Abstract:
A device for providing wireless communication is disclosed. The device includes a retractable antenna connected to modem and PC card. The retractable antenna has a locking mechanism for providing a snap lock to maintain the antenna in the extended position during ordinary use and allowing retraction of the antenna by force when not in use. The retractable antenna has an antenna sleeve which receives the antenna and locks the antenna in the extended position. The antenna also has a pivotal connection for pivoting the antenna and a rotatable connection for rotating the antenna in a direction which differs from the direction of rotation. The antenna is rotatable about two axes and is retractable. In the extended position, the antenna is electrically connected with the PC card and can receive and transmit signals.

Description:
Typically, a PCMCIA wireless modem card has an antenna which transmits and receives signals. The overall performance of the antenna is a function of the length of the antenna. If the antenna is extended and then rotated or pushed back into the PC card rather than in full extension, the performance of the modem card is compromised. 
     Accordingly, what is needed is an antenna for use with a PCMCIA card which locks into place when the antenna is fully extended maximizing the receiving and transmitting capability of the modem and allowing the antenna to retract when not in use. 
     SUMMARY 
     A retractable antenna device is disclosed that is used with a personal computer to provide wireless communication. 
     In accordance with one aspect of the present invention, a device for providing wireless communications includes a PC card, a modem within the PC card, a retractable antenna connected to the modem, the retractable antenna having an extended transmitting/receiving position and a retracted position with respect to the PC card, and a locking mechanism for providing a lock to maintain the antenna in the extended position during ordinary use and retraction of the antenna when not in use. 
     In accordance with another aspect of the present invention, a retractable antenna for a PC card for use in wireless communication includes an antenna sleeve electrically connectable to the PC card, a retractable antenna positioned within the antenna sleeve and slidable within the antenna sleeve from an extended transmitting/receiving position to a retracted storage position, and a locking mechanism provided between the antenna sleeve and the retractable antenna for locking the antenna in the extended transmitting/receiving position to achieve a predetermined transmitting/receiving antenna length. 
     In one more detailed aspect of the invention, the PCMCIA card will transmit and receive radio signals in the 1850 to 1990 megahertz ranges. 
     In another detailed aspect of the invention, the retractable antenna has a pivotable connection for pivoting the antenna about a first axis and a rotatable connection for rotating the antenna in direction which differs from the direction of pivot of the pivotal connection. 
     The foregoing and other advantages of the present invention will become more apparent from following description and accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described in greater detail with reference to the preferred embodiments illustrated in the accompanying drawings, in which like elements bear like reference numerals, and wherein: 
     FIG. 1 is a perspective view of an antenna mounted to a PC card which is connected with a personal computer in accordance with one embodiment of the present invention; 
     FIG. 2 is a perspective view of the PC card with the antenna shown in a retracted and an extended position; 
     FIG. 3 is a perspective view of a snap lock for the antenna of FIG. 1 illustrating an antenna body and an antenna sleeve with the antenna body in a retracted position; 
     FIG. 4 is a side cross sectional view of the snap lock of FIG. 3 in an extended position showing the antenna body and antenna sleeve in the extended and locked position; 
     FIG. 5 is a perspective view of the PC card illustrating the rotation of the antenna about the X-axis and about a pivotal connection; 
     FIG. 6 is a perspective view of an inside surface of a top portion of the PC card with the antenna; and 
     FIG. 7 is a perspective view of an inside surface of a bottom portion of the PC card with the antenna. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 shows one embodiment of a device  10  which provides for wireless communication. The device  10  includes a receive/transmit antenna  12  connected to the base of a PC card  14  which may include a modem or a radio. The PC card  14  plugs into a PCMCIA slot  16  of a personal computer  18  and enables a user to communicate with a wireless system using an air interface. Preferably, the computer card  14  plugs into a PCMCIA type II slot, however, the card may also be designed to be received in other slots. 
     The antenna  12  as illustrated in FIG. 1 has a retracted position and an extended position. As shown in FIG. 2, the antenna  12  can reciprocally move between the retracted position and the extended position, shown in phantom lines as  12 ′, in a direction of arrow A. In the retracted position, the antenna  12  is substantially received by the PC card  14 . In the extended position, the antenna  12 ′ substantially extends beyond the PC card  14 . 
     The overall performance of the antenna is a function of the length of the antenna. If the antenna is extended and then rotated or pushed back into the PC card, the performance of the modem card is compromised. In order to avoid the variable length of the antenna, what is needed is an antenna which locks into place when fully extended providing maximum performance of the PCMCIA card. 
     FIGS. 3 and 4 illustrate the antenna  12  including an antenna body  20  having a pivotal connection  30 . The antenna body  20  is slidable longitudinally within an antenna sleeve  22 . The antenna body  20  has a raised portion  24  on the proximal end with an outer diameter greater than the inside diameter of the antenna sleeve  22 . Adjacent the raised portion  24  is an annular recessed portion or locking groove  25 . Four axial slots  26  on the antenna body  20  form four fingers  21  and allow the antenna body  20  to be squeezed into the antenna sleeve  22 . The antenna sleeve  22  has a neck  28  on the proximal end that is ring shaped with an inner diameter smaller than the inside diameter of a remainder of the sleeve. The neck  28  of the sleeve  22  snaps into a locking groove  25  of the antenna body  20  when the antenna is in the extended and locked position. 
     FIG. 4 is a cross-sectional view of the antenna body  20  and antenna sleeve  22  in the locked position where the four fingers  21  on the antenna body have been squeezed into the antenna sleeve and the neck  28  is snapped into the locking groove  25 . 
     FIG. 5 illustrates one embodiment of the antenna  12 , which pivotally rotates about a pivotal connection  30  from the extended position of FIG. 2, shown in phantom lines as  12 ′, to a raised position where the antenna has been moved in a direction of arrow B. The pivotal connection  30  enables a user to adjust the position of the antenna  12  with respect to the PC card  14 . The pivotal connection  30  may comprise any suitable means including, but not limited to, a hinge, such as a tongue-in-groove hinge. The pivotal connection  30  allows the antenna  12  to pivot about an axis of the pivotal connection. Moreover, the antenna  12  is rotatable within the sleeve  22 , and, therefore, has a rotatable connection for rotating the antenna about an X-axis. Therefore, the antenna  12  can move from the lifted position shown in solid lines to a lowered position, shown in phantom lines as  12 ″, when the antenna is moved in the direction of arrow C. Accordingly, when the antenna  12 ′ is in the extended position, the antenna has multiple axes of rotation. In particular, the antenna  12  can pivot about the pivotal connection  30  and can rotate about the X axis so that the antenna may be moved into the most appropriate position to maximize the effectiveness of use. 
     In a preferred embodiment, the matching circuit comprises an inductor/capacitor (LC) circuit. The connection of the antenna to the electronics of the PC card will be further described below. 
     FIGS. 5-7 illustrate one embodiment of the PC card  14 . In this configuration, the PC card  14  includes a top portion  46 , a bottom portion  48  which is attachable to the top portion, electrical components which are entirely enclosed by the top and bottom portions, and channel portions  50  located in the top and bottom portions. Also, shown is a PCMCIA connector  52 . FIG. 6 shows the top portion  46  having corresponding openings  58 , which receive the alignment pins  54  when the top and bottom portion  46 ,  48  are attached to form a housing  60  for the PC card  14 . FIG. 7 illustrates the bottom portion  48  of the PC card  14  having at least one alignment pin  54  which extends from an inside surface  56  of the bottom portion. (FIG. 7 shows three alignment pins) 
     Preferably, the top and bottom outside surfaces  62 ,  64  of the top and bottom portions  46 ,  48  are substantially coated with a conductive material to provide shielding for the electrical components located inside the PC card  14 . The top and bottom portion  46 ,  48  are preferably otherwise formed of plastic. As best shown in FIG. 7, a cut out portion  76  is provided in the top and bottom outside surfaces  72 ,  74  adjacent to the sleeve  22 , which supports the antenna  12  when the antenna is extended. The cut out portion  76  electrically separates the conductive shielding material and the sleeve  22 . In an alternative embodiment, the inside surfaces  56 ,  60  of the top and bottom portions  46 ,  48  are coated with a conductive material to provide good shielding for the electrical components located inside the PC card  14 . 
     The passage  78  in the sleeve  22  is configured to slidably receive the antenna  12 . Preferably, there is a friction fit between the outer diameter of the antenna portion  32  and the inner diameter of the passage  78  to provide an electrical connection between the antenna  12  and the sleeve  22  and to provide a rotational connection between the antenna and the card. When the antenna  12  is in the extended position, the antenna portion  32  snaps into the sleeve  22 . The end cap  38  mounted at the distal end  40  of the antenna portion  36  has an outer diameter larger than the inner diameter of the passage  78  of the sleeve  22 . The end cap  38  prevents further insertion of the antenna  12  into the PC card  14  beyond a predetermined distance. Moreover, the end cap  38  provides a means for the user to grasp and reciprocally move the antenna  12  between the retracted position and the extended position. 
     A conductive member  82  is provided in the PC card  14  adjacent to the sleeve  22 . The conductive member  82  is connected to electrical components enclosed in the PC card  14 . The conductive member  82  may comprise any suitable means including, but not limited to, a torsion spring, a leaf spring, or a cantilever member. 
     In operation, the device functions to receive and transmit electrical signals to and from the PC card  14 . When the antenna  12  is in the retracted position, the channel portions  50  of the PC card  14  substantially receive the antenna. Further, the antenna portion  36 , covered or wrapped with a nonconductive material, is adjacent to the sleeve  22 . The antenna  12  does not have electrical connection with the antenna sleeve  22  when in the retracted position. By slidably moving the antenna  12  from the retracted position to the extended position, the antenna portion  32 , formed of a conductive material, contacts the sleeve  22 , wherein a signal can be transmitted from electrical components enclosed in the PC card  14  through the conductive member  82  to the sleeve  22  and then to the antenna  12 . As discussed, the antenna  12  can pivot about the pivotal connection  30  and can rotate about the X-axis so that the antenna may be moved into the most appropriate position to maximize the effectiveness of use. 
     The length of the antenna in the locked and fully extended position is a function of the PCMCIA card&#39;s operating frequency. The operating frequency of a PCMCIA card is the number of cycles in which a radio wave is transmitted and received. The frequency is measured in hertz. One hertz is equal to one cycle per second. The relationship between a radio signal&#39;s frequency and its wavelength in meters is calculated using the formula: 
     
       
         Wavelength (m)=300/frequency 
       
     
     In one embodiment the PCMCIA card will transmit and receive a radio signal in the 1850 to 1990 megahertz ranges. As such, the length of the antenna in one embodiment would be one half of a wavelength based on the operating frequency calculated in wavelengths or 0.08 to 0.075 meters. If the frequency of the PCMCIA card is 800 to 900 megahertz, the length of the antenna is 0.375 to 0.333 meters. Thus, in a preferred embodiment, the length of the antenna will be a fraction of a wavelength which maximizes performance of the antenna. 
     The antenna preferably can be extended or retracted between the locked and unlocked position with a force of between 250 and 850 grams. In other words, a force of at least 250 grams is required to disengage the snap lock provided by the neck  28  and the locking groove  25 . 
     The locking retractable antenna for use with a PCMCIA card is designed to lock into place when the antenna  12  is fully extended maximizing the receiving and transmitting capability of the modem. Furthermore, in the retracted position the antenna  12  is substantially received by the PCMCIA card. 
     The PC card  14  shown in the figures is a PCMCIA Type II card, but it is within the scope of the invention to use a PCMCIA Type I or Type III card, as well. Likewise, it is within the scope of the invention that the PC card  14  can be any of a variety of removable cards that are not restricted to the PCMCIA standard specifications. 
     While the invention has been described in detail with reference to the preferred embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made and equivalents employed without departing from the present invention.