Abstract:
A communication system equipped with a shared antenna includes an antenna, a first communication module, a second communication module, and a switch unit. The first communication module processes a first communication signal and transmits the first communication signal to the switch unit. The second communication module processes a second communication signal and transmits the second communication signal to the switch unit. Additionally, the first communication module controls the switch unit to transmit the first communication signal or the second communication signal to the antenna, and the antenna emits the first communication signal or the second communication signal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a communication system, and more particularly to a communication system equipped with an antenna shared by a Bluetooth module and a wireless network module. 
         [0003]    2. Description of the Prior Art 
         [0004]      FIG. 1  illustrates a diagram of a convention wireless network module  100 . The wireless network module  100  includes a baseband/multimedia access control (BB/MAC)  130 , a front end module (FEM)  120 , a main antenna  160 , and an auxiliary antenna  170 . 
         [0005]    The above-mentioned wireless network module  100  is manufactured compliant to the 802.11b/g IEEE standards that transmit wireless network signals  140  at a bandwidth of 2.4 GHz. The main antenna  160  and the auxiliary antenna  170  are coupled to the FEM  120 , and the FEM  120  is coupled to the BB/MAC  130 . The FEM  120  is utilized for converting the digital signals  150  transmitted from the BB/MAC  130  to wireless network signals  140  to be transmitted by the main antenna  160  or the auxiliary antenna  170 . 
         [0006]    When the wireless network module  100  is transmitting the wireless network signals  140 , the wireless network module  100  selects an antenna to be a transmission antenna according to the reception of the main antenna  160  or the auxiliary antenna  170 , the transmission antenna becomes a diversity antenna. In other words, there is usually a predetermined distance set between positions of the main antenna  160  and the auxiliary antenna  170 , thus the wireless network module  100  can gain better reception through the inter-compensation of the main antenna  160  and the auxiliary antenna  170 . Therefore when the main antenna  160  has better reception, the wireless network module  100  will transmit the wireless network signals  140  through the main antenna  160 ; and if the auxiliary antenna  170  has better reception, the wireless network module  100  will transmit the wireless network signals  140  through the auxiliary antenna  170 . 
         [0007]      FIG. 2  illustrates a diagram of a conventional Bluetooth module  200 . The Bluetooth module  200  includes a Bluetooth antenna  210  for transmitting Bluetooth signals  220 , wherein Bluetooth signals  220  transmitted by the Bluetooth module  200  also operate in the bandwidth of 2.4 GHz. 
         [0008]    In general, the current wireless network module and the Bluetooth module are respectively installed on two different printed circuit boards. For example, the wireless network cards sold in the market only provide either a wireless network module or a Bluetooth module. Therefore, in consideration for an end-user, to utilize both wireless network transmission and Bluetooth transmission at the same time requires additional expenses and inconvenience is caused, especially when the two wireless network cards are of different standards. 
         [0009]    At the moment, some mobile phones in the market have the wireless network module and the Bluetooth module installed on the printed circuit board of the mobile phone. In other words, the wireless network module and the Bluetooth module are installed on the same printed circuit board. However, the resulting efficiency will be poor as the wireless network module of this design only utilizes a single antenna, and the Bluetooth module utilizes a chip antenna. 
       SUMMARY OF THE INVENTION 
       [0010]    The claimed invention provides a communication system and an expansion board equipped with a shared antenna to solve the above-mentioned problem. 
         [0011]    The claimed invention discloses an expansion board suitable for cooperating to a first antenna on a portable electronic device. The expansion board comprises a first communication module for processing a first communication signal; a second communication module for processing a second communication signal; and a switch unit respectively coupled to the first communication module and the second communication module, wherein when the expansion card is inserted to the portable electronic device, the switch unit is coupled to the first antenna, and the switch unit switches the first communication module or the second communication module through the first antenna to transit the first communication signal or the second communication signal. 
         [0012]    The claimed invention further discloses a communication system with a shared antenna. The communication system comprises a shared antenna; a first communication module for processing a first communication signal; a second communication module coupled to the first communication module for processing a second communication signal and for receiving a first control signal transmitted from the first communication module; and a switch unit. The switch unit comprises a first transmission end coupled to the first communication module for transmitting the first communication signal; a second transmission end coupled to the second communication module for transmitting the second communication signal; a first control end coupled to the first communication module for receiving the first control signal transmitted from the first communication module; and a third transmission end coupled to the shard antenna for coupling to the first transmission end or the second transmission end according to the first control signal. 
         [0013]    The claimed invention further discloses a communication system with a shared antenna, the communication system comprises a first antenna; a first communication module for processing a first communication signal; a second communication module for processing a second communication signal; a second shared antenna coupled to the second communication module for transmitting the second communication signal; and a switch unit. The switch unit comprises a first transmitting end coupled to the first communication module for transmitting the first communication signal; a second transmitting end coupled to the second communication module for transmitting the second communication signal; a first control end coupled to the first communication module for receiving the first control signal transmitted from the first communication module; and a third transmitting end coupled to the first antenna for coupling to the first transmission end or the second transmission end according to the first control signal. 
         [0014]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  illustrates a diagram of a convention wireless network module. 
           [0016]      FIG. 2  illustrates a diagram of a conventional Bluetooth module. 
           [0017]      FIG. 3  illustrates a diagram of a communication system according to an embodiment of the present invention. 
           [0018]      FIG. 4  illustrates a diagram of a communication system being applied in a notebook computer. 
           [0019]      FIG. 5  illustrates a functional block diagram of a communication system according to the first embodiment of the present invention. 
           [0020]      FIG. 6  illustrates a diagram of a communication system according to a second embodiment of the present invention. 
           [0021]      FIG. 7  illustrates a diagram of a communication system according to a third embodiment of the present invention. 
           [0022]      FIG. 8  illustrates a diagram of an expansion card according to a fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    The present invention is made to solve the problem in the prior art, and to combine the wireless network module and the Bluetooth module on a single printed circuit board.  FIG. 3  illustrates a diagram of a communication system  300  according to an embodiment of the present invention. The communication system  300  includes a wireless network module  100  and a Bluetooth module  200 . The wireless network module  100  includes a baseband/multimedia access control (BB/MAC)  130 , a Front end module (FEM)  120 , a main antenna  160 , and an auxiliary antenna  170 . 
         [0024]    The operational method and the connection of the internal components of the wireless network module  100  and the Bluetooth module  200  are similar to  FIG. 1 , therefore it will not be reiterated. From the above-mentioned, both the wireless network signals  140  transmitted from the wireless network module  100  and the Bluetooth signals  200  transmitted from the Bluetooth module  200  operate in the 2.4 GHz bandwidth. However, when the wireless transmission and receiving range of the wireless network module  100  and the Bluetooth module  200  overlaps, an interference phenomenon will occur, such as a normal interference or a front-end overload. 
         [0025]    A normal interference usually occurs on a baseband processor, this is due to the wireless network module  100  and the Bluetooth module  200  not knowing each other&#39;s bandwidth, which leads to the two primary frequencies being overlapping on the same channel. The front-end overload occurs when two wireless systems do not keep a certain distance from each other, in other words, it is caused by when isolation of the antenna ends are not sufficient, or a harmonic interference is generated when transmission level is too great from both the wireless systems. 
         [0026]    Therefore, when the communication system  300  is being designed, interference can be easily generated due to the insufficient antenna gap between the main antenna  160  of the wireless network module  100 , the auxiliary antenna  170 , and the Bluetooth antenna  210  of the Bluetooth module  200 , hence the transmission efficiency is reduced. 
         [0027]      FIG. 4  illustrates a diagram of a communication system  300  being applied in a notebook computer  400 . In this embodiment, the notebook computer  400  may not have a wireless network module and a Bluetooth module installed, an expansion card that includes a wireless network module and a Bluetooth module can be installed into the notebook computer  400 , yet in other embodiments, the communication system  300  can be directly installed on the motherboard of the notebook computer  400 . 
         [0028]    Whether the communication system  300  is directly installed on the notebook computer  400  or is installed within the expansion card, three antennas are required for receiving and transmitting signals. As the antenna installed on the monitor of the notebook computer  400  will have a better reception, therefore the main antenna  160  of the wireless network module and the auxiliary antenna  170 , and the Bluetooth antenna  210  of the Bluetooth module will be installed on the sides of the monitor so that the communication system  300  can transmit the wireless network signals  140  and the Bluetooth signals  220  through the antennas on the top of the monitor. 
         [0029]    However, if the installation of main antenna  160 , the auxiliary antenna  170 , and the Bluetooth antenna  210  on the top end of the monitor will generate an insufficient gap phenomenon at the antenna end such that the communication system  300  at the same time transmits the wireless network signals and Bluetooth signals that can easily cause interference and affect the transmission efficiency. 
         [0030]    Therefore, if the number of antennas can be reduced such that the gap degree of the antennas is compliant to 25 dB, 30 dB, or 40 dB, hence there will be better transmission efficiency. 
         [0031]    Please refer to  FIG. 5  for an explanation of a first embodiment of the present invention.  FIG. 5  illustrates a functional block diagram of a communication system  500  according to the first embodiment of the present invention. The communication system  500  includes a wireless network module  510 , two signal quality enhancers  511  and  541 , a Bluetooth module  540 , a switch unit  550 , a first antenna  580 , and a second antenna  560 , where the wireless network module  510  includes a BB/MAC  520  and a FEM  530 , and the switch unit  550  includes a control end D and transmission ends A, B, and C. 
         [0032]    The BB/MAC  520  is coupled to the FEM  530  for transmitting digital signals  515  to the FEM  530 . The FEM  530  is coupled to the transmission end A of the switch unit  550  through the signal quality enhancer  511  for converting the digital signals  515  to wireless network signals  590  to be transmitted to the switch unit  550 ; the FEM  530  is also coupled to the first antenna  580  for transmitting the wireless network signals  590  to the first antenna  580 , which to be transmitted. The signal quality enhancer  511  is coupled between the FEM  530  and the transmission end A of the switch unit  550 . 
         [0033]    The Bluetooth module  540  is coupled to the transmission end C of the switch unit  550  through the signal quality enhancer  541  for transmitting Bluetooth signals  595  to the switch unit  550 ; the Bluetooth module  540  is also coupled to the control end D of the switch unit  550  for transmitting a control signal  570  to the control end D of the switch unit  550 . The signal quality enhancer  541  is coupled between the Bluetooth module  540  and the transmission end C of the switch unit  550 . 
         [0034]    In this embodiment, the switch unit  550  turns on and off for 2.4 GHz RF, but in other embodiments, the switch unit  550  can also be a switch unit that can switch RF signals. 
         [0035]    In this embodiment, the signal quality enhancers  511  and  541  are utilized for enhancing signal quality, for example: the signal quality enhancer  511  is utilized for enhancing the wireless network signal quality, and the signal quality enhancer  541  is utilized for enhancing the Bluetooth signal quality. In this embodiment, the signal quality enhancer  511  and  541  can be filters, but in other embodiments, the signal quality enhancer  511  can be an amplifier, or other equivalent device similar to the signal quality enhancer. In other embodiments, if the wireless network signal quality and the Bluetooth quality are satisfactory, then the signal quality enhancers  511  and  541  can be removed, and the FEM  530  can be directly coupled to the transmission end A of the switch unit  550 , and also the Bluetooth module  540  can be directly coupled to the transmission end C of the switch unit  550 . 
         [0036]    As illustrated in  FIG. 5 , before the Bluetooth module  540  transmits the Bluetooth signals  595  (when the Bluetooth module  540  is inactive), the transmission ends A and B of the switch unit  550  are coupled (the transmission end C will not be coupled to the transmission end B). Therefore, in  FIG. 5 , the FEM  530  is coupled to the second antenna  560  through the switch unit  550 . Therefore, the wireless network module  510  can transmit the wireless network signals  590  through the first antenna  580  and the second antenna  560 . The wireless network module  510  can determine whether the wireless networks signals  590  will be transmitted through the first antenna  580  or the second antenna  560  according to the reception of the first antenna  580  and the second antenna  560 . 
         [0037]    When the Bluetooth module  540  is transmitting the Bluetooth signals  595 , the Bluetooth module  540  will transmit the control signal  570  to the control end D of the switch unit  550  such that the transmission end C of the switch unit  550  is coupled to the transmission end B of the switch unit  550  (at the time, the transmission end A will not be coupled to the transmission end B). Therefore, the Bluetooth module  540  can be coupled to the second antenna  560  through the switch unit  550  to transmit the Bluetooth signals  595 . At this time, the wireless network module  510  can transmit the wireless network signals  590  through the first antenna  580 . 
         [0038]    Furthermore, the communication system  500  provided by the preferred embodiment is designed within a printed circuit board  501 , and the printed circuit board  501  is a PCI express card. The express card can be inserted into a PCI express slot of the notebook computer so that the notebook computer has the functions of wireless network (802.11 b/g) and Bluetooth transmission. In the other embodiments, the communication system  500  can be designed within a motherboard of a portable electronic device. 
         [0039]    Therefore, the first embodiment of the present invention can solve the interference problem by the two signals (wireless network signals and Bluetooth signals) in the conventional communication system. Furthermore, a communication system  600  provided by the preferred embodiment can reduce number of antennas through a switching method of the multiplier so that the design of the gap degree between the antennas can be simplified, and the interference phenomenon of the wireless network signals and the Bluetooth signals can be reduced so as to increase transmission efficiency. 
         [0040]      FIG. 6  illustrates a diagram of a communication system  600  according to a second embodiment of the present invention. The communication system  600  includes a wireless network module  610 , two signal quality enhancers  611  and  641 , a Bluetooth module  640 , a switch unit  650 , a first antenna  680 , and a second antenna  660 , where the wireless network module  610  includes a BB/MAC  620  and a FEM  630 , and the switch unit  650  includes control ends D and E, and transmission ends A, B, and C. 
         [0041]    The connections and functions of the components disclosed in the above-mentioned embodiment are similar to the first embodiment, except that the wireless network module  610  is coupled to the control end E of the switch unit  650  to transmit an active control signal  690  to the control end E of the switch unit  650 . 
         [0042]    As illustrated in  FIG. 6 , before the wireless network module  610  and the Bluetooth module  640  respectively transmit the wireless network signals  695  and the Bluetooth signals  696 , the transmission end B of the switch unit  650  may not be coupled to the transmission ends A and C. When the wireless network module  610  is transmitting the wireless network signals  695 , the wireless network module  610  will transmit the control signal  690  to the control end E of the switch unit  650  such that the transmission end B is coupled to the transmission end A and also the FEM  630  can be coupled to the second antenna  660  through the switch unit  650 . Thus the wireless network module  610  can transmit the wireless network signals  695  through the first antenna  680  or the second antenna  660 , in other words, the wireless network module  610  can determine whether the wireless networks signals  695  will be transmitted through the first antenna  680  or the second antenna  660  according to the reception of the first antenna  680  and the second antenna  660 . 
         [0043]    When the Bluetooth module  640  is transmitting the Bluetooth signals  696 , the Bluetooth module  640  will transmit a control signal  670  to the control end D of the switch unit  650  such that the transmission end C is coupled to the transmission end B of the switch unit  650 . Therefore the Bluetooth module  640  can be coupled to the second antenna  660  through the switch unit  650  to transmit the Bluetooth signals  696 . 
         [0044]    Please note that in this preferred embodiment, when the wireless network module  610  and the Bluetooth module  640  respectively transmit the wireless network signals  695  and the Bluetooth module  696  at the same time, the wireless network module  610  and the Bluetooth module  640  will respectively transmit the control signals  690  and  670  to the control ends E and D of the switch unit  650 . At this time, after the switch unit  650  receives the control signals  690  and  670 , the switch unit  650  executes the switch so that the transmission end B is coupled to the transmission end C, hence the Bluetooth module  640  can transmit the Bluetooth signal  696  through the second antenna  660 , and the wireless network module  610  can still transmit the wireless network signals  695  through the first antenna  680 . 
         [0045]    In other words, in this preferred embodiment, priority of the Bluetooth module  640  utilizing the second antenna  660  is higher than the wireless network module  610 . The reason for the design is that the main application of the Bluetooth module  640  is the transmission of voice signals, and the main application of the wireless network module  610  is the transmission of data. Also the priority of transmitting voice signals is usually higher than the priority of transmitting data in order to prevent the voice signals from being interrupted during broadcast. Therefore, the Bluetooth module  640  has a higher priority in utilizing the second antenna  660 . 
         [0046]    In other embodiments, other conditions are taken into consideration, such that the wireless network module  610  has a higher priority to utilize the second antenna  660 . Then if the switch unit  650  at the same time receives the control signals  690  and  670 , the switch unit  650  will couple the transmission end B to the transmission end A. 
         [0047]    Therefore the communication system  600  provided by the preferred embodiment can reduce the number of antennas through a switching method of the switch unit so that the design of the gap degree between the antennas can be simplified, and the interference phenomenon of the wireless network signals and the Bluetooth signals can be reduced. 
         [0048]      FIG. 7  illustrates a diagram of a communication system  700  according to a third embodiment of the present invention. The communication system  700  includes a wireless network module  710 , two signal quality enhancers  711  and  741 , a Bluetooth module  740 , a switch unit  750 , an antenna  760 , where the wireless network module  710  includes a BB/MAC  720  and a FEM  730 , and the switch unit  750  includes a control end D, and transmission ends A, B, and C. 
         [0049]    The connections and functions of the components disclosed in the above-mentioned embodiment are similar to the first embodiment, except that the design of the above-mentioned embodiment utilizes a single antenna design, therefore the wireless network module  710  and the Bluetooth module  740  are only coupled to the control end D of the switch unit  750 . Furthermore, in the initial stage (when the Bluetooth module  740  is not transmitting the Bluetooth signals  790 , and the Bluetooth module  740  is inactive), the transmission end A of the switch unit  550  is coupled to the transmission end B (the transmission C is not coupled to the transmission B). Hence the FEM  730  can be coupled to the antenna  760  through the switch unit  750 , therefore the wireless network module  710  can transmit the wireless network signals  780  through the antenna  760 . 
         [0050]    When the Bluetooth module  740  is transmitting the Bluetooth signals  790 , the Bluetooth module  740  will transmit a control signal  770  to the control end D of the switch unit  750  and the wireless network module  710 . After the switch unit  750  receives the control signals  770 , the switch unit  750  will couple the transmission end C to the transmission end B (at this time, the transmission end A is not coupled to the transmission end B). Furthermore, the control signal  770  at the same time also notifies the wireless network module  710  to temporarily stop transmitting the wireless network signals  780 . Whereby the Bluetooth module  740  can be coupled to the antenna  760  through the switch unit  750  to transmit the Bluetooth signals  790 . 
         [0051]    The wireless network module, the Bluetooth module, and the switch unit of the above-mentioned embodiment can be integrated within an expansion card. Please refer to  FIG. 8  for further explanation.  FIG. 8  illustrates a diagram of an expansion card according to a fourth embodiment of the present invention. 
         [0052]    As illustrated in  FIG. 8 , an expansion card  80  includes a wireless network module  810 , a Bluetooth module  840 , a switch unit  850 , and an interface unit  860 . In this embodiment, the expansion card  80  is a PCI Express card, while in other embodiments, the expansion card  80  can be a PCMCIA card or other types of expansion card. 
         [0053]    The above-mentioned wireless network module  810  is respectively coupled to the switch unit  850  and the interface unit  860 . The switch unit  850  is respectively coupled to the wireless network module  810 , the Bluetooth module  840 , and the interface unit  860 . 
         [0054]    The above-mentioned expansion card  80  is utilized for inserting into an expansion slot  910  of a portable electronic device  900 . A first antenna  960  and a second antenna  980  are installed on a monitor  920  of the portable electronic device  900 . The first antenna  960  and the second antenna  980  are installed on a top end of the monitor  920 , and the first antenna  960  and the second antenna  980  are coupled to the expansion slot  910 . In this embodiment, the portable electronic device  900  can be a laptop or notebook computer, a palmtop, a tablet PC, an origami, or a personal digital assistant (PDA). 
         [0055]    When the expansion card  80  is inserted into the expansion slot  910  of the portable electronic device  900 , the Bluetooth module  840  is coupled to the first antenna  960  through the switch unit  850 , the interface unit  860 , and the expansion slot  910 , whereby either the wireless network module  810  or the Bluetooth module  840  can transmit the Bluetooth signals or the wireless network signals through a switching method of the switch unit  850  and through the first antenna  960 . 
         [0056]    Furthermore, when the expansion card  80  is inserted into the expansion slot  910 , the wireless network module  810  is coupled to the second antenna  980  through the interface unit  860  and the expansion slot  910 , therefore the wireless network module  810  can transmit the wireless network signals through the second antenna  980 . When-the quality of the wireless network signals transmitted by the wireless network module  810  through the second antenna  980  is bad, the wireless network module  810  will output a control signal C 02  to the switch unit  850  to control the switching of the switch unit  850  so that the wireless network module  810  can transmit the wireless network signals through the first antenna  960 . 
         [0057]    Next, if the Bluetooth module  840  intends to transmit the Bluetooth signals through the first antenna  960 , then the Bluetooth module  840  will output a first control signal C 01  to the switch unit  850  to control the switching of the switch unit  850  so that the Bluetooth module  840  can transmit the Bluetooth signals through the first antenna  960 . Thus the wireless network module  810  can process the wireless networks through the second antenna  980 , and the Bluetooth module  840  can process the Bluetooth signals through the first antenna  960 . 
         [0058]    Through the design of this embodiment, the number of antennas can be reduced, and the portable electronic device  900  requires only the first antenna  960  and the second antenna  980  to be installed on each side on the top end of the monitor  920 . In this way, the positioning problem of the first antenna  960  and the second antenna  980  can be solved, and also the interference problem between the wireless signals can be solved. 
         [0059]    In conclusion, the communication system provided by the above-mentioned embodiment utilizes the switch unit to control the transmission and receiving of the antennas. Hence the number of antennas can be reduced, and also the interference phenomenon of the wireless network signals and the Bluetooth signals can be prevented. 
         [0060]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.