Abstract:
A wireless mobile station comprising: 1) an RF transceiver that up-converts a baseband signal to produce an output RF signal; 2) an antenna coupled to the RF transceiver for transmitting the output RF signal; 3) a power supply that supplies power to the RF transceiver; and 4) switching circuitry associated with the antenna that provides a first conduction path between the power supply and the RF transceiver, such that when the antenna is in a first position, the first conduction path is closed and power is supplied to the RF transceiver from the power supply and when the antenna is translated to a second position, the first conduction path is opened and the power is not supplied to the RF transceiver from the power supply.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention is directed, in general, to wireless mobile devices and, more specifically, to an apparatus that visibly disables the RF transmitter circuitry of a wireless mobile device. 
     BACKGROUND OF THE INVENTION 
     There are several hundred million users of wireless mobile devices, including cellular telephones, in the world today. Competition, improved technology, and the building of a large wireless infrastructure have made wireless service widely available, while driving the price of wireless service down to the point where it is affordable to a large segment of the world population. 
     The previous generation of cellular phones were used primarily for voice conversations between a subscriber using a wireless mobile station (i.e., a cell phone) and another party. Increasingly, however, wireless mobile stations are data processing devices, such as personal digital assistant (PDA) systems equipped with cellular/wireless modems. These wireless PDA systems include a variety of handheld computers made by Palm, Inc., Compaq Corporation, Handspring, Inc., and others. The wireless PDA systems are used for web-browser applications, e-mail applications, remote network access, interactive games, and the like. More recently, wireless mobile stations have been introduced into the marketplace that are combination devices that operate both as a cell phone and as a data processing device. 
     The widespread use of wireless mobile devices has not been without its drawbacks, however. Many environments are not suitable for the use of wireless mobile stations. For example, there has been a great deal of concern that wireless mobile stations, primarily cell phones, may interfere with the avionic systems on aircraft. This has lead to a ban on the use of cell phones and other wireless mobile devices (e.g. Palm VII™) on aircraft. Cell phones also have been banned in movie theaters, symphony halls, hospitals, and similar places where the ringing of a cell phone may be a distraction or annoyance. 
     However, many wireless mobile stations also operate in a stand-alone mode in which an application that does not require a wireless capability may be executed. For example, a passenger on an airplane may wish to play a video game on a cell phone or may wish to view his or her appointment calendar when running a personal organizer application on a wireless PDA. The passenger cannot do this, however, if the use of cell phones or wireless PDA devices is prohibited on the plane. Many cell phones and other wireless PDA devices automatically try to establish radio frequency (RF) connections as soon as the devices are turned ON. This is true even if the users do not require RF connections. In attempting to access a local wireless network, these devices transmit RF signals, even if there is no wireless network in the area. In other wireless PDA devices, an RF connection is not automatically established when the device is turned ON, but only in response to a user command. However, there is no way for a flight crew member or a theater operator to simply glance at such a wireless PDA in order to determine that the PDA device is not transmitting or receiving RF signals. The end result is that a total ban on wireless mobile stations of all varieties is generally enforced, without regard to whether or not the wireless mobile stations are transmitting RF power. 
     Therefore, there is a need for a wireless mobile station in which RF power may be disabled in a highly visible and unambiguous manner so that applications that do not require an RF connection may be executed on the wireless mobile station. 
     SUMMARY OF THE INVENTION 
     To address the needs described above, it is a primary object of the present invention to provide a wireless mobile station in which the antenna may be physically translated or even removed in order to disable the power supplied to the internal RF transceiver. The removal of power from the RF transceiver thereby prevents the generation and transmission of any radio frequency (RF) signals. 
     According to a first advantageous embodiment of the present invention, the wireless mobile station comprises: 1) an RF transceiver capable of up-converting a baseband signal to produce an output RF signal; 2) an antenna coupled to the RF transceiver for transmitting the output RF signal; 3) a power supply capable of supplying power to the RF transceiver; and 4) switching circuitry associated with the antenna capable of providing a first conduction path between the power supply and the RF transceiver, such that when the antenna is in a first position, the first conduction path is closed and power is supplied to the RF transceiver from the power supply and when the antenna is translated to a second position, the first conduction path is opened and the power is not supplied to the RF transceiver from the power supply. 
     According to one embodiment of the present invention, translation of the antenna to the second position is highly visible to an observer. 
     According to another embodiment of the present invention, the switch circuitry provides a second conduction path between the power supply and an indicator lamp, such that when the antenna is in the first position, the second conduction path is closed and power is not supplied to the indicator lamp and when the antenna is translated to the second position, the second conduction path is opened and power is supplied to the indicator lamp, thereby illuminating the indicator lamp. 
     According to still another embodiment of the present invention, the indicator lamp produces a bright fluorescent light. 
     According to a second advantageous embodiment of the present invention, the wireless mobile station comprises: 1) an RF transceiver capable of up-converting a baseband signal to produce an output RF signal; 2) a removable antenna coupled to the RF transceiver for transmitting the output RF signal; 3) a power supply capable of supplying power to the RF transceiver; and 4) switching circuitry associated with the removable antenna for providing a first conduction path between the power supply and the RF transceiver, such that when the removable antenna is connected to the wireless mobile station, the first conduction path is closed and power is supplied to the RF transceiver from the power supply and when the antenna is disconnected from the wireless mobile station, the first conduction path is opened and the power is not supplied to the RF transceiver from the power supply. 
     According to yet another embodiment of the present invention, disconnection of the removable antenna from the wireless mobile station is highly visible to an observer. 
     In one embodiment of the present invention, the switch circuitry provides a second conduction path between the power supply and an indicator lamp, such that when the removable antenna is connected to the wireless mobile station, the second conduction path is closed and power is not supplied to the indicator lamp and when the removable antenna is not connected to the wireless mobile station, the second conduction path is opened and power is supplied to the indicator lamp, thereby illuminating the indicator lamp. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form. 
     Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, wherein like numbers designate like objects, and in which: 
         FIG. 1  illustrates an exemplary wireless mobile station embodying the principles of the present invention according to a first embodiment; and 
         FIG. 2  illustrates selected portions of the exemplary wireless mobile station according to a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 and 2 , discussed below, and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitably arranged wireless mobile station. 
       FIG. 1  illustrates exemplary wireless mobile station  100  according to a first embodiment of the present invention. Wireless mobile station  100  comprises antenna  105 , radio frequency (RF) transceiver  110 , transmitter (TX) processing circuitry  115 , microphone  120 , receiver (RX) processor circuitry  125 , speaker  130 , battery  135 , main controller  140 , input/output (I/O) interface (IF)  145 , keypad  150 , display  155 , resistor  180  and NO RF indicator lamp  185 . Wireless mobile station  100  further comprises memory  170 , which stores basic operating system (OS) program  171 , one or more RF application program(s)  172 , and one or more non-RF application programs  173 . Wireless mobile station  100  may be a cell phone, a personal digital assistant (PDA) device equipped with a wireless modem, a two-way pager, a personal communication system (PCS) device, or any other conventional wireless mobile system. 
     Main controller  140  executes basic OS program  171  in order to control the overall operation of wireless mobile station  100 . Main controller  140  controls the reception of forward channel signals and the transmission of reverse channel signals by RF transceiver  110  in accordance with well-known principles. Main controller  140  is also coupled to I/O interface  145 , keypad  150  and display unit  155 . Main controller  140  controls the transmission of signals to and from these elements with methods well known in the art. 
     RF transceiver  110  receives from antenna  105  an incoming RF signal transmitted by a base station of a wireless communication network, such as a cellular phone network. RF transceiver  110  down-converts the incoming RF signal to produce an intermediate frequency (IF) or a baseband signal. The IF or baseband signal is sent to RX processing circuitry  125  which produces a processed baseband signal by filtering, decoding, and/or digitizing the baseband or IF signal to produce a processed baseband. RX processing circuitry  125  transmits the processed baseband signal to speaker  130  (i.e., voice data) or to main controller  140  for further processing (i.e., web data, interactive video game data). 
     TX processing circuitry  115  receives analog or digital voice data from microphone  120  or other outgoing baseband data (i.e., web data, e-mail interactive video game data) from main controller  140  baseband and encodes, multiplexes, and/or digitizes the outgoing baseband data to produce a processed baseband or IF signal. RF transceiver  110  receives the outgoing processed baseband or IF signal from TX processing circuitry  115  and up-converts it to an RF signal that is transmitted via antenna  105 . 
     As the contents of memory  170  indicate, exemplary wireless mobile station  100  is capable of executing both RF applications  172  and non-RF applications  173 . RF applications  172  may include a wireless web browsing application, an interactive video game application, a cellular telephone control program, transmitting or receiving e-mail, and the like. Non-RF applications  173  may include a non-interactive video game, such as solitaire, a calendar application, a spread sheet application, viewing old e-mail stored in an In Box, and the like. According to the principles of the present invention, when exemplary wireless mobile station  100  is being used in an airplane or other environment in which the transmission of RF signals is prohibited, wireless mobile station  100  is capable of executing non-RF applications  173  while indicating to observers (e.g., flight crew) in a highly visible manner that no RF signals are being transmitted. According to an advantageous embodiment of the present invention, antenna  105  may be removed from exemplary wireless mobile station  100  and, when removed, disables the power supplied to RF transceiver  110 . The removal of power from RF transceiver  110  thereby prevents the generation and transmission of any radio frequency (RF) signals. 
     Antenna  105  comprises conductor  191 , which transmits and receives RF signals when antenna  105  is inserted into wireless mobile station  100 . Antenna  105  also comprises conductor  193  and conductor  196 . When antenna  105  is properly inserted in wireless mobile station  100 , conductor  191  is connected to conductor  190 , which is the output line for RF transceiver  110 . Also, when antenna  105  is properly inserted, conductor  193  is connected to conductors  192  and  194 , and conductor  196  is connected to conductors  195  and  197 . 
     Thus, with antenna  105  properly inserted, conductors  195 ,  196  and  197  connect RF transceiver  110  directly to battery  135 , thereby providing power to RF transceiver  110  and permitting wireless mobile station  100  to transmit RF signals. Also, with antenna  105  properly inserted, conductors  192 ,  193 , and  194  connect both terminals of NO RF indicator lamp  185  to ground. With both terminals grounded, no current flows in NO RF indicator lamp  185 , preventing it from lighting. Resistor  180  protects battery  135  from shorting to ground. 
     However, if antenna  105  is removed, conductor  196  is removed and open-circuits the connection between conductors  195  and  197 . This disconnects RF transceiver  110  from battery  135 , thereby disabling power to RF transceiver  110  and preventing wireless mobile station  100  from transmitting RF signals. Also, with antenna  105  removed, conductor  193  is removed and open-circuits the connection between conductors  192  and  194 . This allows current to flow from battery  135  through resistor  180  and through NO RF indicator lamp  185  to ground. The current flow in NO RF indicator lamp  185  causes NO RF indicator lamp  185  to light. 
     According to an exemplary embodiment of the present invention, NO RF indicator lamp  185  is a highly visible colored lamp, such as a bright fluorescent orange, yellow or lime green color, with the legend “NO RF” printed thereon in black lettering. Thus, wireless mobile station  100  provides two highly visible indicators to passersby that wireless mobile station  100  is not transmitting RF signals. First, the absence of antenna  105  indicates that RF signals have been disabled. Second, the bright glow of NO RF indicator lamp  185  also indicates that RF signals have been disabled. Thus, after removing antenna  105 , the operator can use wireless mobile station  100  to perform non-RF application(s)  173 . 
       FIG. 2  illustrates selected portions of exemplary wireless mobile station  100  according to a second embodiment of the present invention. It is not strictly necessary that antenna  105  in  FIG. 1  be removed from wireless mobile station  100  in order to provide a highly visible indicator that RF power has been disabled. 
     In alternate embodiments of the present invention, antenna  105  may be used to open-circuit conductors  193  and  196  by being rotated 90 degrees about the vertical axis, by being partially withdrawn from wireless mobile station  100 , by being depressed into wireless mobile station  100 , or by being translated from a first position to a second position in some other manner. 
     In the example illustrated in  FIG. 2 , antenna  205  comprises a lower antenna portion  205 A and an upper antenna portion  205 B. Lower antenna portion  205 A and upper antenna portion  205 B are rotatably coupled at pivot  210 . Conductor  291  in antenna  205  is connected to pivot  210 , which acts like a pulley as upper antenna portion  205 B is rotated between a vertical position and a horizontal position. Rotating upper antenna portion  205 B raises and lowers conductors  291 ,  293  and  296 , as indicated by the directional arrows. 
     Thus, conductor  291  is connected to conductor  290  (and RF transceiver  110 ) when antenna portion  205 B is in the vertical position. When antenna portion  205 B is in the vertical position, conductor  293  connects conductors  292  and  294 , similar to conductors  192 ,  193  and  194  in  FIG. 1 . When antenna portion  205 B is in the vertical position, conductor  296  connects conductors  295  and  297 , also similar to conductors  195 ,  196  and  197  in  FIG. 1 . Thus, rotating antenna portion  205 B has the same effect of enabling and disabling RF power and switching NO RF indicator lamp  185  ON and OFF as the removal and insertion of antenna  105  in  FIG. 1 . 
     Again, wireless mobile station  100  provides two highly visible indicators to passersby that wireless mobile station  100  is not transmitting RF signals. First, the horizontal rotation of upper antenna portion  205 B indicates that RF signals have been disabled. Second, the bright glow of NO RF indicator lamp  185  also indicates that RF signals have been disabled. 
     Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form.