Patent Publication Number: US-2021167506-A1

Title: Antenna element, antenna module, and communication device

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a continuation of International Application No. PCT/JP2019/030419 filed on Aug. 2, 2019 which claims priority from Japanese Patent Application No. 2018-150512 filed on Aug. 9, 2018. The contents of these applications are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     Field of the Disclosure 
     The present disclosure relates to an antenna element, where a radiation electrode and a ground electrode are arranged so as to lie opposite to each other, an antenna module including the antenna element, and a communication device including the antenna module. 
     Description of the Related Art 
     An antenna element where a radiation electrode and a ground electrode are arranged so as to lie opposite to each other has been known to date. For example, International Publication No. 2012/081288 (Patent Document 1) discloses a radio frequency package including an antenna where a radiation electrode and a ground conductor plate are arranged so as to lie opposite to each other. The antenna is formed as a stack-type patch antenna including a parasitic element and is provided in a position different from the position of a cavity in a multilayer substrate. The radio frequency package enables it to increase a band for radio frequency signals that can be received while controlling the thickness.
     Patent Document 1: International Publication No. 2012/081288   

     BRIEF SUMMARY OF THE DISCLOSURE 
     It is known that when a radiation electrode and a ground electrode are arranged so as to lie opposite to each other in an antenna element, a distance with a certain length from the ground electrode needs to be provided so as to keep capacitance coupling between the radiation electrode and the ground electrode at a suitable strength. For example, in the radio frequency package disclosed in Patent Document 1, a portion of the multilayer substrate where a cavity is formed is thinner than a portion of the multilayer substrate where no cavity is formed. The radiation electrode is positioned at a distance with a certain length from the ground conductor plate by being arranged in the portion in the multilayer substrate where no cavity is formed. 
     When, as in the radio frequency package disclosed in Patent Document 1, a radiation electrode and a ground electrode are arranged in a dielectric substrate having portions different in thickness so as to lie opposite to each other, the radiation electrode and the ground electrode are normally arranged in a thick portion so as to be positioned further away from each other. In some cases, however, depending on the space where the antenna element is arranged, portions that can be formed thick may be limited in the dielectric substrate. In such cases, the radiation electrode and the ground electrode need to be arranged so as to lie opposite to each other in a thin portion in the dielectric substrate, and it may thus be impossible to ensure a distance between the radiation electrode and the ground electrode. As a result, it may be difficult to improve the radiation characteristics of the antenna element. 
     The present disclosure has been made so as to solve the above-described problems and is aimed at improving the radiation characteristics of an antenna element where a radiation electrode and a ground electrode are arranged so as to lie opposite to each other. 
     An antenna element according to an embodiment of the present disclosure includes a dielectric substrate, a first ground electrode, a second ground electrode, a via conductor, and a radiation electrode. The dielectric substrate includes a first portion and a second portion. The first portion is shaped like a flat plate. The second portion is thinner than the first portion. The first ground electrode is arranged in the first portion. The second ground electrode is arranged in the second portion. The via conductor couples the first ground electrode and the second ground electrode. In the first portion, the radiation electrode lies opposite to the first ground electrode in a first thickness direction of the first portion. In the second portion, the radiation electrode lies opposite to the second ground electrode in a second thickness direction of the second portion. A distance between the radiation electrode and the first ground electrode in the first thickness direction is more than a distance between the radiation electrode and the second ground electrode in the second thickness direction. Part of the radiation electrode lies opposite to the first ground electrode without lying opposite to the second ground electrode. 
     An antenna element according to an embodiment of the present disclosure enables it to improve radiation characteristics by part of a radiation electrode lying opposite to a first ground electrode without lying opposite to a second ground electrode. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a block diagram of a communication device including an antenna element. 
         FIG. 2  illustrates an antenna module including an antenna element according to a first embodiment, which is viewed as a plane in the X axis direction. 
         FIG. 3  is a graph indicating simulation results of the reflection characteristics of a radiation electrode obtained when a length W 1  presented in  FIG. 2  is changed. 
         FIG. 4  illustrates an antenna module including an antenna element according to a first variation of the first embodiment, which is viewed as a plane in the X axis direction. 
         FIG. 5  illustrates an antenna module including an antenna element according to a second variation of the first embodiment, which is viewed as a plane in the X axis direction. 
         FIG. 6  is a graph indicating simulation results of the reflection characteristics of a radiation electrode obtained when a length W 1  presented in  FIG. 5  is changed. 
         FIG. 7  is a graph indicating simulation results of the isolation characteristics of two radiation electrodes obtained when the length W 1  presented in  FIG. 5  is changed. 
         FIG. 8  is a perspective view of the external appearance of an antenna module including an antenna element according to a second embodiment. 
         FIG. 9  illustrates the antenna module in  FIG. 8 , which is viewed as a plane in the X axis direction. 
         FIG. 10  illustrates an antenna module according to a first variation of the second embodiment, which is viewed as a plane in the X axis direction. 
         FIG. 11  illustrates an antenna module according to a second variation of the second embodiment, which is viewed as a plane in the X axis direction. 
         FIG. 12  illustrates a communication device according to a third embodiment, which is viewed as a plane in the X axis direction. 
         FIG. 13  illustrates a communication device according to a first variation of the third embodiment, which is viewed as a plane in the X axis direction. 
         FIG. 14  illustrates a communication device according to a second variation of the third embodiment, which is viewed as a plane in the X axis direction. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Embodiments of the present disclosure are described in detail below with reference to the drawings. Identical or corresponding elements in the drawings are given identical reference signs and the descriptions thereon are not repeated in principle. 
       FIG. 1  is a block diagram of a communication device  3000 , which includes an antenna element  10 . A mobile terminal, such as a cellular phone, a smartphone, or a tablet, or a personal computer having a communication function can be named as an example of the communication device  3000 . 
     As illustrated in  FIG. 1 , the communication device  3000  includes an antenna module  1100  and a baseband integrated circuit (BBIC)  2000 , which constitutes a baseband signal processing circuit. The antenna module  1100  includes a radio frequency integrated circuit (RFIC)  140 , which is an example of a radio frequency element, and the antenna element  10 . 
     The communication device  3000  up-converts a baseband signal transmitted from the BBIC  2000  to the antenna module  1100  into a radio frequency signal and emits the radio frequency signal from the antenna element  10 . The communication device  3000  down-converts a radio frequency signal received at the antenna element  10  into a baseband signal and processes the baseband signal in the BBIC  2000 . 
     The antenna element  10  is an antenna array where a plurality of antenna elements (radiation conductors) each shaped like a flat plate are regularly arranged. In  FIG. 1 , the configuration of the RFIC  140  that corresponds four radiation electrodes  110  surrounded by the dotted line, among the plurality of radiation electrodes  110  included in the antenna element  10 , is illustrated. 
     The RFIC  140  includes switches  31 A to  31 D,  33 A to  33 D, and  37 , power amplifiers  32 AT to  32 DT, low noise amplifiers  32 AR to  32 DR, attenuators  34 A to  34 D, phase shifters  35 A to  35 D, a signal synthesis/branching unit  36 , a mixer  38 , and an amplification circuit  39 . 
     The RFIC  140  is, for example, formed as a one chip IC component including circuit elements (switches, power amplifiers, low noise amplifiers, attenuators, and phase shifters) corresponding to the plurality of radiation electrodes  110  included in the antenna element  10 . Alternatively, aside from the RFIC  140 , the circuit elements may be formed as a one chip IC component for each radiation electrode  110 . 
     When radio frequency signals are received, the switches  31 A to  31 D and  33 A to  33 D are switched to the sides of the low noise amplifiers  32 AR to  32 DR, and the switch  37  is coupled to the reception-side amplifier of the amplification circuit  39 . 
     The radio frequency signals received by the radiation electrodes  110  pass through the respective signal paths from the switches  31 A to  31 D to the phase shifters  35 A to  35 D and are synthesized by the signal synthesis/branching unit  36 , down-converted by the mixer  38  into a baseband signal, amplified by the amplification circuit  39 , and then transferred to the BBIC  2000 . 
     When radio frequency signals are transmitted from the antenna element  10 , the switches  31 A to  31 D and  33 A to  33 D are switched to the sides of the power amplifiers  32 AT to  32 DT, and the switch  37  is coupled to the transmission-side amplifier of the amplification circuit  39 . 
     The baseband signal transmitted from the BBIC  2000  is amplified by the amplification circuit  39  and up-converted by the mixer  38 . The up-converted radio frequency signal is caused to branch into four by the signal synthesis/branching unit  36  and pass through the respective signal paths from the phase shifters  35 A to  35 D to the switches  31 A to  31 D to be fed to the radiation electrodes  110 . The directivity of the antenna element  10  can be adjusted by adjusting the degrees of the phase shift of the phase shifters  35 A to  35 D arranged on the signal paths, individually. 
     First Embodiment 
       FIG. 2  illustrates an antenna module  1100  including an antenna element  100  according to a first embodiment, which is viewed as a plane in the X axis direction. In  FIG. 2 , the X axis, the Y axis, and the Z axis are orthogonal to each other. The same applies to  FIGS. 4, 5, and 8 to 14 . 
     As illustrated in  FIG. 2 , the antenna module  1100  includes the antenna element  100  and an RFIC  140 . The antenna element  100  includes a radiation electrode  111 , a ground electrode  131  (a first ground electrode), a ground electrode  132  (a second ground electrode), via conductors  150  and  151 , and a dielectric substrate  120 . The normal direction of the radiation electrode  111  is the Z axis direction. 
     The dielectric substrate  120  includes a portion  101  (a first portion) shaped like a flat plate and a portion  102  (a second portion). In the Z axis direction, the portion  102  is thinner than the portion  101 . The dielectric substrate  120  is formed from an integral dielectric. That is, the dielectric substrate  120  is a substrate made from a dielectric material with a certain dielectric constant so as to be integral. 
     The ground electrodes  131  and  132  are arranged in the portions  101  and  102 , respectively. The ground electrodes  131  and  132  are coupled by the via conductor  150 . The dielectric substrate  120  is formed from an integral dielectric. 
     The radiation electrode  111  is arranged in the portions  101  and  102  over the dielectric substrate  120  so as to lie opposite to the ground electrode  131  in the portion  101  in the thickness direction of the portion  101  (the Z axis direction) and lie opposite to the ground electrode  132  in the portion  102  in the thickness direction of the portion  102  (the Z axis direction). The distance between the radiation electrode  111  and the ground electrode  131  and the distance between the radiation electrode  111  and the ground electrode  132  in the Z axis direction are represented by H 1  and H 2  (=H 1 / 2 ), respectively. The width of the radiation electrode  111  in the Y axis direction is 2.5 mm. Not all of the radiation electrode  111  lies opposite to the ground electrode  132  but part of the radiation electrode  111  lies opposite to the ground electrode  131  without lying opposite to the ground electrode  132 . The radiation electrode  111  that lies opposite to the ground electrode  132  without lying opposite to the ground electrode  131  has a length W 1  in the Y axis direction. 
     The via conductor  151  runs through the ground electrode  131  and couples the radiation electrode  111  and the RFIC  140 . The via conductor  151  is insulated from the ground electrode  131 . 
     The RFIC  140  supplies a radio frequency signal to the radiation electrode  111  through the via conductor  151 . The RFIC  140  receives a radio frequency signal from the radiation electrode  111  through the via conductor  151 . 
     In the portion  102 , a space Spc is formed on the side where the ground electrode  132  is arranged. Since other circuit elements are arranged in the space Spc, the distance between the radiation electrode  111  and the ground electrode  132  cannot be made longer than H 2 . 
     Thus, in the first embodiment, the radiation electrode  111  is arranged so as to also lie opposite to the ground electrode  131  in addition to the ground electrode  132 . The distance H 1  between the radiation electrode  111  and the ground electrode  131  is longer than the distance H 2 . Accordingly, by causing part of the radiation electrode  111  to lie opposite to the ground electrode  131 , the radiation characteristics of the antenna element  100  can be further improved in comparison with the case where all of the radiation electrode  111  lies opposite to the ground electrode  132 . 
       FIG. 3  is a graph indicating simulation results of the reflection characteristics of the radiation electrode  111  (the relation between frequency and return loss (RL)) obtained when the length W 1  presented in  FIG. 2  is changed.  FIG. 3  indicates the reflection characteristics in cases where the length W 1  is 1.0 mm, 1.5 mm, 2.0 mm, or 2.5 mm. 
     It is implied that as the return loss increases, the proportion of the signals emitted outside from the radiation electrode  111  in the radio frequency signals supplied from the RFIC  140  to the radiation electrode  111  is greater. Accordingly, the band width that can bring the return loss equal to or greater than a threshold serves as one of the measures in evaluating the radiation characteristics of the antenna element  100 . That is, it can be said that a larger band width makes the radiation characteristics of the antenna element  100  more favorable. Thus, in  FIG. 3 , while focusing attention on the band width that enables the return loss to be 6 dB or more, the radiation characteristics of the antenna element  100  are compared when the length W 1  is changed. 
     As illustrated in  FIG. 3 , as the length W 1  is larger, the portion of the radiation electrode  111  that lies opposite to the ground electrode  131  increases and thus, the band width that enables the return loss to be 6 dB or more is larger. That is, as the portion of the radiation electrode  111  that lies opposite to the ground electrode  131  increases, the radiation characteristics of the antenna element  100  can be further improved. 
     First Variation of First Embodiment 
     In the first embodiment, the case where the dielectric substrate is formed from an integral dielectric is described. The dielectric substrate may be made up of a plurality of dielectric layers. 
       FIG. 4  illustrates an antenna module  1100 A including an antenna element  100 A according to a first variation of the first embodiment, which is viewed as a plane in the X axis direction. In the configuration of the antenna module  1100 A, the antenna element  100  in  FIG. 2  is replaced with the antenna element  100 A. In the configuration of the antenna element  100 A in  FIG. 4 , the dielectric substrate  120  in  FIG. 2  is replaced with a dielectric substrate  120 A. Since the configuration other than these is similar, the descriptions thereon are not repeated. 
     As illustrated in  FIG. 4 , the dielectric substrate  120 A includes a dielectric layer  121  (a first dielectric layer) and a dielectric layer  122  (a second dielectric layer). The dielectric layer  121  is a first substrate formed from a dielectric material having a first dielectric constant. The dielectric layer  122  is a second substrate formed from a dielectric material having a second dielectric constant. The dielectric substrate  120 A is the substrate made by integrating the dielectric layers  121  and  122  by welding with heat or bonding using a coupling member (e.g. a solder bump), or the like. The first dielectric constant and the second dielectric constant may be different from each other. 
     The dielectric layer  121  is formed in portions  101  and  102 . The dielectric layer  122  is formed in the portion  101 . The ground electrode  131  is arranged on the dielectric layer  122  in the portion  101 . The ground electrode  132  is arranged on the dielectric layer  121  in the portion  102 . The dielectric layers  121  and  122  may be welded together with heat or be bonded using a coupling member, such as a solder bump. The dielectric constant of the dielectric layer  121  may be different from the dielectric constant of the dielectric layer  122 . 
     Second Variation of First Embodiment 
     In each of the first embodiment and the first variation thereof, the antenna element that includes one radiation electrode is described. The number of radiation electrodes may be two or more. In a second variation of the first embodiment, an antenna element that includes two radiation electrodes is described. 
       FIG. 5  illustrates an antenna module  1100 B including an antenna element  100 B according to the second variation of the first embodiment, which is viewed as a plane in the X axis direction. In the configuration of the antenna module  1100 B, the antenna element  100  in  FIG. 2  is replaced with the antenna element  100 B. In the configuration of the antenna element  100 B in  FIG. 5 , a radiation electrode  112  and a via conductor  152  are added to the antenna element  100  in  FIG. 2 . Since the configuration other than these is similar, the descriptions thereon are not repeated. 
     As illustrated in  FIG. 5 , the radiation electrode  112  is arranged away from the radiation electrode  111  in the portion  101 . The via conductor  152  runs through the ground electrode  131  and couples the radiation electrode  112  and the RFIC  140 . The via conductor  152  is insulated from the ground electrode  131 . 
     The RFIC  140  supplies a radio frequency signal to the radiation electrode  112  through the via conductor  152 . The RFIC  140  receives a radio frequency signal from the radiation electrode  112  through the via conductor  152 . 
       FIG. 6  is a graph indicating simulation results of the reflection characteristics of the radiation electrode  112  obtained when the length W 1  presented in  FIG. 5  is changed.  FIG. 6  indicates the reflection characteristics in cases where the length W 1  is 1.0 mm, 1.50 mm, 2.0 mm, or 2.5 mm. Since the respective reflection characteristics of the cases exhibit almost the same way of variation, the reflection characteristics are drawn as an identical curve in  FIG. 6 . That is, the length W 1  has little effect on the reflection characteristics of the radiation electrode  112 . 
       FIG. 7  is a graph indicating simulation results of the isolation characteristics of the two radiation electrodes  111  and  112  (the relation between isolation and frequency) obtained when the length W 1  is changed.  FIG. 7  indicates the isolation characteristics in cases where the length W 1  is 1.0 mm, 1.5 mm, 2.0 mm, or 2.5 mm. 
     The isolation of the two radiation electrodes is a measure indicating how the two radiation electrodes are separated. That is, in the signals that are inputted from one of the radiation electrodes, the proportion of the signals that are not outputted from the other radiation electrode is greater as the isolation between the two radiation electrodes increases. 
     In the frequency band indicated in  FIG. 7 , the respective minimum values of the isolation characteristics are within a range of about 1 dB. That is, the length W 1  has little effect on the isolation characteristics of the radiation electrodes  111  and  112 . 
     Thus, the antenna elements according to the first embodiment and the first variation and the second variation thereof enable it to improve the radiation characteristics. 
     Second Embodiment 
     In a second embodiment, a case where a dielectric substrate of an antenna element is bent is described. 
       FIG. 8  is a perspective view of the external appearance of an antenna module  1200  including an antenna element  200  according to the second embodiment.  FIG. 9  illustrates the antenna module  1200  in  FIG. 8 , which is viewed as a plane in the X axis direction. In  FIG. 8 , to increase the viewability of the coupling relations among the constituents, ground electrodes  281  to  284  illustrated in  FIG. 9  and a plurality of via conductors coupled to the ground electrodes  281  to  284  are not illustrated. 
     As illustrated in  FIGS. 8 and 9 , the antenna module  1200  includes the antenna element  200  and an RFIC  240 . The antenna element  200  includes radiation electrodes  201  to  212 , a dielectric substrate  220 , a ground electrode  231  (a first ground electrode), a ground electrode  232  (a second ground electrode), via conductors  251  to  266 , line conductor patterns  271  to  274 , and the ground electrodes  281  to  284 . 
     The dielectric substrate  220  includes a portion  291  (a first portion) shaped like a flat plate, a portion  292  (a second portion), and a portion  293  shaped like a flat plate. The portion  292  is thinner than the portions  291  and  293 . The dielectric substrate  220  is bent in the portion  292 . 
     The dielectric substrate  220  includes a dielectric layer  221  (a first dielectric layer), a dielectric layer  222  (a second dielectric layer), and a dielectric layer  223 . The dielectric layer  221  is formed in the portions  291  to  293 . The dielectric layer  221  is formed from a material having flexibility (a flexible material). The dielectric layer  221  is bent in the portion  292 . The dielectric layer  222  is formed in the portion  291 . The dielectric layer  223  is formed in the portion  293 . The dielectric substrate  220  may be formed from an integral dielectric. 
     The radiation electrodes  201 ,  204 ,  207 , and  210  are arranged so as to be along the X axis in the portion  291 . The normal direction of the radiation electrodes  201 ,  204 ,  207 , and  210  is the Z axis direction. 
     The ground electrode  231  is arranged on the dielectric layer  222  so as to lie opposite to each of the radiation electrodes  201 ,  204 ,  207 , and  210  in the Z axis direction. 
     The via conductors  251 ,  255 ,  259 , and  263  run through the ground electrode  231  and couple the radiation electrode  201  and the RFIC  240 , the radiation electrode  204  and the RFIC  240 , the radiation electrode  207  and the RFIC  240 , and the radiation electrode  210  and the RFIC  240 , respectively. The via conductors  251 ,  255 ,  259 , and  263  are insulated from the ground electrode  231 . 
     The RFIC  240  supplies radio frequency signals to the radiation electrodes  201 ,  204 ,  207 , and  210  through the via conductors  251 ,  255 ,  259 , and  263 , respectively. The RFIC  240  receives radio frequency signals from the radiation electrodes  201 ,  204 ,  207 , and  210  through the via conductors  251 ,  255 ,  259 , and  263 , respectively. 
     The radiation electrodes  203 ,  206 ,  209 , and  212  are arranged so as to be along the X axis in the portion  293 . The normal direction of the radiation electrodes  203 ,  206 ,  209 , and  212  is the Y axis direction. 
     The ground electrode  232  is formed on the dielectric layer  221  in the portions  291  to  293 . The ground electrode  232  lies opposite to the radiation electrodes  203 ,  206 ,  209 , and  212  in the Y axis direction. The ground electrode  232  is coupled to the ground electrode  231 . 
     The ground electrodes  281  to  284  are formed in the portions  291  to  293  and arranged in the dielectric layer  221  so as to be along the X axis. The ground electrodes  281  to  284  are coupled to the ground electrode  232  by a plurality of via conductors. 
     The radiation electrodes  202 ,  205 ,  208 , and  211  are formed in the portions  291  and  292  and arranged so as to be along the X axis. In the portion  291 , the radiation electrodes  202 ,  205 ,  208 , and  211  lie opposite to the ground electrode  231  in the Z axis direction. In the portion  292 , the radiation electrodes  202 ,  205 ,  208 , and  211  lie opposite to the ground electrode  232  in the thickness direction of the portion  292 . The distance between the radiation electrodes  202 ,  205 ,  208 , and  211  and the ground electrode  231  in the Z axis direction is more than the distance between the radiation electrodes  202 ,  205 ,  208 , and  211  and the ground electrode  232  in the thickness direction of the portion  292 . In the antenna module  1200 , part of each of the radiation electrodes  202 ,  205 ,  208 , and  211  lies opposite to the ground electrode  231  without lying opposite to the ground electrode  232  in the portion  291 . 
     The via conductors  252 ,  256 ,  260 , and  264  run through the ground electrode  231  and couple the radiation electrode  202  and the RFIC  240 , the radiation electrode  205  and the RFIC  240 , the radiation electrode  208  and the RFIC  240 , and the radiation electrode  211  and the RFIC  240 , respectively. The via conductors  252 ,  256 ,  260 , and  264  are insulated from the ground electrode  231 . 
     The line conductor patterns  271  to  274  are formed in the dielectric layer  221  in the portions  291  to  293 . The line conductor pattern  271  is formed between the ground electrodes  232  and  281 . The line conductor pattern  272  is formed between the ground electrodes  232  and  282 . The line conductor pattern  273  is formed between the ground electrodes  232  and  283 . The line conductor pattern  274  is formed between the ground electrodes  232  and  284 . 
     The via conductors  253 ,  257 ,  261 , and  265  run through the ground electrode  231  and couple the line conductor pattern  271  and the RFIC  240 , the line conductor pattern  272  and the RFIC  240 , the line conductor pattern  273  and the RFIC  240 , and the line conductor pattern  274  and the RFIC  240 , respectively. The via conductors  253 ,  257 ,  261 , and  265  are insulated from the ground electrode  231 . 
     The via conductor  254  couples the line conductor pattern  271  and the radiation electrode  203 . The via conductor  258  couples the line conductor pattern  272  and the radiation electrode  206 . The via conductor  262  couples the line conductor pattern  273  and the radiation electrode  209 . The via conductor  266  couples the line conductor pattern  274  and the radiation electrode  212 . 
     The RFIC  240  supplies radio frequency signals to the radiation electrodes  203 ,  206 ,  209 , and  212  through the line conductor patterns  271  to  274 , respectively. The RFIC  240  receives radio frequency signals from the radiation electrodes  203 ,  206 ,  209 , and  212  through the line conductor patterns  271  to  274 , respectively. 
     In the antenna element  200 , the dielectric substrate  220  is bent in the portion  292  and accordingly, the normal direction of the radiation electrodes  201 ,  204 ,  207 , and  210  (which is the Z axis direction), the normal direction of the radiation electrodes  202 ,  205 ,  208 , and  211  (which is the thickness direction of the portion  292 ), and the normal direction of the radiation electrodes  203 ,  206 ,  209 , and  212  (which is the Y axis direction) are different from one another. In the antenna module  1200 , radio frequency signals with polarized waves different in excitation direction can be transmitted and received more easily in comparison with the case where the normals of a plurality of radiation electrodes are parallel. 
     Further, in the antenna element  200 , the dielectric layer  221  is formed from a flexible material and therefore the stress caused in the portion  292  that is bent can be reduced. Accordingly, in the portions  291  and  293 , the evenness of a surface of the dielectric substrate  220  can be maintained. Thus, the deviation of the normal directions of the radiation electrodes  201  to  212  from desired directions can be inhibited. As a result, the decrease in the characteristics of the antenna element  200  caused by bending the dielectric substrate  220  can be inhibited. 
     First Variation of Second Embodiment 
     In the antenna module  1200 , part of each of the radiation electrodes  202 ,  205 ,  208 , and  211  lies opposite to the ground electrode  231  and the RFIC  240  without lying opposite to the ground electrode  232  in the portion  291 . The RFIC  240  need not be arranged in the portion  291 . In a variation of the second embodiment, a configuration where the RFIC  240  is arranged in the portion  293  is described. 
       FIG. 10  illustrates an antenna module  1200 A according to a first variation of the second embodiment, which is viewed as a plane in the X axis direction. In the antenna module  1200 A, the via conductors  253 ,  257 ,  261 , and  265  and the line conductor patterns  271  to  274  are removed from the configuration of the antenna module  1200  in  FIG. 9 . In the antenna module  1200 A, the via conductors  251 ,  255 ,  259 , and  263  of the antenna module  1200  in  FIG. 9  are replaced with via conductors  251 A,  255 A,  259 A, and  263 A, respectively. In the antenna module  1200 A, the via conductors  252 ,  256 ,  260 , and  264  of the antenna module  1200  in  FIG. 9  are replaced with via conductors  252 A,  256 A,  260 A, and  264 A, respectively. In the antenna module  1200 A, the via conductors  254 ,  258 ,  262 , and  266  of the antenna module  1200  in  FIG. 9  are replaced with via conductors  254 A,  258 A,  262 A, and  266 A, respectively. In the antenna module  1200 A, the RFIC  240  is replaced with an RFIC  240 A. In the antenna module  1200 A, line conductor patterns  271 A to  274 A and  275  to  278 , via conductors  251 B,  255 B,  259 B, and  263 B, and via conductors  252 B,  256 B,  260 B, and  264 B are added. Since the configuration other than these is similar, the descriptions thereon are not repeated. 
     As illustrated in  FIG. 10 , the RFIC  240 A is arranged on the dielectric layer  223  in the portion  293  so as to lie opposite to the ground electrode  232 . 
     The line conductor patterns  271 A to  274 A are formed in the dielectric layer  221  in the portions  291  to  293 . The line conductor pattern  271 A is formed between the ground electrodes  232  and  281 . The line conductor pattern  272 A is formed between the ground electrodes  232  and  282 . The line conductor pattern  273 A is formed between the ground electrodes  232  and  283 . The line conductor pattern  274 A is formed between the ground electrodes  232  and  284 . 
     The via conductor  251 A couples the line conductor pattern  271 A and the radiation electrode  201 . The via conductor  255 A couples the line conductor pattern  272 A and the radiation electrode  204 . The via conductor  259 A couples the line conductor pattern  273 A and the radiation electrode  207 . The via conductor  263 A couples the line conductor pattern  274 A and the radiation electrode  210 . 
     The via conductors  251 B,  255 B,  259 B, and  263 B run through the ground electrode  232  and couple the line conductor pattern  271 A and the RFIC  240 A, the line conductor pattern  272 A and the RFIC  240 A, the line conductor pattern  273 A and the RFIC  240 A, and the line conductor pattern  274 A and the RFIC  240 A, respectively. The via conductors  251 B,  255 B,  259 B, and  263 B are insulated from the ground electrode  232 . 
     The RFIC  240 A supplies radio frequency signals to the radiation electrodes  201 ,  204 ,  207 , and  210  through the line conductor patterns  271 A to  274 A, respectively. The RFIC  240 A receives radio frequency signals from the radiation electrodes  201 ,  204 ,  207 , and  210  through the line conductor patterns  271 A to  274 A, respectively. 
     The line conductor patterns  275  to  278  are formed in the dielectric layer  221  in the portions  291  to  293 . The line conductor pattern  275  is formed between the ground electrodes  232  and  281 . The line conductor pattern  276  is formed between the ground electrodes  232  and  282 . The line conductor pattern  277  is formed between the ground electrodes  232  and  283 . The line conductor pattern  278  is formed between the ground electrodes  232  and  284 . 
     The via conductor  252 A couples the line conductor pattern  275  and the radiation electrode  202 . The via conductor  256 A couples the line conductor pattern  276  and the radiation electrode  205 . The via conductor  260 A couples the line conductor pattern  277  and the radiation electrode  208 . The via conductor  264 A couples the line conductor pattern  278  and the radiation electrode  211 . 
     The via conductors  252 B,  256 B,  260 B, and  264 B run through the ground electrode  232  and couple the line conductor pattern  275  and the RFIC  240 A, the line conductor pattern  276  and the RFIC  240 A, the line conductor pattern  277  and the RFIC  240 A, and the line conductor pattern  278  and the RFIC  240 A, respectively. The via conductors  252 B,  256 B,  260 B, and  264 B are insulated from the ground electrode  232 . 
     The RFIC  240 A supplies radio frequency signals to the radiation electrodes  202 ,  205 ,  208 , and  211  through the line conductor patterns  275  to  278 , respectively. The RFIC  240 A receives radio frequency signals from the radiation electrodes  202 ,  205 ,  208 , and  211  through the line conductor patterns  275  to  278 , respectively. 
     The via conductors  254 A,  258 A,  262 A, and  266 A run through the ground electrode  232  and couple the radiation electrode  203  and the RFIC  240 A, the radiation electrode  206  and the RFIC  240 A, the radiation electrode  209  and the RFIC  240 A, and the radiation electrode  212  and the RFIC  240 A, respectively. The via conductors  254 A,  258 A,  262 A, and  266 A are insulated from the ground electrode  232 . 
     The RFIC  240 A supplies radio frequency signals to the radiation electrodes  203 ,  206 ,  209 , and  212  through the via conductors  254 A,  258 A,  262 A, and  266 A, respectively. The RFIC  240 A receives radio frequency signals from the radiation electrodes  203 ,  206 ,  209 , and  212  through the via conductors  254 A,  258 A,  262 A, and  266 A, respectively. 
     Second Variation of Second Embodiment 
     In each of the second embodiment and the first variation thereof, the case where the dielectric substrate of the antenna element includes one bent portion is described. The dielectric substrate may include a plurality of bent portions. In a second variation of the second embodiment, the dielectric substrate includes two bent portions is described. 
       FIG. 11  illustrates an antenna module  1200 B according to the second variation of the second embodiment, which is viewed as a plane in the X axis direction. In the configuration of the antenna module  1200 B, the antenna element  200  of the antenna module  1200  in  FIG. 9  is replaced with an antenna element  200 B. In the configuration of the antenna element  200 B, the dielectric substrate  220  is replaced with a dielectric substrate  220 B while radiation electrodes  202 B,  205 B,  208 B, and  211 B, radiation electrodes  203 B,  206 B,  209 B, and  212 B, ground electrodes  232 B and  281 B to  284 B, via conductors  252 B,  256 B,  260 B, and  264 B, via conductors  253 B,  257 B,  261 B, and  265 B, via conductors  254 B,  258 B,  262 B, and  266 B, and line conductor patterns  271 B to  274 B are added. In the configuration of the dielectric substrate  220 B, the dielectric layer  221  of the dielectric substrate  220  is replaced with a dielectric layer  221 B while portions  292 B and  293 B and a dielectric layer  223 B are added to the dielectric substrate  220 . Since the configuration other than these is similar, the descriptions thereon are not repeated. 
     As illustrated in  FIG. 11 , the portion  293 B is shaped like a flat plate. The portion  292 B is thinner than the portions  291  and  293 B. In the dielectric substrate  220 B, the portion  292 B couples the portion  291  extending in the Y axis direction and the portion  293 B extending in the Z axis direction. 
     The dielectric layer  221 B is formed from a material having flexibility (a flexible material). The dielectric substrate  220 B is bent not only in the portion  292  but also in the portion  292 B (a second portion). The dielectric layer  223 B is formed in the portion  293 B. The dielectric substrate  220 B may be formed from an integral dielectric. 
     The radiation electrodes  203 B,  206 B,  209 B, and  212 B are arranged in the portion  293 B so as to be along the X axis. The normal direction of the radiation electrodes  203 B,  206 B,  209 B, and  212 B is the Y axis direction. 
     The ground electrode  232 B is formed on the dielectric layer  221 B in the portions  291 ,  292 B, and  293 B. The ground electrode  232 B lies opposite to the radiation electrodes  203 B,  206 B,  209 B, and  212 B in the Y axis direction. The ground electrode  232 B is coupled to the ground electrode  231 B. 
     The ground electrodes  281 B to  284 B are formed in the portions  291 ,  292 B, and  293 B and arranged in the dielectric layer  221 B so as to be along the X axis. The ground electrodes  281 B to  284 B are coupled to the ground electrode  232 B by a plurality of via conductors. 
     The radiation electrodes  202 B,  205 B,  208 B, and  211 B are formed in the portions  291  and  292 B and arranged so as to be along the X axis. In the portion  291 , the radiation electrodes  202 B,  205 B,  208 B, and  211 B lie opposite to the ground electrode  231  in the Z axis direction. In the portion  292 B, the radiation electrodes  202 B,  205 B,  208 B, and  211 B lie opposite to the ground electrode  232 B in the thickness direction of the portion  292 B. The distance between the radiation electrodes  202 B,  205 B,  208 B, and  211 B and the ground electrode  231  in the Z axis direction is more than the distance between the radiation electrodes  202 B,  205 B,  208 B, and  211 B and the ground electrode  232 B in the thickness direction of the portion  292 B. In the antenna module  1200 B, part of each of the radiation electrodes  202 B,  205 B,  208 B, and  211 B lies opposite to the ground electrode  231  without lying opposite to the ground electrode  232 B in the portion  291 . 
     The via conductors  252 B,  256 B,  260 B, and  264 B run through the ground electrode  231  and couple the radiation electrode  202 B and the RFIC  240 , the radiation electrode  205 B and the RFIC  240 , the radiation electrode  208 B and the RFIC  240 , and the radiation electrode  211 B and the RFIC  240 , respectively. The via conductors  252 B,  256 B,  260 B, and  264 B are insulated from the ground electrode  231 . 
     The line conductor patterns  271 B to  274 B are formed in the dielectric layer  221 B in the portions  291 ,  292 B, and  293 B. The line conductor pattern  271 B is formed between the ground electrodes  232 B and  281 B. The line conductor pattern  272 B is formed between the ground electrodes  232 B and  282 B. The line conductor pattern  273 B is formed between the ground electrodes  232 B and  283 B. The line conductor pattern  274 B is formed between the ground electrodes  232 B and  284 B. 
     The via conductors  253 B,  257 B,  261 B, and  265 B run through the ground electrode  231  and couple the line conductor pattern  271 B and the RFIC  240 , the line conductor pattern  272 B and the RFIC  240 , the line conductor pattern  273 B and the RFIC  240 , and the line conductor pattern  274 B and the RFIC  240 , respectively. The via conductors  253 B,  257 B,  261 B, and  265 B are insulated from the ground electrode  231 . 
     The via conductor  254 B couples the line conductor pattern  271 B and the radiation electrode  203 B. The via conductor  258 B couples the line conductor pattern  272 B and the radiation electrode  206 B. The via conductor  262 B couples the line conductor pattern  273 B and the radiation electrode  209 B. The via conductor  266 B couples the line conductor pattern  274 B and the radiation electrode  212 B. 
     The RFIC  240  supplies radio frequency signals to the radiation electrodes  203 B,  206 B,  209 B, and  212 B through the line conductor patterns  271 B to  274 B, respectively. The RFIC  240  receives radio frequency signals from the radiation electrodes  203 B,  206 B,  209 B, and  212 B through the line conductor patterns  271 B to  274 B, respectively. 
     In the antenna element  200 B, the dielectric substrate  220 B is bent in the portions  292  and  292 B and accordingly, the normal direction of the radiation electrodes  201 ,  204 ,  207 , and  210  (which is the Z axis direction), the normal direction of the radiation electrodes  202 ,  205 ,  208 , and  211  (which is the thickness direction of the portion  292 ), the normal direction of the radiation electrodes  203 ,  206 ,  209 ,  212 ,  203 B,  206 B,  209 B, and  212 B (which is the Y axis direction), and the normal direction of the radiation electrodes  202 B,  205 B,  208 B, and  211 B (which is the thickness direction of the portion  292 B) are different from one another. In the antenna module  1200 B, radio frequency signals with polarized waves different in excitation direction can be transmitted and received more easily in comparison with the case where the normals of a plurality of radiation electrodes are parallel. 
     Further, in the antenna element  200 B, the dielectric layer  221 B is formed from a flexible material and therefore the stress caused in the portions  292  and  292 B that are bent can be reduced. Accordingly, in the portions  291 ,  293 , and  293 B, the evenness of a surface of the dielectric substrate  220 B can be maintained. Thus, the deviation of the normal directions of the radiation electrodes  201  to  212 , the radiation electrodes  202 B,  205 B,  208 B, and  211 B, and the radiation electrodes  203 B,  206 B,  209 B, and  212 B from desired directions can be inhibited. As a result, the decrease in the characteristics of the antenna element  200 B caused by bending the dielectric substrate  220 B can be inhibited. 
     Thus, the antenna elements according to the second embodiment and the first variation and the second variation thereof enable it to improve the radiation characteristics. 
     Third Embodiment 
     In a third embodiment, a communication device including the antenna element according to the second embodiment is described. 
       FIG. 12  illustrates a communication device  3000  according to the third embodiment, which is viewed as a plane in the X axis direction. As illustrated in  FIG. 12 , the communication device  3000  includes a BBIC  2000 , an antenna module  1300 , and a mounting board  320 . In the configuration of the antenna module  1300 , a connector  321  is added to the antenna module  1200  illustrated in  FIG. 9 . Since the configuration other than this is similar, the descriptions thereon are not repeated. 
     As illustrated in  FIG. 12 , the connector  321  is arranged on the dielectric layer  222  in the portion  291 . The connector  321  is coupled to the RFIC  240  by feeding wiring formed in the dielectric layer  222 . A connector  322  is arranged on the mounting board  320 . The connector  322  is coupled to the connector  321  so as to be attachable and removable. 
     The BBIC  2000  is arranged on a surface of the mounting board  320  using a coupling member, such as a solder bump. The BBIC  2000  is coupled to the connector  322  by feeding wiring formed inside the mounting board  320 . The BBIC  2000  transmits a baseband signal to the RFIC  240  and receives a baseband signal from the RFIC  240  through the feeding wiring and the connector  322 . The BBIC  2000  and the RFIC  240  can be coupled from a longer distance by routing flexible printed circuits (FPCs). 
     First Variation of Third Embodiment 
       FIG. 13  illustrates a communication device  3000 A according to a first variation of the third embodiment, which is viewed as a plane in the X axis direction. As illustrated in  FIG. 13 , the communication device  3000 A includes the BBIC  2000 , an antenna module  1300 A, and a mounting board  320 A. In the configuration of the antenna module  1300 A, the antenna element  200  of the antenna module  1200  in  FIG. 9  is replaced with an antenna element  200 A. In the configuration of the antenna element  200 A in  FIG. 13 , the radiation electrodes  203 ,  206 ,  209 , and  212 , the via conductors  254 ,  258 ,  262 , and  266 , and the dielectric layer  223  are removed from the antenna element  200  in  FIG. 9  while a connector  331  is added. Since the configuration other than these is similar, the descriptions thereon are not repeated. 
     As illustrated in  FIG. 13 , the connector  331  is arranged toward the dielectric layer  221  in the portion  293 . The connector  331  is coupled to the line conductor patterns  271  to  274 . The BBIC  2000  is arranged on a surface of the mounting board  320 A using a coupling member, such as a solder bump. A connector  332  is arranged on the mounting board  320 A. The connector  332  is coupled to the connector  331  so as to be attachable and removable. 
     The BBIC  2000  is coupled to the connector  332  by feeding wiring formed in the mounting board  320 A. The BBIC  2000  transmits a baseband signal to the RFIC  240  and receives a baseband signal from the RFIC  240  through the feeding wiring, the connectors  332  and  331 , the line conductor patterns  271  to  274 , and the via conductors  253 ,  257 ,  261 , and  265 . 
     Second Variation of Third Embodiment 
     In each of the third embodiment and the first variation thereof, the configuration where a dielectric layer that is included in the plurality of dielectric layers making up the antenna element and is formed from a flexible material includes one bent portion is described. Described in a second variation of the third embodiment is a configuration where the dielectric layer includes two bent portions and bends so as to be wound around an end portion of the mounting board. 
       FIG. 14  illustrates a communication device  3000 B according to the second variation of the third embodiment, which is viewed as a plane in the X axis direction. In the configuration of the communication device  3000 B, the antenna module  1300  of the communication device  3000  in  FIG. 12  is replaced with an antenna module  1300 B. In the configuration of the antenna module  1300 B, the antenna element  200  and the RFIC  240  of the antenna module  1300  are replaced with an antenna element  200 C and an RFIC  240 B. 
     In the antenna element  200 C, the radiation electrodes  203 ,  206 ,  209 , and  212 , the dielectric substrate  220 , the line conductor patterns  271  to  274 , the ground electrode  232 , the via conductors  253 ,  257 ,  261 , and  265 , and the via conductors  254 ,  258 ,  262 , and  266  of the antenna element  200  are replaced with radiation electrodes  203 C,  206 C,  209 C, and  212 C, a dielectric substrate  220 C, line conductor patterns  271 C to  274 C, a ground electrode  232 C, via conductors  253 C,  257 C,  261 C, and  265 C, and via conductors  254 C,  258 C,  262 C, and  266 C, respectively. Further, in the antenna element  200 C, radiation electrodes  203 D,  206 D,  209 D, and  212 D, via conductors  253 D,  257 D,  261 D, and  265 D, via conductors  254 D,  258 D,  262 D, and  266 D, line conductor patterns  271 D to  274 D, and ground electrodes  281 C to  284 C are added. In the configuration of the dielectric substrate  220 C, the dielectric layers  221  and  223  and the portion  293  are replaced with dielectric layers  221 C and  223 C and a portion  293 C, respectively, while a dielectric layer  224  and portions  294  and  295  are added. Since the configuration other than these is similar, the descriptions thereon are not repeated. 
     As illustrated in  FIG. 14 , the dielectric layer  221 C (a first dielectric layer) is formed from a flexible material. The dielectric layer  221 C is bent in the portions  292  and  294 . The portion  295  shaped like a flat plate is joined to the portion  294  and extends in the Y axis direction. The dielectric layer  224  is formed in the portion  295 . The dielectric layer  223 C is formed in the portion  293 . The dielectric substrate  220 C is formed so as to be wound around an end portion of the mounting board  320 . The dielectric substrate  220 C may be formed from an integral dielectric. The portion  295  may be fixed to an unillustrated cabinet with a bonding layer interposed therebetween. The portion  295  may be formed so as to be close to the mounting board  320 . 
     The radiation electrodes  203 C,  206 C,  209 C, and  212 C are formed in the portions  293 C and  294  and arranged so as to be along the X axis. In the portion  293 C, the radiation electrodes  203 C,  206 C,  209 C, and  212 C lie opposite to the ground electrode  232 C in the Y axis direction. In the portion  294 , the radiation electrodes  203 C,  206 C,  209 C, and  212 C lie opposite to the ground electrode  232 C in the thickness direction of the portion  294 . 
     The radiation electrodes  203 D,  206 D,  209 D, and  212 D are arranged so as to be along the X axis in the portion  295 . The normal direction of the radiation electrodes  203 D,  206 D,  209 D, and  212 D is the Z axis direction. 
     The ground electrode  232 C is formed on the dielectric layer  221 C in the portions  291 ,  292 ,  293 C,  294 , and  295 . The ground electrode  232 C lies opposite to the radiation electrodes  203 D,  206 D,  209 D, and  212 D in the Z axis direction. The ground electrode  232 C is coupled to the ground electrode  231 . 
     The ground electrodes  281 C to  284 C are formed in the portions  293 C,  294 , and  295  and arranged in the dielectric layer  221 C so as to be along the X axis. The ground electrodes  281 C to  284 C are coupled to the ground electrode  232 C by a plurality of via conductors. 
     The line conductor patterns  271 C to  274 C are formed in the dielectric layer  221 C in the portions  291 ,  292 , and  293 C. The line conductor pattern  271 C is formed between the ground electrodes  232 C and  281 . The line conductor pattern  272 C is formed between the ground electrodes  232 C and  282 . The line conductor pattern  273 C is formed between the ground electrodes  232 C and  283 . The line conductor pattern  274 C is formed between the ground electrodes  232 C and  284 . 
     The via conductors  253 C,  257 C,  261 C, and  265 C run through the ground electrode  231  and couple the line conductor pattern  271 C and the RFIC  240 B, the line conductor pattern  272 C and the RFIC  240 B, the line conductor pattern  273 C and the RFIC  240 B, and the line conductor pattern  274 C and the RFIC  240 B, respectively. The via conductors  253 C,  257 C,  261 C, and  265 C are insulated from the ground electrode  231 . 
     The via conductor  254 C couples the line conductor pattern  271 C and the radiation electrode  203 C. The via conductor  258 C couples the line conductor pattern  272 C and the radiation electrode  206 C. The via conductor  262 C couples the line conductor pattern  273 C and the radiation electrode  209 C. The via conductor  266 C couples the line conductor pattern  274 C and the radiation electrode  212 C. 
     The RFIC  240 B supplies radio frequency signals to the radiation electrodes  203 C,  206 C,  209 C, and  212 C through the line conductor patterns  271 C to  274 C, respectively. The RFIC  240 B receives radio frequency signals from the radiation electrodes  203 C,  206 C,  209 C, and  212 C through the line conductor patterns  271 C to  274 C, respectively. 
     The line conductor patterns  271 D to  274 D are formed in the dielectric layer  221 C in the portions  291 ,  292 ,  293 C,  294 , and  295 . The line conductor pattern  271 D is formed between the ground electrodes  232 C and  281  while formed between the ground electrodes  232 C and  281 C. The line conductor pattern  272 D is formed between the ground electrodes  232 C and  282  while formed between the ground electrodes  232 C and  282 C. The line conductor pattern  273 D is formed between the ground electrodes  232 C and  283  while formed between the ground electrodes  232 C and  283 C. The line conductor pattern  274 D is formed between the ground electrodes  232 C and  284  while formed between the ground electrodes  232 C and  284 C. 
     The via conductors  253 D,  257 D,  261 D, and  265 D run through the ground electrode  231  and couple the line conductor pattern  271 D and the RFIC  240 B, the line conductor pattern  272 D and the RFIC  240 B, the line conductor pattern  273 D and the RFIC  240 B, and the line conductor pattern  274 D and the RFIC  240 B, respectively. The via conductors  253 D,  257 D,  261 D, and  265 D are insulated from the ground electrode  231 . 
     The via conductor  254 D couples the line conductor pattern  271 D and the radiation electrode  203 D. The via conductor  258 D couples the line conductor pattern  272 D and the radiation electrode  206 D. The via conductor  262 D couples the line conductor pattern  273 D and the radiation electrode  209 D. The via conductor  266 D couples the line conductor pattern  274 D and the radiation electrode  212 D. 
     The RFIC  240 B supplies radio frequency signals to the radiation electrodes  203 D,  206 D,  209 D, and  212 D through the line conductor patterns  271 D to  274 D, respectively. The RFIC  240 B receives radio frequency signals from the radiation electrodes  203 D,  206 D,  209 D, and  212 D through the line conductor patterns  271 D to  274 D, respectively. 
     In the antenna element  200 C, the dielectric substrate  220 C is bent in the portions  292  and  294  and accordingly, the normal direction of the radiation electrodes  201 ,  204 ,  207 , and  210 ,  203 D,  206 D,  209 D, and  212 D (which is the Z axis direction), the normal direction of the radiation electrodes  202 ,  205 ,  208 , and  211  (which is the thickness direction of the portion  292 ), the normal direction of the radiation electrodes  203 C,  206 C,  209 C,  212 C in the portion  293 C (which is the Y axis direction), and the normal direction of the radiation electrodes  203 C,  206 C,  209 C, and  212 C in the portion  294  (which is the thickness direction of the portion  294 ) are different from one another. In the antenna module  1200 B, radio frequency signals with polarized waves different in excitation direction can be transmitted and received more easily in comparison with the case where the normals of a plurality of radiation electrodes are parallel. 
     Further, in the antenna element  200 C, the dielectric layer  221 C is formed from a flexible material and therefore the stress caused in the portions  292  and  294  that are bent can be reduced. Accordingly, in the portions  291 ,  293 C, and  295 , the evenness of a surface of the dielectric substrate  220 C can be maintained. Thus, the deviation of the normal direction of each radiation electrode from a desired direction can be inhibited. As a result, the decrease in the characteristics of the antenna element  200 C caused by bending the dielectric substrate  220 C can be inhibited. 
     Thus, the communication devices according to the third embodiment and the first variation and the second variation thereof enable it to improve the radiation characteristics of each antenna element. 
     The embodiments disclosed herein are each planned to be also implemented by being suitably combined within a scope where no contradiction is caused. It should be noted that the above-described embodiments disclosed herein are examples in all respects and not limiting. It is intended that the scope of the present disclosure is not specified by the foregoing description but is specified by the claims and that the present disclosure encompasses all changes within meanings equivalent to the claims and the scope thereof.
           10 ,  100 ,  100 A,  100 B,  200 ,  200 A,  200 B, and  200 C ANTENNA ELEMENTS     31 A to  31 D,  33 A to  33 D, and  37  SWITCHES     32 AR to  32 DR LOW NOISE AMPLIFIERS     32 AT to  32 DT POWER AMPLIFIERS     34 A to  34 D ATTENUATORS     35 A to  35 D PHASE SHIFTERS     36  BRANCHING UNIT     38  MIXER     39  AMPLIFICATION CIRCUIT     101 ,  102 ,  291  to  294 ,  292 B,  293 B, and  293 C PORTIONS     110  to  112 ,  201  to  212 ,  202 B,  203 B to  203 D,  205 B,  206 B to  206 D,  208 B,  209 B to  209 D,  211 B, and  212 B to  212 D RADIATION ELECTRODES     120 ,  120 A,  220 ,  220 B, and  220 C DIELECTRIC SUBSTRATES     121 ,  122 ,  221  to  224 ,  221 B,  221 C,  223 B, and  223 C DIELECTRIC LAYERS     131 ,  132 ,  231 ,  231 B,  232 ,  232 B,  232 C,  281  to  284 ,  281 B to  284 B, and  281 C to  284 C GROUND ELECTRODES     150  to  152 ,  251  to  266 ,  251 A,  251 B,  252 A,  252 B to  266 B,  253 C,  253 D,  254 A to  256 A,  254 C,  254 D,  257 C,  257 D,  258 A to  260 A,  258 C,  258 D,  261 C,  261 D,  262 A to  264 A,  262 B,  262 D,  265 C,  265 D,  266 A,  266 C, and  266 D VIA CONDUCTORS     271  to  274 ,  271 A to  274 A,  271 B to  274 B,  271 C to  274 C,  271 D to  274 D, and  275  to  278  LINE CONDUCTOR PATTERNS     320  and  320 A MOUNT BOARDS     321 ,  322 ,  331 , and  332  CONNECTORS     1100 ,  1100 A,  1100 B,  1200 ,  1200 A,  1200 B,  1300 ,  1300 A, and  1300 B ANTENNA MODULES     3000 ,  3000 A, and  3000 B COMMUNICATION DEVICES