EP1154513A1 - Eingebaute antenne für drahtloses kommunikationsgerät - Google Patents

Eingebaute antenne für drahtloses kommunikationsgerät Download PDF

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Publication number
EP1154513A1
EP1154513A1 EP00939108A EP00939108A EP1154513A1 EP 1154513 A1 EP1154513 A1 EP 1154513A1 EP 00939108 A EP00939108 A EP 00939108A EP 00939108 A EP00939108 A EP 00939108A EP 1154513 A1 EP1154513 A1 EP 1154513A1
Authority
EP
European Patent Office
Prior art keywords
antenna
communication terminal
radio communication
dipole antenna
built
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP00939108A
Other languages
English (en)
French (fr)
Other versions
EP1154513A4 (de
Inventor
Hideo Ito
Kiyoshi Egawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP36828499A external-priority patent/JP2000244219A/ja
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Publication of EP1154513A1 publication Critical patent/EP1154513A1/de
Publication of EP1154513A4 publication Critical patent/EP1154513A4/de
Withdrawn legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
    • H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
    • H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
    • H01Q1/242—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use
    • H01Q1/243—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use with built-in antennas
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
    • H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
    • H01Q1/242—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use
    • H01Q1/243—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use with built-in antennas
    • H01Q1/244—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use with built-in antennas extendable from a housing along a given path
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/28—Combinations of substantially independent non-interacting antenna units or systems
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
    • H01Q9/0421—Substantially flat resonant element parallel to ground plane, e.g. patch antenna with a shorting wall or a shorting pin at one end of the element
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/16—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole
    • H01Q9/28—Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
    • H01Q9/42—Resonant antennas with feed to end of elongated active element, e.g. unipole with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Definitions

  • the present invention relates to an antenna used for radio equipment and portable terminals, etc.
  • FIG. 1 is a schematic diagram showing a configuration of a conventional built-in antenna used for a radio communication terminal.
  • the components shown in the same figure are incorporated in a package of the radio communication terminal, but an overall view of the radio communication terminal will be omitted for brevity of explanations.
  • the conventional radio communication terminal is generally provided with base plate 1 and tabular reverse F-figured antenna 2.
  • X, Y and Z denote the respective coordinate axes.
  • FIG.2 is a schematic diagram showing a configuration of a diversity antenna used for a conventional radio communication terminal.
  • the conventional radio communication terminal is provided with mono-pole antenna 3 as an external antenna in addition to tabular reverse F-figured antenna 2.
  • tabular reverse F-figured antenna 2 which is an internal antenna
  • mono-pole antenna 3 which is an external antenna
  • tabular reverse F-figured antenna used for the conventional radio communication terminal operates as an exciter that excites base plate 1 rather than tabular reverse F-figured antenna 2 itself operates as an antenna. For this reason, an antenna current flows into base plate 1 and the base plate becomes dominant as the antenna.
  • tabular reverse F-figured antenna 2 used for the conventional radio communication terminal has a problem that the gain deteriorates due to influences from the body of the user of the radio communication terminal above.
  • FIG.3A and FIG.3B illustrate actual measured values of the reception characteristic of tabular reverse F-figured antenna 2 used for the conventional radio communication terminal.
  • the size of base plate 1 is 120x36 mm and the frequency is 2180 MHz.
  • FIG.3A illustrates the reception characteristic of a horizontal plane (X-Y plane) of tabular reverse F-figured antenna 2 used for the conventional radio communication terminal in a free space.
  • X-Y plane horizontal plane
  • tabular reverse F-figured antenna 2 since base plate 1 operates as an antenna, tabular reverse F-figured antenna 2 has almost no directivity.
  • FIG.3B illustrates the reception characteristic of a horizontal plane (X-Y plane) of tabular reverse F-figured antenna 2 used for the conventional radio communication terminal during a conversation.
  • X-Y plane horizontal plane
  • the gain of tabular reverse F-figured antenna 2 is decreasing during a conversation. From a comparison between FIG.3A and FIG.3B, it is clear that the decrease in the gain of tabular reverse F-figured antenna 2 is attributable to influences from the body, for example, blocking of radio waves by the head or hand of the user, etc.
  • FIG.4A and FIG.4B illustrate actual measured values of the emission characteristic of tabular reverse F-figured antenna 2 used for the conventional radio communication terminal.
  • FIG.4A illustrates the emission characteristic of a horizontal plane (X-Y plane) of tabular reverse F-figured antenna 2 used for the conventional radio communication terminal in a free space. As shown in FIG.4A, since base plate 1 operates as an antenna, tabular reverse F-figured antenna 2 has almost no directivity.
  • FIG.4B illustrates the emission characteristic of a horizontal plane (X-Y plane) of tabular reverse F-figured antenna 2 used for the conventional radio communication terminal during a conversation.
  • X-Y plane horizontal plane
  • FIG.4B illustrates the gain of tabular reverse F-figured antenna 2 used for the conventional radio communication terminal during a conversation.
  • the gain of tabular reverse F-figured antenna 2 is decreasing during a conversation. From a comparison between FIG.4A and FIG.4B, it is clear that the decrease in the gain of tabular reverse F-figured antenna 2 is attributable to influences from the body, for example, blocking of radio waves by the head or hand of the user, etc.
  • tabular reverse F-figured antenna 2 used for the conventional radio communication terminal has a problem that the gain deteriorates due to influences from the human body.
  • a diversity antenna used for the conventional radio communication terminal above also has a problem that the gain deteriorates due to influences from the human body when tabular reverse F-figured antenna 2 operates.
  • This object of the present invention is attained by providing the radio communication terminal with a dipole antenna, supplying power to the dipole antenna via a balanced/unbalanced conversion circuit having an impedance conversion function so that the antenna has directivity opposite to the human body during a conversation.
  • the object of the present invention is attained by providing a passive element in parallel to the axial direction of an antenna element making up a dipole antenna and adjusting the length in the axial direction of the antenna element making up the dipole antenna, length in the axial direction of the passive element and distance between the antenna element making up the dipole antenna and the passive element appropriately so that the antenna has directivity opposite to the human body during a conversation.
  • the object of the present invention is attained by providing a bar-shaped passive element in such a way that the axial direction of the passive element is quasi-parallel to the axial direction of the bar-shaped antenna element making up the dipole antenna, a reference plane formed by including the passive element and the antennal element making up the dipole antenna is provided in such a way as to intersect with the main plane of the radio communication terminal at right angles and directivity is formed in the direction along the reference plane and perpendicular to the main plane of the radio communication terminal.
  • the object of the present invention is attained by providing the loop plane of a loop antenna so as to intersect with the human body at quasi-right angles, providing the loop antenna in such a way that the circumference of the loop antenna is one wavelength or shorter and supplying power to the loop antenna via a balanced/unbalanced conversion circuit with an impedance conversion function.
  • FIG. 6 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to Embodiment 1 of the present invention.
  • the components shown in the same figure are mounted in a package of a radio communication terminal.
  • An overall view of the radio communication terminal will be omitted for brevity of explanations.
  • the radio communication terminal according to this embodiment is constructed of base plate 11, dipole antenna 12, balanced/unbalanced conversion circuit 13 and power supply terminals 14. Each component will be explained below.
  • Base plate 11 is a tabular grounded conductor and is attached in quasi-parallel to the plane (vertical plane) on which operation buttons, a display and speaker, etc. of the radio communication terminal, which are not shown in the figure, are provided.
  • Dipole antenna 12 is constructed of two rectangular-wave-shaped (comb-tooth-shaped) antenna elements. This miniaturizes the dipole antenna.
  • the two antenna elements making up dipole antenna 12 are placed in such a way that their respective longitudinal directions form a quasi-straight line.
  • Dipole antenna 12 is mounted in such a way that the longitudinal directions of the antenna elements are quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal. As a result, dipole antenna 12 is provided in such a way that the longitudinal directions of the antenna elements are quasi-perpendicular to the horizontal plane. Thus, dipole antenna 12 mainly receives vertical polarized waves parallel to the longitudinal direction in a free space. Furthermore, since the human body acts as a reflector during a conversation, dipole antenna 12 has directivity opposite to the direction of the human body.
  • Balanced/unbalanced conversion circuit 13 is a conversion circuit with an impedance conversion ratio of 1 to 1 or n to 1 (n : integer) and is attached to power supply terminals 14 of dipole antenna 12.
  • One terminal of balanced/unbalanced conversion circuit 13 is connected to a transmission/reception circuit, which is not shown. The other terminal is attached to base plate 11.
  • balanced/unbalanced conversion circuit 13 performs impedance conversion between dipole antenna 12 and the transmission/reception circuit above, making it possible to obtain impedance matching between the two appropriately.
  • balanced/unbalanced conversion circuit 13 converts an unbalanced signal of the transmission/reception circuit above to a balanced signal and supplies the balanced signal to dipole antenna 12, and can thereby minimize the current that flows into base plate 11. This prevents the action of base plate 11 as an antenna, and can thereby suppress a drop of gain of dipole antenna 12 caused by influences from the human body.
  • An unbalanced signal from the transmission/reception circuit above is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and then sent to dipole antenna 12.
  • Dipole antenna 12 supplied with power in this way mainly sends vertical polarized waves parallel to this longitudinal direction.
  • dipole antenna 12 receives vertical polarized waves parallel to the longitudinal direction above.
  • vertical polarized waves from all directions centered on the dipole antenna are received in a free space and during a conversation, since the human body acts as a reflector as described above, of the vertical polarized waves above, those opposite to the human body are mainly received.
  • the signals above received by dipole antenna 12 are sent to the transmission/reception circuit above via balanced/unbalanced conversion circuit 13. Since balanced/unbalanced conversion circuit 13 minimizes the current that flows into base plate 11, the antenna operation by base plate 11 is prevented. This minimizes reduction of the gain caused by influences from the human body.
  • FIG. 8 illustrates actual measured values of the reception characteristic of the built-in antenna for a radio communication terminal according to this embodiment during a conversation.
  • the size of base plate 1 is 120 ⁇ 36 mm
  • the size of dipole antenna 12 is 63 ⁇ 5 mm
  • the distance of dipole antenna 12 from the human body is 5 mm
  • the frequency is 2180 MHz.
  • the direction at 270° from the origin corresponds to the direction of the human body viewed from dipole antenna 12 in FIG.6.
  • dipole antenna has directivity opposite to the direction of the human body. Moreover, any split of directivity is prevented for the above-described reason and a high gain characteristic with suppressed deterioration of gain is maintained compared to the conventional example shown in FIG.3B.
  • balanced/unbalanced conversion circuit 13 adjusts impedance appropriately and can thereby minimize the antenna current that flows into base plate 11 and suppress deterioration of gain of dipole antenna 12 caused by influences from the human body. Furthermore, since dipole antenna 12 is constructed of rectangular-wave-shaped antenna elements, it is possible to miniaturize the built-in antenna for a radio communication terminal. This makes it possible to provide a high gain and small built-in antenna for radio communication terminal with little influence from the human body.
  • Embodiment 2 is a mode in which the method of mounting dipole antenna 12 in Embodiment 1 is changed. Since Embodiment 2 is the same as Embodiment 1 except for the method of mounting dipole antenna 12, detailed explanations thereof will be omitted. Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 1 will be explained below using FIG.7. The parts similar to those in Embodiment 1 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.7 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 2.
  • the built-in antenna for a radio communication terminal according to Embodiment 2 is constructed of base plate 11, dipole antenna 12, balanced/unbalanced conversion circuit 13 and power supply terminals 14.
  • Dipole antenna 12 is mounted in such a way that the longitudinal directions of the antenna elements are quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal. That is, this embodiment is different from Embodiment 1 in that dipole antenna 12 is provided in such a way that the longitudinal directions of the antenna elements are quasi-parallel to the upper surface (horizontal plane).
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the longitudinal direction of the antenna matches the polarization plane, which makes it possible to increase the reception gain.
  • dipole antenna 12 is mounted in such a way that the longitudinal directions of the antenna elements are quasi-parallel to the upper surface of the radio communication terminal, which makes it possible to suppress deterioration of gain caused by influences from the human body and mainly receive horizontal polarized waves. This makes it possible to prevent deterioration of gain due to mismatch between the signal from the other end of communication and the polarization plane and provide a high gain and small built-in antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 3 is a mode in which the configuration and method of mounting dipole antenna 12 in Embodiment 1 is changed. Since Embodiment 3 is the same as Embodiment 1 except for the configuration and method of mounting the dipole antenna, detailed explanations thereof will be omitted. Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 1 will be explained below using FIG.9. The parts similar to those in Embodiment 1 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.9 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 3.
  • the built-in antenna for a radio communication terminal according to Embodiment 3 is constructed of base plate 11, dipole antenna 41, balanced/unbalanced conversion circuit 13 and power supply terminals 14.
  • the two antenna elements making up dipole antenna 41 are placed in such a way that the longitudinal directions are quasi-perpendicular to each other.
  • Dipole antenna 41 is mounted in such a way that the longitudinal direction of one antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal and the longitudinal direction of the other antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • An unbalanced signal from the transmission/reception circuit above is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and then sent to dipole antenna 41.
  • the antenna element placed quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal that makes up dipole antenna 41 supplied with power in this way mainly sends vertical polarized waves parallel to the longitudinal direction of this antenna element. Furthermore, during reception, vertical polarized waves parallel to the longitudinal direction above are received.
  • the antenna element placed quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal that makes up dipole antenna 41 supplied with power in the same way mainly sends horizontal polarized waves parallel to the longitudinal direction of this antenna element. Furthermore, during reception, horizontal polarized waves parallel to the longitudinal direction above are received. In a free space, vertical and horizontal polarized waves from all directions centered on the dipole antenna are received. During a conversation, since the human body acts as a reflector as described above, of the vertical polarized waves and horizontal polarized waves above, the waves opposite to the human body are mainly received.
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal according to this embodiment matches the polarization plane of the signal sent from the other end of communication, allowing reception gain to be increased.
  • balanced/unbalanced conversion circuit 13 can minimize the antenna current that flows into base plate 11 and can thereby suppress deterioration of gain caused by influences from the human body.
  • dipole antenna 41 is constructed of rectangular-wave-shaped antenna elements, making it possible to miniaturize the built-in antenna for a radio communication terminal and provide a high gain and small built-in antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 4 is a mode in which the shape and method of mounting antenna elements making up dipole antenna 12 in Embodiment 1 are changed. Since Embodiment 4 is the same as Embodiment 1 except for the shape of the antenna elements and method of mounting the dipole antenna, detailed explanations thereof will be omitted. Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 1 will be explained below using FIG.10. The parts similar to those in Embodiment 1 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.10 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 4.
  • the built-in antenna for a radio communication terminal according to Embodiment 4 is constructed of base plate 11, dipole antenna 51, balanced/unbalanced conversion circuit 13 and power supply terminals 14.
  • the antenna elements making up dipole antenna 51 are folded at a point close to the center and the folded planes are formed to be quasi-perpendicular to each other.
  • the plane including power supply terminals 14 is called a "first rectangular-wave-shaped plane” and the other plane without power supply terminals 14 is called a "second rectangular-wave-shaped plane".
  • the antenna elements making up dipole antenna 51 in the above configuration are mounted in such a way that the longitudinal direction of the first rectangular-wave-shaped plane is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal apparatus and the longitudinal direction of the second rectangular-wave-shaped plane is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal apparatus.
  • this embodiment is different from Embodiment 1 in that the longitudinal direction of the first rectangular-wave-shaped plane of dipole antenna 51 is quasi-parallel to the upper surface of the radio communication terminal apparatus and the longitudinal direction of the second rectangular-wave-shaped plane is quasi-perpendicular to the upper surface of the radio communication terminal apparatus .
  • dipole antenna 51 is provided during a conversation in such a way that the longitudinal direction of the first rectangular-wave-shaped plane above is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal and the longitudinal direction of the second rectangular-wave-shaped plane above is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal.
  • Embodiment 5 to Embodiment 11 are modes in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal according to Embodiment 1 to Embodiment 4.
  • Embodiment 5 is a mode in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal according to Embodiment 1.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.11.
  • the parts similar to those in Embodiment 1 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.11 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 5.
  • monopole antenna 61 is added to the configuration of the built-in antenna for a radio communication terminal according to Embodiment 1.
  • monopole antenna 61 operates during transmission and dipole antenna 12 and monopole antenna 61 operate during reception to carry out diversity reception.
  • dipole antenna 12 in Embodiment 1 is used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 1.
  • Embodiment 6 is a mode in which the configuration of the monopole antenna in Embodiment 5 is changed.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained using FIG.12.
  • the same configurations as those in Embodiment 5 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.12 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 6.
  • the diversity antenna for a radio communication terminal according to Embodiment 6 is constructed of dipole antenna 12, balanced/unbalanced conversion circuit 13, power supply terminals 14 and monopole antenna 71.
  • Monopole antenna 71 is constructed of a rectangular-wave-shaped antenna element.
  • monopole antenna 71 operates during transmission and dipole antenna 12 and monopole antenna 71 operate during reception to carry out diversity reception.
  • dipole antenna 12 in Embodiment 1 is used as the diversity antenna, which makes it possible to provide a high gain diversity antenna for a radio communication terminal with little influence from the human body. Furthermore, by providing rectangular-wave-shaped monopole antenna 71, it is possible to miniaturize the external antenna.
  • Embodiment 7 is a mode in which the configuration of the monopole antenna in Embodiment 5 is changed.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained using FIG.13.
  • the same configurations as those in Embodiment 5 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.13 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 7.
  • the diversity antenna for a radio communication terminal according to Embodiment 7 is constructed of dipole antenna 12, balanced/unbalanced conversion circuit 13, power supply terminals 14 and monopole antenna 81.
  • Monopole antenna 81 is constructed of a spiral antenna element.
  • monopole antenna 81 operates during transmission and dipole antenna 12 and monopole antenna 81 operate during reception to carry out diversity reception.
  • Embodiment 8 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 1.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained using FIG.14.
  • the same configurations as those in Embodiment 1 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.14 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 8. As shown in this figure, this embodiment has a configuration of the built-in antenna for a radio communication terminal according to Embodiment 1 with dipole antenna 91 added to one side of base plate 11. Dipole antenna 91 has a configuration similar to that of dipole antenna 12.
  • dipole antenna 91 operates during transmission and dipole antenna 12 and dipole antenna 91 operate during reception to carry out diversity reception.
  • dipole antenna 12 in Embodiment 1 and dipole antenna 91 are used as the diversity antenna, and it is therefore possible to provide a high gain diversity antenna for a radio communication terminal with little influence from the human body. Moreover, adopting rectangular-wave-shaped dipole antenna 91 reduces the size of the diversity antenna.
  • Embodiment 9 is a mode in which the method of mounting dipole antenna 91 in Embodiment 8 is changed. Since Embodiment 9 is the same as Embodiment 8 except for the method of mounting dipole antenna 91, detailed explanations thereof will be omitted. Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 8 will be explained below using FIG.15. The parts similar to those in Embodiment 8 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.15 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 9.
  • dipole antenna 91 is mounted in such a way that the longitudinal direction thereof is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal. That is, this embodiment is different from Embodiment 8 in that dipole antenna 12 is mounted in such a way that the longitudinal direction of dipole antenna 12 is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 91 is provided in such a way that this longitudinal direction forms quasi right angles with respect to the human body and at the same time is quasi-parallel to the horizontal plane during a conversation.
  • dipole antenna 91 In the diversity antenna for a radio communication terminal in the above configuration, only dipole antenna 91 operates during transmission and dipole antenna 12 and dipole antenna 91 operate during reception to carry out diversity reception.
  • dipole antenna 12 can suppress deterioration of gain and at the same time mainly receive vertical polarized waves parallel to the longitudinal direction of the antenna element.
  • dipole antenna 91 can not only suppress deterioration of gain but also mainly receive horizontal polarized waves parallel to the longitudinal direction of the antenna element.
  • the signal sent from the other end of communication is often a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal according to this embodiment matches the plane of polarization of the signal sent from the other end of communication and can thereby increase the reception gain.
  • this embodiment uses dipole antenna 12 in Embodiment 1 and dipole antenna 91 as the diversity antenna, and can thereby provide a high gain diversity antenna for a radio communication terminal with little influence from the human body. Moreover, the use of rectangular-wave-shaped dipole antenna 91 can reduce the size of the diversity antenna.
  • Embodiment 10 is a mode in which the dipole antenna used for both transmission and reception in Embodiment 8 is changed to dipole antenna 41 in Embodiment 3.
  • Embodiment 10 is the same as Embodiment 8 except for the configuration and method of mounting the dipole antenna.
  • the same parts in FIG.16 as those in Embodiment 8 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.16 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 10.
  • dipole antenna 41 is mounted in such a way that the longitudinal direction of one antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal and the longitudinal direction of the other antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 41 operates during transmission and dipole antenna 12 and dipole antenna 41 operate during reception to carry out diversity reception.
  • dipole antenna 41 can suppress deterioration of gain and at the same time mainly receive vertical polarized waves and horizontal polarized waves parallel to the longitudinal direction of the antenna element. Furthermore, dipole antenna 12 can not only suppress deterioration of gain but also mainly receive vertical polarized waves parallel to the longitudinal direction of the antenna element.
  • the signal sent from the other end of communication is often a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal matches the plane of polarization of the signal sent from the other end of communication and can thereby increase the reception gain.
  • this embodiment uses dipole antenna 12 in Embodiment 1 and dipole antenna 41 as the diversity antenna, and can thereby provide a high gain diversity antenna for a radio communication terminal with little influence from the human body. Moreover, the use of rectangular-wave-shaped dipole antenna 41 can reduce the size of the diversity antenna.
  • Embodiment 11 is a mode in which the dipole antenna used for reception in Embodiment 10 is changed to dipole antenna 121 with a configuration similar to dipole antenna 41 in Embodiment 3.
  • Embodiment 11 is the same as Embodiment 8 except for the configuration and method of mounting the dipole antenna.
  • the same parts in FIG.17 as those in Embodiment 8 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.17 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 11.
  • dipole antenna 41 and dipole antenna 121 are mounted in such a way that the longitudinal direction of one antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal and the longitudinal direction of the other antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 41 operates during transmission and dipole antenna 41 and dipole antenna 121 operate during reception to carry out diversity reception.
  • dipole antenna 41 can suppress deterioration of gain and at the same time mainly receive vertical polarized waves and horizontal polarized waves parallel to the longitudinal direction of the antenna element. Furthermore, dipole antenna 121 can not only suppress deterioration of gain but also mainly receive vertical polarized waves parallel to the longitudinal direction of the antenna element.
  • the signal sent from the other end of communication is often a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal matches the plane of polarization of the signal sent from the other end of communication and can thereby increase the reception gain.
  • this embodiment uses dipole antenna 121 in Embodiment 1 and dipole antenna 41 as the diversity antenna, and can thereby provide a high gain diversity antenna for a radio communication terminal with little influence from the human body. Moreover, the use of rectangular-wave-shaped dipole antenna 41 can reduce the size of the diversity antenna.
  • Embodiment 12 is a mode in which the configuration of the dipole antenna used in Embodiment 1 to Embodiment 11, Embodiment 17 to Embodiment 42, which will be described later and Embodiment 49 to Embodiment 59, which will be described later is changed.
  • FIG.18 is a schematic diagram showing a configuration of folded-dipole antenna 131 according to Embodiment 12. As shown in this figure, folded-dipole antenna 131 according to Embodiment 12 is formed in such a way that two rectangular-wave-shaped antenna elements are placed in parallel and the ends of these two antenna elements placed in parallel are shorted.
  • the folded-dipole antenna 131 in the above configuration is applicable as a built-in antenna for a radio communication terminal or as a dipole antenna making up a diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • folded-dipole antenna 131 as the dipole antenna to the configuration of each Embodiment above can attain effects similar to those in each Embodiment above and further increase impedance and perform impedance matching easily.
  • Embodiment 13 is a mode in which the configuration of the dipole antenna used in Embodiment 12 is changed.
  • Embodiment 13 is the same as Embodiment 12 except for the configuration of the dipole antenna.
  • FIG.19 is a schematic diagram showing a configuration of folded-dipole antenna 141 used in Embodiment 13. As shown in this figure, folded-dipole antenna 141 according to Embodiment 13 is formed in such a way that two rectangular-wave-shaped antenna elements are placed in parallel and impedance elements 142 are attached to the ends of these two antenna elements placed in parallel.
  • the folded-dipole antenna 141 in the above configuration is applicable as a built-in antenna for a radio communication terminal or as a dipole antenna making up a diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • folded-dipole antenna 141 as the dipole antenna can attain effects similar to those in each Embodiment above and further increase impedance and perform impedance matching easily. Furthermore, using folded-dipole antenna 141 in the above configuration as the dipole antenna can further widen the band and reduce the size of the antenna.
  • Embodiment 14 is a mode in which the configuration of the dipole antenna used in each embodiment above is changed. Embodiment 14 is the same as Embodiment 12 except for the configuration and method of mounting the dipole antenna.
  • FIG.20 is a schematic diagram showing a configuration of dipole antenna 151 used in Embodiment 14. As shown in this figure, dipole antenna 151 according to Embodiment 14 is constructed of a spiral antenna element.
  • the folded-dipole antenna 151 in the above configuration is applicable as a built-in antenna for a radio communication terminal or as a dipole antenna making up a diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • constructing a dipole antenna with a spiral antenna element can further reduce the size of the antenna.
  • Embodiment 15 is a mode in which the configuration of the dipole antenna used in each embodiment above is changed.
  • FIG.21 is a schematic diagram showing a configuration of folded-dipole antenna 161 used in Embodiment 15. As shown in this figure, folded-dipole antenna 161 according to Embodiment 15 is formed in such a way that the two spiral dipole antenna elements described in Embodiment 14 are placed in parallel and the ends of these two antenna elements are shorted.
  • the folded-dipole antenna 161 in the above configuration is applicable as a built-in antenna for a radio communication terminal or as a dipole antenna making up a diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • folded-dipole antenna 161 as the dipole antenna makes it possible to achieve effects similar to those in each embodiment above, improve impedance and perform impedance matching easily. Furthermore, adopting folded-dipole antenna 161 in the above configuration as the dipole antenna can further reduce the size of the antenna.
  • Embodiment 16 is a mode in which the configuration of the dipole antenna used in each Embodiment 15 is changed. Embodiment 16 is the same as Embodiment 15 except for the configuration and method of mounting the dipole antenna.
  • FIG.22 is a schematic diagram showing a configuration of folded-dipole antenna 171 used in Embodiment 16.
  • folded-dipole antenna 171 according to Embodiment 16 is formed in such a way that the two spiral dipole antenna elements described in Embodiment 14 are placed in parallel and impedance elements 142 are attached to the ends of these two antenna elements.
  • the folded-dipole antenna 171 in the above configuration is applicable as a built-in antenna for a radio communication terminal or as a dipole antenna making up a diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • folded-dipole antenna 171 as the dipole antenna makes it possible to achieve effects similar to those in Embodiment 12, widen the band and reduce the size.
  • dipole antennas 131, 141, 161 and 171 above have a self-balancing action, and therefore a configuration without balanced/unbalanced conversion circuit 13 can also be used in Embodiment 12 to Embodiment 16.
  • Embodiment 17 is a mode in which dipole antenna 12 shown in Embodiment 1 is patterned on circuit board 181.
  • FIG.23 is a schematic diagram showing a configuration of dipole antenna 12 placed on circuit board 181 in Embodiment 17. As shown in this figure, dipole antenna 12 is patterned on circuit board 181.
  • this embodiment can achieve effects similar to those in Embodiment 1. Furthermore, patterning dipole antenna 12 shown in Embodiment 1 on circuit board 181 makes it possible to obtain a stable characteristic.
  • this embodiment can also be implemented by patterning the dipole antenna shown in each embodiment above on circuit board 181.
  • Embodiment 18 is a mode in which dipole antenna 12 shown in each embodiment above is patterned on package case 191.
  • FIG.24 is a schematic diagram showing a configuration of dipole antenna 12 placed on package case 191 in Embodiment 18. As shown in this figure, dipole antenna 12 is patterned on circuit board 191.
  • this embodiment can achieve effects similar to those in Embodiment 1. Furthermore, patterning dipole antenna 12 shown in Embodiment 1 on package case 191 makes it possible to obtain a stable characteristic, save the space for installing the antenna and thereby reduce the size of the apparatus.
  • this embodiment can also be implemented by patterning the dipole antenna shown in each embodiment above on circuit board 181.
  • Embodiment 19 is a mode in which the configuration of dipole antenna 12 in Embodiment 1 is changed.
  • Embodiment 19 is the same as Embodiment 1 except for the configuration of dipole antenna 12 and therefore detailed explanations thereof will be omitted. Only differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 1 will be explained using FIG.25. The parts similar to those in Embodiment 1 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.25 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 19.
  • the built-in antenna for a radio communication terminal according to Embodiment 19 is constructed of base plate 11, balanced/unbalanced conversion circuit 13, power supply terminals 14 and dipole antenna 201.
  • One of the two antenna elements making up dipole antenna 201 is formed in a rectangular-wave shape and the other is formed in a bar shape. These two antenna elements are placed in such a way that their respective longitudinal directions form a straight line.
  • the bar-shaped antenna element is placed outside a radio communication terminal, which is not shown.
  • Dipole antenna 201 is mounted in such a way that the longitudinal direction of the rectangular-wave-shaped antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal and the longitudinal direction of the bar-shaped antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 201 is mounted in such a way that the axial direction of the bar-shaped antenna element and the longitudinal direction of the rectangular-wave-shaped antenna element are quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal. This allows dipole antenna 201 to mainly receive vertical polarized waves parallel to the axial direction of the bar-shaped antenna element and the longitudinal direction of the rectangular-wave-shaped antenna element in a free space.
  • the human body acts as a reflector, and therefore dipole antenna 201 has directivity opposite to the human body.
  • Dipole antenna 201 supplied with power in this way mainly sends vertical polarized waves parallel to this longitudinal direction.
  • dipole antenna 201 receives vertical polarized waves parallel to the longitudinal direction above. Therefore, in a free space, vertical polarized waves are received from all directions centered on the dipole antenna and during a conversation, the human body acts as a reflector as described above, and therefore of the vertical polarized waves above, the vertical polarized waves from the direction opposite to the human body are mainly received.
  • dipole antenna 201 can not only suppress deterioration of gain but also mainly receive vertical polarized waves parallel to the longitudinal direction.
  • the signal sent from the other end of communication is often a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal according to this embodiment matches the plane of polarization of the signal sent from the other end of communication and can thereby increase the reception gain.
  • the signal above (balanced signal) received from dipole antenna 201 is sent to the transmission/reception circuit via balanced/unbalanced conversion circuit 13.
  • the current that flows into base plate 11 is suppressed to a minimum by the above-described balanced/unbalanced conversion circuit 13, and therefore the antenna operation by base plate 11 is prevented. This minimizes the reduction of gain caused by influences from the human body.
  • balanced/unbalanced conversion circuit 13 can minimize the antenna current that flows into base plate 11, and can thereby suppress deterioration of gain of dipole antenna 201 caused by influences from the human body. Furthermore, adopting a square-wave shape for one of the antenna elements of dipole antenna 201 makes it possible to reduce the size of the built-in antenna for a radio communication terminal. Therefore, it is possible to provide a high gain and small built-in antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 20 is a mode in which the configuration and method of mounting dipole antenna 201 in Embodiment 19 are changed.
  • Embodiment 20 is the same as Embodiment 19 except for the configuration and method of mounting dipole antenna 201, and therefore detailed explanations thereof will be omitted. Only differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 19 will be explained using FIG.26. The parts similar to those in Embodiment 19 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.26 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 20.
  • the built-in antenna for a radio communication terminal according to Embodiment 20 is constructed of base plate 11, balanced/unbalanced conversion circuit 13, power supply terminals 14 and dipole antenna 211.
  • the two antenna elements making up dipole antenna 211 are placed in such a way that the longitudinal direction of the rectangular-wave-shaped antenna element and the longitudinal direction of the bar-shaped antenna element intersect at quasi-right angles.
  • Dipole antenna 211 is mounted in such a way that the longitudinal direction of the rectangular-wave-shaped antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal and the longitudinal direction of the bar-shaped antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal. That is, this embodiment differs from Embodiment 19 in that dipole antenna 12 is mounted in such a way that the longitudinal direction thereof is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • An unbalanced signal from the transmission/reception circuit above is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and sent to dipole antenna 211.
  • the bar-shaped antennal element placed quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal making up dipole antenna 211 supplied with power in this way mainly sends vertical polarized waves.
  • dipole antenna 211 receives vertical polarized waves parallel to the longitudinal direction above.
  • the rectangular-wave-shaped antenna element placed quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal making up dipole antenna 12 supplied with power in this way mainly sends horizontal polarized waves parallel to this longitudinal direction.
  • dipole antenna 211 receives horizontal polarized waves parallel to the longitudinal direction above. Therefore, in a free space, vertical polarized waves and horizontal polarized waves are received from all directions centered on the dipole antenna and during a conversation, the human body acts as a reflector, and therefore of the vertical polarized waves and horizontal polarized waves above, the waves from the direction opposite to the human body are mainly received.
  • dipole antenna 211 can not only suppress deterioration of gain but also mainly receive both vertical polarized waves and horizontal polarized waves.
  • the signal sent from the other end of communication is often a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection. That is, even if there are either more vertical polarized waves or more horizontal polarized waves, the built-in antenna for a radio communication terminal according to this embodiment matches the plane of polarization of the signal sent from the other end of communication and can thereby increase the reception gain.
  • this embodiment can achieve effects similar to those of Embodiment 20.
  • Embodiment 21 is a mode in which the configuration and method of mounting dipole antenna 201 in Embodiment 19 are changed.
  • Embodiment 21 is the same as Embodiment 19 except for the configuration and method of mounting dipole antenna 201 and therefore detailed explanations thereof will be omitted. Only differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 19 will be explained using FIG.27. The parts similar to those in Embodiment 19 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.27 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 21.
  • the built-in antenna for a radio communication terminal according to Embodiment 21 is constructed of base plate 11, balanced/unbalanced conversion circuit 13, power supply terminals 14 and dipole antenna 221.
  • the two antenna elements making up dipole antenna 221 are folded near the center and the part of the folded antenna element including power supply terminals 14 is rectangular-wave-shaped and the part of the folded antenna element without power supply terminals 14 is bar-shaped.
  • Dipole antenna 221 is placed in such a way that the longitudinal directions of the rectangular-wave-shaped parts of the antenna elements form a quasi-straight line.
  • the bar-shaped parts of the antenna elements are placed outside the package of the radio communication terminal, which is not shown.
  • Dipole antenna 221 in the above configuration is mounted in such a way that the longitudinal directions of the folded rectangular-wave-shaped parts of the antenna elements making up dipole antenna 221 are quasi-parallel to the upper surface (horizontal surface) of the radio communication terminal.
  • the bar-shaped parts of the antenna elements are placed quasi-perpendicular to the upper surface (horizontal surface) of the radio communication terminal.
  • Dipole antenna 221 is mounted in such a way that the longitudinal direction of the rectangular-wave-shaped part of the antenna element is quasi-parallel to the upper surface (horizontal surface) of the radio communication terminal. Mounting dipole antenna 221 in this way makes the axial direction of the bar-shaped part of the antenna element quasi-perpendicular to the upper surface (horizontal surface) of the radio communication terminal.
  • An unbalanced signal from the transmission/reception circuit above is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and then sent to dipole antenna 221.
  • the bar-shaped part of the antenna element placed quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal that makes up dipole antenna 221 supplied with power in this way mainly sends vertical polarized waves parallel to the axial direction of this antenna element. Furthermore, during reception, vertical polarized waves parallel to the axial direction above are received.
  • the rectangular-wave-shaped part of the antenna element placed quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal that makes up dipole antenna 12 supplied with power in the same way mainly sends horizontal polarized waves parallel to this longitudinal direction. Furthermore, during reception, horizontal polarized waves parallel to the longitudinal direction above are received. Thus, in a free space, vertical polarized waves and horizontal polarized waves from all directions centered on the dipole antenna are received, and during a conversation, since the human body acts as a reflector as described above, of the vertical polarized waves, the vertical polarized waves and horizontal polarized waves opposite to the human body are mainly received.
  • dipole antenna 221 to suppress deterioration of gain and mainly receive horizontal polarized waves parallel to the longitudinal direction of the rectangular-wave-shaped part and vertical polarized waves parallel to the axial direction of the bar-shaped part.
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal according to this embodiment matches the polarization plane of the signal sent from the other end of communication, making it possible to increase reception gain.
  • this embodiment can also achieve effects similar to those of Embodiment 20.
  • Embodiment 22 is a mode in which the configuration of the bar-shaped antenna element that makes up dipole antenna 201 in Embodiment 19 is changed.
  • the antenna for a radio communication terminal according to this embodiment will be explained below using FIG.28.
  • the parts similar to those in Embodiment 19 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.28 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 22.
  • the antenna for a radio communication terminal according to Embodiment 22 is constructed of base plate 11, balanced/unbalanced conversion circuit 13 and dipole antenna 231.
  • Dipole antenna 231 adopts a configuration in which the bar-shaped antenna element making up dipole antenna 201 is formed in a rectangular-wave shape.
  • An unbalanced signal from the transmission/reception circuit above is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and then sent to dipole antenna 231.
  • Dipole antenna 231 supplied with power in this way is placed in such a way that the longitudinal direction is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal, and therefore mainly sends vertical polarized waves parallel to this longitudinal direction. Furthermore, during reception, vertical polarized waves parallel to the longitudinal direction above are received.
  • dipole antenna 231 to suppress deterioration of gain and mainly receive vertical polarized waves parallel to the longitudinal direction of the antenna element.
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal according to this embodiment matches the polarization plane of the signal sent from the other end of communication, allowing reception gain to be increased.
  • this embodiment can achieve effects similar to those of Embodiment 19 and at the same time reduce the size of the external antenna.
  • Embodiment 23 is a mode in which the configuration of the bar-shaped antenna element that makes up dipole antenna 211 in Embodiment 20 is changed.
  • the antenna for a radio communication terminal according to this embodiment will be explained below using FIG.29.
  • the parts similar to those in Embodiment 20 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.29 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 23.
  • the antenna for a radio communication terminal according to Embodiment 23 is constructed of base plate 11, balanced/unbalanced conversion circuit 13 and dipole antenna 241.
  • Dipole antenna 241 adopts a configuration in which the bar-shaped antenna element making up dipole antenna 211 is changed to a rectangular-wave shape.
  • Dipole antenna 241 supplied with power in this way is placed in such a way that the longitudinal direction of one antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal and the longitudinal direction of the other antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal, and therefore sends vertical and horizontal polarized waves parallel to these longitudinal directions. Furthermore, during reception, vertical polarized waves and horizontal polarized waves parallel to the longitudinal directions above are received.
  • dipole antenna 241 to suppress deterioration of gain and mainly receive vertical polarized waves and horizontal polarized waves parallel to the longitudinal directions.
  • Dipole antenna 241 can suppress deterioration of gain and mainly receive horizontal polarized waves parallel to the longitudinal direction.
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal matches the polarization plane of the signal sent from the other end of communication, allowing reception gain to be increased.
  • this embodiment can achieve effects similar to those of Embodiment 20 and at the same time reduce the size of the external antenna.
  • Embodiment 24 is a mode in which the configuration of the bar-shaped part of the antenna element that makes up dipole antenna 221 in Embodiment 21 is changed.
  • the antenna for a radio communication terminal according to this embodiment will be explained below using FIG.30.
  • the same configurations as those in Embodiment 21 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.30 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 24.
  • the antenna for a radio communication terminal according to Embodiment 24 is constructed of base plate 11, balanced/unbalanced conversion circuit 13, power supply terminals 14 and dipole antenna 251.
  • Dipole antenna 251 adopts a configuration in which the bar-shaped antenna element making up dipole antenna 221 is changed to a rectangular-wave shape.
  • the operation of the built-in antenna for a radio communication terminal in the above configuration will be explained.
  • An unbalanced signal from the transmission/reception circuit above is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and then sent to dipole antenna 251.
  • the part placed quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal mainly sends vertical polarized waves parallel to this longitudinal direction of this part. Furthermore, during reception, vertical polarized waves parallel to the longitudinal direction above are received.
  • the part placed quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal of the antenna elements that make up dipole antenna 251 supplied with power in the same way mainly sends horizontal polarized waves parallel to this longitudinal direction of this part. Furthermore, during reception, horizontal polarized waves parallel to the longitudinal direction above are received. Thus, in a free space, vertical polarized waves and horizontal polarized waves from all directions centered on the dipole antenna are received, and during a conversation, since the human body acts as a reflector as described above, of the vertical and horizontal polarized waves above, the waves opposite to the human body are mainly received.
  • dipole antenna 251 to suppress deterioration of gain and mainly receive vertical polarized waves and horizontal polarized waves parallel to the longitudinal directions of the respective antenna elements.
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal according to this embodiment matches the polarization plane of the signal sent from the other end of communication, making it possible to increase reception gain.
  • this embodiment can achieve effects similar to those of Embodiment 21 and at the same time reduce the size of the external antenna.
  • Embodiment 25 to Embodiment 38 are modes in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 19 to Embodiment 24.
  • Embodiment 25 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 19.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.31.
  • the configurations similar to those in Embodiment 19 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.31 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 25.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to this Embodiment 19 with additional dipole antenna 261.
  • Dipole antenna 261 has a configuration similar to that of dipole antenna 201.
  • dipole antenna 261 operates during transmission and dipole antenna 201 and dipole antenna 261 operate during reception to carry out diversity reception.
  • dipole antenna 201 in Embodiment 19 and dipole antenna 261 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 19.
  • Embodiment 26 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 20.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.32.
  • the configurations similar to those in Embodiment 20 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.32 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 26.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to this Embodiment 20 with additional dipole antenna 271.
  • Dipole antenna 271 has a configuration similar to that of dipole antenna 211.
  • dipole antenna 271 operates during transmission and dipole antenna 211 and dipole antenna 271 operate during reception to carry out diversity reception.
  • dipole antenna 211 in Embodiment 20 and dipole antenna 271 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 20.
  • Embodiment 27 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 22.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.33.
  • the configurations similar to those in Embodiment 22 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.33 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 27.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to this Embodiment 22 with additional dipole antenna 281.
  • Dipole antenna 281 has a configuration similar to that of dipole antenna 231.
  • dipole antenna 281 operates during transmission and dipole antenna 231 and dipole antenna 281 operate during reception to carry out diversity reception.
  • dipole antenna 231 in Embodiment 22 and dipole antenna 281 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 22.
  • Embodiment 28 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 23.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.34.
  • the configurations similar to those in Embodiment 23 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.34 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 28.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to this Embodiment 23 with additional dipole antenna 291.
  • Dipole antenna 291 has a configuration similar to that of dipole antenna 241.
  • dipole antenna 291 operates during transmission and dipole antenna 241 and dipole antenna 291 operate during reception to carry out diversity reception.
  • dipole antenna 241 in Embodiment 23 and dipole antenna 291 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 23.
  • Embodiment 29 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 19.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.35.
  • the configurations similar to those in Embodiment 1 and Embodiment 19 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.35 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 29.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to this Embodiment 19 with additional dipole antenna 12 shown in Embodiment 1.
  • dipole antenna 201 operates during transmission and dipole antenna 201 and dipole antenna 12 operate during reception to carry out diversity reception.
  • dipole antenna 12 in Embodiment 1 and dipole antenna 201 in Embodiment 19 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 19.
  • Embodiment 30 is a mode in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal in Embodiment 2 and Embodiment 19.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.36.
  • the configurations similar to those in Embodiment 2 and Embodiment 19 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.36 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 30.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to Embodiment 19 with additional dipole antenna 12 shown in Embodiment 2.
  • dipole antenna 201 operates during transmission and dipole antenna 201 and dipole antenna 12 operate during reception to carry out diversity reception.
  • dipole antenna 12 in Embodiment 2 and dipole antenna 201 in Embodiment 19 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 1 and Embodiment 19.
  • Embodiment 31 is a mode in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal in Embodiment 3 and Embodiment 19.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.37.
  • the configurations similar to those in Embodiment 3 and Embodiment 19 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.37 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 31.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to Embodiment 19 with additional dipole antenna 41 shown in Embodiment 3.
  • dipole antenna 201 operates during transmission and dipole antenna 201 and dipole antenna 41 operate during reception to carry out diversity reception.
  • dipole antenna 41 in Embodiment 3 and dipole antenna 201 in Embodiment 19 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 3 and Embodiment 19.
  • Embodiment 32 is a mode in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal in Embodiment 1 and Embodiment 20.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.38.
  • the configurations similar to those in Embodiment 1 and Embodiment 20 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.38 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 32.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to Embodiment 20 with additional dipole antenna 12 shown in Embodiment 1.
  • dipole antenna 211 operates during transmission and dipole antenna 211 and dipole antenna 12 operate during reception to carry out diversity reception.
  • dipole antenna 12 in Embodiment 1 and dipole antenna 211 in Embodiment 20 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 1 and Embodiment 20.
  • Embodiment 33 is a mode in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal in Embodiment 3 and Embodiment 20.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.39.
  • the configurations similar to those in Embodiment 3 and Embodiment 20 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.39 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 33.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to Embodiment 20 with additional dipole antenna 41 shown in Embodiment 3.
  • dipole antenna 211 operates during transmission and dipole antenna 211 and dipole antenna 41 operate during reception to carry out diversity reception.
  • dipole antenna 41 in Embodiment 3 and dipole antenna 211 in Embodiment 20 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 3 and Embodiment 20.
  • Embodiment 34 is a mode in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal in Embodiment 1 and Embodiment 22.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.40.
  • the configurations similar to those in Embodiment 1 and Embodiment 22 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.40 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 34.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antennas for a radio communication terminal according to Embodiment 22 with additional dipole antenna 12 shown in Embodiment 1.
  • dipole antenna 231 operates during transmission and dipole antenna 231 and dipole antenna 12 operate during reception to carry out diversity reception.
  • dipole antenna 12 in Embodiment 1 and dipole antenna 231 in Embodiment 22 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 1 and Embodiment 22.
  • Embodiment 35 is a mode in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal in Embodiment 2 and Embodiment 22.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.41.
  • the configurations similar to those in Embodiment 2 and Embodiment 22 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.41 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 35.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to Embodiment 22 with additional dipole antenna 12 shown in Embodiment 2.
  • dipole antenna 231 operates during transmission and dipole antenna 231 and dipole antenna 12 operate during reception to carry out diversity reception.
  • dipole antenna 12 in Embodiment 2 and dipole antenna 231 in Embodiment 22 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 2 and Embodiment 22.
  • Embodiment 36 is a mode in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal in Embodiment 3 and Embodiment 22.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.42.
  • the configurations similar to those in Embodiment 3 and Embodiment 22 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.42 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 36.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to Embodiment 22 with additional dipole antenna 41 shown in Embodiment 3.
  • dipole antenna 231 operates during transmission and dipole antenna 231 and dipole antenna 41 operate during reception to carry out diversity reception.
  • dipole antenna 41 in Embodiment 3 and dipole antenna 231 in Embodiment 22 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 3 and Embodiment 22.
  • Embodiment 37 is a mode in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal in Embodiment 1 and Embodiment 23.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.43.
  • the configurations similar to those in Embodiment 1 and Embodiment 23 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.43 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 37.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to Embodiment 23 with additional dipole antenna 12 shown in Embodiment 1.
  • dipole antenna 241 operates during transmission and dipole antenna 241 and dipole antenna 12 operate during reception to carry out diversity reception.
  • dipole antenna 12 in Embodiment 1 and dipole antenna 241 in Embodiment 23 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 1 and Embodiment 23.
  • Embodiment 38 is a mode in which a diversity antenna is implemented using the built-in antennas for a radio communication terminal in Embodiment 3 and Embodiment 23.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained below using FIG.44.
  • the configurations similar to those in Embodiment 3 and Embodiment 23 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.44 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 38.
  • the diversity antenna according to this embodiment is constructed of the configuration of the built-in antenna for a radio communication terminal according to Embodiment 23 with additional dipole antenna 41 shown in Embodiment 3.
  • dipole antenna 241 operates during transmission and dipole antenna 241 and dipole antenna 41 operate during reception to carry out diversity reception.
  • dipole antenna 41 in Embodiment 3 and dipole antenna 241 in Embodiment 23 are used as the diversity antenna, which makes it possible to provide a high gain and small diversity antenna for a radio communication terminal with little influence from the human body as in the case of Embodiment 3 and Embodiment 23.
  • Embodiment 39 is a mode in which the configuration of dipole antenna 41 in Embodiment 3 is changed.
  • Embodiment 39 is the same as Embodiment 3 except for the configuration of the dipole antenna, and therefore detailed explanations thereof will be omitted.
  • Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 3 will be explained below using FIG.45. The parts similar to those in Embodiment 3 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.45 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 39.
  • the built-in antenna for a radio communication terminal according to Embodiment 39 is constructed of base plate 11, balanced/unbalanced conversion circuit 13 and dipole antenna 401.
  • One of the two antenna elements making up dipole antenna 401 is formed in a rectangular-wave shape and the other is formed in a bar shape. These two antenna elements are placed in such a way that the longitudinal direction of the rectangular-wave-shaped antenna element intersects the axial direction of the bar-shaped antenna element at quasi-right angles.
  • Dipole antenna 401 is mounted in such a way that the longitudinal direction of the rectangular-wave-shaped antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal.
  • the axial direction of the bar-shaped antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 401 is mounted in such a way that the longitudinal direction of the rectangular-wave-shaped antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal.
  • the axial direction of the bar-shaped antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal. This allows dipole antenna 401 to receive vertical polarized waves parallel to the longitudinal direction and horizontal polarized waves parallel to the longitudinal direction in a free space.
  • the human body acts as a reflector, and therefore dipole antenna 401 has directivity opposite to the human body.
  • An unbalanced signal from the transmission/reception circuit above is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and sent to dipole antenna 401.
  • the rectangular-wave-shaped antenna element of dipole antenna 401 supplied with power in this way mainly sends vertical polarized waves parallel to this longitudinal direction. Furthermore, during reception, it receives vertical polarized waves parallel to the longitudinal direction above.
  • the bar-shaped antenna element of dipole antenna 401 supplied with power in this way mainly sends horizontal polarized waves. Furthermore, during reception, it receives horizontal polarized waves parallel to the axial direction of the bar-shaped antenna element.
  • the signal above (balanced signal) received from dipole antenna 401 is sent to the transmission/reception circuit above via balanced/unbalanced conversion circuit 13.
  • the current that flows into base plate 11 is suppressed to a minimum by above-described balanced/unbalanced conversion circuit 13, and therefore the antenna operation by base plate 11 is prevented. This minimizes the reduction of gain caused by influences from the human body.
  • balanced/unbalanced conversion circuit 13 can minimize the antenna current that flows into base plate 11, and can thereby suppress deterioration of gain of dipole antenna 201 caused by influences from the human body. Furthermore, adopting a rectangular-wave shape for one of the antenna elements of dipole antenna 401 makes it possible to reduce the size of the built-in antenna for a radio communication terminal. Therefore, it is possible to provide a high gain and small built-in antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 40 is a mode in which the configuration of dipole antenna 401 in Embodiment 39 is changed.
  • Embodiment 40 is the same as Embodiment 39 except for the configuration of dipole antenna 401, and therefore detailed explanations thereof will be omitted.
  • Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 39 will be explained below using FIG.46.
  • the parts similar to those in Embodiment 39 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.46 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 40.
  • the built-in antenna for a radio communication terminal according to Embodiment 40 is constructed of base plate 11, balanced/unbalanced conversion circuit 13 and dipole antenna 411.
  • the two antenna elements making up dipole antenna 411 are placed in such a way that the longitudinal direction of the rectangular-wave-shaped antenna element intersects the axial direction of the bar-shaped antenna element at quasi-right angles.
  • Dipole antenna 411 is mounted in such a way that the longitudinal direction of the rectangular-wave-shaped antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • the axial direction of the bar-shaped antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 411 to receive horizontal polarized waves parallel to the longitudinal direction of the rectangular-wave-shaped antenna element and vertical polarized waves parallel to the axial direction of the bar-shaped antenna element in a free space. Furthermore, during a conversation, the human body acts as a reflector, and therefore dipole antenna 401 has directivity opposite to the human body.
  • this embodiment can also achieve effects similar to those of Embodiment 39. Furthermore, by mainly receiving vertical polarized waves using the bar-shaped antenna element and mainly receiving horizontal polarized waves using the rectangular-wave-shaped antenna element, it is possible to change the ratio of polarization of vertical polarized waves to horizontal polarized waves as appropriate and thereby receive at a ratio of polarization according to the purpose of use of the antenna.
  • Embodiment 41 is a mode in which the configuration of dipole antenna 51 in Embodiment 4 is changed.
  • Embodiment 41 is the same as Embodiment 4 except for the configuration of the dipole antenna, and therefore detailed explanations thereof will be omitted.
  • Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 4 will be explained below using FIG.47. The parts similar to those in Embodiment 4 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.47 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 41.
  • the built-in antenna for a radio communication terminal according to Embodiment 41 is constructed of base plate 11, balanced/unbalanced conversion circuit 13, power supply terminals 14 and dipole antenna 421.
  • the two antenna elements making up dipole antenna 421 are folded near the center and the parts of the folded antenna elements including power supply terminals 14 are bar-shaped and the other parts without power supply terminals 14 are rectangular-wave-shaped.
  • the two antenna elements are placed in such a way that their respective bar-shaped parts form a straight line.
  • Dipole antenna 421 is mounted in such a way that the longitudinal direction of the rectangular-wave-shaped antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal.
  • the axial direction of the bar-shaped antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 421 to receive vertical polarized waves parallel to the longitudinal direction of the rectangular-wave-shaped antenna element and horizontal polarized waves parallel to the axial direction of the bar-shaped antenna element in a free space. Furthermore, during a conversation, the human body acts as a reflector, and therefore dipole antenna 421 has directivity opposite to the human body.
  • An unbalanced signal from the transmission/reception circuit above is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and sent to dipole antenna 421.
  • the rectangular-wave-shaped part of dipole antenna 421 supplied with power in this way mainly sends vertical polarized waves parallel to the longitudinal direction of this rectangular-wave-shaped part.
  • dipole antenna 421 receives vertical polarized waves parallel to the longitudinal direction above.
  • the bar-shaped part of the antenna element making up dipole antenna 421 supplied with power in this way mainly sends parallel polarized waves parallel to the axial direction of this part.
  • the signal above (balanced signal) received from dipole antenna 421 is sent to the transmission/reception circuit above via balanced/unbalanced conversion circuit 13.
  • the current that flows into base plate 11 is suppressed to a minimum by above-described balanced/unbalanced conversion circuit 13, and therefore the antenna operation by base plate 11 is prevented. This minimizes the reduction of gain caused by influences from the human body.
  • this embodiment also achieves effects similar to those of Embodiment 39. Furthermore, by mainly receiving vertical polarized waves using the bar-shaped antenna element and mainly receiving horizontal polarized waves using the rectangular-wave-shaped antenna element, it is possible to change the ratio of polarization of vertical polarized waves to horizontal polarized waves as appropriate and thereby receive at a ratio of polarization according to the purpose of use of the antenna.
  • Embodiment 42 is a mode in which the configuration of dipole antenna 421 in Embodiment 41 is changed.
  • Embodiment 42 is the same as Embodiment 41 except for the configuration of dipole antenna 421, and therefore detailed explanations thereof will be omitted.
  • Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 41 will be explained below using FIG.48.
  • the parts similar to those in Embodiment 41 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.48 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 42.
  • the built-in antenna for a radio communication terminal according to Embodiment 42 is constructed of base plate 11, balanced/unbalanced conversion circuit 13, power supply terminals 14 and dipole antenna 431.
  • the two antenna elements making up dipole antenna 431 are folded near the center and the parts of the folded antenna elements including the power supply terminals 14 are rectangular-wave-shaped and the other parts without power supply terminals 14 are bar-shaped.
  • the two antenna elements are placed in such a way that the longitudinal directions of the rectangular-wave-shaped parts form a straight line.
  • Dipole antenna 431 is mounted in such a way that the longitudinal directions of the rectangular-wave-shaped parts are quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • the axial directions of the bar-shaped parts are quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 431 to receive vertical polarized waves parallel to the longitudinal direction of the rectangular-wave-shaped antenna element and horizontal polarized waves parallel to the axial direction of the bar-shaped antenna element in a free space. Furthermore, during a conversation, the human body acts as a reflector, and therefore dipole antenna 401 has directivity opposite to the human body.
  • this embodiment also achieves effects similar to those of Embodiment 39. Furthermore, by mainly receiving vertical polarized waves using the bar shaped antenna element and mainly receiving horizontal polarized waves using the rectangular-wave-shaped antenna element, it is possible to change the ratio of polarization of vertical polarized waves to horizontal polarized waves as appropriate and thereby receive at a ratio of polarization according to the purpose of use of the antenna.
  • Embodiment 43 is a mode in which the configuration of the dipole antenna used in each embodiment above is changed.
  • FIG.49 is a schematic diagram showing a configuration of dipole antenna 441 used in Embodiment 43.
  • the folded-dipole antenna 441 according to Embodiment 43 is formed in such a way that inductance element 442 is inserted between the terminals of the rectangular-wave-shaped antenna elements and power supply terminals 14.
  • the folded-dipole antenna 441 in the above configuration is applicable as the built-in antenna for a radio communication terminal or as the dipole antenna making up the diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • dipole antenna 441 as the dipole antenna can attain effects similar to those in each embodiment above and further increase impedance and perform impedance matching easily. Moreover, using dipole antenna 441 in the above configuration as the dipole antenna makes it possible to implement a double-frequency antenna.
  • Embodiment 44 is a mode in which the configuration of the dipole antenna used in Embodiment 12 is changed.
  • Embodiment 44 is the same as Embodiment 12 except for the configuration of the dipole antenna.
  • FIG.50 is a schematic diagram showing a configuration of dipole antenna 451 used in Embodiment 44.
  • the folded-dipole antenna 451 according to Embodiment 44 is formed in such a way that two rectangular-wave-shaped antenna elements are placed in parallel, these two rectangular-wave-shaped antenna elements placed in parallel are connected near the center using capacitance elements 451 and the ends of these two antenna elements are shorted.
  • the folded-dipole antenna 451 in the above configuration is applicable as the built-in antenna for a radio communication terminal or as the dipole antenna making up the diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • this embodiment can also obtain a configuration similar to that of Embodiment 12. Moreover, using dipole antenna 441 in the above configuration as the dipole antenna makes it possible to implement a double-frequency antenna.
  • Embodiment 45 is a mode in which the configuration of the dipole antenna used in the embodiment above is changed. Embodiment 45 is the same as the embodiment above except for the configuration of the dipole antenna.
  • the parts in FIG.51 similar to those in the embodiment above are assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.51 is a schematic diagram showing a configuration of folded-dipole antenna 461 used in Embodiment 45 .
  • the folded-dipole antenna 461 according to Embodiment 45 is formed in such a way that inductance elements 462 are placed between the ends of the rectangular-wave-shaped antenna elements and power supply terminals 14.
  • the folded-dipole antenna 461 in the above configuration is applicable as the built-in antenna for a radio communication terminal or as the dipole antenna making up the diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • this embodiment can also obtain a configuration similar to that of Embodiment 14. Moreover, using dipole antenna 461 in the above configuration as the dipole antenna makes it possible to implement a double-frequency antenna.
  • Embodiment 46 is a mode in which the configuration of the dipole antenna used in Embodiment 15 is changed.
  • Embodiment 46 is the same as Embodiment 15 except for the configuration of the dipole antenna.
  • the parts in FIG.52 similar to those in the embodiment above are assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.52 is a schematic diagram showing a configuration of folded-dipole antenna 471 used in Embodiment 46.
  • the folded-dipole antenna 471 according to Embodiment 46 is formed in such a way that the two spiral antenna elements of the dipole antenna explained in the above embodiment are placed in parallel, these two antennal elements placed in parallel are connected by capacitance 472 near the center and the ends are shorted.
  • the folded-dipole antenna 471 in the above configuration is applicable as the built-in antenna for a radio communication terminal or as the dipole antenna making up the diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • this embodiment can also obtain a configuration similar to that of Embodiment 15. Moreover, using dipole antenna 471 in the above configuration as the dipole antenna makes it possible to implement a double-frequency antenna.
  • Embodiment 47 is a mode in which the configuration of the dipole antenna used in the embodiment above is changed. Embodiment 47 is the same as the embodiment above except for the configuration of the dipole antenna.
  • the parts in FIG.53 similar to those in the embodiment above are assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.53 is a schematic diagram showing a configuration of dipole antenna 481 used in Embodiment 47.
  • the dipole antenna 481 according to Embodiment 47 is formed in such a way that the two antenna elements of the rectangular-wave-shaped dipole antenna explained in the above embodiment are placed in parallel, power supply terminals 14 of these two antennal elements placed in parallel are shorted.
  • the folded-dipole antenna 481 in the above configuration is applicable as the built-in antenna for a radio communication terminal or as the dipole antenna making up the diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • this embodiment can also obtain a configuration similar to that of Embodiment 12. Moreover, using dipole antenna 481 in the above configuration as the dipole antenna makes it possible to implement a double-frequency antenna.
  • Embodiment 48 is a mode in which the configuration of the dipole antenna used in Embodiment 12 is changed.
  • Embodiment 48 is the same as Embodiment 12 except for the configuration of the dipole antenna.
  • the parts in FIG.54 similar to those in the embodiment above are assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.54 is a schematic diagram showing a configuration of dipole antenna 491 used in Embodiment 48.
  • the dipole antenna 491 according to Embodiment 48 is formed in such a way that the two antenna elements of the spiral dipole antenna explained in Embodiment 14 are placed in parallel, power supply terminals 14 of these two antennal are shorted.
  • the folded-dipole antenna 491 in the above configuration is applicable as the built-in antenna for a radio communication terminal or as the dipole antenna making up the diversity antenna according to Embodiments 1 to 11, Embodiments 17 to 42, which will be described later and Embodiments 49 to 59, which will be described later.
  • this embodiment can also obtain a configuration similar to that of Embodiment 14. Moreover, using dipole antenna 491 in the above configuration as the dipole antenna makes it possible to implement a double-frequency antenna.
  • dipole antennas 441, 451, 461, 471, 481 and 491 above have a self-balancing action, and therefore a configuration without balanced/unbalanced conversion circuit 13 can also be used in Embodiment 43 to Embodiment 48.
  • Embodiment 1 to Embodiment 48 describe cases where antenna elements are rectangular-wave-shaped, but the present invention is not limited to this, and the antenna elements can also be bar-shaped depending on the transmission/reception frequency, the shape and size of the radio equipment that incorporates antennas.
  • Embodiment 49 is a mode in which the configuration of the dipole antenna used in Embodiment 1 is changed and a passive element is provided.
  • Embodiment 49 is the same as Embodiment 1 except for the configuration of the dipole antenna and the passive element.
  • the parts in FIG.55 similar to those in the embodiment above are assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.55 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to Embodiment 49 of the present invention.
  • the built-in antenna for a radio communication terminal according to Embodiment 49 is constructed of base plate 11, dipole antenna 12, balanced/unbalanced conversion circuit 13 and power supply terminals 14.
  • the built-in antenna for a radio communication terminal according to this embodiment is incorporated in a communication terminal apparatus.
  • FIG.56 is a front view showing the appearance of the communication terminal apparatus incorporating the built-in antenna for a radio communication terminal according to this embodiment.
  • speaker 511 is provided at the top of the main plane of package 510.
  • display 512 that displays various kinds of information such as telephone numbers to be called and operation menu.
  • microphone 513 At the bottom of the main plane of package 510 is microphone 513 to catch voice of the user.
  • built-in antenna 514 for a radio communication terminal according to this embodiment is incorporated in package 510. This built-in antenna 514 for a radio communication terminal is installed in such a way that base plate 11 is placed quasi-parallel to the main plane.
  • Dipole antenna 501 is constructed of two bar-shaped antenna elements.
  • the two antenna elements making up dipole antenna 501 are placed in such a way that their respective axial directions form one quasi-straight line.
  • dipole antenna 501 is mounted in such a way that the axial directions of the antenna elements are quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal. Since the radio communication terminal is used in a state shown in FIG.58, dipole antenna 501 is provided in such a way that the axial directions of the antenna elements are quasi-perpendicular to the horizontal plane.
  • dipole antenna 501 mainly receives vertical polarized waves parallel to the axial direction in a free space.
  • dipole antenna 501 since the human body operates as a reflector during a conversation, dipole antenna 501 has directivity opposite to the direction of the human body.
  • Passive element 502 is bar-shaped. Passive element 502 is quasi-parallel to the axial directions of the antenna elements making up dipole antenna 501 and the plane (reference plane) containing the antenna elements making up dipole antenna 501 and passive element 502 intersects with the plane of base plate 11 at quasi-right angles. Since base plate 11 is provided quasi-parallel to the main plane of package 510, the reference plane also intersects with the main plane of package 510 at quasi-right angles.
  • FIG.57 is a cross-sectional view viewed from the direction of arrow A of FIG.55 of the built-in antenna for a radio communication terminal according to this embodiment.
  • passive element 502 is placed in such a way that the plane (reference plane) containing the antenna elements making up dipole antenna 501 and passive element 502 intersects with the plane of base plate 11 at quasi-right angles.
  • the plane containing the antenna elements making up dipole antenna 501 and passive element 502 also intersects with the main plane of package 510 shown in FIG. 56 at quasi-right angles.
  • Dipole antenna 501 supplied with power in this way mainly sends vertical polarized waves, parallel to this axial direction.
  • a transmission signal sent from dipole antenna 501 has directivity along the reference plane and normal to the main plane of package 510 by changing the length of dipole antenna 501, length of passive element 502 and distance between dipole antenna 501 and passive element 502 as appropriate.
  • the radio communication terminal is assumed to be used in a state shown in FIG.58. In this case, since the main plane of package 510 faces the temporal region of the user's head, the transmission signal is transmitted in the direction opposite to the human body by adjusting the length of dipole antenna 501, length of passive element 502 and distance between dipole antenna 501 and passive element 502 as appropriate.
  • dipole antenna 501 receives vertical polarized waves parallel to the axial directions of the antenna elements.
  • directivity opposite to the human body is formed by adjusting the length of dipole antenna 501, length of passive element 502 and distance between dipole antenna 501 and passive element 502 as appropriate, of the vertical polarized waves above, the vertical polarized waves from the direction opposite to the human body are mainly received.
  • the human body acts as a reflector as described above, of the vertical polarized waves above, the vertical polarized waves opposite to the human body are mainly received.
  • the signals above received by dipole antenna 501 are sent to the transmission/reception circuit above via balanced/unbalanced conversion circuit 13. Since balanced/unbalanced conversion circuit 13 above minimizes the current that flows into base plate 11, the antenna operation by base plate 11 is prevented. This suppresses the reduction of gain caused by influences from the human body to a minimum.
  • directivity opposite to the human body is formed for dipole antenna 501 by adjusting the length of dipole antenna 501, length of passive element 502 and distance between dipole antenna 501 and passive element 502 as appropriate, and therefore it is possible to suppress deterioration of gain by influences from the human body.
  • balanced/unbalanced conversion circuit 13 adjusts impedance appropriately and minimizes an antenna current that flows into base plate 11 and can thereby prevent deterioration of gain of dipole antenna 501.
  • Embodiment 50 is a mode in which the method of mounting dipole antenna 501 and passive element 502 in Embodiment 49 is changed. Since Embodiment 50 is the same as Embodiment 49 except for the method of mounting dipole antenna 501 and passive element 502, detailed explanations thereof will be omitted. Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 49 will be explained below using FIG. 59. The parts similar to those in Embodiment 49 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.59 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 50.
  • the built-in antenna for a radio communication terminal according to Embodiment 2 is constructed of base plate 11, balanced/unbalanced conversion circuit 13, power supply terminals 14, dipole antenna 501 and passive element 502.
  • Dipole antenna 501 is mounted in such a way that the axial directions of the antenna elements are quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal. That is, this embodiment is different from Embodiment 49 in that dipole antenna 501 is provided quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the axial direction of the antenna matches the polarization plane, making it possible to increase the reception gain.
  • Embodiment 51 is a mode in which the configuration and method of mounting dipole antenna 501 and passive element 502 in Embodiment 49 are changed. Since Embodiment 51 is the same as Embodiment 49 except for the configuration and method of mounting dipole antenna 501 and passive element 502, detailed explanations thereof will be omitted. Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 49 will be explained below using FIG.60. The parts similar to those in Embodiment 49 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.60 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 51.
  • the built-in antenna for a radio communication terminal according to Embodiment 51 is constructed of base plate 11, balanced/unbalanced conversion circuit 13, power supply terminals 14, dipole antenna 551 and passive element 552.
  • the two antenna elements making up dipole antenna 551 are placed quasi-perpendicular to each other.
  • Passive element 552 is folded near the center and the folded sides are formed in such a way as to intersect with each other at right angles.
  • Dipole antenna 551 is mounted in such a way that one antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal and the other antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal. Furthermore, passive element 552 is mounted in such a way that one of the folded sides is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal and the other side is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • An unbalanced signal from the transmission/reception circuit of the radio communication terminal is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and then sent to dipole antenna 551.
  • the antenna element placed quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal making up dipole antenna 551 supplied with power in this way mainly sends vertical polarized waves parallel to the axial direction of this antenna element.
  • the antenna element placed quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal making up dipole antenna 551 sends horizontal polarized waves parallel to the axial direction of this antenna element.
  • a transmission signal sent from dipole antenna 551 has directivity along the reference plane and normal to the main plane of package 510 by changing the length of dipole antenna 551, length of passive element 552 and distance between dipole antenna 551 and passive element 552 as appropriate.
  • the radio communication terminal is assumed to be used in a state shown in FIG.58. In this case, since the main plane of package 510 faces the temporal region of the user's head, the transmission signal is transmitted in the direction opposite to the human body by adjusting the length of dipole antenna 551, length of passive element 502 and distance between dipole antenna 551 and passive element 552 as appropriate.
  • the antenna element making up dipole antenna 551 placed quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal mainly receives vertical polarized waves parallel to the axial direction of this antenna element.
  • the antenna element making up dipole antenna 551 placed quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal mainly receives horizontal polarized waves parallel to the axial direction of this antenna element.
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal according to this embodiment matches the polarization plane of the signal sent from the other end of communication, allowing reception gain to be increased.
  • Embodiment 52 is a mode in which the configuration and method of mounting dipole antenna 501 and passive element 502 in Embodiment 49 are changed. Since Embodiment 52 is the same as Embodiment 49 except for the configuration and method of mounting dipole antenna 501 and passive element 502, detailed explanations thereof will be omitted. Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 49 will be explained below using FIG.61. The parts similar to those in Embodiment 49 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.61 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 52.
  • the built-in antenna for a radio communication terminal according to Embodiment 52 is constructed of base plate 11, balanced/unbalanced conversion circuit 13, power supply terminals 14, dipole antenna 561 and passive element 562.
  • the two antenna elements making up dipole antenna 561 are folded near the center and the folded sides are formed in such a way as to intersect with each other at right angles.
  • Passive element 552 is folded at a point in a predetermine distance from one end and the folded sides are formed in such a way to intersect at right angles.
  • the sides including both ends of passive element 552 are parallel to each other and the side not including the both ends is formed to be longer than the width of base plate 11.
  • Each antenna element making up dipole antenna 561 in the above configuration is mounted in such a way that the sides including power supply terminals 14 are quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal and the sides not including power supply terminals 14 are quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal.
  • passive element 562 is mounted in such a way that the sides including the ends are quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal and the side not including the ends is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • An unbalanced signal from the transmission/reception circuit above provided for the radio communication terminal is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and then sent to dipole antenna 561.
  • the parts of the antenna elements making up dipole antenna 561 placed quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal supplied with power in this way mainly send vertical polarized waves.
  • the parts of the antenna elements making up dipole antenna 561 placed quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal send horizontal polarized waves.
  • a transmission signal sent from dipole antenna 561 has directivity along the reference plane and normal to the main plane of package 510 by changing the length of dipole antenna 561, length of passive element 562 and distance between dipole antenna 561 and passive element 552 as appropriate.
  • the radio communication terminal is assumed to be used in a state shown in FIG.58. In this case, since the main plane of package 510 faces to the temporal region of the user's head, the transmission signal is transmitted in the direction opposite to the human body by adjusting the length of dipole antenna 561, length of passive element 562 and distance between dipole antenna 561 and passive element 562 as appropriate.
  • FIG.62 illustrates actual measured values of the emission characteristic of the built-in antenna for a radio communication terminal according to this embodiment in a free space.
  • the size of base plate 11 is 27 ⁇ 114 mm
  • the length of the side of the antenna element making up dipole antenna 561 placed quasi-parallel to the upper surface (horizontal plane) of the package of the radio communication terminal apparatus is 33 mm
  • the length of the part of the antenna element making up dipole antenna 561 placed quasi-perpendicular to the upper surface (horizontal plane) of the package of the radio communication terminal apparatus is 17 mm
  • the distance of dipole antenna 12 from the human body is 4 m.
  • the direction at 0° viewed from the origin corresponds to the direction of the human body viewed from dipole antenna 561 in FIG.61.
  • the built-in antenna for a radio communication terminal has directivity opposite to the direction of the human body.
  • FIG.63 illustrates actual measured values of the emission characteristic of the built-in antenna for a radio communication terminal during a conversation.
  • the sizes of the components are the same as those when the emission characteristic shown in FIG.62 are measured.
  • the direction at 0° viewed from the origin corresponds to the direction of the human body viewed from dipole antenna 561 in FIG.63.
  • the built-in antenna for a radio communication terminal has directivity opposite to the direction of the human body. This makes it possible to suppress deterioration of gain caused by influences from the human body during transmission and thereby achieve higher gain than the conventional example shown in FIG.3B.
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal according to this embodiment matches the polarization plane of the signal sent from the other end of communication, allowing reception gain to be increased.
  • Embodiment 53 to Embodiment 59 are modes in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 49 to Embodiment 52.
  • Embodiment 53 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 49.
  • the diversity antenna for a radio communication terminal in this embodiment will be explained using FIG.64.
  • the parts similar to those in Embodiment 49 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.64 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 53.
  • FIG.64 shows the configuration of the built-in antenna for a radio communication terminal in Embodiment 49 with additional monopole antenna 61.
  • monopole antenna 61 operates during transmission and dipole antenna 501 and monopole antenna 61 operate during reception to carry out diversity reception.
  • dipole antenna 501 in Embodiment 49 is used as the diversity antenna, which makes it possible to provide a high gain diversity antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 54 is a mode in which the configuration of the monopole antenna in Embodiment 53 is changed.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained using FIG.65.
  • the same configurations as those in Embodiment 53 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.65 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 54.
  • the diversity antenna for a radio communication terminal according to Embodiment 54 is constructed of dipole antenna 501, balanced/unbalanced conversion circuit 13, power supply terminals 14 and monopole antenna 71.
  • Monopole antenna 71 is constructed of rectangular-wave-shaped antenna elements.
  • monopole antenna 71 operates during transmission and dipole antenna 501 and monopole antenna 71 operate during reception to carry out diversity reception.
  • dipole antenna 501 in Embodiment 49 is used as the diversity antenna, which makes it possible to provide a high gain diversity antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 55 is a mode in which the configuration of the monopole antenna in Embodiment 53 is changed.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained using FIG.66.
  • the same configurations as those in Embodiment 53 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.66 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 55.
  • the diversity antenna for a radio communication terminal according to Embodiment 55 is constructed of dipole antenna 501, balanced/unbalanced conversion circuit 13, power supply terminals 14 and monopole antenna 81.
  • Monopole antenna 81 is constructed of a spiral antenna element.
  • monopole antenna 81 operates during transmission and dipole antenna 501 and monopole antenna 81 operate during reception to carry out diversity reception.
  • this embodiment configured as shown above can also attain effects similar to those in Embodiment 54.
  • Embodiment 56 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 49.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained using FIG. 67.
  • the same configurations as those in Embodiment 49 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.67 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 56. As shown in this figure, this embodiment has the configuration of the built-in antenna for a radio communication terminal according to Embodiment 49 with dipole antenna 621 and passive element 622 added to the side of base plate 11. Dipole antenna 621 has a configuration similar to dipole antenna 501.
  • dipole antenna 621 operates during transmission and dipole antenna 501 and dipole antenna 621 operate during reception to carry out diversity reception.
  • dipole antenna 501 in Embodiment 1 and dipole antenna 621 are used as the diversity antenna, and it is therefore possible to provide a high gain diversity antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 57 is a mode in which the method of mounting dipole antenna 621 and passive element 622 in Embodiment 56 is changed. Since Embodiment 57 is the same as Embodiment 56 except for the method of mounting dipole antenna 621 and passive element 622, detailed explanations thereof will be omitted. Differences of the built-in antenna for a radio communication terminal according to this embodiment from Embodiment 56 will be explained below using FIG.67. The parts similar to those in Embodiment 56 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.68 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 57.
  • dipole antenna 621 is mounted in such a way that its axial direction is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • passive element 622 is also mounted in such a way that its axial direction is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal. That is, this embodiment differs from Embodiment 56 in that the axial direction of dipole antenna 621 is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal and the axial direction of passive element 622 is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 621 is provided in such a way that its axial direction is quasi-parallel to the horizontal plane during a conversation.
  • dipole antenna 621 operates during transmission and dipole antenna 501 and dipole antenna 621 operate during reception to carry out diversity reception.
  • dipole antenna 501 can suppress deterioration of gain and at the same time mainly receive vertical polarized waves parallel to the axial direction of the antenna element.
  • dipole antenna 621 can not only suppress deterioration of gain but also mainly receive horizontal polarized waves parallel to the axial direction of the antenna element.
  • the signal sent from the other end of communication is often a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal matches the plane of polarization of the signal sent from the other end of communication and can thereby increase the reception gain.
  • this embodiment uses dipole antenna 501 in Embodiment 49 and dipole antenna 621 as the diversity antenna, and can thereby provide a high gain diversity antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 58 is a mode in which the dipole antenna used in Embodiment 56 for both transmission and reception is changed to dipole antenna 551 shown in Embodiment 51 and the passive element is changed to passive element 552 shown in Embodiment 51.
  • Embodiment 58 is the same as Embodiment 56 except for the configurations and the method of mounting of the dipole antenna and passive element.
  • the same parts in FIG.69 as those in Embodiment 56 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.69 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 58.
  • dipole antenna 551 is mounted in such a way that the axial direction of one antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal and the axial direction of the other antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 551 operates during transmission and dipole antenna 501 and dipole antenna 551 operate during reception to carry out diversity reception.
  • dipole antenna 551 can suppress deterioration of gain and at the same time mainly receive vertical polarized waves and horizontal polarized waves parallel to the axial direction of the antenna element. Furthermore, dipole antenna 501 can not only suppress deterioration of gain but also mainly receive vertical polarized waves parallel to the axial direction of the antenna element.
  • the signal sent from the other end of communication is often a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection. Thus, even if there are either more vertical polarized waves or more horizontal polarized waves, the built-in antenna for a radio communication terminal according to this embodiment matches the plane of polarization of the signal sent from the other end of communication and can thereby increase the reception gain.
  • this embodiment uses dipole antenna 501 in Embodiment 49 and dipole antenna 551 in Embodiment 51 as the diversity antenna, and can thereby provide a high gain diversity antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 59 is a mode in which dipole antenna 501 in Embodiment 58 used for reception only is changed to dipole antenna 651 having the same configuration as dipole antenna 551 shown in Embodiment 51 and passive element 502 is changed to passive element 652 shown in Embodiment 51.
  • Embodiment 59 is the same as Embodiment 59 except for the configurations and the method of mounting of the dipole antenna and passive element.
  • the same parts in FIG.17 as those in Embodiment 59 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.70 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 59. As shown in this figure, both dipole antenna 551 and dipole antenna 651 are mounted in such a way that the axial direction of one antenna element is quasi-perpendicular to the upper surface (horizontal plane) of the radio communication terminal and the axial direction of the other antenna element is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • dipole antenna 551 operates during transmission and dipole antenna 551 and dipole antenna 651 operate during reception to carry out diversity reception.
  • dipole antenna 551 can suppress deterioration of gain and at the same time mainly receive vertical polarized waves and horizontal polarized waves parallel to the axial direction of the antenna element. Furthermore, dipole antenna 651 can not only suppress deterioration of gain but also mainly receive vertical polarized waves parallel to the axial direction of the antenna element.
  • the signal sent from the other end of communication is often a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal matches the plane of polarization of the signal sent from the other end of communication and can thereby increase the reception gain.
  • this embodiment uses dipole antenna 651 and dipole antenna 551 in Embodiment 51 as the diversity antenna, and can thereby provide a high gain diversity antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 49 to Embodiment 59 above describe the case where each antenna element of the dipole antenna is bar-figured, but the present invention is not limited to this and one or both antenna elements can also be rectangular-wave-shaped.
  • Embodiment 49 to Embodiment 59 describe the case where the passive element is bar-shaped, but the present invention is not limited to this and the passive element can also be rectangular-wave-shaped or spiral.
  • the present invention performs impedance matching between the antenna elements and power supply means appropriately, and can thereby provide a high gain built-in antenna for radio communication terminal with little influence from the human body. Moreover, using a rectangular-wave-shaped antenna element of the dipole antenna makes it possible to provide a small built-in antenna for radio communication terminal.
  • directivity opposite to the human body is formed for the dipole antenna by adjusting the length of the dipole antenna, length of passive element and distance between the dipole antenna and passive element as appropriate, and therefore it is possible to suppress deterioration of gain caused by influences from the human body.
  • directivity opposite to the human body is formed for dipole antenna by adjusting the length of the dipole antenna, length of passive element and distance between the dipole antenna and passive element as appropriate, and therefore it is possible to suppress deterioration of gain of the dipole antenna by influences from the human body.
  • FIG.71 a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 60.
  • the built-in antenna for a radio communication terminal according to this embodiment is constructed of base plate 11, loop antenna 601 and balanced/unbalanced conversion circuit 13.
  • X, Y and Z denote their respective coordinate axes. The components will be explained below.
  • Base plate 11 is a tabular grounded conductor and is mounted quasi-parallel to the plane (vertical plane) of the radio communication terminal provided with operation buttons, a display and speaker, etc. which are not shown.
  • Loop antenna 601 is mounted in such a way that this loop plane is quasi-perpendicular to the plane provided with the above-described display and speaker, etc. and the loop plane is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • loop antenna 601 is provided in such a way that this loop plane is quasi-perpendicular to the human body during a conversation. In this way, virtual intensity of magnetic field is in phase with real intensity of magnetic field on the loop plane, which increases the gain of loop antenna 601.
  • loop antenna 601 is mounted in such a way that this loop plane is quasi-parallel to the upper surface (horizontal plane) of the radio communication terminal.
  • loop antenna 601 is mounted in such a way that the loop plane is quasi-parallel to the horizontal plane.
  • loop antenna 601 has directivity opposite to the human body, that is, directivity toward the front of the sheet in FIG.71.
  • loop antenna 601 is provided in such a way that this circumference is equal to or shorter than quasi-one wavelength of the reception wave.
  • the loop antenna has a nature that when its circumference is longer than one wavelength of the reception wave, the phase of the current that flows into the loop antenna is inverted, and therefore directivity is split. Therefore, loop antenna 601 according to this embodiment is provided in such a way that its circumference is equal to or shorter than quasi-one wavelength of the reception wave, which prevents directivity from being split.
  • Balanced/unbalanced conversion circuit 13 is a conversion circuit with an impedance conversion ratio of 1 to 1 or n to 1 (n: integer) and is attached to the power supply terminals of the dipole antenna. More specifically, one terminal of balanced/unbalanced conversion circuit 13 is connected to a transmission/reception circuit, which is not shown and the other terminal is attached to base plate 11. In this way, balanced/unbalanced conversion circuit 13 performs impedance conversion between loop antenna 601 and the transmission/reception circuit above, making it possible to obtain impedance matching between the two appropriately. Moreover, balanced/unbalanced conversion circuit 13 converts an unbalanced signal of the transmission/reception circuit above to a balanced signal and supplies to loop antenna 601, thus minimizing the current that flows into base plate 11. This prevents the action of base plate 11 as an antenna, and can thereby prevent reduction of the gain of loop antenna 601 caused by influences from the human body.
  • An unbalanced signal from the transmission/reception circuit above is converted to a balanced signal by balanced/unbalanced conversion circuit 13 and then sent to loop antenna 601.
  • Loop antenna 601 supplied with power in this way mainly receives horizontal polarized waves parallel to this loop plane.
  • horizontal polarized waves from all directions centered on the loop antenna are received and, since the human body acts as a reflector as described above during a conversation, of the horizontal polarized waves above, horizontal polarized waves opposite to the human body are mainly received.
  • the signals above received by loop antenna 601 are sent to the transmission/reception circuit above via balanced/unbalanced conversion circuit 13. Since balanced/unbalanced conversion circuit 13 above minimizes the current that flows into base plate 11, the antenna operation by base plate 11 is prevented. This minimizes reduction of the gain caused by influences from the human body.
  • FIG.72 illustrates actual measured values of the reception characteristic of the built-in antenna for a radio communication terminal according to Embodiment 60 during a conversation.
  • the size of base plate 11 is 120 ⁇ 36 mm
  • the size of loop antenna 601 is 63 ⁇ 5 mm
  • the distance of loop antenna 601 from the human body is 5 mm
  • the frequency is 2180 MHz.
  • the direction at 270° viewed from the origin corresponds to the direction of the human body viewed from loop antenna 601 in FIG.6.
  • loop antenna 601 has directivity opposite to the direction of the human body and not only prevents splitting of directivity for the above-described reason but also maintains a high gain characteristic suppressing deterioration of gain compared to the conventional example shown in FIG.3B.
  • loop antenna 601 in such a way that the loop plane of loop antenna 601 is quasi-perpendicular to the human body, increasing the gain of loop antenna 601 and that the circumference of loop antenna 601 is equal to or shorter than quasi-one wavelength, thus preventing the splitting of directivity of loop antenna 601, and balanced/unbalanced conversion circuit 13 minimizes an antenna current that flows into base plate 11, preventing deterioration of gain of loop antenna 601 caused by influences from the human body. This makes it possible to provide a high gain built-in antenna for radio communication terminal with little influence from the human body.
  • Embodiment 61 is a mode in which the method of mounting loop antenna 601 in Embodiment 60 is changed.
  • Embodiment 61 is the same as Embodiment 60 except for the method of mounting loop antenna 601, and therefore detailed explanations thereof will be omitted.
  • Differences of the built-in antenna for a radio communicant terminal according to this embodiment from Embodiment 60 will be explained using FIG.73.
  • the parts similar to those in Embodiment 60 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.73 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 61.
  • Loop antenna 611 is mounted in such a way that this loop plane is quasi-perpendicular to the plane provided with operation buttons, a display and speaker, etc., which are not shown of the radio communication terminal and the loop plane above is quasi-parallel to the side of the radio communication terminal (vertical plane) of the radio communication terminal. That is, this embodiment is different from embodiment 60 in that the loop plane of loop antenna 611 is quasi-parallel to the side of the radio communication terminal (vertical plane) of the radio communication terminal.
  • loop antenna 611 is provided in such a way that this loop plane is quasi-perpendicular to the human body and at the same time quasi-parallel to the vertical plane during a conversation.
  • loop antenna 611 can suppress deterioration of gain and mainly receive vertical polarized waves parallel to the loop plane.
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal according to this embodiment matches the polarization plane of the signal sent from the other end of communication, which makes it possible to increase the reception gain.
  • loop antenna 611 is mounted in such a way that this loop plane is quasi-perpendicular to the human body and the loop plane is quasi-parallel to the side of the radio communication terminal, which makes it possible to suppress deterioration of gain caused by influences from the human body and mainly receive vertical polarized waves. This makes it possible to prevent deterioration of gain due to mismatch with the signal from the other end of communication in the plane of polarization and provide a high gain built-in antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 62 is a mode in which the method of mounting loop antenna 601 in Embodiment 60 is changed.
  • Embodiment 62 is the same as Embodiment 60 except for the method of mounting loop antenna 601, and therefore detailed explanations thereof will be omitted.
  • Differences of the built-in antenna for a radio communicant terminal according to this embodiment from Embodiment 60 will be explained using FIG.74.
  • the parts similar to those in Embodiment 60 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.74 is a schematic diagram showing a configuration of the built-in antenna for a radio communication terminal according to Embodiment 62.
  • loop antenna 621 is constructed in such a way that of the four sides making up the loop plane of loop antenna 601 in Embodiment 60, the side facing the power supply terminals is folded at a midpoint and the folded sides form an angle of quasi 90° with each other.
  • Loop antenna 621 in the above configuration is mounted in such a way that each folded side is quasi-perpendicular to the plane (vertical plane) provided with operation buttons, a display and speaker, etc. and each folded side is quasi-parallel to the upper surface (horizontal plane) and side (vertical plane) of the radio communication apparatus. That is, this embodiment is different from embodiment 60 in that the loop plane of loop antenna 621 is quasi-parallel to the upper surface and the side of the radio communication terminal of the radio communication terminal.
  • loop antenna 621 is provided in such a way that this loop plane is quasi-perpendicular to the human body and at the same time quasi-parallel to the upper surface (horizontal plane) and the side (vertical plane) of the radio communication terminal during a conversation.
  • loop antenna 621 can suppress deterioration of gain and mainly receive not only horizontal polarized waves but also vertical polarized waves parallel to the loop plane.
  • a signal sent from the other end of communication is a mixture of vertical polarized waves and horizontal polarized waves due to various factors such as reflection.
  • the built-in antenna for a radio communication terminal according to this embodiment matches the polarization plane of the signal sent from the other end of communication, which makes it possible to increase the reception gain more than Embodiment 60 and Embodiment 61.
  • loop antenna 621 is mounted in such a way that this loop plane is quasi-perpendicular to the human body and the loop plane above is quasi-parallel to the upper surface and the side of the radio communication terminal, which makes it possible not only to suppress deterioration of gain caused by influences from the human body but also to receive both horizontal polarized waves and vertical polarized waves, thus increasing the gain.
  • This makes it possible to prevent deterioration of gain due to mismatch with the polarization plane of the signal from the other end of communication and provide a high gain built-in antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 63 to Embodiment 67 are modes in which the above-described loop antenna is provided with various means for changing impedance in order to reduce the size or broaden the band of the loop antenna in Embodiment 60 to Embodiment 62.
  • Embodiment 63 is a mode in which a reactance element is used as one of impedance changing means to reduce the size or broaden the band of the loop antenna.
  • the built-in antenna for a radio communication terminal according to Embodiment 63 will be explained using FIG. 75A and FIG. 75B.
  • FIG.75A is a schematic diagram showing a configuration of a first built-in antenna for a radio communication terminal according to Embodiment 63.
  • reactance element 632 is provided at a midpoint facing the power supply terminals of loop antenna element 631.
  • FIG.75B is a schematic diagram showing a configuration of a second built-in antenna for a radio communication terminal according to Embodiment 63.
  • reactance element 632 is provided at a midpoint of two sides, which are perpendicular to the power supply terminals of loop antenna element 631.
  • Providing reactance element 632 at a midpoint of each side making up the loop plane of loop antenna element 631 changes current distribution of loop antenna element 631, making it possible to change impedance of the power supply terminals of loop antenna element 631. Even if loop antenna element 631 is reduced in size, this allows reactance element 632 to change impedance and thereby achieve an impedance characteristic similar to a large loop antenna. Therefore, providing reactance element 632 makes it possible to reduce the size of the loop antenna.
  • this embodiment allows the impedance characteristic of the loop antenna element to be changed.
  • Embodiment 64 is a mode in which a variable capacitive element is used as one of impedance changing means to reduce the size and broaden the band of the loop antenna.
  • the built-in antenna for a radio communication terminal according to Embodiment 64 will be explained using FIG.76.
  • FIG.76 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to Embodiment 5.
  • variable capacitive element 642 is provided at the power supply terminals of loop antenna element 641.
  • this embodiment makes it possible to achieve impedance matching of the loop antenna above by providing variable capacitive element 642 at the power supply terminals of the loop antenna element 641. That is, when the size of loop antenna element 641 is reduced, it is possible to achieve impedance matching for a wide range of frequencies by changing the capacitance of variable capacitive element 642.
  • variable capacitive element 642 is provided at the power supply terminals of the loop antenna element 641, this embodiment allows flexible impedance matching by changing the capacitance of variable capacitive element 642. Therefore, this embodiment can provide a small and wideband built-in antenna for a radio communication terminal.
  • Embodiment 65 is a mode in which a tuning element and switching element are used as one of impedance changing means to reduce the size and broaden the band of the loop antenna.
  • the built-in antenna for a radio communication terminal according to Embodiment 65 will be explained using FIG.77.
  • FIG.77 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to Embodiment 6.
  • a circuit with a pair or a plurality of pairs of serially connected tuning element 652 and switching element 653 aligned in parallel is inserted at the power supply terminals of loop antenna element 651.
  • the loop antenna can be used at the original tuning frequency.
  • tuning element 652 connected to this switching element 653 is inserted in parallel, and therefore the loop antenna tunes a frequency different from the original tuning frequency.
  • tuning element 652 connected to these switching elements 653 is inserted in parallel, and therefore the loop antenna tunes a frequency according to total connected tuning elements 652.
  • the built-in antenna for a radio communication terminal in the above configuration can change the frequency band through switching operation of each switching element 653 and can thereby provide tuning according to various frequency bands.
  • this embodiment can broaden the frequency band.
  • this embodiment can thereby switch between frequency bands and provide a small and wideband built-in antenna for a radio communication terminal.
  • Embodiment 66 is a mode in which the shape of a loop antenna element is changed to reduce the size of the loop antenna.
  • the built-in antenna for a radio communication terminal according to Embodiment 66 will be explained using FIG.78.
  • FIG.78 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to Embodiment 66.
  • part or the whole of loop antenna element 661 is zigzag-shaped. This makes the frequency band of the built-in antenna for a radio communication terminal in the above configuration flexibly changeable, which makes this antenna equivalent to a small antenna.
  • part or the whole of the loop antenna element is zigzag-shaped and this embodiment can thereby provide a small-sized antenna.
  • Embodiment 67 is a mode in which the shape of a loop antenna element is changed to broaden the frequency band of the loop antenna.
  • the built-in antenna for a radio communication terminal according to Embodiment 67 will be explained using FIG.79.
  • FIG.79 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to Embodiment 67.
  • part or the whole of loop antenna element 671 is tabular-shaped.
  • a tabular-shaped antenna has smaller impedance variations with frequency than a linear antenna element, and therefore its frequency band is wider.
  • the built-in antenna for a radio communication terminal in the above configuration can realize a wider frequency band.
  • this embodiment can implement a wideband antenna.
  • Embodiment 68 to Embodiment 70 are modes in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 60 to Embodiment 62.
  • Embodiment 68 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 1.
  • the built-in antenna for a radio communication terminal according to this embodiment will be explained using FIG.80. Configurations similar to those in Embodiment 60 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.80 is a schematic diagram showing a configuration of a diversity antenna for a radio communication terminal according to Embodiment 68.
  • monopole antenna 681 is provided for the built-in antenna for a radio communication terminal in Embodiment 60.
  • monopole antenna 681 operates during transmission and loop antenna 601 and monopole antenna 681 operate during reception to carry out diversity reception.
  • loop antenna 601 in Embodiment 60 is used as the diversity antenna, which makes it possible to provide a high gain diversity antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 69 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 2 and the monopole antenna in Embodiment 68.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained using FIG.81.
  • the same configurations as those in Embodiment 61 and Embodiment 68 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.81 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 69.
  • monopole antenna 681 is provided for the built-in antenna for a radio communication terminal in Embodiment 61.
  • monopole antenna 681 operates during transmission and loop antenna 611 and monopole antenna 681 operate during reception to carry out diversity reception.
  • loop antenna 611 in Embodiment 2 is used as the diversity antenna, which makes it possible to prevent deterioration of gain due to mismatch with the polarization plane of the signal from the other end of communication and provide a high gain diversity antenna for a radio communication terminal with little influence from the human body.
  • Embodiment 70 is a mode in which a diversity antenna is implemented using the built-in antenna for a radio communication terminal in Embodiment 62 and the monopole antenna in Embodiment 68.
  • the diversity antenna for a radio communication terminal according to this embodiment will be explained using FIG. 82.
  • the same configurations as those in Embodiment 62 and Embodiment 68 will be assigned the same reference numerals and detailed explanations thereof will be omitted.
  • FIG.82 is a schematic diagram showing a configuration of the diversity antenna for a radio communication terminal according to Embodiment 70.
  • monopole antenna 681 is provided for the built-in antenna for a radio communication terminal in Embodiment 621.
  • monopole antenna 681 operates during transmission and loop antenna 621 and monopole antenna 681 operate during reception to carry out diversity reception.
  • loop antenna 621 in Embodiment 62 is used as the diversity antenna, which makes it possible to prevent deterioration of gain due to mismatch with the polarization plane of the signal from the other end of communication and provide a high gain diversity antenna for a radio communication terminal with little influence from the human body.
  • the embodiment above describes the case where the base plate, loop antenna and the distance of the loop antenna from the human body and frequency are set as described above, but the present invention is not limited to this and can be modified as appropriate.
  • the present invention is provided with an antenna element in such a way that the loop plane of the antenna element is quasi-perpendicular to the human body and the circumference of the antenna element is equal to or shorter than quasi-one wavelength of the reception wave and impedance matching is implemented between the antenna element and power supply means appropriately, and the present invention can thereby provide a high gain built-in antenna for a radio communication terminal with little influence from the human body.
  • the present invention is ideally applicable to the field of antennas used for radio equipment and portable terminal, etc., and the field of built-in antennas in particular.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Support Of Aerials (AREA)
EP00939108A 1999-12-24 2000-06-21 Eingebaute antenne für drahtloses kommunikationsgerät Withdrawn EP1154513A4 (de)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
JP36828499A JP2000244219A (ja) 1998-12-25 1999-12-24 無線通信端末用内蔵アンテナ
JP36828499 1999-12-24
JP2000056476 2000-03-01
JP2000056476 2000-03-01
JP2000118692 2000-04-19
JP2000118692 2000-04-19
PCT/JP2000/004044 WO2001048860A1 (fr) 1999-12-24 2000-06-21 Antenne constituee d'un terminal de communication radio

Publications (2)

Publication Number Publication Date
EP1154513A1 true EP1154513A1 (de) 2001-11-14
EP1154513A4 EP1154513A4 (de) 2002-07-24

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EP00939108A Withdrawn EP1154513A4 (de) 1999-12-24 2000-06-21 Eingebaute antenne für drahtloses kommunikationsgerät

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Country Link
EP (1) EP1154513A4 (de)
CN (1) CN1345473A (de)
AU (1) AU5428200A (de)
WO (1) WO2001048860A1 (de)

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EP1315233A4 (de) * 2000-08-31 2003-05-28 Matsushita Electric Ind Co Ltd Eingebaute antenne für funkkommunikationsgerät
WO2003069727A1 (fr) * 2002-02-15 2003-08-21 Matsushita Electric Industrial Co., Ltd. Unite d'antenne et systeme de radio portatifs comprenant une unite d'antenne
WO2003073553A1 (fr) * 2002-02-27 2003-09-04 Matsushita Electric Industrial Co., Ltd. Dispositif d'antenne destine a un appareil radioelectrique
EP1363359A1 (de) * 2002-05-13 2003-11-19 Alps Electric Co., Ltd. Ein Antennenmodul
EP1432068A2 (de) * 2002-12-19 2004-06-23 Kabushiki Kaisha Toshiba Gerät zur drahtlosen Kommunikation mit Antenne
EP1414107A4 (de) * 2001-07-25 2004-07-28 Matsushita Electric Ind Co Ltd Vorrichtung mit integrierter antenne
EP1498982A1 (de) * 2003-07-18 2005-01-19 Ask Industries S.p.A. Planare Dipolantenne auf einem einschichtigen dielektrischen Substrat
GB2422723A (en) * 2005-02-01 2006-08-02 Antenova Ltd Compact balanced and unbalanced antenna arrangement
US7199760B2 (en) * 2005-02-03 2007-04-03 Via Telecom Co., Ltd. Mobile phone having a directed beam antenna
GB2505527A (en) * 2012-08-30 2014-03-05 Cambridge Silicon Radio Ltd Balanced antennas with reduced coupling
US8766869B2 (en) 2009-03-31 2014-07-01 Denso Corporation Antenna apparatus
WO2016034887A1 (en) * 2014-09-05 2016-03-10 Smart Antenna Technologies Ltd Reconfigurable casing antenna system
EP3214698A1 (de) * 2016-02-25 2017-09-06 Sercomm Corporation Vertikale kommunikationsvorrichtung
US10535921B2 (en) 2014-09-05 2020-01-14 Smart Antenna Technologies Ltd. Reconfigurable multi-band antenna with four to ten ports
US10581166B2 (en) 2014-09-05 2020-03-03 Smart Antenna Technologies Ltd. Reconfigurable multi-band antenna with independent control

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ES2410085T3 (es) 2000-01-19 2013-06-28 Fractus, S.A. Antenas miniatura rellenadoras de espacio
CN101051705B (zh) * 2006-04-04 2011-06-29 黄启芳 碎形化天线
US8738103B2 (en) 2006-07-18 2014-05-27 Fractus, S.A. Multiple-body-configuration multimedia and smartphone multifunction wireless devices
CN101707281A (zh) * 2009-11-17 2010-05-12 中兴通讯股份有限公司 一种移动终端的分集天线及移动终端
GB2484542B (en) * 2010-10-15 2015-04-29 Microsoft Technology Licensing Llc LTE antenna pair for mimo/diversity operation in the LTE/GSM bands
CN102544761A (zh) * 2010-12-22 2012-07-04 和硕联合科技股份有限公司 电子装置
JP6271480B2 (ja) * 2015-08-26 2018-01-31 株式会社東芝 通信装置、スマートメータ
WO2019216672A1 (ko) * 2018-05-11 2019-11-14 주식회사 아이뷰 소형 다이폴 안테나
KR102431624B1 (ko) * 2018-05-11 2022-08-12 주식회사 아이뷰 소형 다이폴 안테나

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Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1315233A4 (de) * 2000-08-31 2003-05-28 Matsushita Electric Ind Co Ltd Eingebaute antenne für funkkommunikationsgerät
EP1414107A4 (de) * 2001-07-25 2004-07-28 Matsushita Electric Ind Co Ltd Vorrichtung mit integrierter antenne
US6781556B2 (en) 2001-07-25 2004-08-24 Matsushita Electric Industrial Co., Ltd. Built-in antenna apparatus
WO2003069727A1 (fr) * 2002-02-15 2003-08-21 Matsushita Electric Industrial Co., Ltd. Unite d'antenne et systeme de radio portatifs comprenant une unite d'antenne
US7126545B2 (en) 2002-02-15 2006-10-24 Matsushita Electric Industrial Co., Ltd. Antenna unit and portable radio system comprising antenna unit
US7002521B2 (en) 2002-02-27 2006-02-21 Matsushita Electric Industrial Co., Ltd. Antenna device for radio apparatus
WO2003073553A1 (fr) * 2002-02-27 2003-09-04 Matsushita Electric Industrial Co., Ltd. Dispositif d'antenne destine a un appareil radioelectrique
EP1363359A1 (de) * 2002-05-13 2003-11-19 Alps Electric Co., Ltd. Ein Antennenmodul
US6882319B2 (en) 2002-05-13 2005-04-19 Alps Electric Co., Ltd. Antenna module whose antenna characteristics are not adversely affected by a mother board
EP1432068A3 (de) * 2002-12-19 2014-03-26 Kabushiki Kaisha Toshiba Gerät zur drahtlosen Kommunikation mit Antenne
EP1432068A2 (de) * 2002-12-19 2004-06-23 Kabushiki Kaisha Toshiba Gerät zur drahtlosen Kommunikation mit Antenne
EP1498982A1 (de) * 2003-07-18 2005-01-19 Ask Industries S.p.A. Planare Dipolantenne auf einem einschichtigen dielektrischen Substrat
GB2422723A (en) * 2005-02-01 2006-08-02 Antenova Ltd Compact balanced and unbalanced antenna arrangement
GB2422723B (en) * 2005-02-01 2007-04-18 Antenova Ltd Balanced-Unbalanced Antennas
US7199760B2 (en) * 2005-02-03 2007-04-03 Via Telecom Co., Ltd. Mobile phone having a directed beam antenna
US8766869B2 (en) 2009-03-31 2014-07-01 Denso Corporation Antenna apparatus
GB2505527A (en) * 2012-08-30 2014-03-05 Cambridge Silicon Radio Ltd Balanced antennas with reduced coupling
GB2505527B (en) * 2012-08-30 2016-03-02 Qualcomm Technologies Int Ltd Multi-antenna isolation
WO2016034887A1 (en) * 2014-09-05 2016-03-10 Smart Antenna Technologies Ltd Reconfigurable casing antenna system
US10535921B2 (en) 2014-09-05 2020-01-14 Smart Antenna Technologies Ltd. Reconfigurable multi-band antenna with four to ten ports
US10581166B2 (en) 2014-09-05 2020-03-03 Smart Antenna Technologies Ltd. Reconfigurable multi-band antenna with independent control
EP3214698A1 (de) * 2016-02-25 2017-09-06 Sercomm Corporation Vertikale kommunikationsvorrichtung

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WO2001048860A1 (fr) 2001-07-05
EP1154513A4 (de) 2002-07-24
AU5428200A (en) 2001-07-09
CN1345473A (zh) 2002-04-17

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