Abstract:
A system includes a first matching network having a first impedance and a second matching network having a second impedance, where the second impedance is different than the first impedance. The system further includes a switching connector having first and second switching positions, where when the switching connector is in the first switching position an input terminal is connected through the first matching network to a first antenna and where when the switching connector is in the second switching position the input terminal is connected through the second matching network to a second antenna and the first antenna is connected to ground.

Description:
TECHNICAL FIELD OF THE INVENTION 
     Implementations described herein relate generally to antenna matching networks and, more particularly, to an antenna connector for selectively switching a transmitter/receiver front end through either one of two different antenna matching networks. 
     BACKGROUND 
     To optimize conducted performance from a transmitter, receiver or transceiver front end module (FEM), a matching network (matching network A) is often used between the FEM and an external antenna. Because conducted performance is usually measured in a 50 ohm system, the matching network is typically optimized towards the 50 ohm load associated with the external antenna. Other antennas considered for use as an internal antenna, however, may have optimum radiation performance at a different impedance than 50 ohms. A typical solution to this problem is to place a different matching network (matching network B) in series after matching network A to try to match for optimum radiation performance. However, the restriction of including matching network A may, in most cases, decrease the power delivered to the internal antenna compared to if a match is made directly between the FEM and the internal antenna. 
     For example, as shown in  FIG. 1 , FEM  100  may connect to external antenna  110  through matching network A  120  via a connector  130  placed in a first switching position  140 . FEM  100  may connect to internal antenna  150  through matching network A  120  and matching network B  160  via connector  130  placed in a second switching position  170 . Since matching network A  120  has been optimized towards the 50 ohm load of the external antenna, optimization of matching network B towards the load of internal antenna  150 , that is different than 50 ohms, results in a decrease of power delivery to internal antenna  150 . 
     SUMMARY 
     According to one aspect, a system may include a module associated with a transmitter, receiver or transceiver. The system may further include a connector configured to selectively couple the module through a first matching network to a first antenna or through a second matching network to a second antenna, where the first matching network is different than the second matching network and wherein the first antenna is different than the second antenna. 
     Additionally, the connector may include a double pole, double throw switch for selectively coupling the module through the first matching network to the first antenna or through the second matching network to the second antenna. 
     Additionally, the first antenna may have an impedance of 50 ohms. 
     Additionally, the second antenna may have an impedance that is different than 50 ohms. 
     Additionally, the first matching network may be optimized towards a 50 ohm load. 
     Additionally, the second matching network may be optimized towards a load that has an impedance other than 50 ohms. 
     Additionally, the system may include a radiotelephone. 
     Additionally, when the connector couples the module through the second matching network to the second antenna, the connector couples the first antenna to ground. 
     Additionally, when the connector couples the module through the first matching network to the first antenna, the connector de-couples the module from the second antenna. 
     According to another aspect, a system may include a first matching network and a second matching network, where the first matching network is different than the second matching network. The system may further include a switching connector having first and second switching positions, where when the switching connector is in the first switching position an input terminal is connected through the first matching network to a first antenna and where when the switching connector is in the second switching position the input terminal is connected through the second matching network to a second antenna and the first antenna is connected to ground. 
     Additionally, the first matching network may be optimized towards a 50 ohm load. 
     Additionally, the second matching network may be optimized towards a load that has an impedance other than 50 ohms. 
     Additionally, the first antenna may have an impedance of 50 ohms and the second antenna may have an impedance of other than 50 ohms. 
     Additionally, a transmitter, receiver or transceiver may be connected to the input terminal. 
     Additionally, the switching connector may include a double pole, double throw switch. 
     Additionally, the system may include a radiotelephone. 
     According to a further aspect, a switching system may include a first single pole double throw switch and a second single pole double throw switch, where the second switch is ganged to the first switch and where when the first and second switches are in a first switching position, a transceiver circuit is connected to a first antenna via a first antenna matching network and when the first and second switches are in a second switching position, the transceiver circuit is connected to a second antenna via a second antenna matching network and the first antenna is connected to ground. 
     Additionally, the first antenna may be different than the second antenna and the first matching network may be different than the second matching network. 
     Additionally, the first antenna matching network may be optimized towards a 50 ohm load. 
     Additionally, the second antenna matching network may be optimized towards a load that has an impedance other than 50 ohms. 
     Additionally, the first antenna may have an impedance of 50 ohms and the second antenna may have an impedance of other than 50 ohms. 
     Additionally, the system may reside in a radiotelephone. 
     According to an additional aspect, a device may include a module associated with a transmitter, receiver or transceiver. The device may further include means for selectively coupling the module through a first antenna matching network to a first antenna or through a second antenna matching network to a second antenna, where the first antenna matching network may be different than the second antenna matching network and where the first antenna may be different than the second antenna. 
     It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps, components or groups but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, explain the invention. In the drawings, 
         FIG. 1  illustrates an existing switching system for switching between an external antenna and an internal antenna; 
         FIG. 2A  illustrates a two-way connector according to an exemplary implementation placed in a first switching position which connects a front end module to an external antenna via a first matching network (A); 
         FIG. 2B  illustrates the two-way connector of  FIG. 2A  placed in a second switching position which connects the front end module to an internal antenna via a second matching network (C) and also connects the external antenna to ground; 
         FIG. 3A  illustrates one physical implementation of the two-way connector of  FIG. 2A  in which the two-way connector is in a first switching position; 
         FIG. 3B  illustrates another view of the two-way connector of  FIG. 3A  that depicts the front end module being connected to the external antenna through matching network A; 
         FIG. 4A  illustrates the physical implementation of  FIG. 3A  of the two-way connector in which the two-way connector is in a second switching position; 
         FIG. 4B  illustrates another view of the two-way connector of  FIG. 4A  that depicts the front end module being connected to the internal antenna through matching network C; 
         FIG. 5  depicts use of the two-way connector of  FIGS. 2A and 2B  within a communications device. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The following detailed description of the invention refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following detailed description does not limit the invention. 
     Exemplary embodiments use a two-way connector for selectively coupling a transmitter, receiver or transceiver to an external antenna through a matching network that is optimized to a load of the external antenna, or to an internal antenna through a different matching network that is optimized to a load of the internal antenna. When the transmitter, receiver, or transceiver is coupled to the internal antenna, it may be only coupled through the matching network that is optimized to the load of the internal antenna, and not through the matching network optimized to the load of the external antenna. The two-way antenna connector of exemplary embodiments, thus, provides a way to present optimized matching networks both to an external (50 ohm) load and to the internal antenna directly from an output of the transmitter, receiver or transceiver. Using two different matching networks means that both conducted and radiated performance can be optimized, thus, enabling maximum power delivery to both the internal and external antenna. 
     Exemplary Antenna Matching System 
       FIG. 2A  illustrates an antenna matching system  200  for use in selectively connecting a transmitter/receiver/transceiver to a first antenna via a first antenna matching network or to a second antenna via a second antenna matching network. Antenna matching system  200  may connect a front end module  210 , using a two-way connector  220 , through matching network A  230  to an external antenna  240 , or through matching network C  250  to an internal antenna  260 . Front end module  210  may include circuitry that resides in the front end of a transmitter, receiver or transceiver unit. Matching network A  230  may include network circuitry that optimizes conducted performance to the load of external antenna  240 . External antenna  240  may have, for example, a 50 ohm impedance. Matching network C  250  may include network circuitry that optimizes conducted performance to the load of internal antenna  260 . Internal antenna  260  may have an impedance that is different than the impedance of external antenna  240 . The optimum radiation performance of internal antenna  260 , thus, occurs at a different impedance than external antenna  240 . 
     As shown in  FIG. 2A , two-way connector  220  may include a double pole double throw switch (e.g., two single pole double throw switches ganged together) that switches a connection from FEM  210  through matching network A  230  to external antenna  240 , and for opening a connection from FEM  210  through matching network C  250  to antenna  260 . The arrows in  FIG. 2A  illustrate the flow of current to/from FEM  210  and external antenna  240  when two-way connector  220  is in this first switching position. 
       FIG. 2B  illustrates the use of two-way connector  220  for switching a connection from FEM  210  through matching network C to antenna  260 , for opening a connection from FEM  210  through matching network A  230  to external antenna  240 , and for connecting external antenna  240  to ground  270 . External antenna  240  is grounded in this switching position to avoid electrostatic discharge (ESD) problems. The arrows in  FIG. 2B  illustrate the signal transmission paths to/from FEM  210  and antenna  260  when two-way connector  220  is in this second switching position. 
     Exemplary Two-Way Connector 
       FIG. 3A  illustrates a physical configuration of one exemplary implementation of two-way connector  220 . In the exemplary implementation shown, two-way connector  220  may include a center connector  300 , a first connector  305 , a second connector  2   310 , a third connector  315 , a fourth connector  320 , an upper spring  325 , a lower spring  330  and a dielectric insulator  335 . Center connector  300 , connector  1   305 , connector  2   310 , connector  3   315  and connector  4   320  may include an electrically conductive material(s). Dielectric insulator  335  may include an elastic, electrically non-conductive material that insulates connector  1   305  from connector  3   315 , and which may bend along with a displacement of upper spring  325 . 
     As depicted in  FIG. 3A , center connector  300  may include a disc-shaped electrical contact formed on a cylindrical shaft that may move vertically up (i.e., away from connector  3   315 ) and down (towards connector  3   315 ). Center connector  300  may move up to contact a two-way connector housing (not shown in  FIG. 3A ) which is grounded or move down to contact connector  3   315  via a contact point  340 . Moving center connector  300  downwards also moves connector  1   305 , via displacement of upper spring  325 , into contact with connector  4   320  via a contact point  350 , as shown in  FIG. 3A . Moving center connector  300  downwards also moves connector  1   305 , via displacement of upper spring  325 , to break contact with connector  2   310 , as further shown in  FIG. 3A .  FIG. 3A  illustrates two-way connector  210  in a first switching position in which center connector  300  has been moved downwards to contact connector  3   315  via contact point  340 , further causing connector  1   305  to move into contact with connector  4   320  via contact point  350 , and also causing connector  1   305  to break contact with connector  2   310 . 
       FIG. 3B  is another view of two-way connector  220  depicting center connector  300  moved downwards such that connector  1   305  contacts with connector  4   320  and contact between connector  1   305  and connector  2   310  is broken. As shown in  FIG. 3B , when two-way connector  220  is in this switching position, FEM  210  connects to matching network A  230  via connector  1   305  and connector  4   320 , and matching network A  230  connects to external antenna connector  240  via connector  3   315  and center connector  300 . 
       FIG. 4A  illustrates two-way connector  220  in a second switching position in which center connector  300  has been moved upwards to contact ground contact  270 , further causing connector  1   305  to move into contact with connector  2   310  via contact point  400 , and causing connector  1   305  to break contact with connector  4   320 . 
       FIG. 4B  is another view of two-way connector  220  depicting center connector  300  moved upwards such that center connector  300  has contacted ground contact  270 , connector  1   305  has moved into contact with connector  2   310  via contact point  400 , and connector  1   305  has broken contact with connector  4   320 . As shown in  FIG. 4B , when two-way connector  220  is in this switching position, FEM  210  connects to matching network C  250  via connector  1   305  and connector  2   310 , and external antenna connector  240  connects to ground contact  270  via center connector  300 . 
     Exemplary Communication Device Using Two-Way Connector 
       FIG. 5  illustrates a communication device  500  that uses two-way connector  220 . Communication device  500  may include any type of radio-communication device. For example, in one implementation, communication device  500  may include a cellular radiotelephone. 
     As shown, device  500  may include a front end module  210  of a transceiver  510  that is connected to two-way connector  220 . Two-way connector  220  may further be connected to matching network A, to ground  270  and to matching network C  250 . When two-way connector  220  is in the first switching position shown in  FIG. 2A , front end module  210  may be coupled to external antenna  240  via matching network A  230 . When two-way connector  220  is in the second switching position shown in  FIG. 2B , front end module  210  may be coupled to internal antenna  260  via matching network C  250 , and external antenna  240  may be connected to ground  270 . 
     CONCLUSION 
     A two-way connector, as described herein, selectively couples a transmitter, receiver or transceiver to an external antenna through a matching network that is optimized to a load of the external antenna, or to an internal antenna through a different matching network that is optimized to a load of the internal antenna. The two-way antenna connector, thus, presents optimized matching networks to an external antenna that has an impedance of, for example, 50 ohms and to an internal antenna that has a different impedance than the external antenna. The two-way connector enables the use of two different antenna matching networks such that both conducted and radiated performance are matched to optimum, enabling maximum power delivery to both the internal and external antenna. 
     The foregoing description of implementations provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings, or may be acquired from practice of the invention. 
     No element, act, or instruction used in the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.