Patent Publication Number: US-8976068-B2

Title: Antenna apparatus having first and second antenna elements fed by first and second feeder circuits connected to separate ground conductors

Description:
This is a continuation application of International application No. PCT/JP2011/006864 as filed on Dec. 8, 2011, which claims priority to Japanese patent application No. JP 2011-057496 as filed on Mar. 16, 2011, the contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to an antenna apparatus including a plurality of antenna elements, a wireless communication apparatus including the antenna apparatus, and an electronic apparatus having the wireless communication apparatus. 
     2. Description of the Related Art 
     BACKGROUND 
     Portable electronic apparatus including a wireless communication apparatus and a display has been popularized. In this case, the wireless communication apparatus receives broadcasting signals such as broadcasting signals of digital terrestrial television broadcasting, and the display apparatus displays a received broadcasting signal. As a method for achieving reception with high sensitivity, such electronic apparatus uses adaptive control such as a combined diversity method to combine received signals received in in-phase by a plurality of antenna elements. In addition, it is necessary to provide a plurality of antenna elements inside or outside a casing of an electronic apparatus in order to perform adaptive control, and various methods have been proposed about the configuration and arrangement methods of the plurality of antenna elements (See Japanese Patent Laid-open Publication No. JP 2007-281906A, for example.). 
     In the electronic apparatus as described above, it is desirable that the electronic apparatus has high receiver sensitivity in various directions. However, if a plurality of antenna elements, that use radio waves within the same frequency band, are used to increase gain of an antenna apparatus of the electronic apparatus in various directions, then signal mixing from the other antenna elements will be caused due to electromagnetic coupling among the antenna elements. This sometimes led to decreased signal-to-noise ratio during reception with the antenna elements, and substantially decreased gain. 
     SUMMARY 
     In one general aspect, the instant application describes an antenna apparatus including a plurality of antenna elements, a wireless communication apparatus including the antenna apparatus, and an electronic apparatus including the wireless communication apparatus, each capable of solving the above-described problems and capable of substantially preventing the decrease in the gain as compared with the prior art. 
     An antenna apparatus according to the first disclosure is an antenna apparatus including a first antenna element, a second antenna element, and a feeder circuit board including a first feeder circuit that feeds to the first antenna element, and a second feeder circuit that feeds to the second antenna element. The feeder circuit board is a multi-layer board including first and second grounding conductors. A grounding terminal of the first feeder circuit is connected to the first grounding conductor to be grounded, so that a ground current flows through the first grounding conductor when a radio wave is transmitted and received with the first antenna element. A grounding terminal of the second feeder circuit is connected to the second grounding conductor to be grounded, so that a ground current flows through the second grounding conductor when a radio wave is transmitted and received with the second antenna element. 
     The above-described antenna apparatus preferably further includes an insulating substrate on which each of the first and second antenna elements is formed in a form of a conductor pattern. The first antenna element includes a first portion that extends in a predetermined first direction and has one end connected to the first feeder circuit, and a second portion that extends in a predetermined second direction and has one end connected to another end of the first portion. The second antenna element includes a third portion that extends in the first direction and has one end connected to the second feeder circuit, and a fourth portion that extends in a predetermined third direction and has one end connected to another end of the third portion. The antenna apparatus further includes a third grounding conductor formed between the first and third portions on the insulating substrate. 
     In addition, the above-described antenna apparatus preferably further includes fourth and fifth grounding conductors, each formed on the insulating substrate. The third and fourth grounding conductors are formed so as to interpose the first portion therebetween, and the third and fifth grounding conductors are formed so as to interpose the third portion therebetween. 
     Further, the above-described antenna apparatus preferably further includes connecting element that electrically connects the third, fourth and fifth grounding conductors with each other. 
     Still further, in the above-described antenna apparatus the first and second antenna elements preferably have substantially same resonance frequencies as each other. 
     A wireless communication apparatus according to the second disclosure is a wireless communication apparatus including the above-described antenna apparatus, and a wireless communication circuit that transmits and receives a wireless signal by using the antenna apparatus. 
     An electronic apparatus according to the third disclosure is an electronic apparatus including the above-described wireless communication apparatus including an antenna apparatus and a wireless communication circuit that transmits and receives a wireless signal by using the antenna apparatus, and a display apparatus that displays a video signal included in the wireless signal. 
     According to the antenna apparatus, the wireless communication apparatus and the electronic apparatus of the present disclosure, the grounding terminal of the first feeder circuit is connected to the first grounding conductor to be grounded, so that a ground current flows through the first grounding conductor when a radio wave is received with the first antenna element. The grounding terminal of the second feeder circuit is connected to the second grounding conductor to be grounded, so that a ground current flows through the second grounding conductor when a radio wave is received with the second antenna element. Therefore, the first antenna element and the second antenna element can be sparsely coupled with each other. Therefore, it is possible to prevent signal mixing from another antenna element in the first and second antenna elements, and it is possible to substantially prevent the decrease in the gain during the reception of the respective signals. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other aspects and features of the present disclosure will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings throughout which like parts are designated by like reference numerals, and in which: 
         FIG. 1  illustrates a perspective view showing an appearance of an electronic apparatus according to the preferred embodiment of the present disclosure, seen from the front the electronic apparatus; 
         FIG. 2  illustrates a perspective view showing the appearance of the electronic apparatus shown in  FIG. 1  seen from the back of the electronic apparatus; 
         FIG. 3  illustrates a top view showing an insulating substrate  5  and a feeder circuit board  6 , which are provided in an antenna apparatus casing of an antenna apparatus  4  shown in  FIG. 1 ; 
         FIG. 4  illustrates an exploded perspective view schematically showing a configuration of a feeder circuit board  6  shown in  FIG. 3 ; 
         FIG. 5  illustrates a circuit diagram of feeder circuits  107  and  108  shown in  FIG. 4 ; 
         FIG. 6  illustrates a top view showing an insulating substrate  5  and a feeder circuit board  6  provided in an antenna apparatus casing of an antenna apparatus  4 A according to a first modified preferred embodiment of the preferred embodiment of the present disclosure; and 
         FIG. 7  illustrates a top view showing an insulating substrate  5  and a feeder circuit board  6  provided in an antenna apparatus casing of an antenna apparatus  4 B according to a second modified preferred embodiment of the preferred embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Preferred embodiments of the present disclosure will be described hereinafter with reference to the drawings. In the preferred embodiments, components similar to each other are denoted by the same reference numerals. 
       FIG. 1  illustrates a perspective view showing an appearance of an electronic apparatus according to the preferred embodiment of the present disclosure, seen from the front the electronic apparatus, and  FIG. 2  illustrates a perspective view showing the appearance of the electronic apparatus of  FIG. 1  seen from the back of the electronic apparatus. The electronic apparatus of the present preferred embodiment is a portable type television broadcasting receiver apparatus for receiving radio waves within a frequency band (473 MHz to 767 MHz) of digital terrestrial television broadcasting. Referring to  FIGS. 1 and 2 , the electronic apparatus of the present preferred embodiment is configured to include a main unit casing  1 , a stand  2 , a display apparatus  3 , and an antenna apparatus  4 . 
     Referring to  FIGS. 1 and 2 , the stand  2  is formed of resin, and retains the main unit casing  1  in an upright state. In addition, the display apparatus  3  is, for example, a liquid crystal display apparatus or an organic EL (Electronic-Luminescence) display apparatus, which has a thin flat shape, and is provided on the front surface of the main unit casing  1 . Further, the antenna apparatus  4  is pivotably supported to the back surface of the main unit casing  1 . The antenna apparatus  4  is an antenna apparatus using diversity reception system. The antenna apparatus  4  receives the broadcasting signal of the digital terrestrial television broadcasting by using a plurality of antenna elements  7  and  8  (See  FIG. 3 ) described later in detail, amplifies respective received signals, and outputs amplified received signals. 
     In addition, referring to  FIGS. 1 and 2 , a main board for controlling the entire electronic apparatus is built in the main unit casing  1 . Concretely speaking, the main board is configured to include a power supply circuit to supply power voltages to respective circuits on the main board, a drive circuit, and a tuner. In this case, the tuner is a wireless communication circuit to combine two received signals from the antenna apparatus  4  into one received signal by executing diversity processing on the two received signals, and output a video signal and an audio signal included in a combined received signal. The drive circuit displays an image on the display apparatus  3  by executing predetermined image processing on the video signal from the tuner by driving the display apparatus  3 . In addition, the main unit casing  1  has a sound processing circuit which executes predetermined processing on the audio signal from the tuner and outputs a resultant signal to a loudspeaker, a recording apparatus and a reproducing apparatus for the video signal and the audio signal, and a metal member for heat radiation to reduce heat generated from parts such as the main board and so on. It is noted that the antenna apparatus  4  and the above-described tuner constitute a wireless communication apparatus to receive wireless signals. 
       FIG. 3  illustrates a top view showing an insulating substrate  5  and a feeder circuit board  6  (matching board), which are provided in an antenna apparatus casing (antenna cover) of the antenna apparatus  4  of  FIG. 1 . Referring to  FIG. 3 , the antenna apparatus  4  is configured to include the insulating substrate  5  (antenna plate) made of flat-plate-shaped acrylic resin, the feeder circuit board  6 , the antenna elements  7  and  8 , grounding conductors  11 ,  12  and  13 , and jumper conductors  14  and  15 . In this case, the antenna elements  7  and  8 , and the grounding conductors  11 ,  12  and  13  are formed on the upper surface of the insulating substrate  5 , and the jumper conductors  14  and  15  are formed on the lower surface of the insulating substrate  5 . In the present preferred embodiment and its modified preferred embodiments, an xyz coordinate system is defined as shown in  FIG. 3 . Concretely speaking, referring to  FIG. 3 , a longitudinal direction of the insulating substrate  5  is defined as an x axis direction, a direction perpendicular to the x axis on the insulating substrate  5  is defined as a y axis direction, and a direction perpendicular to the insulating substrate  5  is defined as a z axis direction. 
     Referring to  FIG. 3 , the insulating substrate  5  has, for example, a rectangular shape of 218 mm×55 mm, and has one recess portion  5   a  on one long side. The recess portion  5   a  is provided in a portion, which belongs to the antenna apparatus casing of the antenna apparatus  4  and is attached to the main body casing apparatus  1 . In addition, the feeder circuit board  6  is provided at a lower portion of the recess portion  5   a.    
     Referring to  FIG. 3 , the antenna element  7  is a monopole antenna formed in a form of a strip-shaped conductor pattern made of a metal such as copper, on the upper surface of the insulating substrate  5 . The antenna element  7  has a first portion  7   a  and a second portion  7   b . The first portion  7   a  has one end connected to a feeder circuit  107  (See  FIG. 4 ) provided in the feeder circuit board  6 , and extends in a positive direction of the y axis. The second portion  7   b  has one end connected to another end of the first portion  7   a , and extends in a negative direction of the x axis. As shown in  FIG. 3 , the first portion  7   a  and the second portion  7   b  are perpendicular to each other. 
     In addition, referring to  FIG. 3 , the antenna element  8  is a monopole antenna formed in a form of a strip-shaped conductor pattern made of a metal such as copper, on the upper surface of the insulating substrate  5 . The antenna element  8  has a third portion  8   a  and a fourth portion  8   b . The third portion  8   a  has one end connected to a feeder circuit  108  (See  FIG. 4 ) provided in the feeder circuit board  6 , and extends in the positive direction of the y axis. The fourth portion  8   b  has one end connected to another end of the third portion  8   a , and extends in a positive direction of the x axis. As shown in  FIG. 3 , the third portion  8   a  and the fourth portion  8   b  are perpendicular to each other. 
     As shown in  FIG. 3 , the antenna elements  7  and  8  have shapes symmetrical with respect to the y axis. Namely, the first portion  7   a  and the third portion  8   a  are parallel to each other, and each has the same length as each other. In addition, the second portion  7   b  and the fourth portion  8   b  separate and extend in right and left directions, respectively, from the respective another ends of the first portion  7   a  and the third portion  8   a . It is noted that the resonance frequencies of the antenna elements  7  and  8  are set to resonance frequencies, which are substantially the same as each other and fall within the frequency band (473 MHz to 767 MHz) of the digital terrestrial television broadcasting. 
     Further, referring to  FIG. 3 , the grounding conductor  11  is a strip conductor formed between the first portion  7   a  and the third portion  8   a , so as to extend in the y axis direction. In this case, the grounding conductor  11  has one end connected to a grounding conductor  62   g  (See  FIG. 4 ) provided in the feeder circuit board  6 . In addition, the grounding conductor  12  is a strip conductor that has one end connected to the grounding conductor  62   g  (See  FIG. 4 ) provided in the feeder circuit board  6 . The grounding conductor  12  is formed on the left-hand side of the first portion  7   a  of the antenna element  7  of  FIG. 3 , so as to extend in the y axis direction. Further, the grounding conductor  13  is a strip conductor that has one end connected to the grounding conductor  62   g  (See  FIG. 4 ) provided in the feeder circuit board  6 . The grounding conductor  13  is formed on the right-hand side of the third portion  8   a  of the antenna element  8  of  FIG. 3  so as to extend in the y axis direction. The first portion  7   a , the third portion  8   a , the grounding conductors  11 ,  12  and  13  are parallel to each other. The first portion  7   a  is interposed between the grounding conductors  11  and  12 , and the third portion  8   a  is interposed between the grounding conductors  11  and  13 . 
     In addition, referring to  FIG. 3 , another end of the grounding conductor  12 , another end of the grounding conductor  11 , and another end of the grounding conductor  13  extend to the lower surface of the insulating substrate  5  by via conductors each of which penetrates the insulating substrate  5 . Then, another end of the grounding conductor  12  and another end of the grounding conductor  11  are electrically connected to each other via the jumper conductor  14 . Another end of the grounding conductor  11  and another end of the grounding conductor  13  are electrically connected to each other via the jumper conductor  15 . It is noted that the jumper conductors  14  and  15  are not electrically connected to the antenna elements  7  and  8 . The jumper conductors  14  and  15  are electrical connection elements such as zero-ohm chip resistors soldered on the lower surface of the insulating substrate  5 , metal wires or metal foil tapes. 
     Referring to  FIG. 3 , each of the antenna elements  7  and  8  and the grounding conductors  11 ,  12  and  13  has a width of 3 mm, for example. In addition, each of the first portion  7   a  and the third portion  8   a  has a length of 45 mm, for example, and each of the second portion  7   b  and the fourth portion  8   b  has a length of 100 mm, for example. Further, each of the grounding conductors  12  and  13  has a length of 35 mm, and the grounding conductor  11  has a length of 55 mm, for example. 
       FIG. 4  illustrates an exploded perspective view schematically showing a configuration of the feeder circuit board  6  of  FIG. 3 . Referring to  FIG. 4 , the feeder circuit board  6  is a multi-layer wiring board of four layers including layers  61 ,  62 ,  63  and  64 . In this case, the layer  61  includes conductor pads  611 ,  612 ,  613 ,  614  and  615  formed on the upper surface of the layer  61 , and the feeder circuit  108  (antenna circuit) formed on the upper surface of the layer  61 . In addition, the layer  62  includes the grounding conductor  62   g  formed on the upper surface of the layer  62 . Further, the layer  63  includes a grounding conductor  63   g  formed on the lower surface of the layer  63 . Still further, the layer  64  includes the feeder circuit  107  (antenna circuit) formed on the lower surface of the layer  64 . 
     In addition, referring to  FIG. 4 , respective one ends of the grounding conductor  12 , the first portion  7   a  of the antenna element  7 , the grounding conductor  11 , the third portion  8   a  of the antenna element  8  and the grounding conductor  13  are electrically connected to the conductor pads  611 ,  612 ,  613 ,  614  and  615  via springs  71 ,  72 ,  73 ,  74  and  75 , respectively. In addition, the conductor pad  611  is electrically connected to the grounding conductor  62   g  via a via conductor  65 , the conductor pad  613  is electrically connected to the grounding conductor  62   g  via a via conductor  67 , and the conductor pad  615  is electrically connected to the grounding conductor  62   g  via a via conductor  68 . In addition, the conductor pad  612  is connected to the feeder circuit  107  via a via conductor  66 , and the conductor pad  614  is connected to the feeder circuit  108  via a wiring conductor. 
     Namely, referring to  FIG. 4 , the antenna element  7  is connected to the feeder circuit  107  via the spring  72 , the conductor pad  612  and the via conductor  66 , while the antenna element  8  is connected to the feeder circuit  108  via the spring  74  and the conductor pad  614 . In addition, the grounding conductor  11  is connected to the grounding conductor  62   g  via the spring  73 , the conductor pad  613  and the via conductor  67 , the grounding conductor  12  is connected to the grounding conductor  62   g  via the spring  71 , the conductor pad  611  and the via conductor  65 , and the grounding conductor  13  is connected to the grounding conductor  62   g  via the spring  75 , the conductor pad  615  and the via conductor  68 . 
       FIG. 5  illustrates a circuit diagram of the feeder circuits  107  and  108  of  FIG. 4 . Referring to  FIG. 5 , the feeder circuit  107  is configured to include an impedance matching circuit  71 , an amplifier circuit  76 , and a coupling capacitor  81  connected between the impedance matching circuit  71  and the amplifier circuit  76 . In addition, the impedance matching circuit  71  is an LC circuit that is configured to include inductors  72  and  73 , and capacitors  74  and  75 . Further, the amplifier circuit  76  is configured to include an operational amplifier  77 , an inductor  78 , and capacitors  79  and  80 . In addition, the grounding terminal of the feeder circuit  107  is connected to the grounding conductor  63   g  to be grounded. A received signal received by the antenna element  7  is outputted to the above-described tuner via the impedance matching circuit  71  and the amplifier circuit  76 . 
     In addition, referring to  FIG. 5 , the feeder circuit  108  is configured to include an impedance matching circuit  41 , an amplifier circuit  46 , and a coupling capacitor  51  connected between the impedance matching circuit  41  and the amplifier circuit  46 . In addition, the impedance matching circuit  41  is an LC circuit that is configured to include inductors  42  and  43 , and capacitors  44  and  45 . Further, the amplifier circuit  46  is configured to include an operational amplifier  47 , an inductor  48 , and capacitors  49  and  50 . In addition, the grounding terminal of the feeder circuit  108  is connected to the grounding conductor  62   g  to be grounded. A received signal received by the antenna element  8  is outputted to the above-described tuner via the impedance matching circuits  41  and the amplifier circuit  46 . 
     In the antenna apparatus  4  configured as described above, the grounding terminal of the feeder circuit  107  is grounded by being connected to the grounding conductor  63   g , while the grounding terminal of the feeder circuit  108  is grounded by being connected to the grounding conductor  62   g , as shown in  FIG. 4 . Therefore, when a radio wave is received by the antenna element  7 , the received signal received by the antenna element  7  is outputted to the feeder circuit  107 , and a ground current generated in accordance with the receiving operation of the antenna element  7  flows through the grounding conductor  63   g . On the other hand, when a radio wave is received by the antenna element  8 , the received signal received by the antenna element  8  is outputted to the feeder circuit  108 , and a ground current generated in accordance with the receiving operation of the antenna element  8  flows through the grounding conductor  62   g . As a result, the coupling state of the antenna elements  7  and  8  becomes a sparse coupling state, since the ground currents flow through the separate grounding conductors  63   g  and  62   g , respectively, during the receiving operation of the antenna elements  7  and  8 . Therefore, according to the antenna apparatus  4  of the present preferred embodiment, the signal mixing from another antenna element can be prevented, and the decrease in the gain during the signal reception by the antenna elements  7  and  8  can be substantially prevented as compared with the case where the ground currents generated in accordance with the receiving operation of the antenna elements  7  and  8  flow through the same grounding conductor. 
     In addition, since the antenna apparatus  4  of the present preferred embodiment has the grounding conductor  11 , the antenna elements  7  and  8  can be sparsely coupled to each other. Therefore, the decrease in the gain caused by  2 C the coupling of the antenna elements  7  and  8  can be suppressed as compared with the case where the grounding conductor  11  is not provided. In addition, a distance between the antenna elements  7  and  8  can be reduced, and therefore, the size of the antenna apparatus  4  can be reduced. In addition, since the antenna apparatus  4  has the grounding conductors  12  and  13 , the antenna elements  7  and  8  are prevented from being electromagnetically coupled to the other conductors of the electronic apparatus, and the decrease in the gain of the antenna elements  7  and  8  can be prevented. 
     Further, the antenna apparatus  4  of the present preferred embodiment has the jumper conductor  14  that electrically connects the grounding conductors  11  and  12 , and the jumper conductor  15  that electrically connects the grounding conductors  11  and  13 . Therefore, the ground potentials of the grounding conductors  11 ,  12  and  13  are made common and stabilized, as compared with the case where the jumper conductors  14  and  15  are not provided. Therefore, it is possible to prevent the antenna elements  7  and  8  from being electromagnetically coupled to the other conductors of the electronic apparatus, and it is possible to prevent the decrease in the gain of the antenna elements  7  and  8 . 
     Still further, according to the antenna apparatus  4  of the present preferred embodiment, the antenna element  7  has the first portion  7   a , and therefore, a distance between the grounding conductor  63   g  and the second portions  7   b  can be secured. In addition, the antenna element  8  has the third portion  8   a , and therefore, a distance between the grounding conductor  62   g  and the fourth portion  8   b  can be secured. Further, the second portion  7   b  and the fourth portion  8   b  are formed so as to separate in the right and left directions, respectively, from the respective another ends of the first portion  7   a  and the third portion  8   a , and therefore, the degree of coupling between the antenna elements  7  and  8  can be reduced. 
     According to the electronic apparatus of the present preferred embodiment, the digital terrestrial television broadcasting can be received with sensibility higher than that of the prior art since the electronic apparatus includes the antenna apparatus  4 . 
     First Modified Preferred Embodiment 
     In the above-described preferred embodiment, the antenna apparatus  4  is configured to include the grounding conductors  11 ,  12  and  13 , and the jumper conductors  14  and  15 , however, the present disclosure is not limited to this.  FIG. 6  illustrates a top view showing an insulating substrate  5  and a feeder circuit board  6  provided in an antenna apparatus casing of an antenna apparatus  4 A according to the first modified preferred embodiment of the preferred embodiment of the present disclosure. The antenna apparatus  4 A of the present modified preferred embodiment is different from the antenna apparatus  4  (See  FIG. 3 ) of the preferred embodiment only in a point that the jumper conductors  14  and  15  are not provided. 
     Since the antenna apparatus  4 A of the present modified preferred embodiment has the grounding conductor  11 , the antenna elements  7  and  8  can be sparsely coupled with each other. Therefore, the decrease in the gain caused by the coupling of the antenna elements  7  and  8  can be suppressed, as compared with the case where the grounding conductor  11  is not provided. In addition, the distance between the antenna elements  7  and  8  can be reduced, and the size of the antenna apparatus  4  can be reduced. In addition, since the grounding conductors  12  and  13  are provided, the antenna elements  7  and  8  and the other conductors of the electronic apparatus can be prevented from being electromagnetically coupled with each other, and the decrease in the gain of the antenna elements  7  and  8  can be prevented. 
     Second Modified Preferred Embodiment 
       FIG. 7  illustrates a top view showing an insulating substrate  5  and a feeder circuit board  6  provided in an antenna apparatus casing of an antenna apparatus  4 B according to the second modified preferred embodiment of the first preferred embodiment of the present disclosure. The antenna apparatus  4 B of the present modified preferred embodiment is different from the antenna apparatus  4  (See  FIG. 3 ) of the preferred embodiment only in a point that the grounding conductors  12  and  13  and the jumper conductors  14  and  15  are not provided. Since the antenna apparatus  4 B of the present modified preferred embodiment has the grounding conductor  11 , the antenna elements  7  and  8  can be sparsely coupled with each other. Therefore, the decrease in the gain caused by the coupling of the antenna elements  7  and  8  can be suppressed as compared with the case where the grounding conductor  11  is not provided. In addition, the distance between the antenna elements  7  and  8  can be reduced, and the size of the antenna apparatus  4  can be reduced. 
     It is noted that the decrease in the gain of the antenna elements  7  and  8  can be prevented most effectively, when all of the grounding conductors  11 ,  12  and  13  and the jumper conductors  14  and  15  are provided in a manner similar to that of the antenna apparatus  4  of the preferred embodiment. 
     In addition, the antenna apparatuses  4 ,  4 A and  4 B wirelessly receive radio waves within the frequency band of the digital terrestrial television broadcasting in the above-described preferred embodiment and its modified preferred embodiments, however, the present disclosure is not limited to this. Each of the antenna apparatuses  4 ,  4 A and  4 B may wirelessly transmit a high-frequency signal from a wireless transmitter circuit. In addition, in the above-described preferred embodiment and its modified preferred embodiments, the present disclosure has been described by taking the electronic apparatus that is the portable type television broadcasting receiver apparatus for receiving the radio waves within the frequency band of the digital terrestrial television broadcasting as an example, however, the present disclosure is not limited to this. The present disclosure can be applied to a wireless communication apparatus that has the antenna apparatuses  4 ,  4 A or  4 B and a wireless communication circuit to transmit and receive the wireless signals by using the antenna apparatuses  4 ,  4 A or  4 B. In addition, the present disclosure can be applied to an electronic apparatus such as a portable telephone that has the above-described wireless communication apparatus and a display apparatus to display the video signal included in the wireless signal received by the wireless communication apparatus. 
     Industrial Applicability 
     As described above in detail, according to the antenna apparatus, the wireless communication apparatus and the electronic apparatus of the present disclosure, the grounding terminal of the first feeder circuit is connected to the first grounding conductor to be grounded, so that a ground current flows through the first grounding conductor when a radio wave is received with the first antenna element. The grounding terminal of the second feeder circuit is connected to the second grounding conductor to be grounded, so that a ground current flows through the second grounding conductor when a radio wave is received with the second antenna element. Therefore, the first antenna element and the second antenna element can be sparsely coupled with each other. Therefore, it is possible to prevent signal mixing from another antenna element in the first and second antenna elements, and it is possible to substantially prevent the decrease in the gain during the reception of the respective signals. 
     Although the present disclosure has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present disclosure as defined by the appended claims unless they depart therefrom.