JP2006310927A - Antenna assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna assembly composed of a loop-like slot in which directivity can be switched. <P>SOLUTION: The antenna assembly 10 comprises a loop-like slot 3, varactors 4, 5, a coaxial cable 8, a DC power supply 9, and an AC power supply 11. The loop-like slot 3 is made by cutting a predetermined region of a conductor 2 stuck to the entire surface of a dielectric substrate, and the conductor 2 is divided into two conductors 21, 22. The varactors 4, 5 are loaded in the loop-like slot 3 symmetrically to the axis AX1. The DC power supply 9 applies DC voltages of different polarities selectively between the conductors 21, 22 through the coaxial cable 8 to substantially short-circuit or open-circuit one of the varactors 4, 5 and to substantially open-circuit or short-circuit the other. The AC power supply 11 applies an AC voltage between the conductors 21, 22 through the coaxial cable 8 and supplies power to the loop-like slot 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an antenna device capable of electrically switching directivity. The present invention also relates to an antenna device capable of switching the optimum frequency.

  Conventionally, a slot loop antenna including a loop-shaped slot is known as an antenna configured on a planar substrate (Non-Patent Document 1). The slot loop antenna includes a dielectric substrate, a first slot formed on the surface of the dielectric substrate, and a second slot formed on the back surface of the dielectric substrate.

  The dielectric substrate has a relative dielectric constant of 10.2 and a thickness of 0.635 mm. The first slot has a width of 0.5 mm and has a substantially square loop shape. The second slot has a width of 0.5 mm and has a substantially rectangular loop shape.

In the second slot, the slot loop antenna exhibits a strong radiation characteristic in front of the antenna by setting the distance between the slots formed in the long side direction of the substantially rectangular shape to a predetermined distance.
Koji Horii, Toshiaki Kitamura, Masahiro Shimoshiro, “Study on miniaturization of slot loop antenna”, 2001 IEICE Communication Society Conference, p166.

  However, since the conventional slot loop antenna has a radiation pattern characteristic close to omnidirectionality, there is a problem that directivity cannot be switched.

  There is also a problem that the frequency cannot be switched.

  Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide an antenna device that is composed of loop-shaped slots and whose directivity can be switched.

  Another object of the present invention is to provide an antenna device capable of switching frequencies.

  According to the present invention, an antenna device includes m (m is a positive integer) loop-shaped slots, n (n is an integer of 2 or more) variable capacitance elements, a cable, and an antenna control unit. . The m loop-shaped slots are formed on one main surface of the dielectric substrate, and each has a loop shape. The n variable capacitance elements are loaded in m loop-shaped slots. The cable is composed of first and second conductive wires that are substantially parallel. The antenna control unit feeds power to the m loop-shaped slots via the cable and controls the directivity or frequency by controlling the capacity of the n variable capacitive elements.

  Preferably, the antenna device further includes a power feeding unit. The power feeding unit is provided on one main surface of the dielectric substrate and is connected to a cable. Then, at least one variable capacitance element is arranged on each side of the principal surface of the dielectric substrate around the base axis passing through the power feeding portion.

  Preferably, the antenna device further includes first and second conductors. The first conductor is formed in the inner region of the m loop-shaped slots. The second conductor is formed in the outer region of the m loop-shaped slots. The power feeding unit includes a first power feeding unit formed on the first conductor and a second power feeding unit formed on the second conductor.

  Preferably, the antenna control unit is configured to apply a DC voltage between the first conductor and the second conductor, and an AC power supply that applies an AC voltage between the first conductor and the second conductor. Including. The first conducting wire is connected to the first power feeding unit, and the second conducting wire is connected to the second feeding unit.

  Preferably, each of the n variable capacitance elements includes a varactor diode. Among the n variable capacitive elements, the variable capacitive element arranged on one side with respect to the base axis is a first direction from the outer region to the inner region of the loop-shaped slot to be loaded and from the inner region to the outer region. It is connected between two conductors formed on both sides of the loop-like slot to be loaded so that a current flows in either one of the second directions. Of the n variable capacitive elements, the variable capacitive element arranged on the other side with respect to the base axis conducts current in the other direction of the first and second directions of the loop-shaped slot to be loaded. In order to flow, it is connected between two conductors formed on both sides of a looped slot to be loaded.

  Preferably, the n variable capacitance elements include 2 (i + j) (i and j are positive integers) variable capacitance elements each including a varactor diode. The m loop-shaped slots are composed of two or more loop-shaped slots. Of the 2 (i + j) variable capacitive elements, 2i variable capacitive elements loaded in the loop-shaped slot formed on the outermost peripheral side are the first to the inner area from the outer region of the loop-shaped slot to be loaded. It is connected between two conductors formed on both sides of the looped slot to be loaded so that current flows in one direction, either in one direction or in the second direction from the inner region to the outer region. Of the 2 (i + j) variable capacitance elements, 2j variable capacitance elements loaded in the loop-shaped slot formed on the innermost circumferential side are the first and second directions of the loop-shaped slot to be loaded. Are connected between two conductors formed on both sides of the loop-like slot to be loaded so that current flows in the other direction.

  In the antenna device according to the present invention, the capacities of the n variable capacitance elements loaded in the loop-shaped slot are controlled, and a part of the loop-shaped slot that is substantially short-circuited is changed. Then, the excitation state of the loop slot is controlled.

  Therefore, according to the present invention, the directivity of the antenna device using the loop-shaped slot can be changed. Also, the frequency can be switched.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a plan view of an antenna apparatus according to Embodiment 1 of the present invention. 2 is a cross-sectional view of the antenna device taken along line II-II shown in FIG. An antenna device 10 according to Embodiment 1 of the present invention includes a dielectric substrate 1, a conductor 2, a loop slot 3, variable capacitance elements 4 and 5, conductors 6 and 7, a coaxial cable 8, and a DC power supply. 9 and an AC power supply 11.

  The dielectric substrate 1 has a substantially rectangular flat plate shape, and is made of, for example, a printed circuit board. A conductor 2 is attached to the entire surface of one main surface 1A of the dielectric substrate 1, and a predetermined portion of the conductor 2 is deleted to form a loop-shaped slot 3.

  As a result, the conductor 2 is divided into conductors 21 and 22. The conductor 21 is formed in the inner region of the loop-shaped slot 3, and the conductor 22 is formed in the outer region of the loop-shaped slot 3. The conductor 21 has a power feeding part 21A, and the conductor 22 has a power feeding part 22A.

  The loop-shaped slot 3 has a generally square loop shape. More specifically, the loop-shaped slot 3 has straight slots 31 to 37. Each of the straight slots 31 to 37 is disposed substantially parallel to one side of the dielectric substrate 1. The straight slots 33 and 35 are disposed substantially parallel to each other, the straight slot 34 is disposed substantially parallel to the straight slots 32 and 36, and the straight slots 31 and 37 are disposed substantially parallel to each other.

  When the wavelength of the radio wave transmitted and received by the antenna apparatus 10 is λ, each of the straight slots 31, 32, 36, and 37 has a length of λ / 32, and each of the straight slots 33 to 35 has a length of λ / 8. Have a length. As a result, the loop-like slot 3 has a total length of λ / 2. Each of the straight slots 31 to 37 has a width W of λ / 10 or less.

  The variable capacitance element 4 is loaded at a substantially middle point of the straight slot 33 of the loop-shaped slot 3 and connected between the conductors 21 and 22 on both sides of the straight slot 33. The variable capacitance element 5 is loaded at substantially the midpoint of the straight slot 35 of the loop-shaped slot 3 and connected between the conductors 21 and 22 on both sides of the straight slot 35. As a result, the variable capacitance elements 4 and 5 are loaded in the loop-shaped slot 3 symmetrically with respect to the base axis AX1 passing through the power feeding portion 21A.

  The coaxial cable 8 includes a core conductor 81, an insulator 82, and a covered conductor 83. The insulator 82 is provided between the core conductor 81 and the covered conductor 83 and covers the core conductor 81. The covered conductor 83 covers the insulator 82. As a result, the core conductor 81 and the covered conductor 83 are disposed substantially in parallel.

  The conducting wire 6 has one end connected to the core conductor 81 of the coaxial cable 8 and the other end connected to the power feeding portion 21 </ b> A of the conductor 21. The conducting wire 7 has one end connected to the covered conductor 83 of the coaxial cable portion 8 and the other end connected to the power feeding portion 22 </ b> A of the conductor 22.

  The DC power source 9 is connected between the core conductor 81 and the covered conductor 83 of the coaxial cable 8. The DC power supply 9 selectively applies two DC voltages DCV1, DCV2 having different polarities between the core conductor 81 and the covered conductor 83.

  The AC power supply 11 is connected between the core conductor 81 and the covered conductor 83 of the coaxial cable 8. The AC power supply 11 applies an AC voltage RFV between the core conductor 81 and the covered conductor 83.

  The coaxial cable 8 supplies the DC voltages DCV1 and DCV2 from the core conductor 81 and the covered conductor 83 to the conductors 6 and 7, and supplies the AC voltage RFV from the core conductor 81 and the covered conductor 83 to the conductors 6 and 7. That is, the coaxial cable 8 superimposes the AC voltage RFV on the DC voltage DCV1 or DCV2 and supplies it to the conductors 6 and 7 from the core conductor 81 and the coated conductor 83. In this case, the DC voltage DCV1 is a DC voltage having a polarity different from that of the DC voltage DCV2.

  FIG. 3 is a configuration diagram of the variable capacitance element 4 shown in FIGS. 1 and 2. Variable capacitance element 4 includes a resistor 41, a capacitor 42, and a varactor diode 43. Resistor 41 and capacitor 42 are connected in parallel between nodes N3 and N4. The varactor diode 43 is connected between the nodes N2 and N4 so that the cathode is disposed on the node N4 side and the anode is disposed on the node N2 side. As a result, the resistor 41 and the capacitor 42 connected in parallel and the varactor diode 43 are connected in series between the nodes N1 and N2.

  The resistor 41 has a resistance value of 100 kΩ, for example, and the capacitor 42 has a capacitance of 1000 pF, for example. The reason why the resistor 41 has a resistance value of 100 kΩ is to cut off the direct-current voltage applied to the node N1.

  The variable capacitor 5 shown in FIGS. 1 and 2 also has the same configuration as the variable capacitor 4 shown in FIG.

  When the variable capacitance element 4 is loaded in the straight slot 33 of the loop-shaped slot 3, the node N1 of the variable capacitance element 4 is connected to the conductor 22 and the node N2 is connected to the conductor 21. That is, the variable capacitance element 4 is connected between the conductors 21 and 22 so that a current flows from the outer region to the inner region of the loop slot 3.

  When the variable capacitor 5 is loaded in the straight slot 35 of the loop-shaped slot 3, the node N 1 of the variable capacitor 5 is connected to the conductor 21 and the node N 2 is connected to the conductor 22. That is, the variable capacitance element 5 is connected between the conductors 21 and 22 so that a current flows from the inner region to the outer region of the loop-shaped slot 3.

  Thus, among the variable capacitance elements 4 and 5 loaded in the loop-like slot 3 symmetrically with respect to the base axis AX1, the variable capacitance element 4 loaded on one side with respect to the base axis AX1 is the loop to be loaded. Of the variable capacitance elements 4 and 5 that are connected between the conductors 21 and 22 so as to allow current to flow from the outer region to the inner region of the slot 3 and are loaded in the loop slot 3 symmetrically with respect to the base axis AX1, the base axis AX1 On the other hand, the variable capacitance element 5 loaded on the other side is connected between the conductors 21 and 22 so that a current flows from the inner region to the outer region of the loop-shaped slot 3 to be loaded.

  In addition, by loading the variable capacitance elements 4 and 5 into the loop-shaped slot 3 symmetrically with respect to the base axis AX1, the antenna device 10 can change the AC voltage even if the direction of the DC voltage applied to the variable capacitance elements 4 and 5 is changed. The characteristic is that there is no consistent change.

  4 and 5 are first and second conceptual diagrams for explaining the operation of the antenna device 10 shown in FIGS. 1 and 2, respectively. When the DC voltage DCV1 is applied between the core conductor 81 and the covered conductor 83 so that the core conductor 81 of the coaxial cable 8 becomes negative and the covered conductor 83 becomes positive, the conductor 21 becomes negative and the conductor 22 becomes A DC voltage DCV1 is applied between the conductors 21 and 22 so as to be positive.

  Then, a reverse DC voltage is applied to the varactor diode 43 of the variable capacitance element 4, the capacitance of the variable capacitance element 4 becomes small, and the linear slot 33 becomes almost open and is well excited. In addition, a forward DC voltage is applied to the varactor diode 43 of the variable capacitance element 5, the capacitance of the variable capacitance element 5 is increased, and the straight slot 35 is almost short-circuited and is not excited much.

  As a result, the loop-shaped slot 3 is separated into straight slots 31 to 34, 351 and straight slots 352, 36, 37 (see FIG. 4).

  On the other hand, when the DC voltage DCV2 is applied between the core conductor 81 and the covered conductor 83 so that the core conductor 81 of the coaxial cable 8 becomes positive and the covered conductor 83 becomes negative, the conductor 21 becomes positive and the conductor A DC voltage DCV2 is applied between the conductors 21 and 22 so that 22 is negative.

  Then, a forward DC voltage is applied to the varactor diode 43 of the variable capacitance element 4, the capacitance of the variable capacitance element 4 is increased, and the straight slot 33 is almost short-circuited, so that it is not excited much. Further, a dc voltage in the reverse direction is applied to the varactor diode 43 of the variable capacitance element 5, the capacitance of the variable capacitance element 5 is reduced, and the straight slot 35 is almost open and is well excited.

  As a result, the loop-shaped slot 3 is separated into straight slots 31, 32, 331 and straight slots 332, 34 to 37 (see FIG. 5).

  In this way, by switching the polarity of the DC voltage applied between the core conductor 81 and the covered conductor 83, one of the variable capacitive elements 4 and 5 is loaded. The opened straight slot 33 (or straight slot 35) is almost opened (or almost short-circuited), and the straight slot 35 (or straight slot 33) loaded with the other variable capacitance element 5 (or variable capacitance element 4) is almost short-circuited. (Or almost open).

  This is due to the following reason. As described above, among the variable capacitance elements 4 and 5 loaded in the loop-shaped slot 3 symmetrically with respect to the base axis AX1, the variable capacitance element 4 loaded on one side with respect to the base axis AX1 should be loaded. Of the variable capacitance elements 4 and 5 that are connected between the conductors 21 and 22 so as to flow current from the outer region to the inner region of the loop-shaped slot 3 and are loaded in the loop-shaped slot 3 symmetrically with respect to the basic axis AX1, Since the variable capacitance element 5 loaded on the other side with respect to AX1 is connected between the conductors 21 and 22 so as to flow current from the inner region to the outer region of the loop-shaped slot 3 to be loaded, By switching the polarity of the DC voltage applied between the two variable capacitance elements 4 and 5, a forward DC voltage is applied to the varactor diode of one of the two variable capacitance elements 4 and 5, and the other variable capacitance element is controlled. The varactor diode of the capacitor, because the reverse DC voltage is applied.

  FIG. 6 is a diagram showing the definition of the azimuth angle in the antenna device 10 shown in FIGS. 1 and 2. When the antenna device 10 is arranged so that the linear slots 31 and 37 of the loop-shaped slot 3 are substantially parallel to the x-axis, the azimuth angle φ is 0 ° in the positive direction of the x-axis and the positive direction of the y-axis. Is the direction of 90 degrees, and the negative direction of the y-axis is the direction of -90 degrees.

  FIG. 7 is a diagram illustrating a radiation pattern of the antenna device 10 illustrated in FIGS. 1 and 2. In FIG. 7, the vertical axis represents the gain, and the horizontal axis represents the azimuth angle φ. A curve k1 indicates a radiation pattern of the antenna device 10 when a reverse DC voltage is applied to the varactor diode 43 of the variable capacitance element 4, and a curve k2 indicates a reverse direction of the varactor diode 43 of the variable capacitance element 5. The radiation pattern of the antenna device 10 when a direct current voltage of 1 is applied is shown, and the curve k3 shows the radiation pattern when the variable capacitance element is not loaded.

  As described above, the DC power supply 9 applies the DC voltage DCV1 between the core conductor 81 and the coated conductor 83 so that the core conductor 81 of the coaxial cable 8 becomes negative and the coated conductor 83 becomes positive, and the AC power supply 11 When the AC voltage RFV is applied between the core conductor 81 and the covered conductor 83, the straight slot 33 loaded with the variable capacitive element 4 is almost opened, and the straight slot 35 loaded with the variable capacitive element 5 is almost short-circuited. (See FIG. 4) Furthermore, the loop-shaped slot 3 is fed. As a result, the antenna device 10 radiates a beam having a radiation pattern having peaks at about −90 degrees and about 90 degrees (see the curve k1). In this case, the peak at about 90 degrees is larger than the peak at about -90 degrees.

  Further, the DC power source 9 applies a DC voltage DCV2 between the core conductor 81 and the coated conductor 83 so that the core conductor 81 of the coaxial cable 8 is positive and the coated conductor 83 is negative, and the AC power supply 11 is the core conductor. When an AC voltage RFV is applied between 81 and the covering conductor 83, the straight slot 33 loaded with the variable capacitive element 4 is almost short-circuited, and the straight slot 35 loaded with the variable capacitive element 5 is almost opened (FIG. 5). Further, the loop-shaped slot 3 is supplied with power. As a result, the antenna device 10 radiates a beam having a radiation pattern having peaks at about −90 degrees and about 90 degrees (see curve k2). In this case, the peak at about -90 degrees is larger than the peak at about 90 degrees.

  When the variable capacitance element is not loaded, the radiation pattern is flatter than that when the variable capacitance elements 4 and 5 are loaded in the range of the azimuth angle φ of −180 degrees to 180 degrees (see the curve k3).

  Therefore, by loading the variable capacitance elements 4 and 5 into the loop-shaped slot 3 and controlling the polarity of the DC voltage applied to the variable capacitance elements 4 and 5, the antenna device 10 radiates beams having different directivities. .

  As described above, when the DC power supply 9 applies the DC voltage DCV1 between the conductors 21 and 22 so that the core conductor 81 becomes negative and the coated conductor 83 becomes positive, the varactor diode 43 of the variable capacitance element 4 has A reverse DC voltage is applied, and a forward DC voltage is applied to the varactor diode 43 of the variable capacitance element 5. As a result, the capacitance of the variable capacitance element 4 decreases and the capacitance of the variable capacitance element 5 increases.

  When the DC power supply 9 applies the DC voltage DCV2 between the conductors 21 and 22 so that the core conductor 81 becomes positive and the coated conductor 83 becomes negative, the varactor diode 43 of the variable capacitance element 4 has a forward direction. A direct current voltage is applied, and a reverse direct current voltage is applied to the varactor diode 43 of the variable capacitance element 5. As a result, the capacitance of the variable capacitance element 4 increases and the capacitance of the variable capacitance element 5 decreases.

  When the capacitances of the variable capacitance elements 4 and 5 are increased or decreased, the antenna device 10 emits beams having different directivities as shown in FIG.

  Accordingly, the DC power source 9 controls the capacitance of the variable capacitance elements 4 and 5 via the coaxial cable 8 and controls the directivity of the antenna device 10.

  When the AC power supply 11 applies the AC voltage RFV between the conductors 21 and 22 via the coaxial cable 8, the loop slot 3 is excited.

  Accordingly, the AC power supply 11 supplies power to the loop-shaped slot 3.

  In the above, the variable capacitance element 4 is connected between the conductors 21 and 22 so that a current flows from the outer region of the loop-shaped slot 3 to the inner region, and the variable capacitance element 5 is outer from the inner region of the loop-shaped slot 3. Although it has been described that the conductors 21 and 22 are connected so as to pass a current to the region, the present invention is not limited to this, and the variable capacitance element 4 allows the current to flow from the inner region to the outer region of the loop-shaped slot 3. The variable capacitance element 5 may be connected between the conductors 21 and 22 so as to flow current from the outer region of the loop-shaped slot 3 to the inner region.

  That is, in the present invention, of the two variable capacitance elements loaded in the loop-shaped slot 3, the variable capacitance element loaded on one side with respect to the base axis AX1 is outside the loop-shaped slot 3 to be loaded. It is connected between the conductors 21 and 22 on both sides of the loop-shaped slot 3 so that the current flows in any one of the direction from the region to the inner region and the direction from the inner region to the outer region, and the other with respect to the base axis AX1. The variable capacitance element loaded on the side of the loop-shaped slot 3 to be loaded is loop-shaped so that a current flows in the other direction from the outer region to the inner region and from the inner region to the outer region. The conductors 21 and 22 on both sides of the slot 3 are connected.

  According to the first embodiment, the antenna device 10 includes a loop-shaped slot 3, two variable capacitance elements 4 and 5 loaded in the loop-shaped slot 3, and a conductor formed in an inner region of the loop-shaped slot 3. 21 and a coaxial cable 8 connected to the conductor 22 formed in the outer region of the loop-shaped slot 3; a DC power source 9 for controlling the capacity of the two variable capacitance elements 4 and 5 via the coaxial cable 8; Since the AC power supply 11 that feeds power to the loop-shaped slot 3 via the coaxial cable 8 is provided, the directivity of the antenna device 10 using the loop-shaped slot 3 can be controlled.

  The DC power supply 9 and the AC power supply 11 supply power to the loop-shaped slot 3 through the coaxial cable 8 and also control the directivity by controlling the capacitance of the two variable capacitance elements 4 and 5. Is configured.

[Embodiment 2]
FIG. 8 is a plan view of the antenna device according to the second embodiment. The antenna device 10A according to the second embodiment is obtained by replacing the loop-like slot 3 of the antenna device 10 shown in FIG. 1 with the loop-like slots 12 and 13 and the variable capacitive elements 4 and 5 with the variable capacitive elements 14 to 17. Others are the same as the antenna device 10.

  Loop-shaped slots 12 and 13 are formed by removing predetermined portions of the conductor 2 adhered to the entire surface of the main surface 1A of the dielectric substrate 1. The loop-shaped slots 12 and 13 are formed concentrically, and the loop-shaped slot 13 is formed on the inner peripheral side of the loop-shaped slot 12.

  As a result, the conductor 2 is divided into conductors 23 to 25. The conductor 23 is formed in the inner region of the loop-shaped slot 13, the conductor 24 is formed in the region between the loop-shaped slot 12 and the loop-shaped slot 13, and the conductor 25 is formed in the outer region of the loop-shaped slot 13. Formed. The conductor 23 has a power feeding part 23A, and the conductor 25 has a power feeding part 25A.

  The loop-shaped slot 12 has a generally square loop shape. More specifically, the loop-shaped slot 12 has straight slots 121 to 126. Each of the straight slots 122 to 125 is disposed substantially parallel to one side of the dielectric substrate 1. The straight slots 121 and 126 are arranged substantially parallel to each other and extend from one vertex of the square formed by the straight slots 122 to 125 to the outside of the square. In this case, the straight slots 121 and 126 are disposed substantially parallel to the diagonal of the square.

  Further, the loop slot 13 has a generally square loop shape. More specifically, the loop-shaped slot 13 has straight slots 131 to 136. Each of the straight slots 132 to 135 is disposed substantially parallel to one side of the dielectric substrate 1. The straight slots 131 and 136 are arranged substantially parallel to each other, and extend from one vertex of the square formed by the straight slots 132 to 135 to the outside of the square. As a result, the straight slots 131 and 136 are connected to the straight slots 121 and 126 of the loop-shaped slot 12, respectively. Further, the loop-shaped slots 12 and 13 share the power feeding units 23A and 25A.

  The overall length of the loop-shaped slot 12 is λ / 2, and its width W is λ / 10 or less. The total length of the loop-shaped slot 13 is λ / 3, and the width W thereof is λ / 10 or less.

  The variable capacitance element 14 is loaded at substantially the midpoint of the straight slot 122 of the loop-shaped slot 12 and is connected between the conductors 24 and 25 on both sides of the straight slot 122. The variable capacitance element 15 is loaded at a substantially middle point of the straight slot 125 of the loop-shaped slot 12 and connected between the conductors 24 and 25 on both sides of the straight slot 125. As a result, the variable capacitance elements 14 and 15 are loaded in the loop-shaped slot 12 symmetrically with respect to the base axis AX2 that passes through the power feeding portion 23A.

  The variable capacitance element 16 is loaded at a substantially middle point of the straight slot 133 of the loop-shaped slot 13 and connected between the conductors 23 and 24 on both sides of the straight slot 133. The variable capacitance element 17 is loaded at a substantially middle point of the straight slot 134 of the loop-shaped slot 13 and connected between the conductors 23 and 24 on both sides of the straight slot 134. As a result, the variable capacitance elements 16 and 17 are loaded in the loop-shaped slot 13 symmetrically with respect to the base axis AX2 that passes through the power feeding unit 23A.

  Each of variable capacitance elements 14-17 has the same configuration as that of variable capacitance element 4 shown in FIG. When the variable capacitance element 14 is loaded in the straight slot 122 of the loop-shaped slot 12, the node N 1 is connected to the conductor 25 and the node N 2 is connected to the conductor 24. When the variable capacitance element 15 is loaded in the straight slot 125 of the loop-shaped slot 12, the node N 1 is connected to the conductor 24 and the node N 2 is connected to the conductor 25.

  As a result, among the variable capacitance elements 14 and 15 loaded in the loop-shaped slot 12 symmetrically with respect to the base axis AX2, the variable capacitance element 14 loaded on one side of the base axis AX2 is removed from the outer region of the loop-shaped slot 12. The variable capacitance element 15 connected between the conductors 24 and 25 so as to pass a current to the inner region and loaded on the other side of the base axis AX2 has a conductor 24 so that a current flows from the inner region to the outer region of the loop-shaped slot 12. , 25.

  When the variable capacitance element 16 is loaded in the loop-shaped slot 13, the node N 1 is connected to the conductor 24 and the node N 2 is connected to the conductor 23. When the variable capacitance element 17 is loaded in the loop-shaped slot 13, the node N 1 is connected to the conductor 23 and the node N 2 is connected to the conductor 24.

  As a result, among the variable capacitance elements 16 and 17 loaded in the loop-shaped slot 13 symmetrically with respect to the base axis AX2, the variable capacitance element 16 loaded on one side of the base axis AX2 is removed from the outer region of the loop-shaped slot 13. The variable capacitance element 17 connected between the conductors 23 and 24 so as to pass a current to the inner region and loaded on the other side of the base axis AX2 has a conductor 23 so that a current flows from the inner region of the loop-shaped slot 13 to the outer region. , 24 are connected.

  In antenna device 10A, the other end of conducting wire 6 is connected to power feeding portion 23A, and the other end of conducting wire 7 is connected to feeding portion 25A.

  9 and 10 are first and second conceptual diagrams for explaining the operation of the antenna device 10A shown in FIG. 8, respectively.

  When the DC voltage DCV1 is applied between the core conductor 81 and the covered conductor 83 so that the core conductor 81 of the coaxial cable 8 becomes negative and the covered conductor 83 becomes positive, the conductor 23 becomes negative and the conductor 25 becomes A DC voltage DCV1 is applied between the conductors 23 and 25 so as to be positive.

  Then, a reverse DC voltage is applied to the varactor diodes 43 of the variable capacitance elements 14 and 16, and the capacitances of the variable capacitance elements 14 and 16 become small, and the straight slot 122 and the loop slot 13 of the loop slot 12. The straight slot 132 is almost open and is well excited. Further, a forward DC voltage is applied to the varactor diodes 43 of the variable capacitance elements 15 and 17, and the capacitances of the variable capacitance elements 15 and 17 become large, and the straight slot 124 and the loop slot 13 of the loop slot 12. The straight slot 134 is almost short-circuited and does not excite very much.

  As a result, the loop-shaped slot 12 is separated into straight slots 121 to 124, 1251 and straight slots 1252, 126, and the loop-shaped slot 13 is divided into straight slots 131-133, 1341, and straight slots 1342, 135, 136. (See FIG. 9).

  Then, the antenna device 10A radiates a beam having peaks in a direction of about 45 degrees and a direction of about -135 degrees. In this case, the peak in the direction of about 45 degrees is larger than the peak in the direction of about -135 degrees.

  On the other hand, when the DC voltage DCV2 is applied between the core conductor 81 and the covered conductor 83 so that the core conductor 81 of the coaxial cable 8 becomes positive and the coated conductor 83 becomes negative, the conductor 23 becomes positive and the conductor A DC voltage DCV2 is applied between the conductors 23 and 25 so that 25 becomes negative.

  Then, a forward DC voltage is applied to the varactor diodes 43 of the variable capacitance elements 14 and 16, and the capacitances of the variable capacitance elements 14 and 16 become large, and the straight slot 122 and the loop slot 13 of the loop slot 12. The straight slot 133 is almost short-circuited and does not vibrate very much. In addition, a reverse DC voltage is applied to the varactor diodes 43 of the variable capacitance elements 15 and 17, and the capacitances of the variable capacitance elements 15 and 17 become small, and the straight slot 125 and the loop slot 13 of the loop slot 12. The straight slot 134 is almost open and well excited.

  As a result, the loop-shaped slot 12 is separated into straight slots 121, 1221 and straight slots 1222, 123-126, and the loop-shaped slot 13 is divided into straight slots 131, 132, 1331 and straight slots 1332, 134-136. (See FIG. 10).

  Then, the antenna device 10A radiates a beam having peaks in a direction of about 45 degrees and a direction of about -135 degrees. In this case, the peak in the direction of about -135 degrees is larger than the peak in the direction of about 45 degrees.

  In this way, by switching the polarity of the DC voltage applied between the core conductor 81 and the coated conductor 83, one of the variable capacitance elements 14 to 17 (or the variable capacitance elements 15, 17) The straight slots 122 and 133 (or straight slots 125 and 134) loaded are almost opened (or almost short-circuited), and the other variable capacitive elements 15 and 17 (or variable capacitive elements 14 and 16) are loaded. The straight slots 125, 134 (or straight slots 122, 134) can be substantially shorted (or nearly open).

  This is due to the following reason. As described above, among the variable capacitance elements 14 to 17 loaded in the loop-shaped slots 12 and 13 symmetrically with respect to the base axis AX2, the variable capacitance elements 14 and 16 loaded on one side with respect to the base axis AX2 are: Each of the loop-shaped slots 12 and 13 is connected between the conductors 24 and 25 and between the conductors 23 and 24 so that current flows from the outer region to the inner region of the loop-shaped slots 12 and 13 to be loaded, and symmetrically with respect to the base axis AX2. , 13 of the variable capacitance elements 14-17 loaded on the other side with respect to the base axis AX2, respectively, from the inner regions of the loop-shaped slots 12, 13 to be loaded, respectively. Since it is connected between the conductors 24 and 25 and between the conductors 23 and 24 so as to allow current to flow to the outer region, the polarity of the DC voltage applied between the conductors 23 and 25 is switched. A forward DC voltage is applied to the varactor diode 43 of one of the four variable capacitance elements 14 to 17 (or the variable capacitance elements 15 and 17), and the other variable capacitance elements 14 to 17. This is because a reverse DC voltage is applied to the varactor diodes 43 of the variable capacitance elements 15 and 17 (or the variable capacitance elements 14 and 16).

  Therefore, by loading the variable capacitance elements 14 to 17 into the concentric loop-shaped slots 12 and 13 and controlling the polarity of the DC voltage applied to the variable capacitance elements 14 to 17, the antenna device 10A is directed. A beam having a characteristic is emitted.

  In the above, the variable capacitance element 14 is connected between the conductors 24 and 25 so that a current flows from the outer region of the loop-shaped slot 12 to the inner region, and the variable capacitance element 16 is connected to the inner side from the outer region of the loop-shaped slot 13. The variable capacitance element 15 is connected between the conductors 24 and 25 so as to flow current from the inner region of the loop-shaped slot 12 to the outer region so that a current flows to the region. 17 is connected between the conductors 23 and 24 so that a current flows from the inner region to the outer region of the loop-shaped slot 13, but in the present invention, the present invention is not limited thereto. The variable capacitance element 16 is connected between the conductors 24 and 25 so that current flows from the inner region to the outer region of the slot 12, and the variable capacitance element 16 is connected to the outer region from the inner region of the loop slot 13. The variable capacitance element 15 is connected between the conductors 24 and 25 so as to flow current from the outer region of the loop-shaped slot 12 to the inner region so that a current flows. The conductors 23 and 24 may be connected so that a current flows from the outer region to the inner region of the loop-shaped slot 13.

  That is, in the present invention, of the four variable capacitance elements 14 to 17 loaded in the two loop-shaped slots 12 and 13 formed concentrically, the variable loaded on one side with respect to the base axis AX2. Capacitance elements 14 and 16 are loop-shaped slots so that current flows in either direction from the outer region to the inner region and the direction from the inner region to the outer region of loop-shaped slots 12 and 13 to be loaded. The variable capacitance elements 15 and 17 connected between the conductors on both sides of 12 and 13 and loaded on the other side with respect to the base axis AX2 are directed from the outer region to the inner region of the loop-shaped slots 12 and 13 to be loaded. And it is connected between the conductors on both sides of the loop-shaped slots 12 and 13 so that a current flows in either one of the directions from the inner region to the outer region.

  According to the second embodiment, the antenna device 10A is loaded in the two loop-shaped slots 12 and 13, the two variable capacitance elements 14 and 15 loaded in the loop-shaped slot 12, and the loop-shaped slot 13. A coaxial cable 8 connected to two variable capacitors 16 and 17, a conductor 23 formed in the inner region of the loop-shaped slot 13, and a conductor 25 formed in the outer region of the loop-shaped slot 12; Since a DC power source 9 for controlling the capacities of the four variable capacitance elements 14 to 17 through the cable 8 and an AC power source 11 for supplying power to the loop-shaped slots 12 and 13 through the coaxial cable 8 are provided, the loop-shaped slot The directivity of the antenna device 10A using 12 and 13 can be controlled.

  Others are the same as in the first embodiment.

  The conductor 23 constitutes a “first conductor” formed in an inner region of the loop-shaped slot 13 disposed on the innermost peripheral side, and the conductor 25 is formed on the loop-shaped slot 12 disposed on the outermost peripheral side. This constitutes a “second conductor” formed in the outer region.

[Embodiment 3]
FIG. 11 is a plan view of the antenna device according to the third embodiment. The antenna device 10B according to the third embodiment is obtained by replacing the variable capacitors 4 and 5 of the antenna device 10 shown in FIG. 1 with variable capacitors 51 to 58, and adding a loop slot 18 and variable capacitors 61 to 68. Others are the same as the antenna device 10.

  Loop-shaped slots 3 and 18 are formed by removing predetermined portions of the conductor 2 attached to the entire main surface 1A of the dielectric substrate 1. The loop-shaped slots 3 and 18 are formed concentrically, and the loop-shaped slot 18 is formed in contact with the loop-shaped slot 3 at four points.

  As a result, the conductor 2 is divided into conductors 201 to 206. The conductor 201 is formed in an inner region of the loop-shaped slot 18, the conductors 202 to 205 are formed in a region between the loop-shaped slot 3 and the loop-shaped slot 18, and the conductor 206 is formed in the loop-shaped slot 18. Formed in the outer region. The conductor 201 has a power feeding part 201A, and the conductor 206 has a power feeding part 206A.

The loop-shaped slot 18 has a generally rhombic loop shape. More specifically, the loop-shaped slot 18 has straight slots 181 to 184. The intersection of the straight slot 181 and the straight slot 182, the intersection of the straight slot 182 and the straight slot 183, and the intersection of the straight slot 183 and the straight slot 184 are the straight slots 33, 34, It touches the approximate middle point of 35. One end of the straight slot 181 is connected to the intersection of the straight slot 31 and the straight slot 32 of the loop slot 3, and one end of the straight slot 184 is connected to the straight slot 36 and the straight slot 37 of the loop slot 3. And connected to the intersection.
As a result, the loop-shaped slots 3 and 18 share the power feeding units 201A and 206A.

The overall length of the loop-shaped slot 18 is (2) ^1/2 λ / 4, and its width W is λ / 10 or less.

  The variable capacitance element 51 is loaded at a substantially middle point of the straight slot 32 of the loop-shaped slot 3 and connected between the conductors 202 and 206 on both sides of the straight slot 32. The variable capacitance elements 52 and 53 are loaded on both ends of the linear slot 33 of the loop-shaped slot 3. The variable capacitance element 52 is connected between the conductors 202 and 206 on both sides of the linear slot 33, and the variable capacitance element 53 is connected between the conductors 203 and 206 on both sides of the linear slot 33.

  Furthermore, the variable capacitance elements 54 and 55 are loaded on both ends of the linear slot 34 of the loop-shaped slot 3. The variable capacitance element 54 is connected between the conductors 203 and 206 on both sides of the linear slot 34, and the variable capacitance element 55 is connected between the conductors 204 and 206 on both sides of the linear slot 34.

  Furthermore, the variable capacitance elements 56 and 57 are loaded on both ends of the linear slot 35 of the loop-shaped slot 3. The variable capacitance element 56 is connected between the conductors 204 and 206 on both sides of the linear slot 35, and the variable capacitance element 57 is connected between the conductors 205 and 206 on both sides of the linear slot 35.

  Further, the variable capacitance element 58 is loaded at a substantially middle point of the straight slot 36 of the loop-shaped slot 3 and connected between the conductors 205 and 206 on both sides of the straight slot 36.

  As a result, the variable capacitance elements 51 to 58 are loaded in the loop-shaped slot 3 symmetrically with respect to the base axis AX3 that passes through the power feeding unit 201A.

  The variable capacitance elements 61 and 62 are loaded on both ends of the linear slot 181 of the loop-shaped slot 18 and connected between the conductors 201 and 202 on both sides of the linear slot 181.

  The variable capacitance elements 63 and 64 are loaded on both ends of the linear slot 182 of the loop slot 18 and connected between the conductors 201 and 203 on both sides of the linear slot 182.

  Further, the variable capacitance elements 65 and 66 are loaded on both ends of the straight slot 183 of the loop-shaped slot 18 and connected between the conductors 201 and 204 on both sides of the straight slot 183.

  Furthermore, the variable capacitance elements 67 and 68 are loaded on both ends of the straight slot 184 of the loop slot 18 and connected between the conductors 201 and 205 on both sides of the straight slot 184.

  As a result, the variable capacitance elements 61 to 68 are loaded in the loop-shaped slot 18 symmetrically with respect to the base axis AX3 that passes through the power feeding unit 201A.

  Each of variable capacitance elements 51-58 and 61-68 has the same configuration as that of variable capacitance element 4 shown in FIG. When the variable capacitance element 51 is loaded in the straight slot 32 of the loop-shaped slot 3, the node N1 is connected to the conductor 206, and the node N2 is connected to the conductor 202. When the variable capacitance element 52 is loaded in the straight slot 33 of the loop-shaped slot 3, the node N1 is connected to the conductor 206, and the node N2 is connected to the conductor 202.

  When the variable capacitance element 53 is loaded in the straight slot 33 of the loop-shaped slot 3, the node N1 is connected to the conductor 206, and the node N2 is connected to the conductor 203. When the variable capacitance element 54 is loaded in the straight slot 34 of the loop-shaped slot 3, the node N1 is connected to the conductor 206, and the node N2 is connected to the conductor 203.

  When the variable capacitance element 55 is loaded in the straight slot 34 of the loop-shaped slot 3, the node N 1 is connected to the conductor 206 and the node N 2 is connected to the conductor 204. When the variable capacitance element 56 is loaded in the straight slot 35 of the loop-shaped slot 3, the node N <b> 1 is connected to the conductor 206 and the node N <b> 2 is connected to the conductor 204.

  When the variable capacitance element 57 is loaded in the straight slot 35 of the loop-shaped slot 3, the node N1 is connected to the conductor 206, and the node N2 is connected to the conductor 205. When the variable capacitance element 58 is loaded in the straight slot 36 of the loop-shaped slot 3, the node N1 is connected to the conductor 206, and the node N2 is connected to the conductor 205.

  As a result, the variable capacitance elements 51 to 58 loaded in the loop-shaped slot 3 provided on the outer peripheral side allow the current to flow from the outer region to the inner region of the loop-shaped slot 3 between the conductors 202 and 206, the conductor 203, 206, conductors 204 and 206, and conductors 205 and 206 are connected.

  When the variable capacitance elements 61 and 62 are loaded in the straight slot 181 of the loop-shaped slot 18, the node N 1 is connected to the conductor 201 and the node N 2 is connected to the conductor 202. When the variable capacitance elements 63 and 64 are loaded in the straight slot 182 of the loop-shaped slot 18, the node N1 is connected to the conductor 201, and the node N2 is connected to the conductor 203. When the variable capacitance elements 65 and 66 are loaded in the straight slot 183 of the loop-shaped slot 18, the node N 1 is connected to the conductor 201 and the node N 2 is connected to the conductor 204.

  When the variable capacitance elements 67 and 68 are loaded in the straight slot 184 of the loop slot 18, the node N1 is connected to the conductor 201 and the node N2 is connected to the conductor 205.

  As a result, the variable capacitance elements 61 to 68 loaded in the loop-shaped slot 18 provided on the inner circumferential side allow the current to flow from the inner region to the outer region of the loop-shaped slot 18, between the conductors 201, 202 and the conductor 201. , 203, between conductors 201 and 204, and between conductors 201 and 205.

  In antenna device 10B, the other end of conducting wire 6 is connected to power feeding unit 201A, and the other end of conducting wire 7 is connected to feeding unit 206A.

  12 and 13 are first and second conceptual diagrams for explaining the operation of the antenna device 10B shown in FIG. 11, respectively.

  When the DC voltage DCV1 is applied between the core conductor 81 and the covered conductor 83 so that the core conductor 81 of the coaxial cable 8 becomes negative and the covered conductor 83 becomes positive, the conductor 201 becomes negative and the conductor 206 becomes A DC voltage DCV1 is applied between the conductors 201 and 206 so as to be positive.

  Then, a DC voltage in the reverse direction is applied to the varactor diodes 43 of the variable capacitance elements 51 to 58 in the loop-shaped slot 3, and the capacitances of the variable capacitance elements 51 to 58 become small, and the straight slot 32 of the loop-shaped slot 3. ˜36 is almost open and well excited. In addition, a forward DC voltage is applied to the varactor diodes 43 of the variable capacitance elements 61 to 68 in the loop-shaped slot 18, and the capacitances of the variable capacitance elements 61 to 68 are increased, and the linear slots 181 of the loop-shaped slot 18. ˜184 is almost short-circuited and not very excited.

  As a result, in the loop-shaped slot 3, the straight slots 31 to 37 are excited integrally, and the loop-shaped slot 18 includes the straight slot 1811, the straight slot 1812, the straight slots 1813 and 1821, the straight slot 1822, and the straight slots 1823 and 1831. Are separated into a straight slot 1832, straight slots 1833 and 1841, a straight slot 1842 and a straight slot 1843 (see FIG. 12).

  The antenna device 10B can be well matched at a frequency corresponding to the wavelength λ.

  On the other hand, when the DC voltage DCV2 is applied between the core conductor 81 and the covered conductor 83 so that the core conductor 81 of the coaxial cable 8 becomes positive and the covered conductor 83 becomes negative, the conductor 201 becomes positive and the conductor A DC voltage DCV2 is applied between the conductors 201 and 206 so that 206 becomes negative.

  Then, a forward DC voltage is applied to the varactor diodes 43 of the variable capacitance elements 51 to 58 in the loop-shaped slot 3, and the capacitances of the variable capacitance elements 51 to 58 become large, and the linear slots 32 of the loop-shaped slot 3. ˜36 is almost short-circuited and does not vibrate very much. In addition, a reverse DC voltage is applied to the varactor diodes 43 of the variable capacitance elements 61 to 68 in the loop-shaped slot 18, and the capacitances of the variable capacitance elements 61 to 68 become smaller, and the linear slots 181 of the loop-shaped slot 18. ˜184 is almost open and well excited.

  As a result, the loop-shaped slot 3 includes straight slots 31, 3201, straight slots 3202, 3301, straight slots 3302, straight slots 3303, 3401, straight slots 3402, straight slots 3403, 3501, straight slots 3502, straight slots 3503, 3601. The loop-shaped slot 18 is excited by the linear slots 181 to 184 integrally (see FIG. 13).

The antenna device 10B is well matched at a frequency corresponding to the wavelength (2) ^1/2 λ / 2.

  Thus, by switching the polarity of the DC voltage applied between the core conductor 81 and the covered conductor 83, the variable capacitance elements 51 to 58 loaded in the two loop-shaped slots 3 and 18 formed concentrically. , 61-68, one loop-like slot 3 (or loop-like slot 18) loaded with the variable capacitive elements 51-58 (or the variable capacitive elements 61-68) is almost opened (or almost short-circuited) to be variable. The other loop slot 18 (or the loop-shaped slot 3) loaded with the capacitive elements 61 to 68 (or the variable capacitive elements 51 to 58) can be substantially short-circuited (or almost opened).

  This is due to the following reason. As described above, the variable capacitance elements 51 to 58 loaded in the loop-shaped slot 3 are arranged between the conductors 202 and 206 on both sides of the loop-shaped slot 3 so that a current flows from the outer region to the inner region of the loop-shaped slot 3. The variable capacitance elements 61 to 68 connected between the conductors 203 and 206, between the conductors 204 and 206, and between the conductors 205 and 206 and loaded in the loop-shaped slot 18 conduct current from the inner region to the outer region of the loop-shaped slot 18. Since it is connected between the conductors 201 and 202 on both sides of the loop-shaped slot 18, between the conductors 201 and 203, between the conductors 201 and 204, and between the conductors 201 and 205, the DC voltage applied between the conductors 201 and 206 By switching the polarity, one of the 16 variable capacitors 51 to 58, 61 to 68, one of the variable capacitors 51 to 58 (or A dc voltage in the forward direction is applied to the varactor diode 43 of the variable capacitance elements 61 to 68), and a reverse voltage is applied to the varactor diode 43 of the other variable capacitance elements 61 to 68 (or variable capacitance elements 51 to 58). This is because a DC voltage is applied.

  Therefore, the variable capacitance elements 51 to 58 and 61 to 68 are loaded in the loop slots 3 and 18 formed concentrically, and the polarity of the DC voltage applied to the variable capacitance elements 51 to 58 and 61 to 68 is controlled. Thus, the antenna device 10B radiates beams having different frequencies. That is, the antenna measure 10B can switch the frequency by controlling the polarity of the DC voltage applied to the variable capacitance elements 51 to 58 and 61 to 68.

  In the above, the variable capacitance elements 51 to 58 are arranged between the conductors 202 and 206, between the conductors 203 and 206, between the conductors 204 and 206, and between the conductors 205 and 206 so as to flow current from the outer region to the inner region of the loop-shaped slot 3. The variable capacitance elements 61 to 68 are connected between the conductors 201 and 202, between the conductors 201 and 203, between the conductors 201 and 204, and between the conductors 201 and 204 and so as to flow current from the inner region to the outer region of the loop-shaped slot 18. In the present invention, the variable capacitance elements 51 to 58 are not limited to this, but the variable capacitance elements 51 to 58 are connected between the conductors 202 and 206 so that current flows from the inner region to the outer region of the loop-shaped slot 3. Are connected between the conductors 203 and 206, between the conductors 204 and 206, and between the conductors 205 and 206, and the variable capacitance elements 61 to 68 are loop-shaped slots. Between the conductors 201 and 202 to flow current from the outer region to the inner region of 8, between the conductors 201 and 203, may be connected between the between the conductors 201, 204 and conductors 201 and 205.

  That is, in the present invention, of the 16 variable capacitance elements 51 to 58 and 61 to 68 loaded in the two loop slots 3 and 18 formed concentrically, the outer loop slot 3 is loaded. The variable capacitance elements 51 to 58 are arranged so that current flows in one direction from the outer region to the inner region and from the inner region to the outer region of the loop slot to be loaded. The variable capacitance elements 61 to 68 connected between the conductors on both sides of 3 and loaded in the inner loop-shaped slot 18 are directed from the outer region to the inner region of the loop-shaped slot 18 to be loaded and from the inner region to the outer side. It is connected between the conductors on both sides of the loop-shaped slot so that a current flows in the other direction of the region.

  In the above description, it has been described that the loop-shaped slot 18 is formed inscribed in the loop-shaped slot 3, but in the present invention, the present invention is not limited to this, and the loop-shaped slot 18 is formed in the loop-shaped slot 3. It is not necessary to touch.

  Furthermore, in the above description, it has been described that the same number of variable capacitance elements are loaded in the two loop-shaped slots 3 and 18, but in the present invention, the present invention is not limited to this, and the two loop-shaped slots 3 and 18 have A different number of variable capacitance elements may be loaded. That is, in the antenna device 10B, 2 (i + j) (i and j are positive integers) variable capacitance elements are loaded as a whole, and 2i variable capacitance elements out of 2 (i + j) variable capacitance elements. The element is loaded in the outer loop-shaped slot 3, and 2j variable capacitance elements are loaded in the inner loop-shaped slot 18.

  According to the third embodiment, the antenna device 10B is loaded in the two loop-shaped slots 3 and 18, the eight variable capacitance elements 51 to 58 loaded in the loop-shaped slot 3, and the loop-shaped slot 18. A coaxial cable 8 connected to eight variable capacitance elements 61 to 68, a conductor 201 formed in the inner region of the loop-shaped slot 18, and a conductor 206 formed in the outer region of the loop-shaped slot 3; Since the DC power source 9 that controls the capacities of the 16 variable capacitance elements 51 to 58 and 61 to 68 via the cable 8 and the AC power source 11 that feeds the loop-like slots 3 and 18 via the coaxial cable 8 are provided. The frequency of the antenna device 10B using the loop-shaped slots 3 and 18 can be controlled.

  Others are the same as in the first embodiment.

  The conductor 201 constitutes a “first conductor” formed in the inner region of the loop-shaped slot 18 disposed on the innermost peripheral side, and the conductor 206 is formed on the loop-shaped slot 3 disposed on the outermost peripheral side. This constitutes a “second conductor” formed in the outer region.

  In the antenna devices 10, 10 </ b> A, 10 </ b> B according to Embodiments 1 to 3 described above, it has been described that an even number of variable capacitance elements are loaded in the loop-shaped slots 3; 12, 13; 3, 18. In the present invention, not limited to this, an odd number of variable capacitance elements may be loaded in the loop-shaped slots 3; 12, 13; When an odd number of variable capacitance elements are loaded in each loop-shaped slot, the AC matching changes when the direction of the DC voltage applied to each variable capacitance element is changed. Therefore, if the AC matching is allowed to change, an odd number of variable capacitance elements may be loaded in each loop-shaped slot 3; 12, 13; In this case, the odd number of variable capacitance elements loaded in the loop-shaped slots 3: 12, 13; 3, 18 are arranged asymmetrically with respect to the base axes AX 1, AX 2, AX 3. Then, at least one or more odd number of variable capacitance elements are arranged on both sides around the base axes AX1, AX2, AX3.

  In addition, each of the antenna devices 10, 10A, and 10B according to the above-described first to third embodiments is applied to, for example, a monolithic microwave integrated circuit (MMIC: Monolithic Microwave Integrated Circuit). That is, the MMIC in which the antenna devices 10, 10A, and 10B are integrated is manufactured. In this case, each of the antenna devices 10, 10A, and 10B is manufactured by forming a loop-shaped slot on the copper foil surface.

  In addition, each of the antenna devices 10, 10A, and 10B may have a metal body on the back surface, and is used by being attached to a metal housing such as a mobile phone and a television.

  The antenna devices 10, 10A, and 10B each have two conductors 21 and 22, two conductors 23 and 25, and two conductors 201 and 206, which are asymmetrical to each other. No transformer is required.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to an antenna device that includes a loop-shaped slot and can switch directivity. The present invention is also applied to an antenna device capable of switching frequencies.

It is a top view of the antenna apparatus by Embodiment 1 of this invention. It is sectional drawing of the antenna apparatus between the lines II-II shown in FIG. FIG. 3 is a configuration diagram of the variable capacitance element shown in FIGS. 1 and 2. FIG. 3 is a first conceptual diagram for explaining the operation of the antenna device shown in FIGS. 1 and 2. FIG. 3 is a second conceptual diagram for explaining the operation of the antenna device shown in FIGS. 1 and 2. It is a figure which shows the definition of the azimuth in the antenna apparatus shown in FIG. 1 and FIG. It is a figure which shows the radiation pattern of the antenna apparatus shown in FIG. 1 and FIG. 6 is a plan view of an antenna device according to Embodiment 2. FIG. It is a 1st conceptual diagram for demonstrating operation | movement of the antenna apparatus shown in FIG. It is a 2nd conceptual diagram for demonstrating operation | movement of the antenna apparatus shown in FIG. 6 is a plan view of an antenna device according to a third embodiment. FIG. It is a 1st conceptual diagram for demonstrating operation | movement of the antenna apparatus shown in FIG. It is a 2nd conceptual diagram for demonstrating operation | movement of the antenna apparatus shown in FIG.

Explanation of symbols

  1 Dielectric substrate, 2, 21 to 25, 201 to 206 conductor, 3, 12, 13 loop-shaped slot, 4, 5, 14 to 17, 51 to 58, 61 to 68 variable capacitance element, 6, 7 conductor, 8 Coaxial cable, 9 DC power supply, 10, 10A, 10B Antenna device, 11 AC power supply, 21A, 22A, 23A, 25A, 201A, 206A 332, 351, 352, 1221, 1222, 1251, 1252, 1331, 1332, 1341, 1342, 1811-1813, 1821-1823, 1831-1833, 1841-1843, 3301-3303, 3401-3403, 3501-3503 3601, 3602 Straight slot, 41 resistance, 42 capacities Motor, 43 varactor diode, 81 core conductor, 82 an insulator, 83 covering the conductor, AX1～AX3 base shaft, N1-N4 nodes.

Claims (6)

M (m is a positive integer) loop-shaped slots formed on one main surface of the dielectric substrate, each having a loop shape;
N variable capacitors loaded in the m loop-shaped slots (n is an integer of 2 or more);
A cable comprising first and second conductors that are substantially parallel;
An antenna apparatus comprising: an antenna control unit that feeds power to the m loop-shaped slots through the cable and controls directivity or frequency by controlling capacitances of the n variable capacitive elements. A power feeding portion provided on the one main surface and connected to the cable;
2. The antenna device according to claim 1, wherein at least one of the n variable capacitance elements is disposed on each side of the one main surface around a base axis that passes through the power feeding unit. A first conductor formed in an inner region of the m loop-shaped slots;
A second conductor formed in an outer region of the m loop-shaped slots,
The power feeding unit is
A first power feeding unit formed on the first conductor;
The antenna device according to claim 2, further comprising: a second power feeding unit formed on the second conductor. The antenna controller is
A DC power supply for applying a DC voltage between the first conductor and the second conductor;
An AC power source that applies an AC voltage between the first conductor and the second conductor;
The first conductive wire is connected to the first power feeding unit,
The antenna device according to claim 3, wherein the second conducting wire is connected to the second power feeding unit. Each of the n variable capacitance elements includes a varactor diode,
Among the n variable capacitance elements, the variable capacitance element arranged on one side with respect to the base axis is a first direction from the outer region to the inner region of the loop-shaped slot to be loaded and from the inner region. Connected between two conductors formed on both sides of the looped slot to be loaded so that current flows in either direction of the second direction to the outer region;
Among the n variable capacitive elements, the variable capacitive element arranged on the other side with respect to the base axis has a current flowing in one of the first and second directions of the loop-shaped slot to be loaded. 5. The antenna device according to claim 1, wherein the antenna device is connected between two conductors formed on both sides of the loop-shaped slot to be loaded. The n variable capacitance elements are composed of 2 (i + j) (i and j are positive integers) variable capacitance elements each including a varactor diode,
The m loop-shaped slots are composed of two or more loop-shaped slots,
Of the 2 (i + j) variable capacitance elements, 2i variable capacitance elements loaded in the loop-shaped slot formed on the outermost peripheral side are connected from the outer region to the inner region of the loop-shaped slot to be loaded. Between two conductors formed on both sides of the looped slot to be loaded so that current flows in either the first direction or the second direction from the inner region to the outer region. Connected,
Of the 2 (i + j) variable capacitance elements, 2j variable capacitance elements loaded in a loop-shaped slot formed on the innermost circumferential side are the first and second loop-shaped slots to be loaded. 5. The device according to claim 1, wherein the current is passed in one direction of the other direction and is connected between two conductors formed on both sides of the looped slot to be loaded. 6. The antenna device according to 1.

Images