Patent Publication Number: US-2023147252-A1

Title: Power rugged filter module

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. 
     BACKGROUND 
     Field 
     Embodiments of the invention relate to electronic systems, and in particular, to a filter nodule for use in radio frequency (RF) electronics. 
     Description of the Related Technology 
     Filters are used in radio frequency (RF) communication systems to allow signals to pass through at discreet frequencies but reject any frequency outside of the specified range. It is important to manage the power of the filter at high radio frequency to avoid damages on a device. 
     Examples of RF communication systems with one or more filter module include, but are not limited to, mobile phones, tablets, base stations, network access points, customer-premises equipment (CPE), laptops, and wearable electronics. For example, in wireless devices that communicate using a cellular standard, a wireless local area network (WLAN) standard, and/or any other suitable communication standard, a power amplifier can be used for RF signal amplification. An RF signal can have a frequency in the range of about 30 kHz to 300 GHz, such as in the range of about 410 MHz to about 7.125 GHz for certain communications standards. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of one embodiment of a mobile device. 
         FIG.  2    is a schematic diagram of an electronic system  10  for a front end module. 
         FIG.  3 A  is a diagram of a first example of a conventional filter module. 
         FIG.  3 B  is a Smith chart corresponding to the first conventional filter module of  FIG.  3 A . 
         FIG.  4 A  is a diagram of a second example of a conventional filter module. 
         FIG.  4 B  is a Smith chart corresponding to the second conventional filter module of  FIG.  4 A . 
         FIG.  5    is a block diagram showing an example of a filter module. 
         FIG.  6    is a schematic diagram of a diplexer. 
         FIGS.  7 A- 7 B  are examples of graphs illustrating power consumption of the series resonators ( 7 A) and shunt resonators ( 7 B), respectively. 
         FIG.  8    is an example of conductance curve of that represents resonant frequency of a filter module. 
         FIG.  9    is an example of measured power consumptions of filters having different resonant frequencies. 
         FIG.  10    is an example of schematic diagram illustrating connection of resonators for the filter module. 
         FIG.  11    is an example of schematic diagram illustrating connection of resonators for the filter module. 
         FIGS.  12 A- 12 D  are examples of graphs illustrating power consumption of various resonator configurations. 
         FIGS.  13 A-B  show examples of connections of resonators for an octane resonator circuit. 
         FIG.  14 A  is a schematic diagram of one embodiment of a packaged module. 
         FIG.  14 B  is a schematic diagram of a cross-section of the packaged module of  FIG.  14 A  taken along the lines  14 B- 14 B. 
         FIG.  15    is a schematic diagram of one embodiment of a phone board. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The following detailed description of certain embodiments presents various descriptions of specific embodiments. However, the innovations described herein can be embodied in a multitude of different ways, for example, as defined and covered by the claims. In this description, reference is made to the drawings where like reference numerals can indicate identical or functionally similar elements. It will be understood that elements illustrated in the figures are not necessarily drawn to scale. Moreover, it will be understood that certain embodiments can include more elements than illustrated in a drawing and/or a subset of the elements illustrated in a drawing. Further, some embodiments can incorporate any suitable combination of features from two or more drawings. 
       FIG.  1    is a schematic diagram of one example of a mobile device  1000 . The mobile device  1000  includes a baseband system  1001 , a transceiver  1002 , a front end system  1003 , antennas  1004 , a power management system  1005 , a memory  1006 , a user interface  1007 , and a battery  1008 . 
     The mobile device  1000  can be used communicate using a wide variety of communications technologies, including, but not limited to, 2G, 3G, 4G (including LTE, LTE-Advanced, and LTE-Advanced Pro), 5G, WLAN (for instance, Wi-Fi), WPAN (for instance, Bluetooth and ZigBee), WMAN (for instance, WiMax), and/or GPS technologies. 
     The transceiver  1002  generates RF signals for transmission and processes incoming RF signals received from the antennas  1004 . It will be understood that various functionalities associated with the transmission and receiving of RF signals can be achieved by one or more components that are collectively represented in  FIG.  1    as the transceiver  1002 . In one example, separate components (for instance, separate circuits or dies) can be provided for handling certain types of RF signals. 
     The front end system  1003  aids is conditioning signals transmitted to and/or received from the antennas  1004 . In the illustrated embodiment, the front end system  1003  includes power amplifiers (PAs)  1011 , low noise amplifiers (LNAs)  1012 , filters  1013 , switches  1014 , and duplexers  1015 . However, other implementations are possible. 
     For example, the front end system  1003  can provide a number of functionalities, including, but not limited to, amplifying signals for transmission, amplifying received signals, filtering signals, switching between different bands, switching between different power modes, switching between transmission and receiving modes, duplexing of signals, multiplexing of signals (for instance, diplexing or triplexing), or some combination thereof. 
     In certain implementations, the mobile device  1000  supports carrier aggregation, thereby providing flexibility to increase peak data rates. Carrier aggregation can be used for both Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD), and may be used to aggregate a plurality of carriers or channels. Carrier aggregation includes contiguous aggregation, in which contiguous carriers within the same operating frequency band are aggregated. Carrier aggregation can also be non-contiguous, and can include carriers separated in frequency within a common band and/or in different bands. 
     The antennas  1004  can include antennas used for a wide variety of types of communications. For example, the antennas  1004  can include antennas associated transmitting and/or receiving signals associated with a wide variety of frequencies and communications standards. 
     In certain implementations, the antennas  1004  support MIMO communications and/or switched diversity communications. For example, MIMO communications use multiple antennas for communicating multiple data streams over a single radio frequency channel. MIMO communications benefit from higher signal to noise ratio, improved coding, and/or reduced signal interference due to spatial multiplexing differences of the radio environment. Switched diversity refers to communications in which a particular antenna is selected for operation at a particular time. For example, a switch can be used to select a particular antenna from a group of antennas based on a variety of factors, such as an observed bit error rate and/or a signal strength indicator. 
     The mobile device  1000  can operate with beamforming in certain implementations. For example, the front end system  1003  can include phase shifters having variable phase controlled by the transceiver  1002 . Additionally, the phase shifters are controlled to provide beam formation and directivity for transmission and/or reception of signals using the antennas  1004 . For example, in the context of signal transmission, the phases of the transmit signals provided to the antennas  1004  are controlled such that radiated signals from the antennas  1004  combine using constructive and destructive interference to generate an aggregate transmit signal exhibiting beam-like qualities with more signal strength propagating in a given direction. In the context of signal reception, the phases are controlled such that more signal energy is received when the signal is arriving to the antennas  1004  from a particular direction. In certain implementations, the antennas  1004  include one or more arrays of antenna elements to enhance beamforming. 
     The baseband system  1001  is coupled to the user interface  1007  to facilitate processing of various user input and output (I/O), such as voice and data. The baseband system  1001  provides the transceiver  1002  with digital representations of transmit signals, which the transceiver  1002  processes to generate RF signals for transmission. The baseband system  1001  also processes digital representations of received signals provided by the transceiver  1002 . As shown in  FIG.  1   , the baseband system  1001  is coupled to the memory  1006  of facilitate operation of the mobile device  1000 . 
     The memory  1006  can be used for a wide variety of purposes, such as storing data and/or instructions to facilitate the operation of the mobile device  1000  and/or to provide storage of user information. 
     The power management system  1005  provides a number of power management functions of the mobile device  1000 . The power management system  1005  of  FIG.  1    includes an envelope tracker  1060 . As shown in  FIG.  1   , the power management system  1005  receives a battery voltage form the battery  1008 . The battery  1008  can be any suitable battery for use in the mobile device  1000 , including, for example, a lithium-ion battery. 
     The mobile device  1000  of  FIG.  1    illustrates one example of an RF communication system that can include power amplifier(s) implemented in accordance with one or more features of the present disclosure. However, the teachings herein are applicable to RF communication systems implemented in a wide variety of ways. 
       FIG.  2    is a schematic diagram of an electronic system  10  for a front end module. 
     The illustrated electronic system  10  includes power amplifiers  11 A,  11 B, band select switches  15 A,  15 B, duplexers  16 A,  16 B, antenna switches  17 A,  17 B, diplexer  18 , and an antenna  19 . In the circuit shown in  FIG.  2   , a first power amplifier  11 A and a second power amplifier  11 B can provide radio frequency (RF) signals that can be aggregated for transmission by the antenna  19 .  FIG.  2    illustrates the frequency domains of example signals provided by the power amplifiers  11 A and  11 B and the frequency domain of an example carrier aggregated transmit signal provided to the antenna  19 . The power amplifiers  11 A and  11 B are examples of RF sources that provide RF signals. The first power amplifier  11 A can be associated with a first carrier. The first power amplifier  11 A can receive a first carrier and a first input signal and provide a first amplified RF signal. The second power amplifier  11 B can be associated with a second carrier that is separate from the first carrier. 
     In the illustrated electronic system  10 , relatively high isolation of each detected carrier signal from the other carrier can be provided due to isolation provided by one or more of (1) out-of-band filtering of each duplexer  16 A/ 16 B, (2) out-of-band isolation of the antenna diplexer  18 , and (3) the directivity of a forward port of a directional coupler (not shown) to the reverse-traveling wave of the residual interfering carrier. 
     A first antenna switch  17 A can selectively electrically connect the first duplexer  16 A or other circuit elements (e.g., another duplexer associated with a different band of operation) to the diplexer  18 . A second antenna switch  17 B can selectively electrically connect the second duplexer  16 B or other circuit elements to the diplexer  18 . The diplexer  18  is a frequency domain multiplexing circuit that can implement frequency domain multiplexing of the RF signals received from the duplexers  16 A and  16 B, for example, by way of the antenna switches  17 A and  17 B, respectively. 
     The electronic system  10  illustrates FDD duplex filters combined via the diplexer  18 . Any suitable principles and advantages discussed with reference to the electronic system  10  can be implemented in connection with other electronic systems, such as TDD aggregation systems with bulk acoustic wave (BAW) filter(s), and/or thin-film bulk acoustic resonator (FBAR) filter(s) with an additional transmit/receive switch for each band and/or an additional transmit/receive throw in each band select switch. 
       FIG.  3    illustrates a first example of a filter module  100  in which a matching inductor  110  is applied to a band-pass filter  120 . As shown in the circuit diagram of  FIG.  3 A , the matching inductor  110  is connected in series with and preceding the filter  120 . Referring to the Smith chart of  FIG.  3 B , the impedance of the first conventional filter module  100  in the passband of the filter  120  is indicated by a solid line  130 . The impedance  130  appears on the upper half of the Smith chart and is inductive. For comparison purposes, a comparative impedance of the filter  120  alone or without the matching inductor  110  is shown by a dashed line  135 . This comparative impedance  135  appears on the lower half of the Smith chart and is capacitive. 
       FIG.  4    illustrates a second example of a filter module  100   a  in which a matching inductor  110  is applied to a band-pass filter  120 . As shown in the diagram of  FIG.  4 A , the matching inductor  110  is connected in parallel with and preceding the filter  120 . In other words, the inductor  110  is connected between the ground and a node  125  joining the input terminal  115  with the filter  120 . Referring to the Smith chart of  FIG.  4 B , the impedance of the second conventional filter module  100   a  in the passband of the filter  120  is indicated by a solid line  140 . The impedance  140  appears on the upper half of the Smith chart and is inductive. For comparison purposes, the impedance of the filter  120  alone or without the matching inductor  110  shown by a dashed line  145 , which largely appears on the lower half of the Smith chart and is capacitive. 
       FIG.  5    is a block diagram showing an example of a filter module  200 . The filter module  200  includes a filter  220  and a matching circuit  210 . In one example the filter  220  is a band-pass filter that passes a certain band and has an impedance matched to be inductive. 
     As shown in  FIG.  5   , the band-pass filter  220  is disposed along a signal path  208  extending from an input contact  202  of the filter module  200  to an output contact  204  of the filter module  200 . Furthermore, as also shown in  FIG.  5   , the filter module  200  includes a matching circuit  210  connected between the input contact  202  and the filter  220 . 
     It is to be appreciated that, although the filter module  200  includes a filter  220  configured by SAW resonators, other examples are not limited thereto. The filter  220  can include bulk acoustic wave (BAW) resonators or film bulk acoustic wave resonators (FBARs), for example, instead of or in addition to SAW resonators. The matching circuit  210  in the filter module  200  is inductive in the passband of the filter  220  and therefore operates as an inductor. As a result, the filter module  220  according to an example can achieve an impedance in the passband of the filter module that is inductive without adding a matching inductor  110  in a conventional manner. 
     Meanwhile, 5G Wireless Communication has been adapted as the platform for phone, vehicle and IoT communications. The growth rate is unprecedent. Current 5G bands are mainly sub 6 GHz which is sweet band for BAW acoustic filter use. The current BAW technology has the advantage to support frequencies to 6 GHz or above frequencies while SAW technology is limited to below 3 GHz. 
     One of the common problem of BAW design, especially the FBAR design is the power limit due to the fact that its thermal dissipation path is limited by the top/bottom air layers, thus the BAW resonator may be damaged if the power dissipation is over the limit and temperature arises to too high. When operating at 5G frequencies, the optimal piezo-dielectric layer thickness is getting very thin which puts the thermal path further limited. 
     When the operation frequency is at or close to the resonator frequency, the power consumption (dissipation) is high from both acoustic loss and electric loss. 
     Prior solutions in BAW power improvement has been focused on resonator Q-factor improvement, power consumption density reduction or resonator size increase. More specifically, when resonator Q is improved or enhanced, the power dissipation or consumption is reduced at the same delivery power. When the resonator power consumption density is reduced, so the hottest temperature will be lower. However, the power density is averaged across the whole area of resonators and may not reduce the hottest area. When the resonator area that distributes the dissipated power is increased to larger area, the hottest spot temperature can be reduced. However, such improvements for a given frequency band and required performance can be of limited effectiveness. When the BAW resonator consumes high power and heats up, the resonator creates a temperature gradient from the center to edge with the center at the hottest, which explains why the power density reduction and resonator size increase can be of limited effectiveness. 
     According to embodiments of the present disclosure, a filter module with significantly improved power ruggedness is provided, e.g., by reducing power consumption of the filter module and by enhancing an allowed maximum power that the filter module can endure. 
     According to embodiments, resonator frequency can be intentionally shifted a few MHz to out of band. In this embodiment, the acoustic power consumption will be significantly reduced in band and the total delivered power will be significantly improved. 
     According to embodiments, Dual-Quad or Octane Resonator can significantly improve the max power (power ruggedness) by 3 dB from a Quad resonator connection, 6 dB from a Dual connection. Moreover, the Octane resonator can have potential to reduce harmonics and IMD significantly more than 6-12 dB. 
       FIG.  6    is a schematic diagram of a diplexer  600 . The diplexer  600  can be used as a filter module. As shown in  FIG.  6   , the diplexer  600  has an input contact  602  and a first output contact  604  and a second output contact  606 . The signal paths are extended from the input contact  602  to each of the first output contact  604  and the second output contact  606 . The diplexer  600  may be implemented by a plurality of series resonators and a plurality of shunt resonators. Each of the series resonators and the shunt resonators can be a BAW resonator or FBAR. 
     The input contact  602  is connected to a ground via an inductor  610 . The input contact  602  is connected to one end of a parallel connection of an inductor  612  and a capacitor  614 . The other end of the parallel connection of an inductor  612  and a capacitor  614  is connected to a ground via a series connection of a capacitor  616  and an inductor  618 . At least one element connected to the input contact  602  can be understood as a matching circuit configured for impedance matching. 
     On the signal path to the first output contact  604  from the input contact  602 , the diplexer  600  has a plurality of series resonators  620 ,  622 ,  624 . The series resonator  620  is a quad resonator circuit consisting of four resonators. The series resonator  620  be a form of two subsets of resonators connected in series, and each of the two subsets includes two resonators connected in parallel. The series resonator  622  is a dual resonator circuit consisting of two resonators connected in parallel. A node between the series resonators  620 ,  622  is connected to a ground via a series of shunt resonators  640  and an inductor  644 . The resonator  608 - 3  is the quad resonator circuit. A node between the series resonators  622 ,  624  is connected to a ground via a series connection of shunt resonators  642  and an inductor  644 . The first output contact  604  is connected to a ground via a series connection of shunt resonators  646  an inductor  648 . The first output contact  604  is connected to the ground via an inductor  650 . 
     On the signal path to the second output contact  606  from the input contact  602 , the diplexer  600  has a capacitor  630 , and a series resonator  626 . The series resonator  626  is a dual resonator circuit consisting of two resonators connected in series. The other end on the series resonator  626  is connected to a ground via an inductor  632  in parallel with a series connection of a capacitor  634  and an inductor  636 , and a series connection of two shunt resonators  638  and a capacitor  650 . The output contact  606  is connected to the other end of the series resonator  626  via a series connection of two parallel-connected inductors  652 ,  656  and capacitors  654 ,  658 . 
       FIG.  7    is an example of graph illustrating dissipated power (mW) of the series resonators and shunt resonators. In  FIG.  7   , the input power is 32 dBm, and a target frequency band is N79 band, e.g. a range between 4.4 GHz and 5 GHz.  FIG.  7 A  is an example of dissipated power of series resonators.  FIG.  7 B  is an example of dissipated power of shunt resonators. For example, the target frequency band can be a communication band assigned to a filter module. 
       FIG.  8    is an example of conductance curve of that represents resonant frequency of a filter module.  FIG.  8    shows a resonant frequency (Fs) and an anti-resonant frequency (Fp). According to an embodiment, a filter module includes at least one filter. The filter can be implemented by a plurality of series resonators and a plurality of shunt resonators disposed between the series resonators and a ground. Each of the plurality of series resonators and the plurality of shunt resonators is a bulk acoustic wave (BAW) resonator or a film bulk acoustic resonator (FBAR). 
     A BAW resonator is an electromechanical device in which a standing acoustic wave is generated by an electrical signal in the bulk of a piezoelectric material. In the simplest configuration, a device will consist of a piezoelectric material (typically quartz, AlN, or ZnO) sandwiched between two metallic electrodes. 
     BAW resonators are compact, low-cost RF filters that can be used in a wide range of applications up to 6 GHz. Like SAW Filters, BAW filters also operate by converting electrical energy into acoustic or mechanical energy on a piezoelectric material. Since they can operate at higher frequencies, BAW filters are used for many of the new LTE bands above 1.9 GHz. They are also highly effective for LTE/Wi-Fi coexistence filters. Compared to SAW filters, BAW filters can operate at higher frequencies, are less sensitive to temperature changes, however, are more expensive. 
     The film bulk acoustic resonator (FBAR) is a widely-used MEMS device which can be used as a filter, or as a gravimetric sensor for biochemical or physical sensing. Current device architectures require the use of an acoustic mirror or a freestanding membrane and are fabricated as discrete components. 
     FBAR filter generates a bulk wave inside a piezoelectric thin film that is sandwiched between two electrodes. A high-frequency signal is applied to the electrodes and an acoustic wave resonates in the structure at a designed frequency determined primarily by the shape and thickness of the piezoelectric thin film. 
     The filter module include an input terminal, at least one output terminal, at least one filter disposed along each signal path extending from the input terminal to the at least one output terminal, and a matching circuit configured for impedance matching of the at least one filter and coupled to the at least one filter. The input terminal is connected to an antenna. 
     The filter is configured to have a resonator frequency shifted out of a target frequency band. The filter is configured to consume less power such that the power ruggedness is improved. More specifically, the filter is configured to consume less power while operating on the shifted resonator frequency than operating in the target frequency band. The target band is a range of frequency on which an input signal is delivered. For example, the target frequency band is in a range of sub 6 GHz, particularly between 4.4 GHz to 5 GHz. 
     As shown in  FIG.  8   , the resonant frequency (Fs) is where a series resonance or a parallel resonance occurs. The series resonance is a resonance condition that usually occurs in series circuits, where the current becomes a maximum for a particular voltage. In series resonance, the current is maximum at resonant frequency. Parallel resonance occurs when the supply frequency creates zero phase difference between the supply voltage and current producing a resistive circuit. In many ways a parallel resonance circuit may be exactly the same as the series resonance circuit. 
     The resonator frequency of the filter is deviated from the target frequency band by 3 MHz to 20 MHz. The deviation of the resonator frequency may be measured from an edge of the target frequency band. The resonant frequency of the filter can be shifted to be lower or higher than the target frequency band. 
     The resonant frequency of the filter can be determined by the characteristics of electrical element consisting the filter. For example, the resonant frequency of the filter can be determined by a shape and thickness of the piezoelectric thin film of each resonators. In manufacturing procedure, depending on desired power consumption of the filter, each of the characteristics of the electrical element can be collaboratively determined. Any type of manufacturing manner can be adopted, and it is not limited to a specific manner. 
     By shifting the resonant frequency of the filter intentionally, maximum power consumption can be reduced. According to an example, the signal passed the filter can be amplified in order to compensate the amount of reduced power. 
     In this embodiment, as will be described, the filter may include an octane resonator circuit configured to enhance an allowed maximum power of the filter. The octane resonator circuit consists of eight resonators connected to each other in combination of series connection and parallel connection. 
       FIG.  9    is an example of measured power consumptions of filters having different resonant frequencies. The power consumption of each filter has been measured in N79 band, e.g. 4400-5000 MHz. 
     As shown in  FIG.  9   , the power consumption of filter having resonant frequency of 5 GHz is 33 dBm. The power consumption of filter having resonant frequency of 4950 or 4980 MHz is 35 dBm. 
     Therefore, according to an embodiment, the power consumed by the filter has been significantly reduced when the resonant frequency of the filter is shifted higher or lower to be out of the target frequency band, where the target frequency band can be a communication band assigned to the filter. 
       FIG.  10    is an example of schematic diagram illustrating connection of resonators for the filter module  700 . In this embodiment, the filter module  700  includes an input contact  702 , a first output contact  704 , and a second output contact  706 . The filter module further includes a filter disposed along the signal path extending from the input contact to the output contact. The filter is implemented by a plurality of series resonators and a plurality of shunt resonators disposed between the series resonators and a ground. 
     As shown in  FIG.  10   , a quad resonator circuit  708  is placed between an input contact  702  and a first output contact  704 . 
     Along the signal path extending from the input contact  702  to the second output contact  706 , three quad resonator circuits  710 ,  712 ,  714  are placed. A node between the quad resonator circuits  710 ,  712  can be connected to a ground via a dual resonator circuit  716 . A node between the quad resonator circuits  712 ,  714  can be connected to a ground via a quad resonator circuit  718 . 
     Along the signal paths extending from the input contact  702  to the first output contact  704  or to the second output contact  706 , other electrical elements can be added as shown in  FIG.  6   . For example, the filter module  700  includes a matching circuit configured for impedance matching of the filter and coupled to the filter. 
       FIG.  11    is an example of schematic diagram illustrating connection of resonators for the filter module  750 . In this embodiment, the filter module includes  750  a first terminal and at least one second terminal. The first terminal can be referred to as an input contact. The second terminal can be referred to as an output contact. In this embodiment, the filter module  750  includes 2 output contacts, but number of output contact is not limited thereto. 
     The filter module  750  according to an embodiment includes an input contact  752 , a first output contact  754 , and a second output contact  756 . The filter module  750  further includes a filter disposed along the signal path extending from the input contact to the output contact. The filter is implemented by a plurality of resonator circuits. 
     In  FIG.  11   , the quad resonator circuits  708 ,  714  illustrated in  FIG.  10    have been replaced with octane resonator circuits  758 ,  764 . The quad resonator circuits  710 ,  712  in  FIG.  10    have been replaced with hexane resonator circuits  760 ,  762  in  FIG.  11   . In addition, dual resonator circuit  716  has been replaced with quad resonator circuit  766  in  FIG.  11   . 
     More specifically, an octane resonator circuit  758  is placed between an input contact  752  and a first output contact  754 . The octane resonator circuit  758  consists of eight resonators connected to each other in combination of series connection and parallel connection. For example, the eight resonator can be connected in a form of two subsets of resonators connected in series, and each of the subsets is a parallel connection of four resonators. 
     Along the signal path extending from the input contact  752  to the second output contact  756 , two hexane resonator circuits  760 ,  762 , and an octane resonator circuit  764  are placed. The hexane resonator circuits  760 ,  762  consist of six resonators. For example, the hexane resonator circuit  760 ,  762  are configured in a form of two subsets of resonators connected in series, and each of the subsets is three resonators connected in parallel. 
     A node between the hexane resonator circuits  760 ,  762  can be connected to a ground via a quad resonator circuit  766 . A node between the hexane resonator circuit  762  and the octane resonator  764  can be connected to a ground via a quad resonator circuit  768 . 
     Along the signal paths extending from the input contact  752  to the first output contact  754  or to the second output contact  756 , other electrical elements can be added as shown in  FIG.  6   . For example, the filter module  750  includes a matching circuit configured for impedance matching of the filter and coupled to the filter. 
     By using more resonators, particularly using octane resonator circuits, the maximum power that the filter module  750  is able to endure can be enhanced, and the power ruggedness will be improved accordingly. 
     In addition to increasing the number of resonators, it is possible to intentionally shift the resonance frequency as described with  FIG.  8    in order to reduce power consumption, and therefore power ruggedness can be significantly improved. 
       FIG.  12    is an example of graphs illustrating dissipated power (mW) of quad and octane resonators. In  FIG.  12   , the input power is 32 dBm, and a target frequency band is between 4.4 GHz and 5 GHz. 
       FIG.  12 A  is an example of dissipated power (mW) of series resonators, where each of the series resonators is a quad resonator circuit. Each line in  FIG.  12 A  indicates power consumption of different series resonators  710 ,  712 ,  714  operating in frequency band between 4400-5000 MHz, as illustrated in  FIG.  10   . 
       FIG.  12 B  is an example of dissipated power (mW) of shunt resonators, where the resonator  716  is a dual resonator circuit and each of the resonators  708  and  718  is a quad resonator circuit, as illustrated in  FIG.  10   . Each line in  FIG.  12 B  indicates power consumption of different shunt resonators  708 ,  716 ,  718  operating in frequency band between 4400-5000 MHz, 
       FIG.  12 C  is an example of dissipated power (mW) of series resonators, where each of the resonators  760  and  762  is a hexane resonator circuit and the resonator  764  is an octane resonator circuit, as illustrated in  FIG.  11   . Each line in  FIG.  12 C  indicates power consumption of different series resonators  760 ,  762 ,  764  operating in frequency band between 4400-5000 MHz. 
       FIG.  12 D  is an example of dissipated power (mW) of shunt resonators, where the resonator  758  is an octane resonator circuit and each of the resonators  766  and  768  is a quad resonator circuit, as illustrated in  FIG.  11   . Each line in  FIG.  12 D  indicates power consumption of different shunt resonators  758 ,  766 ,  768  operating in frequency band between 4400-5000 MHz. 
     As shown in  FIG.  12   , an octane resonator circuit can significantly improve the allowed maximum power (power ruggedness) of the filter by 3 dB from a quad resonator connection, 6 dB from a dual connection. In addition, the octane resonator circuit can have potential to reduce harmonics and inter-modulation distortion (IMD) significantly more than 6-12 dB. 
       FIG.  13    shows examples of connections of resonators for an octane resonator circuit. In  FIG.  13   , the highlighted side of each resonator indicates a direction of arrangement that is to be a top side of the filter module. 
       FIG.  13 A -( 1 ), ( 3 ), ( 5 ), and ( 7 ) describe a connection of resonators including four subsets connected in series, each of the subsets is a dual resonator connected in parallel. Each connection illustrated in  FIG.  13 A -( 1 ), ( 3 ), ( 5 ), and ( 7 ) has different direction of arrangement for each of the resonators. 
       FIG.  13 A -( 2 ), ( 4 ), ( 6 ), and ( 8 ) describe a connection of resonators including two subsets connected in parallel, each of the subsets is a quad resonator connected in series. Each connection illustrated in  FIG.  13 A -( 2 ), ( 4 ), ( 6 ), and ( 8 ) has different direction of arrangement for each of the resonators. 
       FIG.  13 B -( 1 ), ( 4 ), ( 5 ), and ( 8 ) describe a connection of resonators including four subsets connected in parallel, each of the subsets is a dual resonator connected in series. Each connection illustrated in  FIG.  13 B -( 1 ), ( 4 ), ( 5 ), and ( 8 ) has different direction of arrangement for each of the resonators. 
       FIG.  13 B -( 2 ), ( 3 ), ( 6 ), and ( 7 ) describe a connection of resonators including two subsets connected in series, each of the subsets is a quad resonator connected in parallel. Each connection illustrated in  FIG.  13 B -( 2 ), ( 3 ), ( 6 ), and ( 7 ) has different direction of arrangement for each of the resonators. 
     The octane resonator circuits illustrated in  FIG.  13    have identical characteristics of power ruggedness, and might have different harmonics and IMD depending on its structure. 
       FIG.  14 A  is a schematic diagram of one embodiment of a packaged module  800 .  FIG.  14 B  is a schematic diagram of a cross-section of the packaged module  800  of  FIG.  14 A  taken along the lines  14 A- 16 B. 
     The packaged module  800  includes an IC or die  801 , surface mount components  803 , wirebonds  808 , a package substrate  820 , and encapsulation structure  840 . The package substrate  820  includes pads  806  formed from conductors disposed therein. Additionally, the die  801  includes pads  804 , and the wirebonds  808  have been used to electrically connect the pads  804  of the die  801  to the pads  806  of the package substrate  801 . 
     The die  801  includes a filter module, which can be implemented in accordance with any of the embodiments herein. 
     The packaging substrate  820  can be configured to receive a plurality of components such as the die  801  and the surface mount components  803 , which can include, for example, surface mount capacitors and/or inductors. 
     As shown in  FIG.  14 B , the packaged module  800  is shown to include a plurality of contact pads  832  disposed on the side of the packaged module  800  opposite the side used to mount the die  801 . Configuring the packaged module  800  in this manner can aid in connecting the packaged module  800  to a circuit board such as a phone board of a wireless device. The example contact pads  832  can be configured to provide RF signals, bias signals, power low voltage(s) and/or power high voltage(s) to the die  801  and/or the surface mount components  803 . As shown in  FIG.  14 B , the electrically connections between the contact pads  832  and the die  801  can be facilitated by connections  833  through the package substrate  820 . The connections  833  can represent electrical paths formed through the package substrate  820 , such as connections associated with vias and conductors of a multilayer laminated package substrate. 
     In some embodiments, the packaged module  800  can also include one or more packaging structures to, for example, provide protection and/or facilitate handling of the packaged module  800 . Such a packaging structure can include overmold or encapsulation structure  840  formed over the packaging substrate  820  and the components and die(s) disposed thereon. 
     It will be understood that although the packaged module  800  is described in the context of electrical connections based on wirebonds, one or more features of the present disclosure can also be implemented in other packaging configurations, including, for example, flip-chip configurations. 
       FIG.  15    is a schematic diagram of one embodiment of a phone board  900 . The phone board  900  includes the module  800  shown in  FIGS.  14 A- 14 B  attached thereto. Although not illustrated in  FIG.  15    for clarity, the phone board  800  can include additional components and structures. 
     Applications 
     Some of the embodiments described above have provided examples in connection with wireless devices or mobile phones. However, the principles and advantages of the embodiments can be used for any other systems or apparatus that have needs for power amplifiers. 
     Such envelope trackers can be implemented in various electronic devices. Examples of the electronic devices can include, but are not limited to, consumer electronic products, parts of the consumer electronic products, electronic test equipment, etc. Examples of the electronic devices can also include, but are not limited to, memory chips, memory modules, circuits of optical networks or other communication networks, and disk driver circuits. The consumer electronic products can include, but are not limited to, a mobile phone, a telephone, a television, a computer monitor, a computer, a hand-held computer, a personal digital assistant (PDA), a microwave, a refrigerator, an automobile, a stereo system, a cassette recorder or player, a DVD player, a CD player, a VCR, an MP3 player, a radio, a camcorder, a camera, a digital camera, a portable memory chip, a washer, a dryer, a washer/dryer, a copier, a facsimile machine, a scanner, a multi-functional peripheral device, a wrist watch, a clock, etc. Further, the electronic devices can include unfinished products. 
     Conclusion 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” The word “coupled”, as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Likewise, the word “connected”, as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. 
     Moreover, conditional language used herein, such as, among others, “can,” “could,” “might,” “can,” “e.g.,” “for example,” “such as” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or states are included or are to be performed in any particular embodiment. 
     The above detailed description of embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while processes or blocks are presented in a given order, alternative embodiments may perform routines having steps, or employ systems having blocks, in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined, and/or modified. Each of these processes or blocks may be implemented in a variety of different ways. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed in parallel, or may be performed at different times. 
     The teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments. 
     While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.