Abstract:
Disclosed is a wireless transmitting and receiving antenna which comprises a bobbin made of insulation material and having a first penetration cavity in the center of the bobbin in a lengthwise direction; a first antenna comprising a helical conductor spirally wound on the bobbin and having a resonance frequency, and a matching bar inserted into the cavity of the bobbin, made of a conductor and providing a second penetration cavity in the direction identical with that of the first penetration cavity; a feeder positioned at one part of the bobbin so as to supply signals to the helical conductor; and a second antenna comprising: a rod inserted into the penetration cavities of the bobbin and the matching bar, moving between the penetration cavities in a slipping manner, and wrapped with the insulation material; a conduction material combined to the outer part of the rod, and electrically connecting the feeder and the helical conductor when the rod is inserted into the penetration cavities; and a stopper which is made of a conductor, positioned at the lower part of the rod, and when the rod. is drawn Afro, the penetration cavity, the moving of the stopper is limited, and it is contacted to the feeder so as to supply signals to the rod.

Description:
BACKGROUND OF THE INVENTION 
     (a) Field of the Invention 
     The present invention relates to an antenna for transmitting and receiving radio frequencies. More specifically, the present invention relates to an antenna for transmitting and receiving radio frequencies so as to be used for a mobile communication terminal that operates in two frequency bands and to easily set resonance points. 
     (b) Description of the Related Art 
     Present mobile communication services share identical frequency bands by differing modulation methods or use different frequency bands like the case of cellular phones that operate at 824 to 894 MHz and personal communication services (PCS) that operate at 1.75 to 1.87 GHz. 
     Conventional antennas that use the above-noted frequency bands comprise helical antennas which are installed on an upper part, of portable wireless devices and on which a helical conductor is wound, and whip antennas which penetrate the helical antennas. In the case the whip antenna is withdrawn from the helical antenna, the whip conventional antenna is used after being connected to the helical antenna. 
     When the resonance points are needed to be set, a gap of the helical conductor of the helical antenna is varied or a diameter of the helical antenna is sequentially varied. 
     Since it is difficult to set the resonance points of the resonance frequency and it is not easy to assemble the helical conductor to which the resonance point is already set, precision degrees and productivity are decreased. 
     When withdrawing the whip antenna from the helical antenna and using the whip antenna, since the whip antenna is electrically connected to the helical antenna, the performance of the whip antenna becomes lower because of a coupling effect. 
     Also, conventional feeding is performed after a feeder and a part of the helical conductor are contacted, and since this configuration has a small contact area with the feeder, electrical signals may not be stably supplied because of contact problems. In particular, this configuration can be a problem in that a small outer shock generates a short state between the feeder and the helical conductor. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a wireless transmitting and receiving antenna for quickly and accurately setting the resonance point of the resonance frequency using a simple technical configuration so as to increase productivity, setting the resonance point of a wide resonance frequency band, and electrically separating the whip antenna and the helical antenna so as to not influence the helical antenna when the whip antenna is withdrawn from the helical antenna and used. 
     In one aspect of the present invention, a wireless transmitting and receiving antenna comprises a bobbin of insulation material; a helical conductor spirally wound on the bobbin; a matching bar inserted into a cavity of the bobbin, maintaining a predetermined gap with the helical conductor and setting a resonance point; and a feeder supplying signals to the helical conductor. 
     The matching bar is made of a conductor, is cylindrical, and has a cavity in the center of the matching bar in a lengthwise direction. 
     The bobbin is manufactured according to a molding process while the matching bar is inserted into the bobbin. 
     In another aspect of the present invention, a wireless transmitting and receiving antenna comprises a bobbin made of insulation material and having a first penetration cavity in the center of the bobbin in a lengthwise direction; a first antenna comprising a helical conductor spirally wound on the bobbin and having a resonance frequency, and a matching bar inserted into the cavity of the bobbin, made of a. conductor and. providing a, second penetration cavity. in the direction identical with that of the first penetration cavity, a feeder positioned at one part of the bobbin so as to supply signals to the helical conductor, and a second antenna comprising: a rod inserted into the penetration cavities of the bobbin and the matching bar, moving between the penetration cavities in a slipping manner, and wrapped with the insulation material; a conduction material combined with the outer part of the rod, and electrically connecting the feeder and the helical conductor when the rod is inserted into the penetration cavities; and a stopper which is made of a conductor, is positioned at the lower part of the rod so that when the rod is withdrawn from the penetration cavity the movement of the stopper is limited, and is contacted to the feeder so as to supply signals to the rod. 
     There is provided an insulation pad for disconnecting the electrical contact between the first and second antennas when the first antenna is drawn from the second antenna. 
     In a further aspect of the present invention, a wireless transmitting and receiving antenna comprises a bobbin made of insulation material and having a first penetration cavity in the center of the bobbin in the lengthwise direction; a first antenna comprising a helical conductor spirally wound on the bobbin and having a resonance frequency, and a matching bar inserted into the cavity of the bobbin, made of a conductor and providing a second penetration cavity in the direction identical with that of the first penetration cavity; a feeder insulated with the helical conductor, combined to an lower part of the bobbin, providing a third penetration cavity in the direction identical with that of the first penetration cavity, and contacting the matching bar so as to supply electrical signals, and a tension spring wherein a second antenna comprising a rod is inserted into the penetration cavities of the bobbin and the matching bar, moving in the penetration cavities in a slipping manner, being wrapped with the insulation material, comprising a cap and a conductive stopper for limiting the movements in the upward and downward directions, with the tension spring maintaining a predetermined position after the second antenna is moved and being made of a conductor. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, serve to explain the principles of the invention: 
     FIG. 1 shows an antenna according to a preferred embodiment of the present invention; 
     FIG. 2 shows a matching bar of FIG. 1; 
     FIG. 3 shows a magnified A part of FIG. 1; 
     FIG. 4 shows a whip antenna outwardly extended; 
     FIG. 5 shows a second preferred embodiment of the present invention; 
     FIG. 6 shows a third preferred embodiment of the present invention; 
     FIG. 7 shows a preferred embodiment of a feeder of the present invention; and 
     FIG. 8 shows a collapsed state of the whip antenna of FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following detailed description, only the preferred embodiment of the invention has been shown and described, simply by way of illustration of the best mode contemplated by the inventor(s) of carrying out the invention. As will be realized, the invention is capable of modification in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not restrictive. 
     FIG. 1 shows an antenna for a wireless transmitter and receiver according to a preferred embodiment of the present invention. A whip antenna  3  is provided in a helical antenna  1 . 
     The helical antenna  1  comprises a bobbin  5  which is fixed on an upper part of a portable wireless device (not illustrated), has a predetermined length, and has a cavity in the center part in the vertical direction, and a helical conductor  7  which is wound on the bobbin in a spiral manner. 
     The bobbin  5  is made of a nonconductor, and a matching bar  9  is combined and provided in the inner part of the bobbin  5 . The matching bar  9 , as shown in FIG. 2, has a cavity in the lengthwise direction, and is made of a conductor. When manufacturing the bobbin  5  by a molding process, the matching bar  9  is inserted in the bobbin  5  and they are manufactured as a single unit. 
     The matching bar  9  has a, diameter of R and a length of L, and these values are established according to values of the resonance point to be set in combination with the helical conductor  7 . That is, a value for setting the resonance point of the resonance frequency is previously established, and the diameter and the length of the matching bar  9  are established according to the value. Since a capacitor value for adjusting the resonance point of the resonance frequency is determined according to the diameter and the length, the diameter and the length of the matching bar  9  are established according to the resonance point set by experimental values, and the matching bar  9  is combined with the bobbin  5  according to the above-described method. Outer lower parts of the helical conductor  7  and the bobbin  5  are combined with a first protection substance  11  made of a nonconductor, and a second protection substance  13  made of a nonconductor is combined with the first protection substance  11  and the bobbin  5  so as to wrap the first protection substance  11  and the bobbin  5 . A feeder  15  for providing signals to the helical conductor  7  is provided on a lower part of the first protection substance  11 . The feeder  15  has a cavity that penetrates it in the lengthwise direction. A cylindrical tension spring  17  made of a conductor is provided in the cavity of the feeder  15 . A cylindrical insulation pad  19  is provided between the feeder  15 , the tension spring  17  and the helical conductor  7 . 
     A rod  31  of the whip antenna  3  can be inserted into or drawn from the cavity of the matching bar  9 . The rod  31  comprises a cap for limiting the movement of the rod on an upper part of the rod  31 , and a predetermined part of the rod  31  is wound with a conduction substance  33 . It is preferable that when helical conductor  7  and the tension spring  17  connected to the feeder  15  the helical conductor  7  and the tension spring  17  connected to the feeder  15  are contacted so that the conduction substance  33  is positioned to transmit signals of the feeder  15  to the helical conductor  7 . When the rod  31  is withdrawn from the helical antenna  7 , a stopper  35  (shown in FIG. 4) made of a conductor that is provided to a lower part of the rod  31  in order for the lower part of the rod  31  to contact the feeder  15  transmits the signals of the feeder  15  only to the whip antenna  3 , and concurrently prevents it from being completely separated from the helical antenna. 
     That is, when the whip antenna  3  is withdrawn from the helical antenna  1 , the whip antenna  3  does not provide the signals of the feeder  15  to the helical conductor  7  because of the insulation pad  19 , but instead provides the signals of the feeder  15  to the whip antenna  3  via the stopper  35  of the whip antenna  3 . 
     Determination of a size and length of the matching bar  9  will now be described in detail. 
     A target value for moving the resonance point of the resonance frequency is established. The resonance frequency relates to a capacitance value between the matching bar  9  and the helical conductor  7 . The capacitance value is inversely proportional to the distance between the matching bar  9  and the helical conductor  7  (the distance is represented as distance ‘d’ in FIG.  3 .), and is proportional to an area made by the matching bar  9  and the helical conductor  7 . Hence, the matching bar  9  can adjust the resonance point by varying the diameter and the distance using experimental values. As mentioned above, the resonance frequency can be adjusted in a diversified manner according to frequency bands by varying the diameter and the length of the matching bar  9 . 
     Operation of the helical antenna  1  and the whip antenna  3  will be described hereinafter, and a process for transmitting signals to the helical antenna will be described now. The signals transmitted via the feeder  15  are provided to the helical conductor  7  passing through the tension spring  17  and then through the conduction substance  33  combined with the outer part of the rod  31 . When the whip antenna  3  is withdrawn from the helical antenna  1 , as shown in FIG. 4, the conduction substance  33  is moved, and the feeder  15  and the helical conductor  7  are electrically disconnected. The stopper  35  provided on the lower part of the rod  31  is closely attached to the lower part of the feeder  15  and therefore movement of the stopper  35  is limited, and concurrently signals are supplied to the whip antenna  3  from the feeder  15 . Therefore, the helical antenna  1  is operated only while the whip antenna  3  is inserted, and the whip antenna  1  operates after it is withdrawn from the helical antenna  1 . Therefore, the helical antenna  1  and the whip antenna  3  are individually operated to prevent the performance from being lowered by the coupling effect. 
     FIG. 5 shows a second preferred embodiment of the present invention. FIG. 5 shows a cross sectional view of a top-loading antenna into which the matching bar  9  is inserted. In the top-loading antenna, the helical antenna is combined with the upper part of the whip antenna, and this second preferred embodiment can adjust the resonance point by using the matching bar  9 . 
     A helical antenna is fixed ore a top part of the top loading antennae, and when the whip antenna is withdrawn, a fixing end is fixed to the feeder and the lower part of the whip antenna. When the whip antenna maintains a predetermined gap with the helical antenna formed on the top part, a coupling is formed, and frequencies vary according to length of the whip antenna by the degree of induced coupling, and in the frequency bands, impedance becomes wider as inductance and capacitance vary. 
     The helical antenna is operated when the whip antenna is inserted, and at this time, since there is a matching bar  9  provided in the helical antenna, the frequencies can be varied according to diameters, sizes and lengths of the matching bar  9 , and the frequency bands become wider. 
     FIG. 6 shows a cross sectional view of a bottom loading antenna cut in the lengthwise direction, and a matching bar  9  is inserted into the bottom-loading antenna. 
     When the whip antenna is withdrawn, a coupling is induced by the matching bar configured in the whip antenna and the helical antenna, the bottom loading antenna is operated, and the band width is determined by a matching value of the whip antenna and the helical antenna. When impedance components and capacitance components are varied according to the coupling degrees of the helical antenna, the bandwidth becomes wider and the length of the whip antenna becomes shorter. When the whip antenna is inserted, the helical antenna is operated, and the configuration and performance of the helical antenna is identical with those previously described. 
     FIG. 7 shows a preferred embodiment of a feeder of the present invention. A whip antenna  3  is withdrawn from the helical antenna  1  in the figure. 
     The helical antenna  1  comprises a bobbin  5  which is fixed on an upper part of a portable wireless device (not illustrated), has a predetermined length, and has a cavity in the center part in the vertical direction and a helical conductor  7  which is wound on the bobbin in a spiral manner. The helical conductor  7  and the feeder  15  are short. 
     The bobbin  5  is made of a nonconductor, and a matching bar  9  is combined and provided in the inner part of the matching bar  9 . The matching bar  9  has a cavity in the lengthwise direction, and is made of a conductor. When manufacturing the bobbin  5  by a molding process, the matching bar  9  is inserted in the bobbin  5  and they are manufactured as a single unit. 
     The matching bar  9  has a diameter of R and a length of L, and these values are established according to values of the resonance point to be set in combination with the helical conductor  7 . That is, a value of setting the resonance point of the resonance frequency is previously established, and the diameter and the length of the matching bar  9  are established according to the value. Since a capacitor value for adjusting the resonance point of the resonance frequency is determined according to the diameter and the length, the diameter and the length of the matching bar  9  are established according to the resonance point set by experimental values and. the matching bar  9  is combined with the bobbin  5  according to the above-described method. A feeder  15  is provide to the lower parts of the bobbin  5  and the matching bar  9  A cavity penetrates the inner part of the feeder  15  in the lengthwise direction. 
     The feeder  15  and the helical conductor  7  are separated, and the feeder  15  and the matching bar  9  are tightly combined in a surface-contacted state. That is, the upper part of the feeder  15  is tightly fixed to the lower part of the matching bar  9 . 
     A cylindrical tension spring  17  is provided to the inner cavity of the feeder  15 . The tension spring  17  made of a conductor has a predetermined elasticity so as to fix the whip antenna  3  at a predetermined position after the whip antenna  3  is moved in the upper or lower direction. 
     The rod  31  of the whip antenna  3  is provided to the cavity of the matching bar  9  in order for the rod  31  to be inserted or withdrawn as shown in FIG.  8 . The rod  31  comprises a cap  101  in the lower part of the rod  31  so as to restrict downward movement, and a stopper  35 , made of a conductor, for limiting upward movement and transmitting electrical signals to a radiating element  103 . 
     Determination of a size and length of the matching bar  9  will now be described in detail. 
     A target value for moving the resonance point of the resonance frequency is established. The resonance frequency relates to a capacitance value between the matching bar  9  and the helical conductor  7 . The capacitance value is inversely proportional to the distance between the: matching bar  9  and the helical conductor  7 , and is proportional to an area made by the matching bar  9  and the helical conductor  7 . Hence, the matching bar  9  can adjust the resonance point by varying the diameter and the distance using experimental values. As mentioned above, the resonance frequency can be adjusted in a diversified manner according to frequency bands by varying the diameter and the length of the matching bar  9 . 
     Operation of the helical antenna  1  and the whip antenna  3  will now be described. When the whip antenna  3  is inserted, the moving of the cap  101  positioned at the upper part of the rod  31  is limited by an antenna cover. The tension spring  17  maintains insertion by tightening of one part of the rod  31 . 
     Regarding a signal transmission process to the helical antenna  1 , the electrical signals are transmitted to the matching bar  9  tightly contacted to the feeder, via the feeder  15 , and the matching bar  9  and the helical conductor  7  form a coupling. Therefore, the signals are transmitted. The frequencies can be varied by the configuration of the feeder, the sizes and the diameter of the matching bar  9 , and the gap between the helical conductor  7  and the matching bar  9 . Also, by adjusting the resonance point according to rotation number of the helical conductor  7 , two resonance frequencies can be formed. 
     Regarding an operation of the whip antenna  3 , when the whip antenna  3  is withdrawn, the moving of the stopper  35  positioned at the lower part of the rod  31  is restricted by the feeder  15 . The tension spring  17  maintains withdrawn states by tightening of one part of the rod  31 . 
     Regarding a signal transmission process to the, whip antenna  3 , the electrical signals are transmitted to the matching bar  9  tightly contacted to the feeder, via the feeder  15 , and the matching bar  9  and the helical conductor  7  form a coupling. At this time, the matching bands of the whip antenna  3  are varied by matching degrees of the helical antenna  1 . The electrical signals transmitted via the feeder  15  are transmitted to the radiating element  103  of the whip antenna  3  through the tension spring  17  and the stopper  35 . At this time, the length of the radiating element  103  can be reduced by the coupling operation of the helical conductor  7  and the matching bar  9 . Also, regarding the length of the radiating element  103  of the whip antenna  3 , since the capacitance components are varied according to the matching degrees of the helical conductor  7 , matching bands become wider. Hence, two resonance points can be derived. 
     Therefore, two frequency resonance points can be set by the matching bar, and the electrical signals can be freely transmitted and durability can be improved by combining the one surface of the matching bar and the feeder. 
     While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.