Patent Publication Number: US-6222505-B1

Title: Composite antenna apparatus

Description:
This application is the national phase under 35 U.S.C. §371 of PCT International Application No. PCT/JP97/04427 which has an International filing date of Dec. 3, 1997 which designated the United States of America. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a composite antenna apparatus for transmitting and receiving different frequencies and which is capable of providing a plurality of mobile communication services on differing frequency bands with a single portable terminal. 
     DESCRIPTION OF THE PRIOR ART 
     In recent years, mobile communication services using various frequency bands have come into use. In order to provide a plurality of mobile communication services on a single terminal apparatus, the number of composite type antennas has increased. 
     Diagram  1  is a perspective diagram showing the components, in simplified form, of a kind of composite antenna apparatus known as a mobile-use 2-cycle shared double whip antenna as an example of a conventional mobile terminal antenna similar to that disclosed at the 1994 Electronic Communications Conference Autumn Session Exhibit B-73. In the diagram, reference numeral  1  represents the body of the portable terminal,  2  is a first antenna joined to the body  1  and  3  is a second antenna joined in a similar fashion. 
     In composite antennas for use with mobile terminals such as the mobile-use 2-cycle shared double whip type composite antenna shown in diagram  1 , the first antenna  2  has a length h 1 , about half the wavelength of the low frequency f 1  and the second antenna  3  has a length h 2  about half the wavelength of the high frequency f 2 . In this kind of composite antenna apparatus, signals at a low frequency f 1  and signals at a high frequency f 2  are fed to the first antenna  2  and the second antenna  3  respectively. 
     Diagrams  2  and  3  are explanatory views showing, respectively, the vertical plane of the emission pattern, calculated according to the law of moments, of the effect of the first antenna  2  short circuiting when the second antenna is fed and of the effect of the second antenna  3  short circuiting when the first antenna  2  is fed. Although diagram  2  shows that there is little effect due to the first antenna  2  short circuiting when the second antenna  3  is fed, as can be seen from diagram  3 , when the second antenna  3  short circuits after the first antenna  2  is fed, the emission pattern changes greatly from the normal dipole antenna emission pattern due to the influence of the second antenna  3 . 
     Thus in a conventional composite antenna apparatus, since one antenna (the second antenna  3 ) may influence the other antenna (the first antenna  2 ) while the first antenna  2  is being fed with the result the that the emission pattern is changed greatly from a normal dipole antenna emission pattern, the problem arises that gain in the horizontal plane is reduced and so the antenna is unsuitable for a portable terminal used by a person communicating in a random environment in all horizontal directions. 
     The further problem arises that the arrangement of the two antennas  2 ,  3 , in parallel increases the occupied volume and therefore decreases the portability of the portable terminal. 
     The purpose of the present invention is to solve the above mentioned problems by the provision of a composite antenna apparatus having antennas corresponding respectively to two different mobile communication services on the same axis. The respective antennas have equivalent gain in the horizontal plane as well as a reduced occupied volume. 
     Furthermore, it is a purpose of the present invention to provide a composite antenna apparatus which improves the portability of the portable terminal by using the movability of respective antennas constructed on the same axis so that they may be stored in the wireless body when not in use. 
     DISCLOSURE OF THE INVENTION 
     The composite antenna apparatus of the invention according to the scope of claim  1  provides for, at one end of a coaxial line, a balun, connected to an inner conductor and connected to the balun, one end of a helical element formed by a pair of line conductors. The other end of the helical element is aligned symmetrically, facing the balun, by turning it around the coaxial line using the coaxial line as a center and connected to the outer conductor at the other end of the coaxial line where the inner conductor connecting terminal joined to the inner conductor and the outer conductor connecting terminal joined to the outer conductor are located. In such a way, the composite antenna apparatus formed by the helical antenna fed by the coaxial line and the monopole antenna created by the outer conductor of the coaxial line running through its center are constructed on the same axis, thus allowing equivalent gain in the horizontal plane and a reduction in the occupied volume. 
     The composite antenna apparatus of the invention according to the scope of claim  2  includes, on the same axis, a monopole antenna created by the outer conductor of said coaxial line and a two-wire wound helical antenna fed by said coaxial line and constructed by a pair of helical elements and a single coaxial line. In this way, a composite antenna apparatus having equivalent gain in the horizontal plane and a reduction in the occupied volume can easily be constructed. 
     The composite antenna apparatus of the invention according the scope of claim  3  includes, on the same axis, a monopole antenna created by the outer conductor of the coaxial line and a four-wire wound helical antenna fed by the coaxial line. The helical antenna is formed by providing a balun and a phase delay element on one end of a single coaxial line, one end of a first helical element is connected directly to the balun and an end of a second helical element is connected to the balun through the phase delay element. In this way, it is possible to improve the symmetry of the emission pattern and provide more equivalent gain in the horizontal plane. 
     The composite antenna apparatus of the invention according to the scope of claim  4  includes, on the same axis, a monopole antenna created by the outer conductor of the coaxial line and a plurality of helical antennas formed by grouping a plurality of coaxial lines so that the outer conductors are in mutual contact, placing a balun at the end of each coaxial line, connecting one end of the helical element to each balun and connecting the other end of the helical element to the outer conductor at the other end of the coaxial line. In such a way, it is possible to construct, on a single axis, antennas corresponding respectively to a plurality of different kinds of services as well as providing equivalent gain in the horizontal plane and reduced occupied volume. 
     The composite antenna apparatus of the invention according to the scope of claim  5  includes, on a single axis, a monopole antenna created by the outer conductor of the coaxial line and two four-wire wound helical antennas formed by providing a first phase delay element and a first balun at one end of a first coaxial line and a second phase delay element and a second balun at one end of a second coaxial line, one end of the two pairs of helical elements forming the first helical antenna is connected to the first balun either directly or through the first phase delay element and one end of the two pairs of helical elements forming the second helical antenna is connected to the second balun either directly or through the second phase delay element. In such a way, it is possible to construct on a single axis antennas respectively corresponding to three different kinds of services and, due to the improvement in the symmetry of the emission pattern, to provide equivalent gain in the horizontal plane. 
     The composite antenna apparatus of the invention according to the scope of claim  6  provides an outer conductor connecting terminal connected to the outer conductor and an inner conductor connecting terminal connected to the inner conductor of the coaxial line placing at one end of the coaxial line mutually insulated slide-action contactors rotatable around the center of the axis of rotation orthogonal to the axis of the coaxial line. In such a way, the composite antenna apparatus, when not in use, may be piled and compacted within the wireless body, thus improving its portability. 
     The composite antenna apparatus of the invention according to the scope of claim  7  provides an antenna composed of helical and monopole antennas being both extendable and storable, their upper ends being electrically insulated from the coaxial line and sub-antennas being arranged in series. When in the stored position, one of the wireless circuits is connected to the connecting terminal of the sub-antenna element. When in the extended position, the wireless circuit connected to the connecting terminal of the sub-antenna element when in the stored position is connected to the outer conductor connecting terminal and the other wireless circuit is connected between the outer and inner conductor connecting terminals. In such a way, it is possible to store the composite antenna apparatus in the wireless body when not in use, thus improving its portability. When in the stored position, gain is ensured by feeding the sub-antenna element. 
     The composite antenna apparatus of the invention according to the scope of claim  8  uses a helical conductor made by winding a wire conductor into a helical shape as a sub-antenna element. In such a way, the sub-antenna can act as a helical monopole antenna thus ensuring gain when in the stored position. 
     The composite antenna apparatus of the invention according to the scope of claim  9  uses a bent conductor formed from a zigzag shaped wire conductor as a sub-antenna element. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Diagram  1  is a perspective view showing a simplified structure of a conventional composite antenna apparatus. 
     Diagram  2  is an explanatory view showing the emission pattern in the vertical plane of a conventional composite antenna apparatus when the second antenna is fed and the first antenna short circuits. 
     Diagram  3  is an explanatory view showing the emission pattern in the vertical plane of a conventional composite antenna apparatus when the first antenna is fed and the second antenna short circuits. 
     Diagram  4  is a perspective view showing the simplified structure of a composite antenna apparatus according to the first embodiment of the invention. 
     Diagram  5  is a perspective view showing a simplified structure of a composite antenna apparatus according to the second embodiment of the invention. 
     Diagram  6  is a view in plan showing schematically the connection of the central conductor of the coaxial line and the helical element in the second embodiment above. 
     Diagram  7  is a front elevation showing the simplified structure of a composite antenna apparatus according to the third embodiment of the invention. 
     Diagram  8  is a perspective view showing the simplified structure of the portable terminal used by the composite antenna apparatus in accordance with embodiment 4 of the invention. 
     Diagram  9  is a perspective view showing the simplified structure of the moveable fastening member of the composite antenna according to embodiment 4 of the invention. 
     Diagram  10  is a perspective view showing the simplified structure of the portable terminal, with antenna extended, used by the composite antenna apparatus according to embodiment 5 of the invention. 
     Diagram  11  is a perspective view of the simplified structure of the antenna as housed according to embodiment 5 of the invention. 
     Diagram  12  is a perspective view showing the simplified structure of the portable terminal, with antenna extended, used by the composite antenna apparatus according to embodiment 6 of the invention. 
     Diagram  13  is a perspective view showing the simplified structure of the antenna as housed according to embodiment 6 of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In order to explain the invention in greater detail, the preferred embodiments will be set out making reference to the accompanying figures. 
     Embodiment 1 
     Diagram  4  is a perspective view showing the simplified structure of the composite antenna apparatus according to embodiment 1 of the invention and shows schematically the composite antenna apparatus used with a portable terminal as the combination, on the same axis, of a monopole antenna created by the outer conductor of the coaxial line and the helical antenna fed by said coaxial line. In the diagram,  11  is the coaxial line,  12  is the inner conductor of said coaxial line  11 , similarly  13  is its outer conductor.  14  is the inner conductor connecting terminal connected to the inner conductor  12  at one end of the coaxial line  11 .  15  is the outer conductor connecting terminal connected to the outer conductor  13  at the same end as the inner conductor connecting terminal  14  of the coaxial line  11 . 
       16  is the balun which is placed at the end opposite the outer conductor connecting terminal  15  and the inner conductor connecting terminal  14  on the coaxial line  11  and is connected to the inner conductor  12  on said coaxial line  11 .  17  is a helical element formed from the pair of wire conductors. One end of the helical element  17  is connected to the balun  16 , the other end is symmetrically aligned facing the balun  16  by turning it around the coaxial line using the coaxial line as a center and is connected to the outer conductor  13  of the coaxial line  11  at the end to which the outer conductor connecting terminal  15  and the inner conducting connecting terminal of said coaxial line  11  are attached. 
       18  is a first wireless circuit connected to the outer conductor  13  of the coaxial line  11  through the outer conductor connecting terminal  15 .  19  is a second wireless circuit connected respectively to the inner conductor  12  of the coaxial line  11  through the inner conductor connecting terminal  14  and to the outer conductor  13  of the coaxial line  11  through the outer conductor connecting terminal  15 . The first wireless circuit  18  and second wireless circuit  19  communicate on different frequency bands. In the example in the diagram, the frequency band of the first wireless circuit  18  is lower than that of the second wireless circuit  19 . 
     The operation of the invention will now be explained. 
     The helical element  17  is formed by a helical antenna fed by the coaxial line  11  to which the second wireless circuit  19  is connected through the outer conductor connecting terminal  15  and the inner conductor connecting terminal  14 . Modal variation between the pair of helical elements  17  and the coaxial line  11  in the helical antenna are carried out by the balun  16  placed between the helical element  17  and the inner conductor  12  of the coaxial line  11 . Since the helical antenna generates a conical beam in the direction of the axis of the coaxial line  11 , equivalent gain is achieved in the same horizontal plane. 
     The outer conductor  13  of the coaxial line  11  to which the first wireless circuit  18  is connected through the outer conductor connecting terminal  15  functions as a monopole antenna element thus creating a nondirectional antenna in the horizontal plane. 
     In this way, the antenna structure displays line symmetry with respect to the coaxial line due to the fact that the helical element  17  in the helical antenna symmetrically winds around the coaxial line  11  and a monopole antenna is created by the outer conductor  13  of the coaxial line  11  acting as an antenna element. 
     Therefore the axes with respect to the emission pattern correspond and thus create respectively non-directional antennas in the horizontal plane. 
     Furthermore since such things as the conductor length and the helical pitch of the monopole antenna are independently created without the need to change the shape of the helical element  17 , no change is observable in the emission pattern generated by the helical element  17 . 
     As shown above, according to the first embodiment, since there is provided a composite antenna apparatus comprised, on the same axis, by a helical antenna created by a pair of helical elements  17  fed by the coaxial line  11  and by a monopole antenna consisting of the outer conductor  13  running through the center of the helical antenna acting as an antenna element, equivalent gain is achieved in the horizontal plane and occupied volume is decreased. 
     Embodiment 2. 
     In embodiment 1 above, a composite antenna apparatus for use with a portable terminal comprised of a two-wire wound helical antenna using a pair of helical elements and a monopole antenna created by the outer conductor of the coaxial line was explained. It is possible, however, to combine, on the same axis, four-wire wound helical antenna using two pairs of helical elements and a monopole antenna created by the outer conductor of the coaxial line. 
     Diagram  5  is a perspective view showing the schematic structure of a composite antenna apparatus according to the second embodiment of the invention. Diagram  6  is a schematic plan view of the connection of the central conductor of the coaxial line with the helical element. In the diagram,  11  is the coaxial line,  12  is its inner conductor,  13  is its outer conductor,  14  is the inner conductor connecting terminal,  15  is the outer conductor connecting terminal,  16  is the balun,  18  is the first wireless circuit and  19  is the second wireless circuit. These are similar to those elements having like reference numerals in FIG. 4 of embodiment 1. 
       20  is a phase delay element placed at the end opposite to that of the outer conductor connecting terminal  15  and the inner conductor connecting terminal  14  of the coaxial line  11  and is connected to the balun  16  which is in turn connected to the inner conductor of the said coaxial line  11 .  21  is the first helical element formed from a pair of wire conductors and, in a similar manner to the helical element  17  in the first embodiment, is directly connected at one end to the balun  16 .  22  is the second helical element formed from a pair of wire conductors and is connected at one end to the balun  16  through the phase delay element  20 . The other ends of the first helical element  21  and the second helical element  22  are aligned symmetrically facing the balun  16  and the phase delay element  20  by turning them around the coaxial line  11  using the line as a center and are connected to the outer conductor  13  of the coaxial line  11  at the end to which the inner conductor connecting terminal  14  and the outer conductor connecting terminal  15  of said coaxial line  11  are attached. 
     The operation of the invention will now be explained. 
     In the first helical member  21 , the second wireless circuit  19  is fed, only via the balun  16 , by the coaxial line  11  connected between the outer conductor connecting terminal  15  and the inner conductor connecting terminal  14 . In the second helical element  22 , the second wireless circuit  19  is fed, via the balun  16  and the phase delay element  20 , by the coaxial line  11  connected between the inner conductor connecting terminal  14  and the outer conductor connecting terminal  15 . In such a way, a four-wire wound helical antenna is formed. Modal variation between the coaxial line  11  and the first and second helical elements  21 ,  22  in the helical antenna are carried out by the balun  16 . The second helical element  22  receives a fixed phase delay from the phase delay element  20  and is fed at the delayed phase by the first helical element  21 . Therefore the present helical antenna generates a more symmetrical conical beam with respect to the coaxial line  11  when compared to the two wire wound helical antenna in the first embodiment. 
     On the other hand, the outer conductor  13  of the coaxial line  11  to which the first wireless circuit  18  is connected through the outer conductor connecting terminal  15  functions as a monopole antenna element in the same way as in the first embodiment and thus creates a non-directional antenna in the horizontal plane. 
     In such a way, the first and second helical elements  21 ,  22  of the helical antenna turn symmetrically around the coaxial line  11  and a monopole antenna is created by the outer conductor  13  of the coaxial line  11  functioning as an antenna element. Therefore the structure of the antenna displays line symmetry with respect to the coaxial line and the axes correspond as regards the emission pattern and therefore creates a non-directional antenna in the horizontal plane. 
     Furthermore, since such things as conductor length or helical pitch can be independently created in the monopole antenna without any change to the shape of the first helical element  21  or the second helical element  22 , there is no change to the emission pattern generated by the first helical element  21  and the second helical element  22 . 
     In such a way, according to the second embodiment, since a composite antenna apparatus is formed by the combination, on the same axis, of a four-wire wound helical antenna created by the first and second helical elements  21 ,  22  fed by the coaxial line  11  and by an outer conductor passing through its center and creating an antenna element acting as a monopole antenna, equivalent gain is achieved in the horizontal direction together with a reduction in the occupied volume. 
     Embodiment 3. 
     In each of the above embodiments, a composite antenna for use with a portable terminal comprising, on the same axis, a single helical antenna using a helical element fed by a coaxial line and a monopole antenna created by the outer conductor of the said coaxial line was explained. However, it is possible to combine a plurality of helical antennas with a single monopole antenna. 
     Diagram  7  is a frontal view of the schematic structure of a composite antenna according to the third embodiment of the invention. The diagram shows in schematic form, a composite antenna for use with a portable terminal constructed by the combination, on a single axis, of a two four-wire wound helical antennas constructed from two pairs of helical elements and a single monopole antenna created by two coiled lines of the outer conductor in the coaxial line. The relevant parts of the diagram have the same reference numerals as in FIG.  5 . 
     In the diagram,  23  is the first of the two coaxial lines mentioned above and is coilingly disposed in electrical connection with the outer connector  13 .  24  is the second of the aforementioned pair of coaxial lines.  25  a first inner conductor connecting terminal connected to the inner conductor  12  at one end of the first coaxial line  23 ,  26  is a second inner conductor connecting terminal connected to the inner conductor  12  at one end of the second coaxial line  24 ,  27  is an outer conductor connecting terminal which is connected to the outer conductor  13  at one end of the first coaxial line  23  and the second coaxial line  24 . 
       28  is a first balun connected to the inner conductor  12  of said first coaxial line  23  at the end opposite to the first outer conductor connecting terminal  27  and the inner conductor connecting terminal  25  of the first coaxial line  23 .  29  is a first phase delay element connected to the inner conductor  12  of the first coaxial line  23  through the first balun  28 .  30  is a second balun connected to the inner conductor  12  of said second coaxial line  24  at the end opposite to the second outer conductor connecting terminal  27  and the inner conductor connecting terminal  26  of the second coaxial line  24 .  31  is a second phase delay element connected to the inner conductor  12  of the second coaxial line  24  through the second balun  30 . 
       32  is a helical element comprised of two pairs of wire conductors constituting the first helical antenna,  33  is a helical element comprised of two pairs of wire conductors constituting the second helical antenna. The end of one pair of helical elements  32  constituting the first helical antenna is connected to the first balun  28 , the end of the other pair is connected to the first balun  28  through the first phase delay element  29 . In like manner, one end of one pair of the helical elements  33  constituting the second helical antenna is directly connected to the balun  30 , the end of the other pair is connected to the second balun  30  through the second phase delay element  31 . 
     The other end of the helical elements  32  and  33  constituting the first and second helical antennas respectively are turned symmetrically around the first and second coaxial lines  23 , 24  using the coiled first and second coaxial lines  23 ,  24  as a center so as to face the first and second phase delay elements  29 , 31  and is then connected to the outer conductor  13  of the first and second coaxial lines  23 , 24  at the end to which the first inner conductor connecting terminal  25 , and the second outer and inner conductor connecting terminals  26 , 27  of said first and second coaxial lines  23 , 24  are connected. 
       34  is a third wireless circuit connected to the inner conductor  12  of the second coaxial line  24  through the second inner conductor connecting terminal  26  and to the outer conductor  13  of the first and second coaxial lines  23 ,  24  through the outer conductor connecting terminal  27 . The first wireless circuit  18  is connected to the outer conductor  13  of the first and second coaxial lines  23 , 24  through the outer conductor connecting terminal  27 . The second wireless circuit  19  is connected respectively to the inner conductor  12  of the first coaxial line  23  through the first outer conductor connecting terminal  25  and to the outer conductor  13  of the first and second coaxial lines  23 , 24  through the outer conductor connecting terminal  27 . The second wireless circuit  19  and the third wireless circuit  34  communicate on different frequency bands and, as shown in the diagram, the frequency band of the second wireless circuit is slightly higher than that of the third wireless circuit  34 . 
     In such a way, a four-wire wound first helical antenna created by the helical element  32  and fed by the first coaxial line and a four-wire wound second helical antenna fed by the second coaxial line  24  by the helical element  33  are formed as is a monopole antenna formed by using the outer conductor of the coiled first and second coaxial lines  23 , 24  as an antenna element. 
     The operation of the invention will now be explained. 
     The first helical antenna formed by the helical element  32  is fed by the first coaxial line  23  and, in a fashion similar to the four-wire wound antenna of the second embodiment, generates a conical beam at a corresponding frequency band. In the same way, the second helical antenna formed by the helical element  33  is fed by the second coaxial line  24  and generates a conical beam at a corresponding frequency band. In this way, the composite antenna apparatus of the third embodiment is characterized by two shared frequencies generating a conical beam at respective frequency bands. Since each of the first and second helical antennas have a four-wire wound structure, there is an improvement in the symmetry of the emission pattern. 
     Since the outer conductor  13  of the first and second coaxial lines  23 , 24  to which the first wireless circuit  18  is attached through the outer conductor connecting terminal  27  are mutually contacting and electrically connected, a monopole antenna element is created which functions as a non-directional antenna in the horizontal plane in a way similar to the first and second embodiments. 
     In the third embodiment, the helical elements  32 , 33  of the first and second helical antennas are turned symmetrically around the first and second coaxial lines  23 ,  24 . A monopole antenna is created by the outer conductors  13  of the first and second coaxial lines  23 , 24 , which are coiled so as to be electrically connecting, and which acts as an antenna element. Therefore the antenna structure displays line symmetry with respect to the coaxial line, the axes of the emission pattern correspond to each other and respective non-directional antennas in the horizontal plane are created. 
     Furthermore, since the conductor length or helical pitch of the monopole antenna can be independently created without changing the shape of the helical elements  32 , 33 , no change is observed in the shape of the emission pattern generated by the first and second helical antennas. 
     As shown above, according to the third embodiment, since a composite antenna apparatus is formed from the combination, on a single axis, of a first four-wire wound helical antenna fed by the first coaxial line  23 , created by the helical element  32  and a second four-wire wound helical antenna fed by the second coaxial line  24 , created by the helical element  33 , together with a monopole antenna formed by the outer conductors  13  running through the center of the first and second coaxial lines and acting as an antenna element. Therefore it is possible to construct, on the same axis, an antenna corresponding respectively to three different kinds of services. As a result, it is possible to achieve more equivalent gain in the horizontal plane and also reduce occupied volume. 
     Although the above explanation centered on the use respectively of two four-wire wound helical antennas, it is possible to create a composite antenna apparatus using three or more helical antennas. Furthermore the helical antennas are not limited to the four-wire wound type, two-wire wound helical antennas may also be used. 
     Embodiment 4 
     Diagram  8  is a perspective diagram showing the schematic structure of the portable terminal used with the composite antenna apparatus according to embodiment 4. Diagram  9  is a perspective diagram showing the schematic structure of the movable fitting of the antenna apparatus. In diagrams  8  and  9 , the relevant elements have the same reference numerals as in diagram  1 . 
     In the diagrams,  35  is the wireless body containing the first and second wireless circuits  18 , 19  to which the composite antenna apparatus. The composite antenna is in turn connected the composite antenna device which is connected rotatably to the wireless body.  36  is the axis of rotation for rotatably connecting the composite antenna to the wireless body  35 . The direction of its axis is orthogonal to that of the coaxial line  11  of the composite antenna.  37  is a first slide-action contactor which rotates around the axis of rotation  36 .  38  is a second slide-action contactor which is electrically insulated from the first slide-action contactor  37  and rotates around the axis of rotation  36 . The first slide-action contactor  37  is electrically connected to the inner conductor  12  of the coaxial line  11  and functions as an inner conductor connecting terminal. The second slide-action contactor is electrically connected to the outer conductor  13  of the coaxial line  11  and functions as an outer conductor connecting terminal. 
     The operation of the invention will now be explained. 
     The principle of the operation of the composite antenna is the same as that of embodiments 1 to 3. When fed by the second wireless circuit  19  through the coaxial line  11 , the antenna operates as a helical antenna generating a conical beam, when fed by the first wireless circuit  18 , the outer conductor  13  of the coaxial line  11  which feeds the helical antenna acts as a monopole antenna. 
     The first wireless circuit  18  is usually connected to the outer conductor  13  of the coaxial circuit  11  through the second slide-action connector  38  which functions as an outer conductor connecting terminal. 
     Furthermore, the second wireless circuit  19  is usually connected between the inner conductor  12  of the coaxial line  11  through the first slide-action connector  37  which functions as a inner conductor connecting terminal and the outer conductor  13  of the coaxial line  11  through the second slide-action connector  38 . In other words, even if the antenna apparatus comprising the helical antenna fed by the coaxial line  11  and the monopole antenna based on the outer conductor  13  of the coaxial line  11  is rotated using the axis of rotation  36 , no difference in the connection of the first and second wireless circuits  18 , 19  with the inner and outer connectors  11 , 12  of the coaxial line  11  will result due to the action of the first and second slide-action connectors  37 , 38 . 
     Therefore when the portable terminal is not in use, the composite antenna apparatus may be fixed in the stacked position in the wireless body  35 . When in use, if the composite antenna apparatus is rotated and fixed in the unstacked position out of the wireless body  35  as shown in diagram  8 , equivalent gain in the horizontal plane may be obtained. 
     In such a way, according to embodiment 4, it is possible to create a freely rotating antenna apparatus using the axis of rotation  36  as a center, and since the antenna apparatus may be fixed in the stacked position in the wireless body when not in use, the portability of the portable terminal is improved. 
     Embodiment 5 
     As was explained in embodiment 4, the portability of the portable terminal may be improved by rotating and fixing the composite antenna in the stacked position in the wireless body. However portability of the terminal may also be improved by storing the composite antenna inside the wireless body 
     Diagrams  10  and  11  are schematic block diagrams showing the composite antenna according to embodiment 5 of the present invention. Diagrams  10  and  11  show respectively schematic representations of the composite antenna apparatus as extended from the wireless body and as stored in the wireless body. The relevant components of diagrams  10  and  11  have equivalent reference numerals to those in diagrams  8  and  9 . 
     In the diagrams,  39  is the antenna storage unit connected to the first and second wireless circuits  18 , 19  built into the wireless body and which stores the composite antenna apparatus comprised of a helical antenna fed by a coaxial line  11  and a monopole antenna based on the outer conductor  13  of the coaxial line  11 .  40  is a sub-antenna element arranged in series at the top part of the composite antenna apparatus stored in the antenna storage unit  39  so as not to be electrically connected to the coaxial line  11 .  41  is the connecting terminal of the sub-antenna element  40 . In the fifth embodiment, a helical conductor wound helically on the wire conductor connected to the connecting terminal  41  is used as a sub-antenna  40 .  42  is a first spring contact connecting the connecting terminal  41  of the sub-antenna element  40  with the first wireless circuit  19  when the composite antenna apparatus is stored in the antenna storage unit  39  of the wireless body  35  and connected to the outer conductor connecting terminal  15  provided at the lower end of the coaxial line  11  as a switching means when the antenna is extended from the antenna storage unit  39 .  43  is a second spring contact functioning as a switching means and connecting a second wireless circuit between the outer conductor connecting terminal  15  and inner conductor connecting terminal  14  provided at the lower end of the coaxial line  11  only when the antenna is extended from the antenna storage unit  39 . 
     The operation of the invention will now be explained. 
     The operating principle of the composite antenna apparatus is the same as that of embodiments one to three. When fed by the second wireless circuit  19  through the coaxial line  11 , the antenna operates as a helical antenna generating a conical beam. When fed by the first wireless circuit  18 , the outer conductor  13  of the coaxial line  11  which feds the helical antenna acts as a monopole antenna element. 
     When the portable terminal is not in use, as shown in diagram  11 , the composite antenna apparatus may be stored in the antenna storage unit  39  of the wireless body  35 . When in use, as shown in diagram  10 , the composite antenna apparatus may be extended from the antenna storage unit  39  of the wireless body  35 . As shown in diagram  10 , when the composite antenna apparatus in use is extended from the antenna storage unit  39 , the first wireless circuit  18  is connected through the first spring connection  42  to the outer conductor connecting terminal  15  disposed at the lower end of the coaxial line  11 . The second wireless circuit  19  is connected between the outer conductor connecting terminal  15  and the inner conductor connecting terminal  14  placed at the lower end of the coaxial line  11  through the second spring connection  43 . A non-directional antenna in the horizontal plane is created because this helical antenna fed through the coaxial line  11  generates a conical beam and the outer conductor  13  of the coaxial line  11  acts as a monopole antenna element. 
     When use of the portable terminal is completed, as shown in diagram  11 , the composite antenna apparatus may be stored in the antenna storage unit  39  of the wireless body  35 . In such a way, the first wireless circuit  18  is connected, through the first spring connection  42 , to the connecting terminal  41  of the sub-antenna element  40  created by the helical conductor, the connecting terminal being arranged in series and electrically insulated from the upper part of the coaxial line  11 . The second spring connection  43  in the second wireless circuit  19  becomes disconnected as the contact between the inner conductor connecting terminal  15  and the outer conductor connecting terminal  14  in the lower part of the coaxial line  11  becomes disrupted. At such times, the gain of the composite antenna apparatus when in the stored position is ensured by feeding the sub-antenna created by the helical conductor by the first wireless circuit  18  and by using said helical conductor as a helical monopole antenna. 
     In this way, the invention according to embodiment 5 provides spring shaped connections  42 ,  43  as switching means. The composite antenna formed by the combination of a helical antenna fed by the coaxial line  11  and the monopole antenna created by the outer conductor  13  of the coaxial line  11  acting as an antenna element is movable in the axial direction and can be stored in the antenna storage unit  39  provided in the wireless body. Therefore when the composite antenna is in the stored position, the portability of the portable unit is improved and gain can be ensured by feeding the sub-antenna element created by the helical conductor and operating it as a helical monopole antenna. 
     Embodiment 6 
     As explained above in embodiment 5, the helical conductor may be used as a sub-antenna element. However the sub-antenna element is however not limited to such embodiments. 
     Diagrams  12  and  13  are schematic block diagrams showing a composite antenna according to embodiment 6 of the present invention, which uses a bent conductor as a sub-antenna element. Diagrams  12  and  13  schematically show the composite antenna respectively as extended from and stored in the wireless body. The relevant components have the same reference numerals as in diagrams  10  and  11 . In the diagrams,  44  is a sub-antenna element comprised by the conductor formed from a zigzag shaped wire conductor and is disposed in series at the top of the composite antenna apparatus stored in the antenna storage unit  39  so as not to be in electrical contact with the coaxial line  11 . 
     The operation of the invention will now be explained. 
     The principle of operation of the composite antenna apparatus constituted in such a manner is basically the same as embodiment 5 above. When extended from the antenna storage unit  39 , the antenna operates by a helical antenna fed by the coaxial line  11  and monopole antenna created by the outer conductor  13  of the coaxial line  11 . Even when stored in the antenna storage unit  39 , gain is ensured by the sub-antenna element  44  created by the folded conductor being fed by the first wireless circuit  18 . 
     Thus according to embodiment 6 the portability of the portable terminal is improved and gain is ensured when the antenna is in the stored position. 
     Industrial Applicability 
     As shown above, the composite antenna apparatus of the present invention is a combination, on the same axis, of a helical antenna fed by the coaxial line  11  and a monopole antenna created by the outer conductor which runs through the center of the coaxial line acting as an antenna element. As a result, since equivalent gain is achieved in the horizontal plane as well as a reduction in occupied volume, the wireless antenna device may be used to receive a plurality of mobile communication services on different wave bands. Furthermore since improved portability due to the movability of the said antenna device allows for its storage in the wireless body when not in use, the device is adapted for use as an antenna device for a portable terminal.