Abstract:
A method for packaging a radio frequency integrated circuit (RFIC) in multiple packages begins by determining a 1 st  position of the RFIC die in a 1 st  package wherein the positioning is such to minimize adverse affects of parasitic components of coupling between the radio frequency input/output section and an antenna. Once the position within the 1 st  package has been determined, the corresponding parasitics are measured to determine their values. The processing then continues by determining a 2 nd  position of the RFIC die in a 2 nd  package based on the values of the parasitic components. Accordingly, the 2 nd  position places the die within the 2 nd  package such that the parasitic components of coupling between the RF I/O section to the antenna within the 2 nd  package substantially matches the parasitic components of coupling the RFIO section to the antenna in the 1 st  package. Accordingly, different packages may be used with the same RFIC die, while maintaining the desired noise reduction.

Description:
This patent application is claiming priority under 35 USC § 120 and 121 as a divisional patent application of patent application entitled RFIC DIE-PACKAGE CONFIGURATION, having a Ser. No. of 10/702,402 (now issued U.S. Pat. No. 6,998,709), and a filing date of Nov. 5, 03. 

   BACKGROUND OF THE INVENTION 
   1. Technical Field of the Invention 
   This invention relates generally to wireless communication devices and more particularly to radio frequency integrated circuits used within such wireless communication devices. 
   2. Description of Related Art 
   Communication systems are known to support wireless and wire lined communications between wireless and/or wire lined communication devices. Such communication systems range from national and/or international cellular telephone systems to the Internet to point-to-point in-home wireless networks. Each type of communication system is constructed, and hence operates, in accordance with one or more communication standards. For instance, wireless communication systems may operate in accordance with one or more standards including, but not limited to, IEEE 802.11, Bluetooth, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution systems (LMDS), multi-channel-multi-point distribution systems (MMDS), and/or variations thereof. 
   Depending on the type of wireless communication system, a wireless communication device, such as a cellular telephone, two-way radio, personal digital assistant (PDA), personal computer (PC), laptop computer, home entertainment equipment, et cetera communicates directly or indirectly with other wireless communication devices. For direct communications (also known as point-to-point communications), the participating wireless communication devices tune their receivers and transmitters to the same channel or channels (e.g., one of the plurality of radio frequency (RF) carriers of the wireless communication system) and communicate over that channel(s). For indirect wireless communications, each wireless communication device communicates directly with an associated base station (e.g., for cellular services) and/or an associated access point (e.g., for an in-home or in-building wireless network) via an assigned channel. To complete a communication connection between the wireless communication devices, the associated base stations and/or associated access points communicate with each other directly, via a system controller, via the public switch telephone network, via the Internet, and/or via some other wide area network. 
   For each wireless communication device to participate in wireless communications, it includes a built-in radio transceiver (i.e., receiver and transmitter) or is coupled to an associated radio transceiver (e.g., a station for in-home and/or in-building wireless communication networks, RF modem, etc.). As is known, the transmitter includes a data modulation stage, one or more intermediate frequency stages, and a power amplifier. The data modulation stage converts raw data into baseband signals in accordance with a particular wireless communication standard. The one or more intermediate frequency stages mix the baseband signals with one or more local oscillations to produce RF signals. The power amplifier amplifies the RF signals prior to transmission via an antenna. 
   As is also known, the receiver is coupled to the antenna and includes a low noise amplifier, one or more intermediate frequency stages, a filtering stage, and a data recovery stage. The low noise amplifier receives inbound RF signals via the antenna and amplifies then. The one or more intermediate frequency stages mix the amplified RF signals with one or more local oscillations to convert the amplified RF signal into baseband signals or intermediate frequency (IF) signals. The filtering stage filters the baseband signals or the IF signals to attenuate unwanted out of band signals to produce filtered signals. The data recovery stage recovers raw data from the filtered signals in accordance with the particular wireless communication standard. 
   A critical issue with any mixed signal circuit, including radio transceivers, is minimizing noise, especially at the sensitive points within the mixed signal circuitry. In radio transceivers, one sensitive point is the receiver input that receives radio frequency (RF) signals from an antenna. To minimize noise sensitivity, a receiver input includes a low noise amplifier to receive and subsequently amplify incoming RF signals. Further, most low noise amplifiers are designed to have an input impedance to substantially match the impedance of the antenna at radio frequencies. Alternatively, the receiver may include an impedance matching circuit between the antenna and low noise amplifier to provide the desired impedance matching. 
   When the RF transceiver is implemented as an integrated circuit, it includes a die mounted within a package. The packages die (i.e., the integrated circuit) is then mounted on a printed circuit board, which includes the antenna. Conventional packaging of the die may be done using commercial packages (e.g., ball grid array (BGA), LPCC, et cetera) where the die is placed in the center of the package. While such packaging has provided adequate performance in the past, as radio frequencies increase and/or the data throughput demands increase, such conventional packaging provides unacceptable levels of parasitic components (e.g., capacitance and/or inductance). Such parasitics increase the noise levels of the radio frequency integrated circuit, degrade the input signal to the radio receiver, degrade output power of the radio transmitter, and thus limit the radio transceiver&#39;s overall performance. 
   Therefore, a need exists for a radio frequency integrated circuit die packaging configuration that minimizes adverse affects of packaging parasitics. 
   BRIEF SUMMARY OF THE INVENTION 
   The radio frequency integrated circuit (RFIC) die-package configuration of the present invention substantially meets these needs and others. In one embodiment, a method for packaging a radio frequency integrated circuit (RFIC) in multiple packages begins by determining a 1 st  position of the RFIC die in a 1 st  package wherein the positioning is such to minimize adverse affects of parasitic components of coupling between the radio frequency input/output section and an antenna. Once the position within the 1 st  package has been determined, the corresponding parasitics are measured to determine their values. The processing then continues by determining a 2 nd  position of the RFIC die in a 2 nd  package based on the values of the parasitic components. Accordingly, the 2 nd  position places the die within the 2 nd  package such that the parasitic components of coupling between the RF I/O section to the antenna within the 2 nd  package substantially matches the parasitic components of coupling the RFIO section to the antenna in the 1 st  package. Accordingly, different packages may be used with the same RFIC die, while maintaining the desired noise reduction. 
   In another embodiment, a radio frequency integrated circuit (RFIC) includes a die, and a package. In this embodiment, the die includes a radio frequency input/output (RF I/O) section, a radio frequency to baseband conversion section and a baseband processing section. The packaging includes a ball grid array and an antenna. The antenna is located on one edge of the package. Solder balls of the ball grid array proximal to the antenna are used to couple the RF I/O section of the die to the antenna. By minimizing the trace length of coupling between the RF I/O section of the die and the antenna, the parasitic components are reduced thereby improving overall radio transceiver performance. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a schematic block diagram of a wireless communication system in accordance with the present invention; 
       FIG. 2  is a schematic block diagram of a wireless communication device in accordance with the present invention; 
       FIG. 3  is a graphical representation of a radio frequency integrated circuit in accordance with the present invention; 
       FIG. 4  is a graphical representation of coupling a die to an antenna in accordance with the present invention; 
       FIG. 5  is a cross-sectional side view of the coupling illustrated in  FIG. 4 ; 
       FIG. 6  is an alternate graphical representation of coupling a die to an antenna in accordance with the present invention; and 
       FIG. 7  is a logic diagram of a method for multiple packaging of a radio frequency integrated circuit in accordance with the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  is a schematic block diagram illustrating a communication system  10  that includes a plurality of base stations and/or access points  12 - 16 , a plurality of wireless communication devices  18 - 32  and a network hardware component  34 . The wireless communication devices  18 - 32  may be laptop host computers  18  and  26 , personal digital assistant hosts  20  and  30 , personal computer hosts  24  and  32  and/or cellular telephone hosts  22  and  28 . The details of the wireless communication devices will be described in greater detail with reference to  FIG. 2 . 
   The base stations or access points  12 - 16  are operably coupled to the network hardware  34  via local area network connections  36 ,  38  and  40 . The network hardware  34 , which may be a router, switch, bridge, modem, system controller, et cetera provides a wide area network connection  42  for the communication system  10 . Each of the base stations or access points  12 - 16  has an associated antenna or antenna array to communicate with the wireless communication devices in its area. Typically, the wireless communication devices register with a particular base station or access point  12 - 14  to receive services from the communication system  10 . For direct connections (i.e., point-to-point communications), wireless communication devices communicate directly via an allocated channel. 
   Typically, base stations are used for cellular telephone systems and like-type systems, while access points are used for in-home or in-building wireless networks. Regardless of the particular type of communication system, each wireless communication device includes a built-in radio and/or is coupled to a radio. The radio includes a highly linear amplifier and/or programmable multi-stage amplifier as disclosed herein to enhance performance, reduce costs, reduce size, and/or enhance broadband applications. 
     FIG. 2  is a schematic block diagram illustrating a wireless communication device that includes the host device  18 - 32  and an associated radio  60 . For cellular telephone hosts, the radio  60  is a built-in component. For personal digital assistants hosts, laptop hosts, and/or personal computer hosts, the radio  60  may be built-in or an externally coupled component. 
   As illustrated, the host device  18 - 32  includes a processing module  50 , memory  52 , radio interface  54 , input interface  58  and output interface  56 . The processing module  50  and memory  52  execute the corresponding instructions that are typically done by the host device. For example, for a cellular telephone host device, the processing module  50  performs the corresponding communication functions in accordance with a particular cellular telephone standard. 
   The radio interface  54  allows data to be received from and sent to the radio  60 . For data received from the radio  60  (e.g., inbound data), the radio interface  54  provides the data to the processing module  50  for further processing and/or routing to the output interface  56 . The output interface  56  provides connectivity to an output display device such as a display, monitor, speakers, et cetera such that the received data may be displayed. The radio interface  54  also provides data from the processing module  50  to the radio  60 . The processing module  50  may receive the outbound data from an input device such as a keyboard, keypad, microphone, et cetera via the input interface  58  or generate the data itself. For data received via the input interface  58 , the processing module  50  may perform a corresponding host function on the data and/or route it to the radio  60  via the radio interface  54 . 
   Radio  60  includes a host interface  62 , digital receiver processing module  64 , an analog-to-digital converter  66 , a filtering/gain module  68 , an IF mixing down conversion stage  70 , a receiver filter  71 , a low noise amplifier  72 , a transmitter/receiver switch  73 , a local oscillation module  74 , memory  75 , a digital transmitter processing module  76 , a digital-to-analog converter  78 , a filtering/gain module  80 , an IF mixing up conversion stage  82 , a power amplifier  84 , a transmitter filter module  85 , and an antenna  86 . The antenna  86  may be a single antenna that is shared by the transmit and receive paths as regulated by the Tx/Rx switch  73 , or may include separate antennas for the transmit path and receive path. The antenna implementation will depend on the particular standard to which the wireless communication device is compliant. 
   The digital receiver processing module  64  and the digital transmitter processing module  76 , in combination with operational instructions stored in memory  75 , execute digital receiver functions and digital transmitter functions, respectively. The digital receiver functions include, but are not limited to, digital intermediate frequency to baseband conversion, demodulation, constellation demapping, decoding, and/or descrambling. The digital transmitter functions include, but are not limited to, scrambling, encoding, constellation mapping, modulation, and/or digital baseband to IF conversion. The digital receiver and transmitter processing modules  64  and  76  may be implemented using a shared processing device, individual processing devices, or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on operational instructions. The memory  75  may be a single memory device or a plurality of memory devices. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, and/or any device that stores digital information. Note that when the processing module  64  and/or  76  implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory storing the corresponding operational instructions is embedded with the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. 
   In operation, the radio  60  receives outbound data  94  from the host device via the host interface  62 . The host interface  62  routes the outbound data  94  to the digital transmitter processing module  76 , which processes the outbound data  94  in accordance with a particular wireless communication standard (e.g., IEEE 802.11 Bluetooth, et cetera) to produce digital transmission formatted data  96 . The digital transmission formatted data  96  will be a digital base-band signal or a digital low IF signal, where the low IF typically will be in the frequency range of one hundred kilohertz to a few megahertz. 
   The digital-to-analog converter  78  converts the digital transmission formatted data  96  from the digital domain to the analog domain. The filtering/gain module  80  filters and/or adjusts the gain of the analog signal prior to providing it to the IF mixing stage  82 . The IF mixing stage  82  converts the analog baseband or low IF signal into an RF signal based on a transmitter local oscillation  83  provided by local oscillation module  74 . The power amplifier  84  amplifies the RF signal to produce outbound RF signal  98 , which is filtered by the transmitter filter module  85 . The antenna  86  transmits the outbound RF signal  98  to a targeted device such as a base station, an access point and/or another wireless communication device. 
   The radio  60  also receives an inbound RF signal  88  via the antenna  86 , which was transmitted by a base station, an access point, or another wireless communication device. The antenna  86  provides the inbound RF signal  88  to the receiver filter module  71  via the Tx/Rx switch  73 , where the Rx filter  71  bandpass filters the inbound RF signal  88 . The Rx filter  71  provides the filtered RF signal to low noise amplifier  72 , which amplifies the signal  88  to produce an amplified inbound RF signal. The low noise amplifier  72  provides the amplified inbound RF signal to the IF mixing module  70 , which directly converts the amplified inbound RF signal into an inbound low IF signal or baseband signal based on a receiver local oscillation  81  provided by local oscillation module  74 . The down conversion module  70  provides the inbound low IF signal or baseband signal to the filtering/gain module  68 . The filtering/gain module  68  filters and/or gains the inbound low IF signal or the inbound baseband signal to produce a filtered inbound signal. 
   The analog-to-digital converter  66  converts the filtered inbound signal from the analog domain to the digital domain to produce digital reception formatted data  90 . The digital receiver processing module  64  decodes, descrambles, demaps, and/or demodulates the digital reception formatted data  90  to recapture inbound data  92  in accordance with the particular wireless communication standard being implemented by radio  60 . The host interface  62  provides the recaptured inbound data  92  to the host device  18 - 32  via the radio interface  54 . 
   As one of average skill in the art will appreciate, the wireless communication device of  FIG. 2  may be implemented using one or more integrated circuits. For example, the host device may be implemented on one integrated circuit, the digital receiver processing module  64 , the digital transmitter processing module  76  and memory  75  may be implemented on a second integrated circuit, and the remaining components of the radio  60 , less the antenna  86 , may be implemented on a third integrated circuit. As an alternate example, the radio  60  may be implemented on a single integrated circuit. As yet another example, the processing module  50  of the host device and the digital receiver and transmitter processing modules  64  and  76  may be a common processing device implemented on a single integrated circuit. Further, the memory  52  and memory  75  may be implemented on a single integrated circuit and/or on the same integrated circuit as the common processing modules of processing module  50  and the digital receiver and transmitter processing module  64  and  76 . 
     FIG. 3  is a graphical representation of a radio frequency integrated circuit (RFIC) that includes a die  100 , and a package  108 . The die  100  includes a radio frequency I/O (RFIO) section  102 , a radio frequency to baseband conversion section  104  and a baseband processing section  106 . With reference to  FIG. 2 , the RFIO section  102  includes the low noise amplifier  72 , the receiver filter module  71 , the T/R switch module  73 , the transmit filter module  85 , and the power amplifier  84 . The RF to baseband conversion section  104 , with reference to  FIG. 2 , includes the down conversion module  70 , filter/gain module  68 , analog-to-digital converter  66 , digital-to-analog converter  78 , filter/gain module  80 , up-conversion module  82  and local oscillation module  74 . The baseband processing section  106 , with reference to  FIG. 2 , includes the digital receiver processing module  64 , memory  75  and digital transmitter processing module  76 . 
   Returning to the discussion of  FIG. 2 , the package  108  includes a plurality of connections  110 , which may include a ball grid array or the package may be an LPCC. In any configuration of the package  108 , the die  100  is positioned to minimize the trace connection from the RFIO section  102  to the antenna  112 . In this embodiment, the antenna  112  is mounted and/or fabricated on a printed circuit board (PCB) which is coupled via PCB traces  114  to the RF I/O section  102 . Note that the die is off-centered with respect to the package  108  to provide the minimal distance coupling between the RF I/O section  102  and antenna  112 . Remaining connections for the baseband processing section  106  may include longer traces within package  108  to interconnecting solder balls and/or pins of the package to the PCB without adversely affecting the overall performance of the RFIC. Accordingly, by minimizing the distance between the RF I/O section  102  and the antenna  112 , the corresponding parasitics that are produced by the printed circuit board trace  114 , the coupling of the die  100  to the package  108 , and the coupling of the package  108  to the printed circuit board traces  114  are minimized such that at radio frequencies (e.g., 2.4 gigahertz, 5.25 gigahertz), the parasitics have negligible affect on the performance of the radio frequency integrated circuit. 
     FIG. 4  is a more detailed graphical representation of coupling the RFIO section  102  of die  100  to antenna  112 . In this embodiment, the plurality of connections  110  includes a ball grid array  120 . The solder balls of the ball grid array  120  closest to antenna  112  are used to couple the RF I/O section  102  to the package  108 . Corresponding solder balls and/or pins of the package are then used to couple to PCB traces  114  to provide the connectivity to antenna  112 . This is further illustrated in  FIG. 5 . 
     FIG. 5  illustrates a side view of the coupling illustrated in  FIG. 4 . In this illustration, solder ball connections  118  couple RF I/O section  102  of die  100  to the package  108 . Within the package  108  there are traces and/or vias that couple to solder balls and/or pins on the opposite surface of package  108 . The other solder balls are then used to connect to the printed circuit board traces  114 , which couple to the antenna  112 . Accordingly, a minimal distance between the RF I/O section  102  and the antenna  112  may be obtained thereby minimizing the parasitic components and the adverse affects on the performance of the RFIC. 
     FIG. 6  illustrates an alternate configuration of the RFIC. In this configuration, the antenna  112  is fabricated on the package  108 . The RF I/O section  102  of die  100  is connected via package traces  115  and corresponding solder balls to the antenna  112  within the package. As such, the distance between the RF I/O section  102  and the antenna  112  may be further reduced thereby further reducing the corresponding parasitics and minimizing the adverse affects caused thereby. 
     FIG. 7  is a logic diagram of a method for multiple packaging of a radio frequency integrated circuit. The process begins at Step  130  where a 1 st  position of the RFIC die in a 1 st  package (e.g., a ball grid array package) is determined. The position is selected to minimize adverse affects of parasitic components of the coupling between the RFIO section of the die and an antenna as described above. Such coupling includes the coupling of the die to the package and the coupling of the package to the antenna, which may be via traces of a printed circuit board and/or traces within the package. The 1 st  position may be offset from center and may further be at an edge of the 1 st  package. The parasitic components may include inductance and/or capacitance. 
   The process then proceeds to Step  132  where the values of the parasitic components are determined. The process then proceeds to Step  134  where a 2 nd  position of the RFIC die within a 2 nd  package (e.g., LPCC) is determined based on the values of the parasitic components. The positioning within the 2 nd  die is selected such that the values of the parasitic components between the RF I/O section and the antenna substantially match the values of the parasitic components of the coupling between the RFIO section to the antenna in the 1 st  package. 
   The process then proceeds to Step  136  where a determination is made as to whether the die will be packaged in the 1 st  package or the 2 nd  package. When packaged in the 1 st  package, the process proceeds to Step  138  where the RFIC die is packaged within the 1 st  package in accordance with the 1 st  position. If the die is to be packaged in the 2 nd  package, the process proceeds to Step  140  where the RFIC die is packaged within the 2 nd  package in accordance with the 2 nd  position. 
   As one of average skill in the art will appreciate, the term “substantially” or “approximately”, as may be used herein, provides an industry-accepted tolerance to its corresponding term. Such an industry-accepted tolerance ranges from less than one percent to twenty percent and corresponds to, but is not limited to, component values, integrated circuit process variations, temperature variations, rise and fall times, and/or thermal noise. As one of average skill in the art will further appreciate, the term “operably coupled”, as may be used herein, includes direct coupling and indirect coupling via another component, element, circuit, or module where, for indirect coupling, the intervening component, element, circuit, or module does not modify the information of a signal but may adjust its current level, voltage level, and/or power level. As one of average skill in the art will also appreciate, inferred coupling (i.e., where one element is coupled to another element by inference) includes direct and indirect coupling between two elements in the same manner as “operably coupled”. As one of average skill in the art will further appreciate, the term “compares favorably”, as may be used herein, indicates that a comparison between two or more elements, items, signals, etc., provides a desired relationship. For example, when the desired relationship is that signal  1  has a greater magnitude than signal  2 , a favorable comparison may be achieved when the magnitude of signal  1  is greater than that of signal  2  or when the magnitude of signal  2  is less than that of signal  1 . 
   The preceding discussion has presented a radio frequency integrated circuit die/packaging configuration that substantially reduces the adverse affects caused by parasitic components of the coupling between an antenna and the RF input/output section of a radio frequency integrated circuit. As one of average skill in the art will appreciate, other embodiments may be derived from the teaching of the present invention without deviating from the scope of the claims.