Patent Application
20150172426
The present invention generally relates to mobile communications and, more particularly, to optimizing antenna performance of an antenna within a mobile communication device based on the mobile communication device's diverse housing material.
It has become common for mobile communication devices to be provided with a choice of different mobile device housing configurations, wherein each different configuration has a housing made of different materials for the same or similar mobile communication device models. Each mobile communication device's housing material may have different electrical parameters associated therewith. Such differing electrical parameters affect the optimal antenna performance of one or more of the communication antennas within the mobile communication device's housing. For example, ceramic, composite, metal or plastic housings all have different electrical parameters that ultimately affect antenna performance. The antenna performance is affected by the different housing materials detuning the antenna out of the frequency band of interest. In particular, if a mobile communication device's antenna is tuned to operate with a plastic housing or cover while operating in the 850 MHz transmit or receive band, replacement of the plastic cover with a ceramic housing with no additional correction applied to an antenna matching circuit will detune the antenna response to a lower frequency band of about 770 MHz due to the higher dielectric constant of the ceramic housing. The final result will be degradation of the mobile communication device's antenna efficiency.
For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which:
While the specification concludes with claims defining features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the description in conjunction with the drawings. As required, detailed embodiments are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ embodiments in virtually any appropriately detailed structure. Further the terms and phrases used herein are not to the intended to be limiting but rather to provide an understandable description of the invention.
What is needed is a system and method for a mobile communication device that determines the type of housing material installed on the mobile communication device so that the circuitry of the mobile communication device can retune the antennas according to the housing material and thereby maintain antenna transmit and receive efficiency.
A mobile communication device is provided that has a housing with a front housing portion and a rear housing portion. The rear housing portion is made of a material that affects the efficient operation of a mobile communication device antenna when transmitting or receiving different frequencies. The rear housing portion includes an actuator configuration adapted to be sensed by an actuator sensor within the mobile communication device when the rear and front housing portions are assembled. The actuator configuration provides an indication of the particular material of which the rear housing portion is constructed. Upon sensing the actuator configuration the mobile communication device is configured to tune the antenna to operate efficiently at the frequency band of operation when proximate to the rear housing portion.
A wireless communication device for use with the wireless communication system in accordance with this disclosure may be a portable, handheld or mobile telephone or smart phone, a Personal Digital Assistant (PDA), a portable computer, portable television and/or similar mobile device or other similar communication device. In the following description, the communication device will be referred to generally as a UE (User Equipment) for illustrative purposes and as such is not intended to limit the disclosure to any particular type of wireless communication device.
Exemplary embodiments provide a system and method that enables the UE to determine the housing material of the UE so as to adjust or tune the transmit or receive antennas to operate more efficiently in each transmit or receive band used by the UE transceiver.
The processor 118 is connected to the transceiver circuit to provide a wide variety of control signals, data and other electrical connections. In this embodiment the processor 118 provides, among other things, a tuning signal or tuning offset signal that is ultimately used by the antenna tuner circuit for tuning the antenna for the transmit or receive frequency band based on the particular material or material composition of the rear housing portion 112. The processor 118 is connected to an actuator sensor 120. Actuator sensor 120 is configured such that when the rear housing portion 112 is connected to the front housing 110, thereby completing the housing assembly of the UE 100, the actuator configuration 122 is sensed by the actuator sensor 120. The actuator sensor 120 thereby provides an actuator sensor signal 124 that can be read by the processor 118. The processor 118 utilizes the actuator sensor signal 124 to recognize the type of material used to make the rear housing portion 112. In this embodiment the actuator configuration 122 is a physical structure or feature positioned on the inside of the rear housing 126 and aligned to interact with or be sensed by the actuator sensor 120, which is positioned on the inside of the front housing 110. In some embodiments the actuator sensor 120 may be configured or positioned on a surface of a printed circuit board (PCB) mounted on the inside of the front housing 110.
Referring now to
It is understood that in some embodiments the rear housing portion 210 may not entirely cover the backside of the UE. More particularly, in some embodiments the rear housing portion 210 may partially cover the backside of the UE and/or be positioned to cover an area of the housing proximate to the antenna that the transceiver transmits or receives radiofrequency signals on.
Additionally, in some embodiments a user of the UE may or may not be able to remove the rear housing portion 210 and exchange it with another rear housing portion made of a different material. In some embodiments the UE determines the rear cover portion material composition when the phone is first turned on. While in alternate embodiments the UE checks every time it is power cycled and/or periodically to determine whether a present rear housing portion has been exchanged for another rear housing portion that is made of a different material.
Additionally, in various embodiments the actuator configuration may be comprised of a variety of physical shapes or materials that are used to actuate the switch or switches that make up the actuator sensor. For example, the actuator configuration/actuator sensor combination may comprise one or more magnets/and magnetic switches, carbon pills/and resistive switches, capacitance sources/and capacitive sensors, posts/and optical readers, raised portions and switch pads or reflowed mechanical switches, etc. Additionally, the actuator sensor may be located on a PCB, micro circuit or other reasonable facsimile thereof as shown in
Upon sensing the actuator configuration 506, the actuator sensor 508 provides an actuator sensor signal 510 to the processor 512. The processor 512 reads the actuator sensor signal 510 and uses it to determine an appropriate tuning signal(s) to provide to an antenna tuner circuit 516. In some embodiments the processor 512 uses the actuator sensor signal 510 to lookup in a tuner state database 517 the housing material type. As shown in
The tuning signal 514 is provided from the processor 512 to the antenna tuning circuit 516 and received by one or more digital to analog (D/A) converters 522, which convert the tuning signal 514 into appropriate voltages that adjust the impedance of the variable capacitors C1 and C2. The adjustment of the variable capacitors C1 and C2 set the impedance of the antenna tuner circuit 516 so that the antenna 504 is tuned (i.e., impedance matched) with the transceiver 520 for the particular frequency band and the particular housing material 502. Each time the frequency band of the transceiver 520 changes, the processor 512 will provide the appropriate tuning signal 514 to the tuning circuit 516 so that the antenna is properly tuned for both the changed frequency band being used by the UE and the particular housing material on the UE.
The tuning signal 514 provided by the processor is usually a digital signal, which in some embodiments is received by the antenna tuning circuit 516 and decoded to determine voltages to be provided to one or more variable capacitors, such as capacitors C1 and C2. In other embodiments the digital signal provided by the processor 512 is received by a D/A converter 522 within or outside of the antenna tuner circuit 516. The D/A converter 522 converts the digital tuning signal 514 to appropriate voltage values which are received by the capacitive tuners C1 and C2. The capacitive tuners C1 and C2 may be barium strontium titanate (BST) tunable capacitors, micro-electro-mechanical systems (MEMS) tunable capacitors, field effect transistor (FET) tunable capacitors, or other known or created tunable impedance circuits.
Additionally as shown in the tuner state database 517 of
Described another way,
In some embodiments, the impedance of the antenna tuning circuit 516 is set by adjusting one or more tunable capacitors, for example C1 and/or C2. The impedance is set such that the antenna 504 operating proximate to the housing material 502 will closely match the impedance of the transceiver 520 operating at a selected or particular frequency band. In various embodiments the tuner state database 517 is stored within a memory device, which can be read by the processor 512. The processor uses the actuator sensor signal 510 and the operating frequency of the transceiver 522 select an appropriate tuning state (i.e., tuning signal 514) from the data base 517 to provide to the antenna tuner circuit 516. Each time the transceiver 520 changes its operating frequency band, the processor 512 accesses and reads the tuner state database 512 to retrieve the appropriate tuning signal 514 to provide to the antenna tuner circuit 516 for the particular housing material and frequency band.
Referring now to
At step 706, after the material type or actuator sensor signal is read by the processor, the processor may determine the particular material, from a plurality of materials, which the UE housing is composed of or the particular material on a portion of the UE housing that is proximate to an antenna contained within the UE housing. At step 708, the processor retrieves a tuning signal from the tuner state database. The tuner state database is stored within a memory device of the UE. At step 710, the processor provides the tuning signal to an antenna tuner circuit. The tuning signal is one of a plurality of predetermined tuning signals that are available in the database for each particular housing material type and frequency band combination that may be used by the UE transceiver. In some embodiments, the tuning signal is a binary signal provided to the antenna tuner circuit. In other embodiments the tuning signal is provided to a digital to analog converter, which in turn provides predetermined voltages to the tuning capacitors (or other tunable impedance devices) in the tuning circuit to tune the antenna such that the impedance between the transceiver and the antenna for the particular frequency is matched for the particular housing material that is proximate to the antenna.
At step 712, the processor may periodically check the actuator sensor state to determine if the housing portion that is proximate to the antenna has been changed with another housing portion that is composed of a different material. If it is determined that the actuator sensor state has changed, then at step 714 the method goes back to step 706. Conversely, if it is determined that the actuator sensor state has not changed, then at step 714 the method loops back to step 712 wherein at some predetermined periodic time period the actuator sensor state is rechecked.
In some embodiments, removal of the factory rear housing cover and exchanging it for a different rear housing cover may set a flag within the microprocessor that voids a UE's warranty. For example, if the original rear housing cover has an actuator configuration of a 1 1, and it is replaced with a rear housing cover that does not have any actuator configuration (i.e., 0 0), then when the processor senses the actuator sensor circuit it will read the 0 0, which will be indicative of a rear cover housing material change. If a rear cover housing material change is sensed, than a warranty void flag can be set and stored within the UE's memory such that if the phone is brought in for repair or warranty work due to a malfunction, the warranty will be invalidated or voided due to the swapping of the original rear cover with another as indicated by reading the warranty status of the warranty void flag by a service technician.
In the foregoing specification, embodiments have been described with reference to specific examples. It will, however, be evident that various modifications and changes may be made therein without departing from the broader scope of the invention as set forth in the appended claims. For example, although the actuator configuration is described as being on the inside of the rear housing portion, instead the actuator sensors may be on the inside of the rear housing portion such that different number of sensors is provided depending on the particular material that the rear housing portion is constructed. The front housing material composition or type may also be detected by a similar means and technique.
Some of the above embodiments, as applicable, may be implemented using a variety of different processing systems. For example, the Figures and the discussion thereof describe an exemplary architecture and method which is presented merely to provide a useful reference in discussing various aspects of the disclosure. Of course, the description of the architecture and method has been simplified for purposes of discussion, and is just one of many different types of appropriate architectures and methods that may be used in accordance with the disclosure. Those skilled in the art will recognize that the boundaries between program, electronic and physical elements are merely illustrative and that alternative embodiments may merge elements or impose an alternate compositions or decompositions of functionality upon various elements. Although the preferred embodiment has been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
