PATENT DOCUMENT

Publication Number: US-8682403-B2
Application Number: US-201213439582-A
Country: US
Kind Code: B2

Title: Filter having impedance matching circuits

Abstract:
A filter package is provided with a support structure, a filter device having terminals, impedance matching circuits formed on the support structure and electrically connected to at least some of the terminals of the filter device, and at least one electrical ground structure electrically connected to the impedance matching circuits. Moreover, the filter package has an outer housing to contain the support structure, filter device impedance matching circuits, and at least one ground structure.

Claims:
What is claimed is: 
     
       1. A filter, comprising:
 a support structure; 
 a filter element having plural terminals; 
 at least one electrical ground structure, the electrical ground structure comprising a ground plane supported by the support structure, the ground plane having openings; 
 impedance matching circuits electrically coupled between at least some of the plural terminals of the filter device and the ground plane, the impedance matching circuits comprising impedance matching lines supported by the support structure in the openings in the ground plane so that that impedance matching lines and the ground plane are substantially in a common plane; and 
 an outer housing containing the support structure, the filter element, the impedance matching circuits, and the at least one electrical ground structure. 
 
     
     
       2. The filter of  claim 1 , wherein the support structure comprises a substrate carrier mounted on a base provided inside the outer housing, and wherein the impedance matching circuits are provided on the substrate carrier. 
     
     
       3. The filter of  claim 1 , wherein the support structure comprises an internal surface of the outer housing, and wherein the impedance matching circuits are provided on the internal surface of the outer housing. 
     
     
       4. The filter of  claim 1 , further comprising:
 input and output transmission lines on the support structure to provide an input signal to, and output signal from, the filter device; and 
 leadframe pads electrically connected to the input and output transmission lines and to the electrical ground structure. 
 
     
     
       5. The filter of  claim 1 , wherein the impedance matching lines are on a surface of the support structure and electrical lengths of the impedance matching lines are tuned for corresponding ones of the at least some plural terminals. 
     
     
       6. The filter of  claim 5 , wherein the impedance matching lines comprise bond wires to ground, lengths of the bond wires being tuned for corresponding ones of the at least some plural terminals. 
     
     
       7. The filter of  claim 1 , wherein at least one of the impedance matching lines is connected to a discrete matching component. 
     
     
       8. The filter of  claim 7 , wherein the discrete matching component comprises at least one of a capacitance and an inductance. 
     
     
       9. The filter of  claim 1 , wherein at least one of the impedance matching circuits comprises a transmission line formed on the support structure. 
     
     
       10. The filter of  claim 1 , wherein the outer housing is mounted to at least one of a substrate and a circuit board. 
     
     
       11. A method of making a filter, comprising:
 providing a support structure; 
 providing a filter element having plural terminals; 
 providing at least one electrical ground structure, the electrical ground structure comprising a ground plane supported by the support structure, the ground plane having openings; 
 providing impedance matching circuits electrically coupled between at least some of the plural terminals of the filter device and the ground plane, the impedance matching circuits comprising impedance matching lines supported by the support structure in the openings in the ground plane so that that impedance matching lines and the ground plane are substantially in a common plane; and 
 providing an outer housing containing the support structure, the filter element, the impedance matching circuits, and the at least one electrical ground structure. 
 
     
     
       12. The method of  claim 11 , wherein the support structure comprises a substrate carrier mounted on a base provided inside the outer housing, and wherein the impedance matching circuits are provided on the substrate carrier. 
     
     
       13. The method of  claim 11 , wherein the support structure comprises an internal surface of the outer housing, and wherein the impedance matching circuits are provided on the internal surface of the outer housing. 
     
     
       14. The method of  claim 11 , further comprising:
 providing input and output transmission lines on the support structure to provide an input signal to, and output signal from, the filter device; and 
 electrically connecting leadframe pads to the input and output transmission lines and to the electrical ground structure. 
 
     
     
       15. The method of  claim 11 , wherein the impedance matching lines are on a surface of the support structure and electrical lengths of the impedance matching lines are tuned for corresponding ones of the at least some plural terminals. 
     
     
       16. The method of  claim 15 , wherein the impedance matching lines comprise bond wires to ground, comprising tuning lengths of the bond wires for corresponding ones of the at least some plural terminals. 
     
     
       17. The method of  claim 11 , wherein at least one of the impedance matching lines is connected to a discrete matching component. 
     
     
       18. The method of  claim 11 , wherein the discrete matching component comprises at least one of a capacitance and an inductance. 
     
     
       19. The method of  claim 11 , wherein at least one of the impedance matching circuits comprises a transmission line formed on the support structure. 
     
     
       20. The method of  claim 11 , further comprising mounting the outer housing to at least one of a substrate and a circuit board.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of and claims priority to U.S. patent application Ser. No. 13/007,708 filed on Jan. 17, 2011, published as US 2011/0109403 A1, which is a continuation of U.S. patent application Ser. No. 11/985,812 filed Nov. 16, 2007, issued as U.S. Pat. No. 8,060,156, which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/866,118 filed Nov. 16, 2006, and U.S. Provisional Application No. 60/867,272 filed Nov. 27, 2006, which are all hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The invention relates generally to a filter for use in a wireless communications device. 
     BACKGROUND 
     Wireless communications devices, such as wireless terminals or wireless base stations, include wireless transceivers to perform wireless communications, such as radio frequency (RF) communications. A wireless transceiver commonly includes one or more filters, such as a band pass filter, a band reject filter, or other types of filters. A band reject filter is used to reject or attenuate signals having frequencies within a particular band, while allowing frequencies outside the band to pass through. A band pass filter, on the other hand, allows frequencies within a band to pass through, while rejecting or attenuating signals having frequencies outside the band. Other types of filters include low pass filters, high pass filters, and so forth. 
     Certain types of high performance filters use external impedance matching circuits that are connected to terminals of the filter. An “external” matching circuit refers to a matching circuit that is located outside a package of the filter. An issue associated with using external matching circuits is that impedances associated with electrical connecting structures between electronic circuitry inside the filter package and the external matching circuits can limit effectiveness of the filter at higher frequencies. Therefore, many conventional filters may not be effectively used in high-frequency wireless communications devices. Moreover, due to issues associated with external matching circuits, some high performance filters may simply omit the use of matching circuits for some terminals of the filters, which can come at the expense of reduced filter performance. 
     SUMMARY 
     In general, a filter package has an outer housing, a support structure, and a filter device having plural terminals. Matching circuits formed on the support structure are electrically connected to at least some of the plural terminals of the filter device. The matching circuits are electrically connected to at least one electrical ground structure. The support structure, filter device, matching circuits, and at least one ground structure are contained in the outer housing. 
     Other or alternative features will become apparent from the following description, from the drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of a substrate assembly for use in a filter package with internal matching circuits, according to an embodiment. 
         FIG. 1B  is a bottom view of the substrate assembly of  FIG. 1A . 
         FIGS. 2 and 3  are cross-sectional views of different embodiments of a filter package. 
         FIGS. 4A-4B ,  5 A- 5 B,  6 , and  7  illustrate other embodiments of substrate assemblies used in filter packages. 
         FIG. 8  is a cross-sectional view of a multi-layer substrate assembly, according to another embodiment. 
         FIG. 9  is a schematic view of a filter package on a circuit board, according to an embodiment. 
         FIG. 10  is a block diagram of an example arrangement including a mobile station and a base station in a wireless communications network, where at least one of the mobile station and base station can include a filter package according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous details are set forth to provide an understanding of some embodiments. However, it will be understood by those skilled in the art that some embodiments may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible. 
     In accordance with some embodiments, a filter package includes an outer housing containing a filter device and internal impedance matching circuits that are electrically connected to the filter device. The filter device can be a “high frequency” filter device in some example implementations. A “high-frequency” filter device is able to operate at relatively high frequencies, such as in the gigahertz (GHz) range. As examples, such high-frequency filter devices include surface acoustic wave (SAW) filter devices, bulk acoustic wave (BAW) filter devices, and other types of filter devices. In some examples, the filter devices are designed to be band rejection filter devices, in which signals having frequencies within a band of frequencies are rejected (or attenuated), whereas signals having frequencies outside the band of frequencies are accepted (or allowed to pass through the filter device). Another type of filter device is a band pass filter device, in which signals having frequencies within the band are allowed to pass through the filter device, whereas signals having frequencies outside the band are rejected (or attenuated). In other implementations, other types of filter devices can be employed, such as low pass filter devices, high pass filter devices, and so forth. 
     The filter package can be used in a wireless communications device or in some other type of electronic device. 
     In accordance with some embodiments, internal impedance matching circuits contained within the outer housing of a filter package provide for higher quality impedance matching and allow for more effective operations at high frequencies (e.g., in the GHz range such as 1 GHz or greater). The internal impedance matching circuits can be in the form of matching transmission lines or discrete matching components. The matching circuits are electrically connected to at least one ground structure within the filter package outer housing. By providing internal matching circuits that can be connected to an internal ground structure, external matching components (located outside the filter package outer housing) can be avoided or reduced. Providing internal matching circuits allows for electrical connection structures between the inside of the filter package and external matching components to be omitted or reduced, which is beneficial since such electrical connection structures tend to introduce discontinuity, as well as parasitic and resistive losses that may adversely affect filter device performance at higher frequencies. For example, resistances introduced by such electrical connection structures can cause unacceptable passband loss. Also, by providing matching circuits internally within the filter package and avoiding or reducing external matching components, the footprint taken up by the filter package and associated circuitry can be reduced to provide for more efficient usage of space of a circuit board on which the filter package is to be mounted. Also, by reducing the number of external matching components that have to be electrically coupled to the filter device, manufacturing yield of circuit boards can be improved (by reducing the number of components on the circuit board) and test repeatability (as well as performance) can be improved. This can lead to enhanced efficiencies during mass production or manufacture. 
       FIG. 1A  is a perspective view of a substrate assembly that can be provided within a filter package according to an embodiment. The substrate assembly depicted in  FIG. 1A  include a substrate carrier  110  (or other type of support structure) on which is mounted a filter device  102 . In the embodiment of  FIG. 1A , the bottom surface of the filter device  102  is mounted on an upper surface of the substrate carrier  110 . In different embodiments, other forms of attachment between the filter device  102  and the substrate carrier  110  can be provided, as discussed further below. 
     An upper surface  104  of the filter device  102  provides various contact terminals (where each contact terminal is formed of an electrically conductive material) that are electrically connected to internal nodes of the filter device  102 . In an alternative implementation, the contact terminals can be provided on other parts of the filter device  102 . Two of the contact terminals provided on the upper surface  104  of the filter device  102  are an input terminal and an output terminal that are electrically connected by bond wires  126  and  128 , respectively, to an input transmission line  112  and an output transmission line  114 , respectively. The input transmission line  112  is electrically connected to receive an input signal from outside the filter package, and the output transmission line  114  is to provide an output signal (after filtering applied by the filter device  102  on the input signal) to the outside of the filter package. In the embodiment of  FIG. 1A , the transmission lines  112  and  114  can be much shorter and closer to bond wires  126  and  128  to further minimize resistive losses. In a typical implementation, the filter package is mounted on a circuit board. The input and output signals are signals provided over conductive traces of the circuit board. 
     The upper surface  104  of the filter device  102  also has other contact terminals that are electrically connected by bond wires  122  to corresponding matching transmission lines  106 , and by bond wires  124  to corresponding matching transmission lines  107 . In the depicted embodiment, the matching transmission lines  106  and  107  are provided on the upper surface of the substrate carrier  110  (as are the input and output transmission lines  112 ,  114 ). Typically these matching transmission lines are relatively short, to provide relatively small values of inductance, and to provide a relatively high quality factor (e.g., low resistive loss can be important for reducing pass band losses). The matching transmission lines  106 ,  107  can be any one of microstrip lines (where a microstrip line is a conducting strip separated from a ground plane by a dielectric layer), striplines (where a stripline is a conducting strip sandwiched between two parallel ground planes separated from the conducting strip by dielectric), coplanar waveguide lines (a conductor separated by a pair of coplanar ground lines), or other types of transmission lines. 
     As discussed further below, the transmission lines  106 ,  107  can also (or alternatively) be provided on the bottom surface of the substrate carrier  110  in other implementations. As yet another alternative, the substrate carrier  110  can be omitted with the transmission lines formed on an inner surface of the filter package outer housing. Alternatively, instead of using matching transmission lines, discrete components can be used instead to provide impedance matching. Examples of impedance matching discrete components include resistors, capacitors, and inductors. More generally, the matching transmission lines and/or matching discrete components are referred to as “matching circuits,” which are generally circuits (either in the form of transmission lines or in the form of discrete components, or both) that are used to provide impedance matching. The matching circuits provide relatively small high-Q matching inductances that are useful for reducing pass band loss. 
     Although not depicted in  FIG. 1A , note that at least some of the matching transmission lines  106 ,  107  can also be electrically connected to discrete matching components, if desired. 
     As further depicted in  FIG. 1A , a ground plane  108  is provided on the upper surface of the substrate carrier  110 , with the ground plane  108  having openings to receive the transmission lines  106 ,  107  and the input and output transmission lines  112 ,  114 . Note that gaps are provided between sides of the transmission lines  106 ,  107 ,  112 ,  114 , and the ground plane  108 . To electrically connect the matching transmission lines  106 ,  107  to the ground plane  108 , bond wires  130  (one set of bond wires  130  is labeled  130 A) and  131  (one set of bond wires  131  is labeled  131 A) can be used. Shunting the transmission lines  106 ,  107  to ground using the bond wires  130 ,  131  of  FIG. 1A  allows for provision of high-Q inductors. 
     The bond wires  130  electrically connect the matching transmission lines  106  to the ground plane  108 , whereas the bond wires  131  electrically connect the transmission lines  107  to the ground plane  108 . As depicted in  FIG. 1A , each matching transmission line  106 ,  107  is electrically connected by a corresponding pair of bond wires to the ground plane  108 . In different implementations, each transmission line  106 ,  107  can be electrically connected by just one bond wire to the ground plane  108 , or alternatively, by more than two bond wires to the ground plane  108 . 
     The connection point of a set of one or more bond wires to a matching transmission line  106  or  107  can be varied to achieve a desired electrical length of the transmission line. By moving the connection point of the set of one or more bond wires to the matching transmission line  106  or  107  further away from the filter device  102 , a longer electrical length of the transmission line is provided. On the other hand, by moving the connection point of the set of one or more bond wires to the matching transmission line closer to the filter device, a shorter length of the transmission line is provided. Effectively, by varying the electrical length of the matching transmission line, the amount of inductance that is electrically connected to a corresponding contact terminal of the filter device is varied. Each transmission line  106  or  107  can be considered a shunt stub that is tunable to a specific electrical length by shorting the transmission line to ground at a desired location of the transmission line. In the example of  FIG. 1A , note that the connection point of the pair of bond wires  130 A to the corresponding matching transmission line  106  is closer to the filter device  102  than the connection point of the pair of bond wires  131 A to the corresponding transmission line  107 . Therefore, the electrical length of the transmission line  106  connected to bond wires  130 A is shorter than the electrical length of the transmission line  107  connected to bond wires  131 A. Note that in the example of  FIG. 1A , the electrical lengths of the transmission lines  106 ,  107  correspond to physical lengths shorter than the physical lengths of the transmission lines  106 ,  107 , due to locations of the connection points of the bond wires  130 ,  131  away from the ends of the transmission lines. 
     During manufacturing of the filter package, the locations of the connection points of the bond wires to different matching transmission lines can be tuned according to the impedance matching needs of the different contact terminals of the filter device  102 . Such tuning can provide more effective matching circuits to improve performance of the filter package. By using internal matching circuits according to some embodiments, filter performance can be optimized for various internal nodes of the filter device. The impedance matching for the contact terminals of the filter device can be performed inside the filter package, close to the filter device, such that a smaller resistive loss and less inherent parasitic are associated with the matching circuits and filter package. Moreover, the impedance matching can be performed with high accuracy and high repeatability since the electrical lengths of matching transmission lines can be tuned for different contact terminals of the filter device. 
     The ground plane  108  and the transmission lines  106 ,  107  can be formed on the upper surface of the substrate carrier  110  by depositing an electrically conductive layer on the upper surface of the substrate carrier  110  and etching the deposited electrically conductive layer to provide the ground plane  108 , transmission lines  106 ,  107 , and transmission lines  112 ,  114 . In other implementations, other techniques of forming the ground plane  108  and transmission lines  106 ,  107 ,  112 , and  114  can be used. 
     Note that the substrate carrier  110  can be formed of a dielectric material (that is electrically insulating), such as ceramic or the like. 
       FIG. 1B  shows the bottom view of the substrate carrier  110  of  FIG. 1A , where the bottom view has a ground plane  116  with cutouts  117 A and  117 B to allow for an input contact pad  118  and an output contact pad  120  provided on the bottom surface of the substrate carrier  110 . The input contact pad  118  and the output contact pad  120  are electrically connected to electrically conductive structures (depicted in  FIGS. 2 and 3  and discussed below) to allow for the input and output pads  118 ,  120  to receive and transmit input and output signals, respectively. The small circles in  FIG. 1B  represent vias to interconnect the input contact pad  118 , the output contact pad  120 , and the ground plane  116 , to the input transmission line  112 , output transmission line  114 , and ground plane  108 , respectively. 
     The ground plane  116  and the input and output contact pads  118 ,  120  can be formed by depositing an electrically conductive layer on the lower surface of the substrate carrier  110 , and then etching the deposited electrically conductive layer to form the ground plane  116  and input and output contact pads  118 ,  120 . 
       FIG. 2  shows the substrate assembly depicted in  FIGS. 1A-1B  provided in a chamber  200  defined by an outer housing of the filter package. The outer housing includes side walls  202 , a bottom segment  204 , and a top cap  206  (or other covering structure). The outer housing can be formed of an electrically insulating material such as ceramic or the like. During manufacture of the filter package, the substrate assembly that includes the substrate carrier  110  and the filter device  102  is first provided into the chamber  200  of the outer housing. The input and output contact pads  118 ,  120  on the bottom surface of the substrate carrier  110  are electrically connected to package interconnect structures  210  and  212 , respectively, which extend through the lower segment  204  of the outer housing to electrically connect to external pads  214 ,  216 , respectively. The package interconnect structures can include vias (vertical interconnect structures) and an internal metal layer (horizontal interconnect structure). Note that the base  208  provided by the bottom segment  204  can provide connection pads corresponding to the contact pads  118 ,  120  of the substrate carrier  110 . The external pads  214 ,  216  are electrically contacted to external electrically structures, such as electrical structures provided on a circuit board. The ground plane  116  can be attached to the housing base ground area with solder reflow or conductive epoxy or the like. The input contact pad  118  and the output contact pad  120  can also be attached to housing base pads which are connected to the external pads  214  and  216 . 
     Once the substrate assembly is positioned on a base  208  provided in the chamber  200  of the outer housing, and the electrical connection has been made between the input and output pads  118 ,  120  and the package interconnect structures  210 ,  212 , the top cap  206  can be attached to the side walls  202  of the outer housing. The top cap  206  can be adhesively attached, or attached by some other attachment or bonding mechanism, to the side walls  202  of the outer housing. Once assembled, as depicted in  FIG. 2 , the outer housing and the substrate assembly including the substrate carrier  110  and filter device  102  form the filter package depicted in  FIG. 2 . Note that the substrate assembly is completely enclosed by the outer housing made up of the top cap  206 , side walls  202 , and lower segment  204 . 
       FIG. 3  shows a slightly different embodiment of the filter package. The filter package of  FIG. 3  uses a different mounting mechanism between the substrate assembly and the base  208  of the lower segment  204  of the outer housing. In  FIG. 3 , the mounting mechanism is in the form of metal or solder bumps  240  that are electrically connected to package interconnect structures  210 ,  212  ( FIG. 2 ). In the  FIG. 3  embodiment, a matching transmission line  250  is depicted as being provided on the bottom side of the substrate carrier  110 . Providing matching transmission line(s) on both sides of the substrate carrier  110  allows for miniaturization or reduction in size of the substrate assembly so that the filter package can be made even smaller. 
     As noted above, the substrate carrier  110  can be omitted in other implementations, with the filter device  102  provided directly on the base  208  of the outer housing of the filter package. In such an implementation, the matching transmission lines (similar to  106 ,  107 ) can be formed on the base  208 . 
     In a variant of the embodiments discussed above, the input and output transmission lines  112  and  114  can be electrically connected by bond wires to leadframe pads of the package. Also, it is possible that the ground plane  108  can be connected by bond wires to ground leadframe pads of the package. 
       FIGS. 4A and 4B  show a variation of the substrate assembly depicted in  FIGS. 1A-1B , where common reference numerals are used to identify common elements. In  FIGS. 4A and 4B , a cavity  300  is provided in or through the substrate carrier  110 A, such that the filter device  102  can fit inside the cavity  300 . The cavity  300  can extend all the way through the substrate carrier  110 A, or alternatively, the cavity  300  can be a recess that does not extend all the way through the substrate carrier  110 A. By providing the cavity  300 , the filter device is at least slightly embedded inside the substrate carrier  110  such that the upper surface  104  of the filter device  102  is closer to the upper surface of the substrate carrier  110 A. This can reduce the length of the bond wires  122 ,  124 ,  126 ,  128  used to electrically connect the contact terminals of the filter device  102  to the corresponding transmission lines  106 ,  107 ,  112 ,  114  on the substrate carrier  110 A. Reducing the length of the bond wires allows for reduced inductances, which may improve high-frequency performance of the filter device  102 . 
       FIGS. 5A-5B  illustrate a variation of the embodiment of  FIGS. 4A-4B . In  FIGS. 5A-5B , instead of using bond wires  130 ,  131  to electrically connect matching transmission lines  106 ,  107  to the ground plane  108 , the  FIG. 5A  embodiment instead directly connects an end portion of matching transmission lines  400 ,  401  to the ground plane  108 . As depicted in  FIG. 5A , end portions  402  of corresponding matching transmission lines  400  are electrically contacted to the ground plane  108 . Similarly, end portions  404  of corresponding matching transmission lines  401  are electrically contacted to the ground plane  108 . The lengths of the matching transmission lines  400 ,  401  can be varied during the manufacturing process of the substrate assembly depicted in  FIG. 5A  to provide different electrical lengths for matching inductances electrically connected to corresponding contact terminals of the filter device  102 . Note that in this embodiment, the electrical lengths of the transmission lines  400 , 401  are proportional to the physical lengths of the transmission lines  400 ,  401 . 
     The benefit of using the  FIGS. 5A-5B  embodiment is that bond wires  130 ,  131  do not have to be used, which can improve manufacturing yield. 
       FIG. 6  is a top view of a substrate assembly including a substrate carrier  501  according to another embodiment. In  FIG. 6 , matching transmission lines  500  are provided for connection to corresponding contact terminals on the upper surface of the filter device  102 . Bond wires electrically connecting the matching transmission lines  500  to the filter device  102  and to the ground plane  108  are not depicted for purposes of clarity. In addition,  FIG. 6  shows that input and output transmission lines  502  and  504  are further electrically connected to discrete components that are used for impedance matching for the transmission lines  502 ,  504 . In the example of  FIG. 6 , the input transmission line  502  is electrically connected to matching discrete components  506  and  507 , which are both interconnected between the transmission line  502  and the ground plane  508 . Similarly, the output transmission line  504  is electrically connected to matching discrete components  508 ,  509 , which are both interconnected between the transmission line  504  and the ground plane  108 . The discrete components can be implemented with one or more devices, such as capacitors, resistors, inductors, and so forth. Note that input transmission line  502  and output transmission line  504  may also optionally each include an intermediate discrete component between matching discrete components  506  and  507  or between matching discrete components  508  and  509 . 
     Vias  510  and  512  are provided on corresponding transmission lines  502  and  504  to allow for the transmission lines  502 ,  504  to be electrically connected to input and output contact pads on the other side of the substrate carrier  501 . Note that the bottom side of the substrate carrier  501  can have structures similar to that depicted in  FIG. 1B  in one implementation. 
     Although not depicted in  FIG. 6 , note that at least some of the matching transmission lines  500  can also be electrically connected to discrete matching components, if desired. 
       FIG. 7  shows the bottom view of a carrier structure  501  according to another embodiment. Note that the structures depicted in the bottom view of  FIG. 7  can be used in conjunction with the structures in the top view of  FIG. 6 , or alternatively, can be used with a different arrangement on the upper surface of the substrate carrier (such as in an arrangement where matching transmission lines  500  are omitted). 
     The bottom view depicted in  FIG. 7  shows that matching transmission lines  520  can also be provided on the bottom surface of the substrate carrier  501 . These matching transmission lines  520  are electrically connected by vias  522  to corresponding electrical structures  524  ( FIG. 6 ) on the upper surface ( FIG. 6 ) of the substrate carrier  501 . 
       FIG. 8  shows a cross-sectional view of a substrate assembly according to another embodiment. In the example of  FIG. 8 , two dielectric layers  550  and  552  are provided, with an electrically conductive layer  554  provided on the top surface, an electrically conductive layer  558  provided between the dielectric layers, and an electrically conductive layer  556  provided on the bottom surface. To electrically connect conductive structures on the upper layer  554  and the bottom layer  558 , vias  560  can be used. The upper and lower conductive layers  554 ,  556 , as well as the intermediate electrically conductive layer  558 , can be used to implement transmission lines and/or ground planes. 
       FIG. 9  shows an example filter package  600  provided on a circuit board  602 . As depicted in  FIG. 9 , a substrate carrier  110  with the filter device  102  (e.g., in the form of an acoustic or microelectromechanical systems die) is provided inside the package  600 . 
     The filter device  102  includes various internal components  604  (e.g., resonators) and internal nodes  605  that are connected to contact terminals  606 ,  608 ,  610 ,  612 , and  614 . A pad or contact point  620  on the circuit board  602  provides the input signal to the filter package  600 , while a pad or contact point  622  on the circuit board  602  receives an output signal from the filter package  600 . The pads or contact points  620 ,  622  are electrically connected through respective package transitions  624 ,  626  (e.g., package terminals, castellations, pins, vias, electrodes, etc.) to the substrate carrier  110 . In the embodiment of  FIG. 9 , matching circuits  628 ,  630  on the substrate carrier  110  are electrically connected to corresponding contact terminals  606 ,  610  (such as by bond wires) of the filter device  102 . Typically, the contact terminals  606 ,  610  are input and output contact terminals for receiving input signals and transmitting output signals, respectively. 
     In addition, the contact terminals  608 ,  612  of the filter device  102  are electrically connected to matching transmission lines  632 ,  634 , respectively, similar to the matching transmission lines described above. Each of the matching transmission lines  632 ,  634  are electrically connected, such as by bond wires or by other electrical connection, to ground. Each of the transmission lines  632 ,  624  act as a matching inductor to the shunt resonators. 
     In the example of  FIG. 9 , the remaining contact terminal  614  of the filter device  102  is not electrically connected to a matching transmission line, but instead, is directly electrically connected to the ground plane  108 . More than one contact terminal  614  can be used when multiple shunt resonators or internal components exist. 
     As further depicted in  FIG. 9 , the filter package  600  can further have package transitions  632 ,  634 ,  636  (e.g., package terminals, castellations, vias, pins, electrodes, etc.) that are electrically connected to external ground (ground of the circuit board  602 ). The ground plane(s) inside the filter package  600  is (are) electrically connected through these package transitions  632 ,  634 ,  636  to external ground. 
       FIG. 10  shows an example arrangement of a wireless communications network that includes a mobile station  700  and a base station  702  that are able to communicate wirelessly, such as using radio frequency (RF) signaling  704 , with each other. In accordance with some embodiments, any one of the filter packages can be provided in at least one of the mobile station  700  and base station  702 . As depicted in  FIG. 10 , a filter package  708  is provided in an RF transceiver  706  of the mobile station, while a filter package  714  is provided in an RF transceiver  712  of the base station  702 . The RF transceivers  706 ,  712  are electrically connected to processors  710 ,  716  in the respective mobile station  700  and base station  702 . The processor  710 , RF transceiver  706 , and filter package  708  can be provided on a common circuit board, such as that depicted in  FIG. 9 . Similarly, the processor  716 , RF transceiver  712 , and filter package  714  of the base station  702  can be provided on a common circuit board. 
     Each of the mobile station  700  and base station  702  is an example of a wireless communications device. In other applications, filter packages according to some embodiments can be used in other types of electronic devices. 
     In the foregoing description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details. While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention.

Metadata:
Filing Date: 20120404
Publication Date: 20140325
Grant Date: 20140325
Priority Date: 20061116
Inventors: GAGNON ERIC
JIAN CHUN-YUN
Assignee: APPLE INC
CPC Classifications: [{"code": "Y10T29/49016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/48227", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/48227", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/48091", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49117", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H03H9/0542", "inventive": true, "first": true, "tree": "[]"}, {"code": "H03H9/0552", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L2224/49171", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/3011", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/30107", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/49171", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/30111", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/30107", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/3011", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/48091", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49117", "inventive": false, "first": false, "tree": "[]"}, {"code": "H03H9/0552", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03H9/0542", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01L2924/30111", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 40186091