Abstract:
A high-frequency module includes a diplexer, first and second high-frequency switches, a SAW duplexer, first and second LC filters functioning as first and second filters, and an SAW filter functioning as a third filter. The module defines a unit that integrates front-end sections of first to third communication systems, a digital cellular system (1.8 GHz band), a personal communication service (1.9 GHz band) and a global system for mobile communications (900 MHz band).

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to high-frequency modules and mobile communication apparatuses including high-frequency modules, and more particularly, to a high-frequency module which can be shared by three different communication systems and a mobile communication apparatus including such a high-frequency module.  
           [0003]    2. Description of the Related Art  
           [0004]    A triple-band portable telephone has been proposed which can operate in a plurality of frequency bands, such as those in a digital cellular system (DCS) using the 1.8 GHz band, a personal communication service (PCS) using the 1.9 GHz band, and a global system for mobile communications (GSM) using the 900 MHz, as a mobile communication apparatus.  
           [0005]    [0005]FIG. 12 is a block diagram of a front-end section of a general triple-band portable telephone. FIG. 12 shows a case in which first to third communication systems having frequencies that are different from each other are set to the DCS using the 1.8 GHz, the PCS using the 1.9 GHz, and the GSM using the 900 MHz.  
           [0006]    The front-end section of the triple-band portable telephone is provided with an antenna  1 , a diplexer  2 , first to third high-frequency switches  3   a  to  3   c , first and second LC filters  4   a  and  4   b , and first to third SAW filters  5   a  to  5   c . The diplexer  2  couples a transmission signal sent from one of the DCS, the PCS, and the GSM with the antenna  1  during transmission, and distributes a receiving signal sent from the antenna  1  to one of the DCS, the PCS, and the GSM during receiving. The first high-frequency switch  3   a  switches between the transmission-section side of the DCS and the PCS, and the receiving-section side of the DCS and the PCS. The second high-frequency switch  3   b  switches between the receiving section Rxd side of the DCS and the receiving section Rxp side of the PCS. The third high-frequency switch  3   c  switches between the transmission-section Txg side and the receiving section Rxg side of the GSM. The first LC filter  4   a  passes transmission signals for the DCS and the PCS and attenuates the harmonics of the transmission signals. The second LC filter  4   b  passes a transmission signal for the GSM and attenuates the harmonics of the transmission signal. The first SAW filter  5   a  passes a receiving signal for the DCS and attenuates the harmonics of the receiving signal. The second SAW filter  5   b  passes a receiving signal for the PCS and attenuates the harmonics of the receiving signal. The third SAW filter  5   c  passes a receiving signal for the GSM and attenuates the harmonics of the receiving signal.  
           [0007]    The operation of the triple-band portable telephone will be described for the DCS first. During transmission, the first high-frequency switch  3   a  turns on the transmission section Txdp side to send a transmission signal that was sent from the transmission section Txdp and that has passed through the first LC filter  4   a , to the diplexer  2 , the diplexer  2  performs coupling, and then the signal is sent from the antenna  1 . During receiving, a receiving signal received by the antenna  1  is distributed by the diplexer  2 , the receiving signal sent from the antenna  1  is sent to the first switch  3   a , which is located on the DCS and PCS side, the first high-frequency switch  3   a  turns on the receiving section side to send the signal to the second high-frequency switch  3   b , and the second high-frequency switch  3   b  turns on the receiving section Rxd side of the DCS to send the signal to the receiving section Rxd of the DCS through the first SAW filter  5   a . A similar operation is also performed for transmission and receiving for the PCS.  
           [0008]    A case in which the GSM is used will be described next. During transmission, the third high-frequency switch  3   c  turns on the transmission section Txg side to send a transmission signal which was sent from the transmission section Txg and has passed the second LC filter  4   b , to the diplexer  2 , the diplexer  2  performs coupling, and the signal is sent from the antenna  1 . During receiving, a receiving signal received by the antenna  1  is distributed by the diplexer  2 , the receiving signal sent from the antenna  1  is sent to the third high-frequency switch  3   c , and the third high-frequency switch  3   c  turns on the receiving section Rxg side to send the signal to the receiving section Rxg of the GSM through the third SAW filter  5   c.    
           [0009]    Since the triple-band portable telephone, which is one of the conventional mobile communication apparatuses, uses three high-frequency switches, at least six diodes constituting the high-frequency switches are required. As a result, the triple-band portable telephone uses a very large amount of power, and a battery mounted to the triple-band portable telephone can be used only for a short period. Also, the operation of each diode is controlled in many operation modes, and thus, a complicated circuit is required.  
         SUMMARY OF THE INVENTION  
         [0010]    In order to overcome the problems described above, preferred embodiments of the present invention provide a high-frequency module having a low power consumption and a compact circuit, and a mobile communication apparatus including such a high-frequency module.  
           [0011]    According to a preferred embodiment of the present invention, a high-frequency module includes integrated front-end sections of first to third communication systems having frequencies that are different from each other, the high-frequency module includes a diplexer arranged to couple a transmission signal sent from any of the first to third communication systems to an antenna during transmission and arranged to distribute a receiving signal sent from the antenna to any of the first to third communication systems during receiving, a first high-frequency switch arranged to separate a transmission section for the first and second communication systems and receiving sections for the first and second communication systems, a SAW duplexer arranged to separate a receiving section for the first communication system and a receiving section for the second communication system, and a second high-frequency switch arranged to separate a transmission section and a receiving section for the third communication system.  
           [0012]    The high-frequency module may further include at least one of a first filter arranged to pass a transmission signal sent from the first and second communication systems, a second filter arranged to pass a transmission signal sent from the third communication system, and a third filter arranged to pass a receiving signal for the third communication system.  
           [0013]    In the high-frequency module, the SAW duplexer may include a SAW filter and a phase conversion component connected to the SAW filter.  
           [0014]    According to another preferred embodiment of the present invention, a high-frequency module includes front-end sections of first to third communication systems having frequencies that are different from each other, the front-end sections including a diplexer arranged to couple a transmission signal sent from any of the first to third communication systems to an antenna during transmission and arranged to distribute a receiving signal sent from the antenna to any of the first to third communication systems during receiving, a first high-frequency switch arranged to separate a transmission section for the first and second communication systems and receiving sections for the first and second communication systems, a SAW duplexer arranged to separate a receiving section for the first communication system and a receiving section for the second communication system, and a second high-frequency switch arranged to separate a transmission section and a receiving section for the third communication system, wherein the diplexer, the first and second high-frequency switches, and the SAW duplexer are integrated in a laminated member including a plurality of laminated sheet layers.  
           [0015]    The high-frequency module may be configured such that all elements of the diplexer and a portion of the elements of the first and second high-frequency switches and the SAW duplexer are built in the laminated member, and the remaining elements of the first and second high-frequency switches and the SAW duplexer are mounted on the laminated member.  
           [0016]    According to a high-frequency module of various preferred embodiments of the present invention, since a diplexer, first and second high-frequency switches, and an SAW duplexer are provided, and the SAW duplexer separates a receiving section for a first communication system and a receiving section for a second communication system, the number of high-frequency switches is reduced. As a result, the number of diodes used is reduced, and the power consumption of the high-frequency modules is greatly reduced. This means that a low-power-consumption, high-frequency module is provided. In addition, a current is not required during the signal receiving operation.  
           [0017]    Since the diplexer, the first and second high-frequency switches, and the SAW duplexer, which constitute the high-frequency module, are integrated into a laminated member obtained by laminating a plurality of sheet layers preferably formed of ceramic, the matching characteristic, the attenuation characteristic, or the isolation characteristic of each component is obtained. Therefore, a matching circuit is not required between the diplexer and the first and second high-frequency switches, or between the first high-frequency switch and the SAW duplexer. Consequently, the high-frequency module becomes much more compact than conventional devices.  
           [0018]    The diplexer preferably includes inductors and capacitors. The first and second high-frequency switches preferably include diodes, inductors, and capacitors. The SAW duplexer preferably includes SAW filters and transmission lines. The first and second LC filters preferably include inductors and capacitors. These elements are built in, or mounted on a laminated member and are connected by connections disposed inside of the laminated member. Therefore, the high-frequency module is constituted by a single laminated member and is very compact. In addition, loss caused by wirings for connecting components is greatly reduced, and as a result, the loss of the entire high-frequency module is greatly reduced.  
           [0019]    Since the lengths of the inductors and the transmission lines built in the laminated member are reduced by a wavelength reduction effect, the insertion losses of these inductors and the transmission lines are greatly reduced. Therefore, a compact and low-loss high-frequency module is provided.  
           [0020]    According to another preferred embodiment of the present invention, a mobile communication apparatus includes a high-frequency module according to one of the preferred embodiments described above, which high-frequency module defines the front-end sections of the first to third communication systems, receiving sections for the first to third communication systems, and transmission sections for the first to third communication systems.  
           [0021]    According to a mobile communication apparatus of a preferred embodiment of the present invention, since a front-end section defined by a high-frequency module which allows power consumption to be reduced is provided, the power consumption of the mobile communication apparatus itself can also be reduced.  
           [0022]    According to a mobile communication apparatus of various preferred embodiments of the present invention, since a high-frequency module used can reduce power consumption and does not require a current during receiving, the mobile communication apparatus having this high-frequency module can have low power consumption and does not require any current when waiting for a call. As a result, a battery mounted in the mobile communication apparatus can be used for a much longer period than in conventional devices.  
           [0023]    In addition, since the compact and low-loss high-frequency module is used, the mobile communication apparatus having this high-frequency module is made compact and has a high performance.  
           [0024]    Other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]    [0025]FIG. 1 is a block diagram of a high-frequency module according to a preferred embodiment of the present invention.  
         [0026]    [0026]FIG. 2 is a circuit diagram of a diplexer constituting the high-frequency module shown in FIG. 1.  
         [0027]    [0027]FIG. 3 is a circuit diagram of a first high-frequency switch constituting the high-frequency module shown in FIG. 1.  
         [0028]    [0028]FIG. 4 is a circuit diagram of a second high-frequency switch constituting the high-frequency module shown in FIG. 1.  
         [0029]    [0029]FIG. 5 is a circuit diagram of a SAW duplexer constituting the high-frequency module shown in FIG. 1.  
         [0030]    [0030]FIG. 6 is a circuit diagram of a first LC filter constituting the high-frequency module shown in FIG. 1.  
         [0031]    [0031]FIG. 7 is a circuit diagram of a second LC filter constituting the high-frequency module shown in FIG. 1.  
         [0032]    [0032]FIG. 8 is an exploded perspective view of a main portion of the high-frequency module shown in FIG. 1.  
         [0033]    FIGS.  9 ( a ) to FIG. 9( h ) are top views of a first dielectric layer to an eighth dielectric layer constituting a laminated member of the high-frequency module shown in FIG. 8.  
         [0034]    FIGS.  10 ( a ) to FIG. 10( e ) are top views of a ninth dielectric layer to a 13th dielectric layer constituting the laminated member of the high-frequency module shown in FIG. 8, and FIG. 10( f ) is a bottom view of the 13th dielectric layer constituting the laminated member of the high-frequency module shown in FIG. 8.  
         [0035]    [0035]FIG. 11 is a block diagram showing a portion of the structure of a mobile communication apparatus using the high-frequency module shown in FIG. 1.  
         [0036]    [0036]FIG. 12 is a block diagram showing the structure of a front end section of a general triple-band portable telephone (mobile communication apparatus). 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0037]    Preferred embodiments of the present invention will be described below by referring to the drawings.  
         [0038]    [0038]FIG. 1 is a block diagram of a high-frequency module  10  according to a preferred embodiment of the present invention. The high-frequency module  10  preferably includes a diplexer  11 , first and second high-frequency switches  12  and  13 , a SAW duplexer  14 , first and second LC filters  15  and  16  defining first and second filters, and a SAW filter  17  defining a third filter, and functions as a front end section of first to third communication systems, preferably, a DCS (1.8 GHz band), a PCS (1.9 GHz band), and a GSM (900 MHz band).  
         [0039]    A first port P 11  of the diplexer  11  is connected to an antenna ANT, a second port P 12  is connected to a first port P 21  of the first high-frequency switch  12 , and a third port P 13  is connected to a first port P 31  of the second high-frequency switch  13 .  
         [0040]    A second port P 22  of the first high-frequency switch  12  is connected to a first port P 51  of the first LC filter  15 , and a third port P 23  is connected to a first port P 41  of the SAW duplexer  14 .  
         [0041]    A second port P 52  of the first LC filter  15  is connected to a transmission section Txdp shared by the DCS and the PCS, and second and third ports P 42  and P 43  of the SAW duplexer  14  are connected to a receiving section Rxd of the DCS and a receiving section Rxp of the PCS, respectively.  
         [0042]    A second port P 32  of the second high-frequency switch  13  is connected to a first port P 61  of the second LC filter  16 , and a third port P 33  is connected to a first port P 71  of the SAW filter  17 .  
         [0043]    A second port P 62  of the second LC filter  16  is connected to a transmission section Txg of the GSM, and a second port P 72  of the SAW filter  17  is connected to a receiving section Rxg of the GSM.  
         [0044]    [0044]FIG. 2 is a circuit diagram of the diplexer  11  constituting the high-frequency module shown in FIG. 1. The diplexer  11  is provided with the first to third ports P 11  to P 13 , inductors L 11  and L 12 , and capacitors C 11  to C 15 .  
         [0045]    Between the first port P 11  and the second port P 12 , the capacitors C 11  and C 12  are connected in series. The connection point between them is grounded through the inductor L 11  and the capacitor C 13 .  
         [0046]    Between the first port P 11  and the third port P 13 , a parallel circuit including the first inductor L 12  and the first capacitor C 14  is connected. An end of the parallel circuit located at the third port P 13  side is grounded through the first capacitor C 15 .  
         [0047]    In other words, a high-pass filter which passes transmission and receiving signals in the DCS (1.8 GHz band) and the PCS (1.9 GHz band) is defined between the first port P 11  and the second port P 12 . A low-pass filter which passes transmission and receiving signals in the GSM (900 MHz band) is defined between the first port P 11  and the third port P 13 .  
         [0048]    [0048]FIG. 3 is a circuit diagram of the first high-frequency switch  12  constituting the high-frequency module shown in FIG. 1. The first high-frequency switch  12  is provided with the first to third ports P 21  to P 23 , a control terminal Vc 1 , diodes D 11  and D 12 , inductors L 21  to L 23 , capacitors C 21  and C 22 , and a resistor R 1 .  
         [0049]    Between the first port P 21  and the second port P 22 , the diode D 11  is connected such that its anode is disposed at the first port P 21  side. The diode  11  is also connected in parallel to a series circuit including the inductor L 21  and the capacitor C 21 . The second port P 22  side of the diode D 11 , namely, its cathode, is grounded through the inductor L 22  defining a choke coil.  
         [0050]    Between the first port P 21  and the third port P 23 , the inductor L 23  is connected. The third port P 23  side of the inductor L 23  is grounded through the diode D 12  and the capacitor C 22 . The connection point of the anode of the diode D 12  and the capacitor C 22  is connected to the control terminal Vc 1  through the resistor R 1 .  
         [0051]    [0051]FIG. 4 is a circuit diagram of the second high-frequency switch  13  constituting the high-frequency module shown in FIG. 1. The second high-frequency switch  13  is provided with the first to third ports P 31  to P 33 , a control terminal Vc 2 , diodes D 21  and D 22 , inductors L 31  and L 32 , a capacitor C 31 , and a resistor R 2 .  
         [0052]    Between the first port P 31  and the second port P 32 , the diode D 21  is connected such that its anode is disposed at the first port P 31  side. The second port P 32  side of the diode D 21 , namely, its cathode, is grounded through the inductor L 31  defining a choke coil.  
         [0053]    Between the first port P 31  and the third port P 33 , the inductor L 32  is connected. The third port P 33  side of the inductor L 32  is grounded through the diode D 22  and the capacitor C 31 . The connection point of the anode of the diode D 22  and the capacitor C 31  is connected to the control terminal Vc 2  through the resistor R 2 .  
         [0054]    [0054]FIG. 5 is a circuit diagram of the SAW duplexer  14  constituting the high-frequency module shown in FIG. 1. The SAW duplexer  14  is provided with the first to third ports P 41  to P 43 , SAW filters SAW 1  and SAW 2 , inductors L 41  and L 42 , and capacitors C 41  to C 44 . Between the first port P 41  and the second port P 42 , the capacitor C 41 , the SAW filter SAW 1 , and a phase conversion unit  141  are connected in series. Between the first port P 41  and the third port P 43 , the capacitor C 41 , the SAW filter SAW 2 , and a phase conversion unit  142  are connected in series.  
         [0055]    The phase conversion unit  141  includes the inductor L 41  and the capacitors C 42  and C 43 . Both ends of the inductor L 41  are connected to the ground through the capacitors C 42  and C 43 . The phase conversion unit  142  includes the inductor L 42  and the capacitor C 44 . The SAW filter SAW 2  side of the inductor L 42  is connected to the ground through the capacitor C 44 .  
         [0056]    In the phase conversion unit  141 , the inductance of the inductor L 41  and the capacitances of the capacitors C 42  and C 43  are specified such that the input impedance of the SAW filter SAW 1  is open in the frequency band (1.8 GHz band) of the DCS connected to the second port P 42 . In the same way, in the phase conversion unit  142 , the inductance of the inductor L 42  and the capacitance of the capacitors C 44  are specified such that the input impedance of the SAW filter SAW 2  is open in the frequency band (1.9 GHz band) of the PCS connected to the third port P 43 .  
         [0057]    [0057]FIG. 6 is a circuit diagram of the first LC filter  15  constituting the high-frequency module shown in FIG. 1. The first LC filter  15  is provided with the first and second ports P 51  and P 52 , inductors L 51  and L 52 , and capacitors C 51  to C 53 .  
         [0058]    Between the first port P 51  and the second port P 52 , a parallel circuit defined by the inductor L 51  and the capacitor C 51 , and a parallel circuit defined by the inductor L 52  and the capacitor C 52  are connected in series, and the connection point of these parallel circuits is grounded by the capacitor C 53 .  
         [0059]    [0059]FIG. 7 is a circuit diagram of the second LC filter  16  constituting the high-frequency module shown in FIG. 1. The second LC filter  16  is provided with the first and second ports P 61  and P 62 , an inductor L 61 , and capacitors C 61  to C 63 .  
         [0060]    Between the first port P 61  and the second port P 62 , a parallel circuit defined by the inductor L 61  and the capacitor C 61  is connected in series, and both ends of the parallel circuit are grounded through the capacitors C 62  and C 63 .  
         [0061]    [0061]FIG. 8 is an exploded perspective view of a main section of the high-frequency module  10  having the circuit structure shown in FIG. 1. The high-frequency module  10  includes a laminated member  18 . The laminated member  18  includes in its inside, although not shown, the inductors L 11  and L 12  and the capacitors C 11  to C 15  of the diplexer  11 , the inductors L 21  and L 23  and the capacitor C 22  of the first high-frequency switch  12 , the inductor  32  and the capacitor C 31  of the second high-frequency switch  13 , the inductors L 41  and L 42  and the capacitors C 42  to C 44  of the SAW duplexer  14 , the inductors L 51  and L 52  and the capacitors C 51  to C 53  of the first LC filter  15 , and the inductor L 61  and the capacitors C 61  to C 63  of the second LC filter  16 .  
         [0062]    The following elements are preferably mounted on the front surface of the laminated member  18 : the diodes D 11  and D 12 , the inductor (choke coil) L 22 , the capacitor C 21 , and the resistor R 1  of the first high-frequency switch  12 ; the diodes D 21  and D 22 , the inductor (choke coil) L 31 , and the resistor R 2  of the second high-frequency switch  13 ; the SAW filters SAW 1  and SAW 2 , and the capacitor C 41  of the SAW duplexer  14 ; and the SAW filter  17 .  
         [0063]    From the side surfaces to the bottom surface of the laminated member  18 , eighteen external terminals Ta to Tr extend. The external terminals Ta to Tr are preferably formed by screen printing or another suitable method. The external terminals Ta and Tb define the second port P 42  of the SAW duplexer  14 . The external terminal Tc defines the control terminal Vc 1  of the first high-frequency switch  12 . The external terminal Td defines the second port P 62  of the second LC filter  16 . The external terminal Tf defines the second port P 52  of the first LC filter  15 . The external terminal Tg defines the control terminal Vc 2  of the second high-frequency switch  13 . The external terminal Ti defines as the first port P 11  of the diplexer  11 . The external terminals Tk and Tl define the second port P 72  of the SAW filter  17 . The external terminals Tn and To define the third port P 43  of the SAW duplexer  14 . The external terminals Te, Th, Tj, Tm, Tp, Tq, and Tr define the ground terminals.  
         [0064]    A metal cap  20  is placed on the laminated member  18  so as to cover the front surface of the laminated member  18 . Protrusions  201  and  202  of the metal cap  20  are connected to the external terminals Th and Tq of the laminated member  18 .  
         [0065]    [0065]FIG. 9( a ) to FIG. 9( h ) and FIG. 10( a ) to FIG. 10( f ) are the top views of dielectric layers constituting the high-frequency module shown in FIG. 8, and FIG. 10( g ) is the bottom view of the dielectric layer shown in FIG. 10( f ). The laminated member  18  is preferably formed by sequentially laminating first to  14 th dielectric layers  18   a  to  18   n  preferably made from ceramic having barium oxide, aluminum oxide, and silica as main components from the top, by baking at a baking temperature of about 1000° C. or more, and by turning it upside down. In other words, the 14th dielectric layer  18   n  defines the top layer of the laminated member  18 , and the first dielectric layer  18   a  defines the bottom layer of the laminated member  18 .  
         [0066]    On the upper surface of the first dielectric layer  18   a , the external terminals Ta to Tr are provided. On the upper surfaces of the second, fourth, and 13th dielectric layers  18   b ,  18   d , and  18   m , ground electrodes Gp 1  to Gp 3  are provided, respectively. On the upper surfaces of the third to sixth and 10th to 12th dielectric layers  18   c  to  18   f  and  18   j  to  18   l , capacitor electrodes Cp 1  to Cp 19  are provided.  
         [0067]    In addition, on the upper surfaces of the seventh to ninth dielectric layers  18   g  to  18   i , stripline electrodes ST 1  to ST 26  are provided. On the upper surface of the 14th dielectric layer  18   n , a wiring Li is provided.  
         [0068]    Furthermore, on the lower surface of the 14th dielectric layer ( 18   nu  in FIG. 10( g )), lands La for mounting the diodes D 11 , D 12 , D 21 , and D 22 , the inductors L 22  and L 31 , the capacitors C 22  and C 41 , the resistors R 1  and R 2 , and the SAW filters SAW 1 , SAW 2 , and  17  on the front surface of the laminated member  18  are provided. Viahole electrodes Vh are formed at predetermined positions in the third to 14th dielectric layers  18   c  to  18   n.    
         [0069]    With this structure, the inductor L 11  (see FIG. 2) of the diplexer  11  includes the stripline electrodes ST 4 , ST 13 , and ST 22 , and the inductor L 12  (see FIG. 2) includes the stripline electrodes ST 2 , ST 11 , and ST 21 . The capacitor C 11  (see FIG. 2) preferably includes the capacitor electrodes Cp 16 , Cp 17 , and Cp 19 . The capacitor C 12  (see FIG. 2) preferably includes the capacitor electrodes Cp 16 , Cp 18 , and Cp 19 . The capacitor C 13  (see FIG. 2) preferably includes the capacitor electrode Cp 4  and the ground electrodes Gp 1  and Gp 2 . The capacitor C 14  (see FIG. 2) is preferably includes the capacitor electrodes Cp 7 , Cp 8 , and Cp 12 . The capacitor C 15  (see FIG. 2) preferably includes the capacitor electrodes Cp 7  and Cp 12  and the ground electrodes Gp 1  and Gp 2 .  
         [0070]    The inductor L 21  (see FIG. 3) of the first high-frequency switch  12  includes the stripline electrodes ST 7 , ST 17 , and ST 25 , and the inductor L 23  (see FIG. 2) includes the stripline electrodes ST 3  and ST 12 . The capacitor C 22  (see FIG. 3) includes the capacitor electrode Cp 5  and the ground electrodes Gp 1  and Gp 2 .  
         [0071]    The inductor L 32  (see FIG. 4) of the second high-frequency switch  13  includes the stripline electrodes ST 6  and ST 15 . The capacitor C 32  (see FIG. 4) includes the capacitor electrode Cp 6  and the ground electrodes Gp 1  and Gp 2 .  
         [0072]    The inductor L 41  (see FIG. 5) of the SAW duplexer  14  includes the stripline electrodes ST 5 , ST 14 , and ST 23 , and the inductor L 42  (see FIG. 5) includes the stripline electrodes ST 1 , ST 10 , and ST 20 . The capacitor C 42  (see FIG. 5) includes the capacitor electrode Cp 3  and the ground electrodes Gp 1  and Gp 2 , the capacitor C 43  (see FIG. 5) includes the capacitor electrode Cp 2  and the ground electrodes Gp 1  and Gp 2 , and the capacitor C 44  (see FIG. 5) includes the capacitor electrode Cp 1  and the ground electrodes Gp 1  and Gp 2 .  
         [0073]    The inductor L 51  (see FIG. 6) of the first LC filter  15  includes the stripline electrodes ST 8 , ST 18 , and ST 26 , and the inductor L 52  (see FIG. 6) includes the stripline electrodes ST 9  and ST 19 . The capacitor C 51  (see FIG. 6) includes the capacitor electrodes Cp 11  and Cp 14 , the capacitor C 52  (see FIG. 6) includes the capacitor electrodes Cp 11  and Cp 15 , and the capacitor C 53  (see FIG. 6) includes of the capacitor electrode Cp 11  and the ground electrode Gp 2 .  
         [0074]    The inductor L 61  (see FIG. 7) of the second LC filter  16  includes the stripline electrodes ST 16  and ST 24 . The capacitor C 61  (see FIG. 7) includes the capacitor electrodes Cp 10  and Cp 13 , the capacitor C 62  (see FIG. 7) includes the capacitor electrode Cp 9  and the ground electrode Gp 2 , and the capacitor C 63  (see FIG. 7) includes the capacitor electrode Cp 10  and the ground electrode Gp 2 .  
         [0075]    The operation of the high-frequency module  10  having the circuit structure shown in FIG. 1 will be described next. When a transmission signal is transmitted from the DCS (1.8 GHz band) or from the PCS (1.9 GHz band), a voltage of 1 V is applied to the control terminal Vc 1  in the first high-frequency switch  12  to connect the first port P 21  and the second port P 22  in the first high-frequency switch  12  to transmit the transmission signal sent from the DCS or sent from the PCS, from the antenna ANT through the first LC filter  15 , the first high-frequency switch  12 , and the diplexer  11 .  
         [0076]    In this case, the first LC filter  15  passes the transmission signal sent from the DCS or the PCS and attenuates the harmonics of the transmission signal. In the second high-frequency switch  13 , a voltage of 0 V is applied to the control terminal Vc 2  to disable the second high-frequency switch  13 .  
         [0077]    When a transmission signal is transmitted from the GSM (900 MHz band), a voltage of 1 V is applied to the control terminal Vc 2  in the second high-frequency switch  13  to connect the first port P 31  and the second port P 32  in the second high-frequency switch  13  to transmit the transmission signal sent from the GSM, from the antenna ANT through the second LC filter  16 , the second high-frequency switch  13 , and the diplexer  11 .  
         [0078]    In this case, the second LC filter  16  passes the transmission signal sent from the GSM and attenuates the harmonics of the transmission signal. In the first high-frequency switch  12 , a voltage of 0 V is applied to the control terminal Vc 1  to disable the first high-frequency switch  12 .  
         [0079]    When a receiving signal for the DCS is received, a voltage of 0 V is applied to the control terminal Vc 1  of the first high-frequency switch  12  to connect the first port P 21  and the third port P 23  in the first high-frequency switch  12 , and the DCS receiving signal is sent to the second port P 42  side in the SAW duplexer  14 , so that the DCS receiving signal received by the antenna ANT is sent to the receiving section Rxd of the DCS through the diplexer  11 , the first high-frequency switch  12 , and the SAW duplexer  14 .  
         [0080]    In this case, the SAW duplexer  14  passes the DCS receiving signal and attenuates the harmonics of the receiving signal. In the second high-frequency switch  13 , a voltage of 0 V is applied to the control terminal Vc 2  to disable the second high-frequency switch  13 .  
         [0081]    When a receiving signal for the PCS is received, a voltage of 0 V is applied to the control terminal Vc 1  in the first high-frequency switch  12  to connect the first port P 21  and the third port P 23  in the first high-frequency switch  12 , and the PCS receiving signal is sent to the third port P 43  side in the SAW duplexer  14 , so that the PCS receiving signal received by the antenna ANT is sent to the receiving section Rxp of the PCS through the diplexer  11 , the first high-frequency switch  12 , and the SAW duplexer  14 .  
         [0082]    In this case, the SAW duplexer  14  passes the PCS receiving signal and attenuates the harmonics of the receiving signal. In the second high-frequency switch  13 , a voltage of 0 V is applied to the control terminal Vc 2  to disable the second high-frequency switch  13 .  
         [0083]    When a receiving signal for the GSM is received, a voltage of 0 V is applied to the control terminal Vc 2  in the second high-frequency switch  13  to connect the first port P 31  and the third port P 33  in the second high-frequency switch  13  to send the GSM receiving signal received by the antenna ANT to the receiving section Rxg of the GSM through the diplexer  11 , the second high-frequency switch  13 , and the SAW filter  17 .  
         [0084]    In this case, the SAW filter  17  passes the GSM receiving signal and attenuates the harmonics of the receiving signal. In the first high-frequency switch  12 , a voltage of 0 V is applied to the control terminal Vc 1  to disable the first high-frequency switch  12 .  
         [0085]    According to the high-frequency module of the above-described preferred embodiment, since the diplexer, the first and second high-frequency switches, and the SAW duplexer are provided, and the SAW duplexer separates the receiving section of the first communication system and the receiving section of the second communication system, the number of high-frequency switches is reduced. As a result, the number of diodes used is reduced, and the power consumption of the high-frequency modules is greatly reduced. In addition, a current is not required during a signal receiving operation.  
         [0086]    Since the diplexer, the first and second high-frequency switches, and the SAW duplexer, which constitute the high-frequency module, are integrated into the laminated member obtained by laminating a plurality of sheet layers formed of ceramic, the matching characteristic, the attenuation characteristic, or the isolation characteristic of each component is obtained. Therefore, a matching circuit is not required between the diplexer and the first and second high-frequency switches, or between the first high-frequency switch and the SAW duplexer. Consequently, the high-frequency module is very compact. In on example of preferred embodiments of the present invention, the resulting laminated member had approximate dimensions of 7.0 mm by 5.0 mm by 1.8 mm, and the laminated member included the diplexer, the first and second high-frequency switches, the SAW duplexer, the first and second LC filters, and the SAW filter.  
         [0087]    The diplexer preferably includes inductors and capacitors. The first and second high-frequency switches preferably includes diodes, inductors, and capacitors. The SAW duplexer preferably includes SAW filters and transmission lines. The first and second LC filters preferably include inductors and capacitors. All of these elements are preferably built into, or mounted on the laminated member, and are preferably connected by connection members located inside of the laminated member. Therefore, the high-frequency module is defined by a single laminated member and is very compact. In addition, a loss caused by wirings for connecting components is greatly reduced, and as a result, the loss of the entire high-frequency module is greatly reduced.  
         [0088]    Since the lengths of the inductors and the transmission lines built in the laminated member are reduced by a wavelength reduction effect, the insertion losses of these inductors and transmission lines are greatly reduced. Therefore, a compact and low-loss high-frequency module can be produced, and a compact and high-performance mobile communication apparatus on which the high-frequency module is mounted can also be produced.  
         [0089]    [0089]FIG. 11 is a block diagram showing a portion of the structure of a triple-band portable telephone, which is a mobile communication apparatus. In this telephone, a DCS using the 1.8 GHz band, a PCS using the 1.9 GHz band, and a GSM using the 900 MHz band are preferably combined.  
         [0090]    The triple-band portable telephone  30  is provided with the high-frequency module  10  (see FIG. 1), in which an antenna ANT and the front end sections of the DCS, the PCS, and the GSM are integrated, a transmission section Txdp shared by the DCS and the PCS, a receiving section Rxp of the PCS, a receiving section Rxd of the DCS, a transmission section Txg of the GSM, and a receiving section Rxg of the GSM.  
         [0091]    The port P 11  of the high-frequency module  10  is connected to the antenna ANT, and the ports P 43 , P 42 , P 52 , P 62 , and P 72  are connected to the receiving section Rxp of the PCS, the receiving section Rxd of the DCS, the transmission section Txdp common to the DCS and the PCS, the transmission section Txg of the GSM, and the receiving section Rxg of the GSM, respectively.  
         [0092]    According to the triple-band portable telephone described above, since the high-frequency module greatly reduces power consumption and does not require a current during receiving, the mobile communication apparatus having this high-frequency module can have low power consumption and does not use any current when waiting for a call. As a result, a battery mounted in the mobile communication apparatus can be used for a much longer period.  
         [0093]    In addition, since the compact and low-loss high-frequency module is used, the mobile communication apparatus having this high-frequency module is very compact and provides excellent performance.  
         [0094]    In the high-frequency module of various preferred embodiments described above, the laminated member preferably includes in the inside thereof, all of the elements of the diplexer, and a portion of the elements of the first and second high-frequency switches and the SAW duplexer, and the remaining elements of the first and second high-frequency switches and the SAW duplexer are mounted on the laminated member. A structure in which all the elements of the diplexer, the first and second high-frequency switches, and the SAW duplexer are mounted on the same printed circuit board may be used. Alternatively, a structure in which all the elements of the diplexer, and a portion of the elements of the first and second high-frequency switches and the SAW duplexer are built in a laminated member, and the remaining elements of the first and second high-frequency switches and the SAW duplexer are mounted on the same printed circuit board may be used.  
         [0095]    In the above case, the phase conversion units of the SAW duplexer are preferably defined by lumped constant elements obtained by combining inductors and capacitors. Even if the phase conversion units are defined by distributed constant elements such as striplines, the same advantages are obtained.  
         [0096]    In the above case, the SAW filters are mounted on the front surface of the laminated member. They may be mounted in a cavity formed on the lower surface or each surface of the laminated member.  
         [0097]    In the above case, the SAW filters are bare chip elements but may also be disposed in a package.  
         [0098]    While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details can be made without departing from the spirit and scope of the invention.