RF integrated circuit with transmitter and multipurpose output ports and methods for use therewith

An RF integrated circuit (IC) includes a first IC port for coupling a first transmit signal in a first frequency band to at least one external device and a second IC port for coupling a second transmit signal in a second frequency band to the at least one external device. A transmitter module responds to outbound data to generate the first transmit signal in a first mode of operation and to generate the second transmit signal in a second mode of operation, wherein the transmitter module generates the first transmit signal and the second transmit signal in a selected one of a plurality of wireless telephony formats based on a control signal, and wherein the plurality of wireless telephony formats includes a code divisional multiple access format and at least one non-code division multiple access format.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates generally to mobile communication devices and more particularly to a circuit for transmitters implemented via RF integrated circuits.

2. Description of Related Art

Communication systems are known to support wireless and wire line communications between wireless and/or wire line 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 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 through an antenna interface and includes a low noise amplifier, one or more intermediate frequency stages, a filtering stage, and a data recovery stage. The low noise amplifier (LNA) 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.

RF transmitters can generate polar coordinate transmissions that are simultaneously amplitude modulated and phase modulated to carry more data over a single transmitted signal. The modulation can be performed in two phases with phase modulation occurring first in a phase locked loop and amplitude modulation being induced on the phase modulated signal by the power amplifier.

Wireless communication systems may operate in accordance with different 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), radio frequency identification (RFID), and/or variations thereof. The construction of multi-format devices can be a challenge to designers that wish to simplify their designs and make them more efficient. Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of ordinary skill in the art through comparison of such systems with the present invention.

BRIEF SUMMARY OF THE INVENTION

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a schematic block diagram of an embodiment of a communication system in accordance with the present invention. In particular a communication system is shown that includes a communication device10that communicates real-time data24and non-real-time data26wirelessly with one or more other devices such as base station18, non-real-time device20, real-time device22, and non-real-time and/or real-time device30. In addition, communication device10can also optionally communicate over a wireline connection with non-real-time device12, real-time device14and non-real-time and/or real-time device16.

In an embodiment of the present invention the wireline connection28can be a wired connection that operates in accordance with one or more standard protocols, such as a universal serial bus (USB), Institute of Electrical and Electronics Engineers (IEEE) 488, IEEE 1394 (Firewire), Ethernet, small computer system interface (SCSI), serial or parallel advanced technology attachment (SATA or PATA), personal computer memory card international association (PCMCIA) or other wired communication protocol, either standard or proprietary.

The wireless connection can communicate in accordance with a wireless network protocol such as IEEE 802.11, Bluetooth, Ultra-Wideband (UWB), WIMAX, or other wireless network protocol, a wireless telephony data/voice protocol such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Enhanced Data Rates for Global Evolution (EDGE), Personal Communication Services (PCS), or a code division multiple access (CDMA) protocol such as wideband CDMA (WCDMA) other wireless telephony protocol or other wireless communication protocol, either standard or proprietary. In particular, communication device10is capable of communicating over two or more different frequency bands such as the 750, 850, 900, 1800 or 1900 MHz bands or other frequency bands. For instance, communication device10can communicate via a 900 MHz band with base station18and/or non-real-time and/or real-time device30and communicate via a 1800 MHz band with non-real-time device20and/or real-time device22. Further, the wireless communication path can include separate transmit and receive paths that use separate carrier frequencies and/or separate frequency channels. Alternatively, a single frequency or frequency channel can be used to bi-directionally communicate data to and from the communication device10.

Communication device10can be a mobile phone such as a cellular telephone, a PC data card that communicates over a wireless telephony network, a personal digital assistant, game console, personal computer, laptop computer, or other device that performs one or more functions that include communication of voice and/or data via the wireless communication path. In an embodiment of the present invention, the real-time and non-real-time devices12,14,16,18,20,22, and30can be base stations, access points, or other communication devices such as personal computers, laptops, PDAs, mobile phones, cellular telephones, devices equipped with wireless local area network or Bluetooth transceivers, FM tuners, TV tuners, digital cameras, digital camcorders, or other devices that either produce, process or use audio, video signals or other data or communications.

In operation, the communication device includes one or more applications that include voice communications such as standard telephony applications, voice-over-Internet Protocol (VoIP) applications, local gaming, Internet gaming, email, instant messaging, multimedia messaging, web browsing, audio/video recording, audio/video playback, audio/video downloading, playing of streaming audio/video, office applications such as databases, spreadsheets, word processing, presentation creation and processing and other voice and data applications. In conjunction with these applications, the real-time data26includes voice, audio, video and multimedia applications including Internet gaming, etc. The non-real-time data24includes text messaging, email, web browsing, file uploading and downloading, etc.

In an embodiment of the present invention, the communication device10includes an integrated circuit, such as an RF integrated circuit that includes one or more features or functions of the present invention. Such integrated circuits shall be described in greater detail in association withFIGS. 2-8that follow.

FIG. 2is a schematic block diagram of an embodiment of an integrated circuit in accordance with the present invention. A voice and data RF integrated circuit (IC)70is shown that implements mobile communication device35, such as an embodiment of communication device10, in conjunction with microphone60, keypad/keyboard58, memory54, speaker62, display56, camera76, antenna interface52and wireline port64. In addition, RF IC70includes a transceiver73with RF and baseband modules for formatting and modulating data and voice signals into RF real-time data26and non-real-time data24and transmitting this data via optional off-chip power amplifier modules80and82and antenna interfaces72and74coupled to corresponding antennas, and for receiving RF data and RF voice signals via these antennas. A particular structure is shown that operates in two different frequency bands via separate optional power amplifier modules (80,82), antenna interfaces (72,74) and antennas, however one more shared multi-band components can likewise be employed.

Further, RF IC70includes an input/output module71with appropriate encoders and decoders for communicating via the wireline connection28via wireline port64, an optional memory interface for communicating with off-chip memory54, a codec for encoding voice signals from microphone60into digital voice signals, a keypad/keyboard interface for generating data from keypad/keyboard58in response to the actions of a user, a display driver for driving display56, such as by rendering a color video signal, text, graphics, or other display data, and an audio driver such as an audio amplifier for driving speaker62and one or more other interfaces, such as for interfacing with the camera76or the other peripheral devices.

Off-chip power management circuit95includes one or more DC-DC converters, voltage regulators, current regulators or other power supplies for supplying the RF IC70and optionally the other components of mobile communication device35and/or its peripheral devices with supply voltages and or currents (collectively power supply signals) that may be required to power these devices. Off-chip power management circuit95can operate from one or more batteries, line power and/or from other power sources, not shown. In particular, off-chip power management module can selectively supply power supply signals of different voltages, currents or current limits or with adjustable voltages, currents or current limits in response to power mode signals received from the voice data RF IC70. RF IC70optionally includes an on-chip power management circuit95′ for replacing the off-chip power management circuit95.

In an embodiment of the present invention, the RF IC70is a system on a chip integrated circuit that includes at least one processing device. Such a processing device, for instance, processing module225, 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 associated memory may be a single memory device or a plurality of memory devices that are either on-chip or off-chip such as memory54. 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 RF IC70implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the associated memory storing the corresponding operational instructions for this circuitry is embedded with the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry.

In operation, the RF IC70executes operational instructions that implement one or more of the applications (real-time or non-real-time) attributed to communication devices10as discussed in conjunction withFIG. 1. Further, transceiver73includes a transmitter module in accordance with the present invention as will be described in conjunction withFIG. 3.

FIG. 3is a schematic block diagram of an embodiment of an RF transceiver in accordance with the present invention. In particular, transceiver73of RF IC70is shown along with other external components of mobile communication device35including antenna interfaces (72,74) and antennas (171,171′) and optional power amplifier modules (80,82). Inbound RF signals152are received via the antenna171and antenna interface72to produce received signal153. In turn, receiver127generates inbound data160for processing in accordance with one or more applications of mobile communications of device35. In addition, inbound data160can also be generated by receiver127′ based on received signals153′ produced from inbound RF signal152′ via antenna171′ and antenna interface74.

Transmitter module129responds to outbound data162to generate the transmit signal155in a first frequency band in a first mode of operation. In a second mode of operation, transmitter module129generates the transmit signal155′ in a second frequency band. As discussed in conjunction withFIG. 1, the first and second frequency bands can be chosen from the 750, 850, 900, 1800, 1900 MHz bands or other frequency bands corresponding to other frequencies and selected in response to control signal147. Further, in response to control signal147, the transmitter module129generates the transmit signal155and/or155′ in a selected one of a plurality of wireless telephony formats, such as WCDMA or one or more other CDMA formats, GSM, EDGE, universal mobile telecommunication system (UMTS), high-speed packet access (HSPA) and/or other wireless telephony formats (either CDMA or non-CDMA). In an embodiment of the present invention, control signal147is generated by a processor such as processor225of RF IC70in accordance with a wireless telephony application. However, control signal147can optionally be generated by other elements of mobile communication device35.

The RF IC70includes an IC port180for coupling a transmit signal155in a first frequency band to optional power amplifier module80, antenna interface72and antenna171that are external to the RF IC70. Similarly, IC port182couples transmit signal155′ in a second frequency band to optional power amplifier module82, antenna interface74and antenna171′. The IC ports180and182can be input/output (I/O) pins, pads or other ports for connecting the RF IC70to external devices, via a circuit board, socket or other connection. It should be noted that the flexible multi-format configuration of transmitter module129allows RF IC70to couple to the optional power amplifiers (80,82) and external antenna structure with only two ports, saving additional ports of the RF IC70for other I/O.

The optional power amplifier module80amplifies the transmit signal155to ultimately produce outbound RF signal170via antenna interface72. The antenna171transmits the outbound RF signals170to a targeted device such as a base station, an access point and/or another wireless communication device. Similarly, the optional power amplifier module82amplifies the transmit signal155′ to ultimately produce outbound RF signal170′ via antenna interface74. The antenna171′ transmits the outbound RF signals170′ to a targeted device such as a base station, an access point and/or another wireless communication device.

Antenna interfaces72and74can each include a transmit/receive switch, a duplexer/diplexer, an impedance matching network and/or a filter. Further, while antennas171and171′ are shown as single shared antennas, the receivers127and127′ may each employ separate antennas or share a multiple antenna structure that includes two or more antennas. In another embodiment, the receiver127,127′ and/or transmitter module129may share a multiple input multiple output (MIMO) antenna structure that includes a plurality of antennas. Each antenna may be fixed, programmable, an antenna array or other antenna configuration.

FIG. 4is a schematic block diagram of another embodiment of an RF transceiver in accordance with the present invention. In particular, an embodiment is shown that operates similarly to the embodiment ofFIG. 3with similar elements being referred to by common reference numerals. In this embodiment however, transceiver173is itself a stand alone RF IC that includes receivers127and127′ and transmitter module129. Transceiver173can perform all of the functions transceiver73discussed in conjunction with RF IC70, but be included in a separate RF IC.

The transceiver173includes an IC port184for coupling a transmit signal155in a first frequency band to optional power amplifier module80, antenna interface72and antenna171that are external to the transceiver173. Similarly, IC port186couples transmit signal155′ in a second frequency band to optional power amplifier module82, antenna interface74and antenna171′. The IC ports184and186can be input/output (I/O) pins, pads or other ports for connecting the transceiver173to external devices, via a circuit board, socket or other connection. It should be noted that the flexible multi-format configuration of transmitter module129allows transceiver173to couple to the optional power amplifiers (80,82) and external antenna structure with only two ports, saving additional ports of the transceiver173for other I/O.

FIG. 5is a schematic block diagram of another embodiment of an RF transceiver in accordance with the present invention. In particular, an embodiment is shown that operates similarly to the embodiments ofFIGS. 3-4with similar elements being referred to by common reference numerals. In this embodiment however, transmitter module129is itself a stand alone RF IC.

The transmitter module129includes an IC port188for coupling a transmit signal155in a first frequency band to optional power amplifier module80, antenna interface72and antenna171that are external to the transmitter module129. Similarly, IC port190couples transmit signal155′ in a second frequency band to optional power amplifier module82, antenna interface74and antenna171′. The IC ports188and190can be input/output (I/O) pins, pads or other ports for connecting the transmitter module129to external devices, via a circuit board, socket or other connection. It should be noted that the flexible multi-format configuration allows transmitter module129to couple to the optional power amplifiers (80,82) and external antenna structure with only two ports, saving additional ports of the transmitter module129for other I/O.

FIG. 6is a schematic block diagram of an embodiment of an RF transmitter in accordance with the present invention. Transmitter module129includes transmitter processing module146, digital to analog converter (DAC) module200, mixer modules210and220, driver modules214and224, divider module234and phase-locked loop (PLL) module230. The transmitter processing module146, DAC module200, Mixer modules210and220and driver modules214and224are each capable of operating in a mixed signal environment with in-phase (I) and quadrature-phase (Q) components.

In operation, transmitter processing module146, generates baseband data, such as baseband I & Q data148and/or phase data232in response to the outbound data162. In particular, transmitter processing module146responds to a format selection indicated by the control signal147to generate baseband data in accordance with the particular wireless telephony format selected (e.g., WCDMA, GSM, EGDE, etc.). While described as “baseband”, this baseband data can be either at true baseband (zero intermediate frequency (IF)) or at some low IF, such a few MHz or less.

Note that the processing performed by the transmitter processing module146can include, but is not limited to, scrambling, encoding, puncturing, mapping, modulation, and/or digital baseband to IF conversion. Further note that the transmitter processing module146may be implemented using a shared processing device, individual processing devices, or a plurality of processing devices and may further include memory. 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 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 module146implements 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.

The digital-to-analog conversion (DAC) module200can include a digital to analog converter, a filter, such as a smoothing filter and/or gain module. The DAC module200converts the baseband I & Q signals148from the digital domain to the analog domain. The filter and/or gain module filters and/or adjusts the gain of the analog signals to produce baseband I & Q signals202, that are provided to the mixer modules210and220for up-conversion to RF.

Phase-locked loop (PLL) module230generates a PLL signal240based on a reference oscillation164from a crystal, digital RF synthesizer or other frequency reference generation device and based on a particular carrier frequency242selected by transmitter processing model146in accordance with the particular wireless telephony format that has been selected. Divider module234produces two local oscillation signals, RF oscillation236and RF oscillation238for use by mixer modules210and220in upconverting the baseband I & Q signals202to their required carrier frequencies. In addition transmitter. Divider module234can include one or more simple dividers, or fractional dividers for producing the necessary local oscillation frequencies to track the desired carrier frequencies of the transmit signals155and155′, based on any IF frequency employed as discussed above in conjunction with transmitter processing module146.

Mixer module210converts the baseband I & Q signals202into RF I & Q signals212based on the RF oscillation236. Mixer module220converts the baseband I & Q signals202into RF I & Q signals222based on the RF oscillation238. An example implementation of a mixer module is presented in conjunction withFIG. 7that follows.

Driver modules214and224include can pre-amplifiers for producing transmit signals155and155′ that driver optional off-chip power amplifier modules80and82. Alternatively driver modules214and224further include their own on-chip power amplifiers in place of the optional off-chip power amplifiers80and82. The pre-amplifier and/or power amplifier can include a polar amplification stage capable of amplitude modulating a phase modulated input signal, based on AM signal244, to produce an amplitude and phase modulated signal. Driver modules214and224can optionally include a transmit filter module for attenuating unwanted spurs and harmonics.

Depending on the selected wireless telephony format, the transmitter processing module146can generate the baseband data as I and Q data148, used in the I and Q path formed by DAC module200, mixer modules210and220and driver module214and224to generate amplitude and phase modulated transmit signals155and155′. Alternatively, transmitter processing module146can generate all or a portion of the baseband data as phase data232for directly phase modulating the PLL signal240that produces the RF oscillations236and238, to generate amplitude and phase modulated transmit signals155and155′.

For example, when a WCDMA format is selected, transmitter processing module146can generate baseband I and Q data148and transmitter module129can operate using the I and Q path formed by DAC module200, mixer modules210and220and driver module214and224to generate amplitude and phase modulated transmit signals155and155′. If an EDGE format is selected, transmitter processing module146can either generate baseband I and Q data148and transmitter module129can operate using the I and Q path formed by DAC module200, mixer modules210and220and driver module214and224to generate amplitude and phase modulated transmit signals155and155′, or, in EDGE format operation, an AM signal will be transmitted instead of the in-phase signals. In the latter case, transmitter processing module146will generate phase data232that is used by PLL module230to generate a phase modulated PLL signal240. In particular, baseband I and Q data202can include AM data and baseband I and Q signals can include AM signals244that can be passed to mixer modules210and220to produce a polar transmission. The driver modules214and224will further amplify the signal.

Further, if a GSM format is selected, transmitter processing module146can generate phase data232that is used by PLL module230to generate a phase modulated PLL signal240. The mixer modules210,220and driver modules214and224can be operated in saturation to directly couple and amplify these phase modulated signals to produce transmit signals155and/or155′ at their respective frequencies. By using common transmitter elements in processing selected formats, redundant components can be eliminated and integrated circuit real estate can be reduced.

While specific wireless telephony formats are discussed above, other wireless telephony formats can similarly be implemented using the transmitter processing module129described above. In addition, while two RF paths are shown for producing transit signals155and155′, additional RF paths can be included for use in conjunction with additional frequency bands.

FIG. 7is a schematic block diagram of an embodiment of a mixer module in accordance with the present invention. In particular, mixer module300include a pair of mixer/programmable gain amplifiers304and a phase shift network306that produces a 90-degree phase shift that operate to mix the baseband I and Q signals (312,314) (such as baseband I and Q signals202) with the RF oscillation310to produce RF I and Q signals (322,324) (such as RF I and Q signals212). For certain selected formats, such as the GSM format example described in conjunction withFIG. 6, the Mixer/PGAs304can be operated in saturation to directly pass an RF oscillation310that has already been phase modulated. In addition, when baseband I signal312includes an AM signal244for polar transmission, such as in the EDGE example discussed in conjunction withFIG. 6, the AM signal244is passed to mixer and a power amplifier or pre-power amplifier, such as driver module214and/or224discussed in conjunction withFIG. 6.

FIG. 8is a flow chart of an embodiment of a method in accordance with the present invention. In particular, a method is presented for use in conjunction with one or more of the functions and features described in conjunction withFIGS. 1-7. In step400, a first transmit signal in a first frequency band is coupled to at least one external device via a first IC port. In step402, a second transmit signal in a second frequency band is coupled to the at least one external device via a second IC port. In step404, the first transmit signal is generated based on outbound data in a first mode of operation, wherein the first transmit signal is generated in a selected one of a plurality of wireless telephony formats based on a control signal. In step406, the second transmit signal is generated based on the outbound data in a second mode of operation, wherein the second transmit signal is generated in the selected one of the plurality of wireless telephony formats based on the control signal and wherein the plurality of wireless telephony formats includes a code divisional multiple access format and at least one non-code division multiple access format.

In an embodiment of the present invention, the code divisional multiple access format includes a wideband code divisional multiple access format. The non-code divisional multiple access format can includes a GSM Association format, such as a GSM or EDGE format. The plurality of wireless telephony formats can include three or more wireless telephony formats.

In an embodiment of the present invention, step404includes: generating baseband data in response to the outbound data and based on the control signal; generating at least one baseband signal in response to the baseband data; generating at least one first RF signal based on the at least one baseband signal and a first RF oscillation; and generating the first transmit signal, based on the first RF signal. Step408can include: generating at least one second RF signal based on the at least one baseband signal and a second RF oscillation; and generating the second transmit signal, based on the second RF signal, wherein when the code division multiple access format is selected, the baseband data includes in-phase and quadrature-phase data, the at least one baseband signal includes in-phase and quadrature-phase signals, and the at least one first RF signal includes in-phase and quadrature-phase first RF signals, and wherein the at least one second RF signal includes in-phase and quadrature-phase second RF signals.

Step406can further include: generating a phase locked loop (PLL) signal based on a reference oscillation; and generating the first RF oscillation based on the PLL signal. Step406can further include generating the second RF oscillation based on the PLL signal.

When the GSM format is selected, the baseband data can include phase data, and the PLL signal can be phase modulated based on the phase data. When the EDGE format is selected, the baseband data can either include in-phase and quadrature-phase data, or the baseband data can include amplitude modulation (AM) data and phase modulated (PM) data, the at least one baseband signal includes an AM signal, the PLL signal can be phase modulated based on the phase data, and the at least one first RF signal can be amplitude modulated based on the AM signal, and the at least one second RF signal can be amplitude modulated based on the AM signal.