Patent Publication Number: US-11025758-B2

Title: Electric signal transmission line in a communication device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Stage of International Patent Application No. PCT/EP2017/066006, filed on Jun. 28, 2017, which is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     Aspects of the present invention relate to a communication device comprising a casing which houses a battery. Aspects of the present invention also relate to a method for assembling a communication device. 
     BACKGROUND 
     In general, a communication device, e.g. a cellular phone, is provided with a battery to supply energy to the functions and units requiring it. Access to the battery is often provided by removing a back cover. 
     SUMMARY 
     The inventors of the present invention have identified problems and drawbacks associated with the cellular phone battery. For example, resonances, also called lossy resonances, originate from the battery and affect neighbouring components, and the result is impaired performance of the cellular phone and its components. Neighbouring components, due to their positions in relation to the battery, may also contribute to an increase of the thickness of the cellular phone. 
     An object of the embodiments of the invention is thus to provide an improvement of the performance of the cellular phone. 
     Another object is to provide a cellular phone with a reduced thickness. 
     According to a first aspect of the invention, the above-mentioned objects of the present invention are attained by providing a communication device comprising a casing. The casing houses a battery extending in a main extension plane. The casing comprises a back cover which is configured to cover the battery, the back cover extending in a second plane substantially parallel to the main extension plane. The communication device comprises an electrical signal transmission line which comprises a first portion and a second portion. The second portion is connected to a processing unit of the communication device, wherein the first portion along its longitudinal extension is connected to at least one electrical component. The first portion extends alongside the battery, and the first portion extends in a third plane substantially perpendicular to the main extension plane. The electrical signal transmission line may be a planar transmission line. 
     The main extension plane is the plane in which the battery has its largest area. Typically the battery (and the communication device) extends in two further planes mutually orthogonal and orthogonal to the main extension plane which however have a smaller area than the main extension plane. The main extension plane is typically parallel to the screen and back of the communication device (assuming a flat back cover and a flat screen). 
     By placing the first portion of electrical signal transmission line alongside the battery, the electrical signal transmission line is less affected by the resonances originating from the battery. Further, the grounding of the first portion of the electrical signal transmission line is facilitated by the inventive position of the first portion of the electrical signal transmission line compared to a position on top of the battery. By the inventive position of the electrical signal transmission line, the performance of the communication device is improved. Further, by the inventive position of the first portion of the electrical signal transmission line the thickness of the communication device can be reduced. 
     In an implementation form of a communication device according to the first aspect, the first portion of the electrical signal transmission line is connected to each of the at least one electrical component by a respective resilient contact. The resilient contact is attached and connected to the first portion of the electrical signal transmission line. Each electrical component has a contact portion, and the resilient contact resiliently abuts against the contact portion of the electrical component. An advantage with this implementation form is that the connection of the electrical component to the electrical signal transmission line is facilitated. Further, the disconnection of the electrical component, if needed, is also facilitated. 
     In a further implementation form of a communication device according to the first aspect, the communication device comprises a plurality of resilient contacts each connecting one of the at least one electrical component to the first portion of the electrical signal transmission line. An advantage with this implementation form is that the connection of one or more electrical components to the electrical signal transmission line is facilitated. One resilient contact may connect one electrical component, or a plurality of resilient contacts may connect one and the same electrical component. 
     In another implementation form of a communication device according to the first aspect, the at least one electrical component comprises a plurality of electrical components, whereby the first portion along its longitudinal extension is connected to the plurality of electrical components. An advantage with this implementation form is that the connection of a plurality of electrical components is improved, and the electrical components and the electrical signal transmission line are subjected to less lossy resonance from the battery. Hereby, the performance of the communication device is further improved. 
     In yet another implementation form of a communication device according to the first aspect, each resilient contact comprises a first contact portion and a second contact portion. The first contact portion comprises a resilient member which resiliently abuts against the contact portion of the electrical component. The second contact portion is attached to and connected to the first portion of the electrical signal transmission line, wherein the second contact portion extends in a fourth plane substantially parallel to the third plane. An advantage with this implementation form is that the connection of the electrical component to the electrical signal transmission line is further improved and facilitated, and the contact is less affected by the lossy resonance from the battery. Hereby, the performance of the communication device is further improved. 
     In still another implementation form of a communication device according to the first aspect, the casing comprises a front which is opposite the back cover and extends in a fifth plane substantially parallel to the main extension plane. The casing comprises a surrounding frame which mounts the back cover to the front. The battery is situated inside the frame and between the front and the back cover. The first portion of the electrical signal transmission line is configured to be placed between the battery and the frame. An advantage with this implementation form is that the electrical signal transmission line is less affected by the resonance originating from the battery, and the performance of the electrical signal transmission line and the communication device is improved. 
     In an implementation form of a communication device according to the first aspect, a longitudinal stiffener is attached to the first portion of the electrical signal transmission line. The stiffener extends alongside the first portion of the electrical signal transmission line in a sixth plane substantially parallel to the third plane. An advantage with this implementation form is that the electrical signal transmission line is made more robust and the connection of the at least one electrical component is further improved. Hereby, the performance of the communication device is further improved. 
     In a further implementation form of a communication device according to the first aspect, the casing comprises an inner wall situated between the battery and the frame. The inner wall extends alongside the battery in a seventh plane substantially perpendicular to the main extension plane. The combination of the first portion of the electrical signal transmission line and the stiffener is fastened to the inner wall by means of at least one fastener, e.g. a plurality of fasteners. Each fastener may be a clip. An advantage with this implementation form is that the first portion of the electrical signal transmission line is firmly attached to the frame of the communication device. Hereby, the performance of the communication device is further improved. 
     In another implementation form of a communication device according to the first aspect, the inner wall and the fastener are electrically conductive, wherein the first portion of the electrical signal transmission line is grounded by the fastener. An advantage with this implementation form is that an efficient grounding of the first portion of the electrical signal transmission line is attained. Hereby, the performance of the communication device is further improved. 
     In yet another implementation form of a communication device according to the first aspect, the stiffener is electrically conductive, and the first portion of the electrical signal transmission line is grounded by the stiffener. An advantage with this implementation form is that an efficient grounding of the first portion of the electrical signal transmission line is attained. Hereby, the performance of the communication device is further improved. 
     In still another implementation form of a communication device according to the first aspect, the electrical signal transmission line comprises a stripline. The stripline may be configured to operate in the Radio Frequency, RF, range. The stripline may be in form of a so-called RF (Radio Frequency) flexi. An advantage with this implementation form is that the stripline is suitable to be arranged as disclosed above for the electrical signal transmission line. An advantage with this implementation form is that the electrical signal transmission line is made more robust and the connection of the at least one electrical component is further improved. Hereby, the performance of the communication device is further improved. An alternative to the stripline may be a microstrip, suspended stripline, coplanar waveguide, or slotline. 
     In an implementation form of a communication device according to the first aspect, the second portion of the electrical signal transmission line is bent in relation to the first portion of the electrical signal transmission line in order to be connected to the processing unit of the communication device. An advantage with this implementation form is that the electrical signal transmission line is made more robust and the connection of the at least one electrical component is further improved. Hereby, the performance of the communication device is further improved. 
     In a further implementation form of a communication device according to the first aspect, the second portion of the electrical signal transmission line extends in an eighth plane substantially parallel to the main extension plane. An advantage with this implementation form is that the thickness of the communication device is kept at a minimum. 
     In another implementation form of a communication device according to the first aspect, each of the at least one electrical component is an antenna radiating element. Thus, according to this implementation form, the resilient contact resiliently abuts against the contact portion of the antenna radiating element in a resilient manner. When the at least one electrical component is an antenna radiating element, the processing unit may suitably be a transmitter-and-receiver unit, e.g. a transceiver. By means of this implementation form, the resonance of the battery has a reduced influence on the antenna radiating element/-s, and consequently, the performance of the communication device is further improved. 
     In yet another implementation form of a communication device according to the first aspect, each antenna radiating element is attached to the back cover. Each antenna radiating element may be attached to the back cover by plating, printing, chemical etching etc. The respective antenna element may be attached to the inside surface of the back cover or to the outside surface of the back cover. Each antenna radiating element may be attached to the back cover by being moulded into the back cover. An advantage with this implementation form is that each antenna radiating element is spaced apart from the battery as well as other metallic parts of the communication device in an efficient way, and that the resonance of the battery or any other electrically conductive components and parts has a reduced influence on the antenna radiating elements. Further, when being attached to the back cover, the connection of the antenna radiating elements to the electrical signal transmission line is effected in an efficient way simply by mounting the back cover to the frame of the communication device. 
     According to a second aspect of the invention, the above-mentioned objects of the present invention are attained by providing a method for assembling a communication device comprising a casing having a back cover, a front and a surrounding frame. The frame is configured to mount the back cover to the front, and at least one electrical component is attached to the back cover. The method comprises the steps of:
         placing a battery inside the frame;   placing a first portion of an electrical signal transmission line alongside the battery between the battery and the frame;   connecting a second portion of the electrical signal transmission line to a processing unit of the communication device; and   connecting the first portion of the electrical signal transmission line to each of the at least one electrical component, wherein the step of connecting the first portion of the electrical signal transmission line to each of the at least one electrical component is effected by attaching the back cover to the frame.       

     By this method, the communication device is efficiently and securely assembled, especially when the at least one electrical component is attached to the back cover. By this method, a good performance of the communication device is assured. 
     The additional step of placing a processing unit inside the frame may be added, e.g. between the step of placing a battery inside the frame and the step of placing a first portion of an electrical signal transmission line alongside the battery. 
     By “connected” is meant that two connected units can be electrically connected directly to one another, e.g. via an electrically conductive path, or indirectly connected/coupled to one another through some electrical means, for example a transformer or capacitor. By “substantially” in the context of “substantially parallel” is meant that the plane in question is essentially parallel to another plane, but that there may be a deviation or difference of a few degrees. By “substantially” in the context of “substantially perpendicular” is meant that the plane in question is essentially perpendicular to another plane, but that there may be a deviation or difference of a few degrees (e.g. at maximum ±10, ±5, or ±2 degrees) from the right angle (90 degrees). 
     The above-mentioned features and embodiments, respectively, may be combined in various possible ways providing further advantageous embodiments. Further applications and advantages of the present invention will be apparent from the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The appended drawings are intended to clarify and explain different embodiments of the present invention, in which: 
         FIG. 1  is a schematic exploded view of an electrical signal transmission line of an embodiment of the communication device according to the present invention; 
         FIG. 2  is a schematic perspective view of the electrical signal transmission line of  FIG. 1 ; 
         FIG. 3  is a schematic perspective view of an alternative to the fasteners in  FIGS. 1-2 ; 
         FIG. 4  is a schematic perspective view of an embodiment of the communication device according to the present invention; 
         FIG. 5  is a schematic perspective view of the embodiment of  FIG. 4 ; 
         FIG. 6  is a schematic perspective view of the embodiment of  FIG. 4 ; 
         FIG. 7  is a schematic cut-away view of an embodiment of the communication device according to the present invention; 
         FIG. 8  is an enlargement of a portion of the embodiment of  FIG. 7 ; 
         FIG. 9  is a schematic cross-section view of an electrical signal transmission line of an embodiment of the communication device according to the present invention; 
         FIG. 10  is a schematic cross-section view of an electrical signal transmission line of an embodiment of the communication device according to the present invention; 
         FIG. 11  is a cross-section view of the embodiment of  FIG. 7 ; 
         FIG. 12  is an enlargement of a portion of the cross-section view of  FIG. 11 ; 
         FIG. 13  is a schematic perspective view of the back cover of an embodiment of the communication device according to the present invention; 
         FIG. 14  is a schematic perspective view of the back cover of another embodiment of the communication device according to the present invention; 
         FIG. 15  is a schematic perspective view of the back cover of yet another embodiment of the communication device according to the present invention; 
         FIG. 16  is a schematic partial perspective view of an embodiment of the communication device according to the present invention; and 
         FIG. 17  is a flow chart illustrating aspects of the method according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The communication device  102  herein disclosed may be denoted as a user device, a User Equipment (UE), a mobile station, an internet of things (IoT) device, a sensor device, a wireless terminal and/or a mobile terminal, enabled to communicate wirelessly in a wireless communication system, sometimes also referred to as a cellular radio system. The UEs may further be referred to as mobile telephones or cellular telephones with wireless capability. The UEs in the present context are for example portable, pocket-storable, hand-held, computer-comprised enabled to communicate voice and/or data, via the radio access network, with another entity, such as another receiver or a server. 
     With reference to  FIG. 1 , an electrical signal transmission line  118 , which is part of or included in a communication device  102  (as shown starting with  FIG. 4 ), is shown in an exploded view. The electrical signal transmission line  118  comprises a first portion  122  and a second portion  120 . The second portion  120  is provided with a connector  121 , e.g. a board-to-board RF connector, configured to be connected to a processing unit  124  (see  FIG. 4 ) of the communication device  102 . The first portion  122  is provided with a plurality of matching components  123  for tuning one or a plurality of electrical components  116  e.g. in the form of antenna radiating elements  117 . In the example of  FIG. 1 , four matching components  123  are provided. Further, the first portion  122  is provided with a plurality, e.g. four as shown in  FIG. 1 , resilient contacts  128  attached and connected to the first portion  122 . A longitudinal stiffener  146  can be attached to the first portion  122  of the electrical signal transmission line  118  and extends alongside the first portion  122 . The stiffener  146  may be glued to the first portion  122 . Further, the stiffener  146  is provided with openings  147  configured to receive the matching components  123 .  FIG. 1  also shows a plurality of fasteners  152 . In this embodiment each fastener  152  is in the form of a clip  154 . The fasteners  152  will be discussed in more detail in connection with other Figures hereinbelow. 
     In  FIG. 2 , the stiffener  146  has been attached, e.g. by glue, to the first portion  122  of the electrical signal transmission line  118 , and the matching components  123  have been received by the openings  147 . The resilient contacts  128  have also been attached to the first portion  122 . 
     In  FIG. 3 , an alternative to the fasteners  152  of  FIGS. 1-2  is illustrated. Instead of three separate fasteners  152 , one single fastener  252  is provided. The fastener  252  comprises three clips  254  which are attached to one another by intermediate members  255 . 
       FIG. 4  illustrates how the first portion  122  of the electrical signal transmission line  118  is about to be inserted in its final position in the communication device  102 . The processing unit  124  of the communication device  102 , to which the connector  121  of the second portion  120  of the electrical signal transmission line  118  is to be attached, is shown. The processing unit  124  may be a transmitter-and-receiver unit, e.g. a transceiver for RF signals. This of course depends on the electrical component(s) to be connected to the electrical signal transmission line  118 . E.g. if an electrical component to be connected to the electrical signal transmission line is a speaker or a microphone the processing unit  124  could also be an audio processing unit.  FIG. 4  also illustrates the surrounding frame  144  and the battery  106  of the communication device  102 . 
     With reference to  FIG. 5 , the electrical signal transmission line  118  is yet closer to its final assembled position as at least the first portion  122  is now already in its final position in the surrounding frame  144 . 
     With reference to  FIGS. 6-7 , the entire communication device  102  is illustrated. However, in  FIG. 6  the back cover  110  is not present. The communication device  102  includes a casing  104  which houses the battery  106 . The battery  106  extends in a main extension plane  108 . The casing  104  comprises a back cover  110  which is configured to cover the battery  106 . The back cover  110  extends in a second plane  114  substantially parallel to the main extension plane  108 . Opening the back cover  110  provides access to essentially the entire battery  106 . 
     As disclosed above, the communication device  102  further includes the electrical signal transmission line  118  comprising the first portion  122  and the second portion  120 . As shown in  FIG. 6 , the second portion  120  is connected to the processing unit  124 . The first portion  122  extends alongside the battery  106  in a third plane  126  substantially perpendicular to the main extension plane  108 . The second portion  120  of the electrical signal transmission line  118  extends in an eighth plane  158  substantially parallel to the main extension plane  108 . The second portion  120  of the electrical signal transmission line  118  is bent in relation to the first portion  122  of the electrical signal transmission line  118  in order to be connected to the processing unit  124 . 
     With reference to  FIGS. 6-7 , the casing  104  comprises a front  140  (see  FIG. 11 ) which is opposite the back cover  110  and extends in a fifth plane  142  (see  FIG. 6 ) substantially parallel to the main extension plane  108 . The casing  104  comprises a surrounding frame  144  which mounts the back cover  110  to the front  140 . The battery  106  is located inside the frame  144  and between the front  140  and the back cover  110 . The first portion  122  of the electrical signal transmission line  118  is configured to be placed between the battery  106  and the frame  144 . The casing  104  also includes an inner wall  148  (see  FIGS. 4 and 12 ) which is situated between the battery  106  and the frame  144 . The inner wall  148  extends alongside the battery  106  in a seventh plane  150  substantially perpendicular to the main extension plane  108  (see  FIGS. 4 and 12 ). The stiffener  146  is attached to the first portion  122  of the electrical signal transmission line  118  and extends alongside the first portion  122  of the electrical signal transmission line  118  in a sixth plane  147  (see  FIGS. 6 and 12 ) substantially parallel to the third plane  126 . With reference to  FIG. 7 , the combination of the first portion  122  of the electrical signal transmission line  118  and the stiffener  146  is fastened to the inner wall  148  by means of the at least one fastener  152 , e.g. a plurality of fasteners  152 , such as three fasteners  152  as shown in  FIG. 7 . In the present example, the inner wall  148  and the fasteners  152  are electrically conductive, wherein the first portion  122  of the electrical signal transmission line  118  is grounded by the fastener  152  and the inner wall  148  (for further details see  FIG. 9  and associated text). Alternatively, the stiffener could be electrically conductive, and the first portion  122  of the electrical signal transmission line  118  would then be grounded by the stiffener. 
     As illustrated in  FIGS. 7-8 , where part of the back cover is cut away for illustrative purposes, the first portion  122  along its longitudinal extension is connected to a plurality of electrical components  116 . The first portion  122  along its longitudinal extension is provided with a plurality of resilient contacts  128 . The electrical signal transmission line  118  is connected to each of the plurality of electrical components  116  by a respective resilient contact  128  which is attached and connected to the first portion  122  of the electrical signal transmission line  118 . Each electrical component  116  has a contact portion  130 . The resilient contact  128  resiliently abuts against the contact portion  130  of the electrical component  116 . In the present embodiment, four resilient contacts  128  are present and accordingly also four electrical components  116  are present. Each electrical component is in the form of an antenna radiating element  117 . In  FIG. 8 , only one antenna radiating element  117  is shown. With reference to  FIG. 8 , each resilient contact  128  comprises a first contact portion  132  and a second contact portion  134 . The first contact portion  132  includes a resilient member  136 , e.g. in the form of a tongue, which resiliently abuts against the contact portion  130  of the electrical component  116 . The second contact portion  134 , which may be in the form of a flap, is attached to and connected to the first portion  122  of the electrical signal transmission line  118 . The second contact portion  134  extends in a fourth plane  138  substantially parallel to the third plane  126 . 
     With reference to  FIG. 9 , the electrical signal transmission line  118  may be a planar transmission line, e.g. a stripline  156 . More precisely, the stripline  156  may be an RF flexi. The stripline  156  comprises a central conductor  157 , e.g. made of copper, or any suitable electrically conductive metal or material. The central conductor  157  is surrounded by a dielectric material  160 , and the dielectric material  160  is surrounded by four grounded layers  162 , which may be made of copper, or any suitable electrically conductive metal or material. When the first portion  122  of the electrical signal transmission line  118  is grounded by the electrically conductive fasteners  152  and the inner wall  148 , all of the four grounded layers  162  are grounded via the fasteners  152 , i.e. there is a grounding path through the stripline structure. If the four grounded layers  162  instead are grounded by an electrically conductive stiffener, in a corresponding way there is a grounding path through the stripline structure to the stiffener. 
     With reference to  FIG. 10 , the connection of the resilient contact  128  to the first portion  122  of the electrical signal transmission line  118  is schematically illustrated. A central conductor  157  is surrounded by a dielectric material  160 , and the dielectric material  160  is surrounded by four grounded layers  162 . The central conductor  157  and the grounded layers  162  may be made of copper, or any suitable electrically conductive material. The second contact portion  134  of the resilient contact  128  is attached and connected to the first portion  122  of the electrical signal transmission line  118  by means of an electrically conductive solder  164 . The second contact portion  134  of the resilient contact  128  is electrically connected to the central conductor  157  via an electrically conductive member  166  and via the solder  164 . Thus, an electrically conductive path is provided between the second contact portion  134  and the central conductor  157 . The member  166  may be made of copper or any suitable electrically conductive material. In addition, dielectric layers  165  are provided outside the grounded layers  162  except for where the solder  164  attaches the second contact portion  134  to the first portion  122  of the electrical signal transmission line  118 . In  FIG. 10 , the third plane  126  of the first portion  122  is shown. Further, it is illustrated that the second contact portion  134  extends in a fourth plane  138  substantially parallel to the third plane  126 . 
     With reference to  FIG. 11 , which is a cross-section view of the communication device  102  disclosed above, some of the planes are further illustrated. The battery  106  of communication device  102  is shown, and the battery  106  extends in the main extension plane  108 . The back cover  110 , which is configured to cover the battery  106 , extends in the second plane  114  substantially parallel to the main extension plane  108 . The front  140  of the casing  104 , which is opposite the back cover  110 , extends in the fifth plane  142  substantially parallel to the main extension plane  108 . 
     With reference to  FIG. 12 , which is an enlargement of the cross-section view of the communication device disclosed above  FIG. 11 , some of the planes are further illustrated. As mentioned above, the battery  106  extends in the main extension plane  108 . The back cover  110  extends in the second plane  114  which is substantially parallel to the main extension plane  108 . The front  140  extends in the fifth plane  142  which is substantially parallel to the main extension plane  108 . The first portion  122  of the electrical signal transmission line  118  extends alongside the battery  106  in the third plane  126  substantially perpendicular to the main extension plane  108 . The stiffener  146  extends alongside the first portion  122  of the electrical signal transmission line  118  in the sixth plane  147  substantially parallel to the third plane  126 . The inner wall  148 , which is situated between the battery  106  and the frame  144 , extends alongside the battery  106  in the seventh plane  150  which is substantially perpendicular to the main extension plane  108 . In addition,  FIG. 12  also discloses the fastener  152  which attaches the electrical signal transmission line  118  and the stiffener  146  to the inner wall  148   
     With reference to  FIGS. 13-15 , the back covers of embodiments of the communication device  102  according to the present invention are illustrated, wherein each of the at least one electrical component  116 ;  616  is an antenna radiating element  117 ;  617  and wherein each antenna radiating element  117 ;  617  is attached to the back cover  110 ;  610 . 
     In  FIG. 13 , four antenna radiating elements  117  are shown, each connected to the first portion  122  of the electrical signal transmission line  118  via a resilient contact  128 . The back cover  110 , e.g. the inside surface of the back cover  110 , is provided with a decoration foil, or decoration layer, with a printed antenna pattern. The pattern is printed with an electrically conductive ink on the decoration foil. 
     In  FIG. 14 , eight antenna radiating elements  117  are provided by being printed on decorated glass of the back cover  510 . The eight antenna radiating elements  117  may be provided on the inside of the back cover  510 . Each antenna radiating element  117  of the eight antenna radiating elements  117  is connected to a first portion  122  of an electrical signal transmission line  118  via a resilient contact  128 . For the arrangement in  FIG. 14 , two electrical signal transmission lines  118  would be installed in the communication device  102 . 
     In  FIG. 15 , eight electrical components  616  in the form of FPC, Flexible Printed Circuit, antenna radiating elements  617  are attached to the back cover  610  by being glued to a decorated glass  615  of the back cover  610 , e.g. on the inside of the back cover  610 . As in  FIG. 14 , two electrical signal transmission lines  118  would be installed in the communication device  102 . Each antenna radiating element  617  of the eight antenna radiating elements  617  is connected to a first portion  122  of an electrical signal transmission line  118  via a resilient contact  128 . 
     With reference to  FIG. 16 , a partial perspective view of another embodiment of the communication device according to the present invention is illustrated. As for the previous embodiments disclosed above, the communication device  300  of  FIG. 16  comprises an electrical signal transmission line  118 . The first portion  122  of the electrical signal transmission line  118  along its longitudinal extension is connected to at least one electrical component  313 , e.g. an audio component, such as a loudspeaker, or a microphone. The electrical component  313  may extend in a ninth plane  317 . The electrical component  313  comprises at least one contact surface  312 . In  FIG. 16 , the electrical component  313  includes two contact surfaces  312 . The contact surface  312  extends in a tenth plane  314  substantially parallel to the main extension plane  108  of the battery  106  and to the ninth plane  317 . The resilient member  136  of the first contact portion  132  of the resilient contact  128  is configured to resiliently abut against the contact surface  312  of the electrical component  313 . 
     With reference to  FIG. 17  and  FIGS. 4-8 , an embodiment of the method for assembling a communication device  102  is now described. The communication device  12  comprises a casing  104  having a back cover  110 , a front  140  and a surrounding frame  144 . The frame  144  is configured to mount the back cover  110  to the front  140 . At least one electrical component  116 , e.g. an antenna radiating element  117 , is attached to the back cover  110 . The method comprises the steps of:
         placing  401  a battery  106  inside the frame  144 , as illustrated in  FIG. 4 ;   placing  402  a first portion  122  of an electrical signal transmission line  118  alongside the battery  106  between the battery  106  and the frame  144 , as illustrated by  FIGS. 4 and 5 ;   connecting  403  a second portion  120  of the electrical signal transmission line  118  to a processing unit  124  of the communication device  102 , as illustrated in  FIGS. 5-6 ; and   connecting the first portion  122  of the electrical signal transmission line  118  to each of the at least one electrical component  116 , wherein the step of connecting the first portion  122  of the electrical signal transmission line  118  to each of the at least one electrical component  116  is effected by attaching  404  the back cover  110  to the frame  144 , as illustrated in  FIGS. 7-8 .       

     The additional step of placing a processing unit inside the frame may be added, e.g. between the step of placing a battery inside the frame and the step of placing a first portion of an electrical signal transmission line alongside the battery. 
     The features of the different embodiments disclosed above may be combined in various possible ways providing further advantageous embodiments. 
     Finally, it should be understood that the invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.