multi-band stages.
Again, with switches 220 and 230 both in a closed position communications device 10 is configured to operate in the cellular mode and provide communications at frequencies in the range of 824-960 MHz, BW=15% to cover GSM850 and 900 bands 1710-2170 MHz, BW=23.7% to cover DCS/PCS/WCDMA. With switches 220 and 230 both in an open position communications device 10 is configured to operate in the WLAN mode and provide communications at frequencies in the range of 2.4-2.48 GHz, BW=3.5% for 802.11 b/g/n 4.9-5.9 GHz, BW=18.5% to indoor/outdoor 802.11 a/n.
Although
Whereas current MXN platforms allocate one antenna or N antennas for Multiple-Input-Multiple-Output (MIMO) systems to predetermined frequency bands, the present invention may integrate more radios into one platform using the multi-band to multi-band frequency reconfigurable antenna. In accordance with the present invention the mobile platform may adaptively tune to different configurations to meet end user requirements and to optimize radio performance in terms of RF interference rejection and ElectroMagnetic Interference and Capabilities (EMI/EMC) assessments. A minimum number of antenna elements may be used to support both MIMO and switch diversity.
By now it should be apparent that a multi-band frequency reconfigurable antenna with a single feeding point may be used to cover the five cellular bands that include GSM 850, PCS 1900, GSM 900, DCS 1800 and IMT 2000 and the two WLAN bands. The inventive reconfigurable antenna may reduce the number of required antennas and the number of associated RF switches while providing tunability that covers the wireless communication frequency bands. The savings in platform space from the reduction in RF switches and RF switch control lines provides a cost-effective multi-radio wireless platform environment.
Thus, by implementing natural higher order harmonics on multi-band reconfigurable antenna designs the antenna higher order resonance is used to build multi-band to multi-band frequency reconfigurable antenna. In these inventive embodiments the multi-band to multi-band frequency reconfigurability may be enabled using switches. Space allocation may be minimized and the number of RF cables through the hinge may be reduced.
While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
