CONFIGURABLE FILTER BANDS FOR RADIO FREQUENCY COMMUNICATION

Configurable filter bands for radio frequency communication are disclosed. In one aspect, a radio frequency module includes a plurality of n-plexers, each of the n-plexers including n filters, each of the filters configured to pass at least one radio frequency band, and at least two of the radio frequency bands having overlapping frequencies, an antenna terminal, and an antenna switch module configured to connect two or more of the n-plexers to the antenna terminal.

CROSS-REFERENCE TO RELATED APPLICATION(S)

BACKGROUND

Field

Embodiments of this disclosure relate to radio frequency front-end modules that include configurable filters.

Description of the Related Technology

With 5G development, carrier aggregation (CA) is being implemented in radio frequency (RF) modules. To support carrier aggregation, multiple filters are ganged together within a multiplexer. To support 5G, many different filters are included in order to pass frequencies associated with a plurality of radio frequency bands. It can be costly to provide a separate filter for each and every band required to support 5G.

SUMMARY

One aspect of this disclosure is a radio frequency module comprising: a plurality of n-plexers, each of the n-plexers including n filters, each of the filters configured to pass at least one radio frequency band, and at least two of the radio frequency bands having overlapping frequencies; an antenna terminal; and an antenna switch module configured to connect two or more of the n-plexers to the antenna terminal.

In some embodiments, a first one of the n-plexers includes a first filter configured to pass a first one of the at least two radio frequency bands having overlapping frequencies, and a second one of the n-plexers includes a first filter configured to pass a second one of the at least two radio frequency bands having overlapping frequencies.

In some embodiments, the second filter is further configured to pass a third radio frequency band different from the first and second radio frequency bands.

In some embodiments, the antenna switch module is further configured to connect the antenna terminal to the first n-plexer and the second n-plexer to enable communications over the first radio frequency band and the third radio frequency band.

In some embodiments, the antenna switch module is further configured to connect the antenna terminal to the second n-plexer and a third n-plexer to enable communications over the second radio frequency band and a fourth radio frequency band different from the first to third radio frequency bands, the third n-plexer is configured to pass the fourth radio frequency band.

In some embodiments, the second filter is further configured to pass a transmit portion of the third radio frequency band and pass a transmit portion of the third radio frequency band, and the second n-plexer further includes a third filter configured to pass a receive portion of a fifth radio frequency band and a receive portion of the third radio frequency band.

In some embodiments, the third n-plexer includes a fourth filter configured to pass a receive portion of the third radio frequency band, a fifth filter configured to pass a transmit portion of the fifth radio frequency band, and a sixth filter configured to pass transmit and receive portions of the fourth radio frequency band.

In some embodiments, the antenna switch module is further configured to connect the antenna terminal to the first n-plexer, the second n-plexer, and a fourth n-plexer including a seventh filter configured to pass a sixth radio frequency band to enable communications over the first, third, and sixth radio frequency bands.

In some embodiments, a second one of the n-plexers includes a second filter configured to pass a transmit portion of a third radio frequency band and a third one of the n-plexers includes a fourth filter configured to pass a receive portion of the third radio frequency band, the antenna switch module is further configured to connect the antenna terminal to the second n-plexer and the third n-plexer to enable communication over the third radio frequency band.

In some embodiments, connecting of the antenna terminal to two or more of the n-plexers enables E-UTRAN, New Radio, Dual Connectivity (ENDC) multiple-input multiple-output (MIMO) and downlink (DL)CA.

In some embodiments, the at least two of the radio frequency bands having overlapping frequencies is used for ENDC MIMO and DL CA.

In some embodiments, the at least two of the radio frequency bands include band B25Tx and band B3Rx.

Another aspect is a mobile device comprising: an antenna configured to transmit and receive radio frequency signals; and a front-end system coupled to the antenna and including a plurality of n-plexers, each of the n-plexers including n filters, each of the filters configured to pass at least one radio frequency band, and at least two of the radio frequency bands having overlapping frequencies, an antenna terminal coupled to the antenna, and an antenna switch module configured to connect two or more of the n-plexers to the antenna terminal.

In some embodiments, a first one of the n-plexers includes a first filter configured to pass a first one of the at least two radio frequency bands having overlapping frequencies, and a second one of the n-plexers includes a first filter configured to pass a second one of the at least two radio frequency bands having overlapping frequencies.

In some embodiments, the second filter is further configured to pass a third radio frequency band different from the first and second radio frequency bands.

In some embodiments, the antenna switch module is further configured to connect the antenna terminal to the first n-plexer and the second n-plexer to enable communications over the first radio frequency band and the third radio frequency band.

In some embodiments, the antenna switch module is further configured to connect the antenna terminal to the second n-plexer and a third n-plexer to enable communications over the second radio frequency band and a fourth radio frequency band different from the first to third radio frequency bands, the third n-plexer is configured to pass the fourth radio frequency band.

Yet another aspect is a radio frequency module comprising: a front-end including a plurality of n-plexers, each of the n-plexers including n filters, each of the filters configured to pass at least one radio frequency band, and at least two of the radio frequency bands having overlapping frequencies, an antenna terminal, and an antenna switch module configured to connect two or more of the n-plexers to the antenna terminal; and an antenna coupled to the antenna terminal, the front-end and the antenna being enclosed within a common package.

In some embodiments, a first one of the n-plexers includes a first filter configured to pass a first one of the at least two radio frequency bands having overlapping frequencies, and a second one of the n-plexers includes a first filter configured to pass a second one of the at least two radio frequency bands having overlapping frequencies.

In some embodiments, the second filter is further configured to pass a third radio frequency band different from the first and second radio frequency bands.

DETAILED DESCRIPTION

The International Telecommunication Union (ITU) is a specialized agency of the United Nations (UN) responsible for global issues concerning information and communication technologies, including the shared global use of radio spectrum.

The 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications standard bodies across the world, such as the Association of Radio Industries and Businesses (ARIB), the Telecommunications Technology Committee (TTC), the China Communications Standards Association (CCSA), the Alliance for Telecommunications Industry Solutions (ATIS), the Telecommunications Technology Association (TTA), the European Telecommunications Standards Institute (ETSI), and the Telecommunications Standards Development Society, India (TSDSI).

Working within the scope of the ITU, 3GPP develops and maintains technical specifications for a variety of mobile communication technologies, including, for example, second generation (2G) technology (for instance, Global System for Mobile Communications (GSM) and Enhanced Data Rates for GSM Evolution (EDGE)), third generation (3G) technology (for instance, Universal Mobile Telecommunications System (UMTS) and High Speed Packet Access (HSPA)), and fourth generation (4G) technology (for instance, Long Term Evolution (LTE) and LTE-Advanced).

The technical specifications controlled by 3GPP can be expanded and revised by specification releases, which can span multiple years and specify a breadth of new features and evolutions.

In one example, 3GPP introduced carrier aggregation (CA) for LTE in Release 10. Although initially introduced with two downlink carriers, 3GPP expanded carrier aggregation in Release 14 to include up to five downlink carriers and up to three uplink carriers. Other examples of new features and evolutions provided by 3GPP releases include, but are not limited to, License Assisted Access (LAA), enhanced LAA (eLAA), Narrowband Internet of things (NB-IOT), Vehicle-to-Everything (V2X), and High Power User Equipment (HPUE).

3GPP introduced Phase 1 of fifth generation (5G) technology in Release 15, and plans to introduce Phase 2 of 5G technology in Release 16 (targeted for 2020). Subsequent 3GPP releases will further evolve and expand 5G technology. 5G technology is also referred to herein as 5G New Radio (NR).

5G NR supports or plans to support a variety of features, such as communications over millimeter wave spectrum, beamforming capability, high spectral efficiency waveforms, low latency communications, multiple radio numerology, and/or non-orthogonal multiple access (NOMA). Although such RF functionalities offer flexibility to networks and enhance user data rates, supporting such features can pose a number of technical challenges.

The teachings herein are applicable to a wide variety of communication systems, including, but not limited to, communication systems using advanced cellular technologies, such as LTE-Advanced, LTE-Advanced Pro, and/or 5G NR.

Example Communication Networks and Wireless Communication Devices

FIG.1Ais a schematic diagram of one example of a communication network10. The communication network10includes a macro cell base station1, a small cell base station3, and various examples of user equipment (UE), including a first mobile device2a, a wireless-connected car2b, a laptop2c, a stationary wireless device2d, a wireless-connected train2e, a second mobile device2f, and a third mobile device2g.

Although specific examples of base stations and user equipment are illustrated inFIG.1A, a communication network can include base stations and user equipment of a wide variety of types and/or numbers.

For instance, in the example shown, the communication network10includes the macro cell base station1and the small cell base station3. The small cell base station3can operate with relatively lower power, shorter range, and/or with fewer concurrent users relative to the macro cell base station1. The small cell base station3can also be referred to as a femtocell, a picocell, or a microcell. Although the communication network10is illustrated as including two base stations, the communication network10can be implemented to include more or fewer base stations and/or base stations of other types.

Although various examples of user equipment are shown, the teachings herein are applicable to a wide variety of user equipment, including, but not limited to, mobile phones, tablets, laptops, IoT devices, wearable electronics, customer premises equipment (CPE), wireless-connected vehicles, wireless relays, and/or a wide variety of other communication devices. Furthermore, user equipment includes not only currently available communication devices that operate in a cellular network, but also subsequently developed communication devices that will be readily implementable with the inventive systems, processes, methods, and devices as described and claimed herein.

The illustrated communication network10ofFIG.1Asupports communications using a variety of cellular technologies, including, for example, 4G LTE and 5G NR. In certain implementations, the communication network10is further adapted to provide a wireless local area network (WLAN), such as WiFi. Although various examples of communication technologies have been provided, the communication network10can be adapted to support a wide variety of communication technologies.

Various communication links of the communication network10have been depicted inFIG.1A. The communication links can be duplexed in a wide variety of ways, including, for example, using frequency-division duplexing (FDD) and/or time-division duplexing (TDD). FDD is a type of radio frequency communications that uses different frequencies for transmitting and receiving signals. FDD can provide a number of advantages, such as high data rates and low latency. In contrast, TDD is a type of radio frequency communications that uses about the same frequency for transmitting and receiving signals, and in which transmit and receive communications are switched in time. TDD can provide a number of advantages, such as efficient use of spectrum and variable allocation of throughput between transmit and receive directions.

In certain implementations, user equipment can communicate with a base station using one or more of 4G LTE, 5G NR, and WiFi technologies. In certain implementations, enhanced license assisted access (eLAA) is used to aggregate one or more licensed frequency carriers (for instance, licensed 4G LTE and/or 5G NR frequencies), with one or more unlicensed carriers (for instance, unlicensed WiFi frequencies).

As shown inFIG.1A, the communication links include not only communication links between UE and base stations, but also UE to UE communications and base station to base station communications. For example, the communication network10can be implemented to support self-fronthaul and/or self-backhaul (for instance, as between mobile device2gand mobile device20.

The communication links can operate over a wide variety of frequencies. In certain implementations, communications are supported using 5G NR technology over one or more frequency bands that are less than 6 Gigahertz (GHz) and/or over one or more frequency bands that are greater than 6 GHz. For example, the communication links can serve Frequency Range 1 (FR1), Frequency Range 2 (FR2), or a combination thereof. In one embodiment, one or more of the mobile devices support a HPUE power class specification.

In certain implementations, a base station and/or user equipment communicates using beamforming. For example, beamforming can be used to focus signal strength to overcome path losses, such as high loss associated with communicating over high signal frequencies. In certain embodiments, user equipment, such as one or more mobile phones, communicate using beamforming on millimeter wave frequency bands in the range of 30 GHz to 300 GHz and/or upper centimeter wave frequencies in the range of 6 GHz to 30 GHz, or more particularly, 24 GHz to 30 GHz.

Different users of the communication network10can share available network resources, such as available frequency spectrum, in a wide variety of ways.

In one example, frequency division multiple access (FDMA) is used to divide a frequency band into multiple frequency carriers. Additionally, one or more carriers are allocated to a particular user. Examples of FDMA include, but are not limited to, single carrier FDMA (SC-FDMA) and orthogonal FDMA (OFDMA). OFDMA is a multicarrier technology that subdivides the available bandwidth into multiple mutually orthogonal narrowband subcarriers, which can be separately assigned to different users.

Other examples of shared access include, but are not limited to, time division multiple access (TDMA) in which a user is allocated particular time slots for using a frequency resource, code division multiple access (CDMA) in which a frequency resource is shared amongst different users by assigning each user a unique code, space-divisional multiple access (SDMA) in which beamforming is used to provide shared access by spatial division, and non-orthogonal multiple access (NOMA) in which the power domain is used for multiple access. For example, NOMA can be used to serve multiple users at the same frequency, time, and/or code, but with different power levels.

Enhanced mobile broadband (eMBB) refers to technology for growing system capacity of LTE networks. For example, eMBB can refer to communications with a peak data rate of at least 10 Gbps and a minimum of 100 Mbps for each user. Ultra-reliable low latency communications (uRLLC) refers to technology for communication with very low latency, for instance, less than 2 milliseconds. uRLLC can be used for mission-critical communications such as for autonomous driving and/or remote surgery applications. Massive machine-type communications (mMTC) refers to low cost and low data rate communications associated with wireless connections to everyday objects, such as those associated with Internet of Things (IoT) applications.

The communication network10ofFIG.1Acan be used to support a wide variety of advanced communication features, including, but not limited to, eMBB, uRLLC, and/or mMTC.

FIG.1Bis a schematic diagram of one example of a mobile device2acommunicating via cellular and WiFi networks. For example, as shown inFIG.1B, the mobile device2acommunicates with a base station1of a cellular network and with a WiFi access point3of a WiFi network.FIG.1Balso depicts examples of other user equipment (UE) communicating with the base station1, for instance, a wireless-connected car2band another mobile device2c. Furthermore,FIG.1Balso depicts examples of other WiFi-enabled devices communicating with the WiFi access point3, for instance, a laptop4.

Although specific examples of cellular UE and WiFi-enabled devices is shown, a wide variety of types of devices can communicate using cellular and/or WiFi networks. Examples of such devices, include, but are not limited to, mobile phones, tablets, laptops, Internet of Things (IoT) devices, wearable electronics, customer premises equipment (CPE), wireless-connected vehicles, wireless relays, and/or a wide variety of other communication devices.

In certain implementations, UE, such as the mobile device2aofFIG.1B, is implemented to support communications using a number of technologies, including, but not limited to, 2G, 3G, 4G (including LTE, LTE-Advanced, and LTE-Advanced Pro), 5G NR, WLAN (for instance, WiFi), WPAN (for instance, Bluetooth and ZigBee), WMAN (for instance, WiMax), and/or GPS. In certain implementations, enhanced license assisted access (eLAA) is used to aggregate one or more licensed frequency carriers (for instance, licensed 4G LTE and/or 5G NR frequencies), with one or more unlicensed carriers (for instance, unlicensed WiFi frequencies).

Furthermore, certain UE can communicate not only with base stations and access points, but also with other UE. For example, the wireless-connected car2bcan communicate with a wireless-connected pedestrian2d, a wireless-connected stop light2e, and/or another wireless-connected car2fusing vehicle-to-vehicle (V2V) and/or vehicle-to-everything (V2X) communications.

Although various examples of communication technologies have been described, mobile devices can be implemented to support a wide range of communications.

Various communication links have been depicted inFIG.1B. The communication links can be duplexed in a wide variety of ways, including, for example, using frequency-division duplexing (FDD) and/or time-division duplexing (TDD). FDD is a type of radio frequency communications that uses different frequencies for transmitting and receiving signals. FDD can provide a number of advantages, such as high data rates and low latency. In contrast, TDD is a type of radio frequency communications that uses about the same frequency for transmitting and receiving signals, and in which transmit and receive communications are switched in time. TDD can provide a number of advantages, such as efficient use of spectrum and variable allocation of throughput between transmit and receive directions.

Different users of the illustrated communication networks can share available network resources, such as available frequency spectrum, in a wide variety of ways. In one example, frequency division multiple access (FDMA) is used to divide a frequency band into multiple frequency carriers. Additionally, one or more carriers are allocated to a particular user. Examples of FDMA include, but are not limited to, single carrier FDMA (SC-FDMA) and orthogonal FDMA (OFDMA). OFDM is a multicarrier technology that subdivides the available bandwidth into multiple mutually orthogonal narrowband subcarriers, which can be separately assigned to different users.

Other examples of shared access include, but are not limited to, time division multiple access (TDMA) in which a user is allocated particular time slots for using a frequency resource, code division multiple access (CDMA) in which a frequency resource is shared amongst different users by assigning each user a unique code, space-divisional multiple access (SDMA) in which beamforming is used to provide shared access by spatial division, and non-orthogonal multiple access (NOMA) in which the power domain is used for multiple access. For example, NOMA can be used to serve multiple users at the same frequency, time, and/or code, but with different power levels.

Certain RF communication systems include multiple transceivers for communicating using different wireless networks, over multiple frequency bands, and/or using different communication standards. Although implementing an RF communication system in this manner can expand functionality, increase bandwidth, and/or enhance flexibility, a number of coexistence issues can arise between the transceivers operating within the RF communication system.

For example, an RF communication system can include a cellular transceiver for processing RF signals communicated over a cellular network and a wireless local area network (WLAN) transceiver for processing RF signals communicated over a WLAN network, such as a WiFi network. For instance, the mobile device2aofFIG.1Bis operable to communicate using cellular and WiFi networks.

Although implementing the RF communication system in this manner can provide a number of benefits, a mutual desensitization effect can arise from cellular transmissions interfering with reception of WiFi signals and/or from WiFi transmissions interfering with reception of cellular signals.

In one example, cellular Band 7 can give rise to mutual desensitization with respect to 2.4 Gigahertz (GHz) WiFi. For instance, Band 7 has an FDD duplex and operates over a frequency range of about 2.62 GHz to 2.69 GHz for downlink and over a frequency range of about 2.50 GHz to about 2.57 GHz for uplink, while 2.4 GHz WiFi has TDD duplex and operates over a frequency range of about 2.40 GHz to about 2.50 GHz. Thus, cellular Band 7 and 2.4 GHz WiFi are adjacent in frequency, and RF signal leakage due to the high power transmitter of one transceiver/front-end affects receiver performance of the other transceiver/front-end, particularly at border frequency channels.

In another example, cellular Band 40 and 2.4 GHz WiFi can give rise to mutual desensitization. For example, Band 40 has a TDD duplex and operates over a frequency range of about 2.30 GHz to about 2.40 GHz, while 2.4 GHz WiFi has TDD duplex and operates over a frequency range of about 2.40 GHz to about 2.50 GHz. Accordingly, cellular Band 40 and 2.4 GHz WiFi are adjacent in frequency and give rise to a number of coexistence issues, particularly at border frequency channels.

Desensitization can arise not only from direct leakage of an aggressor transmit signal to a victim receiver, but also from spectral regrowth components generated in the transmitter. Such interference can lie relatively closely in frequency with the victim receive signal and/or directly overlap it.

FIG.2is a schematic diagram of one embodiment of a mobile device800. The mobile device800includes a baseband system801, a transceiver802, a front-end system803, antennas804, a power management system805, a memory806, a user interface807, and a battery808.

The transceiver802generates RF signals for transmission and processes incoming RF signals received from the antennas804. 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 inFIG.2as the transceiver802. In one example, separate components (for instance, separate circuits or dies) can be provided for handling certain types of RF signals.

The front-end system803aids in conditioning signals transmitted to and/or received from the antennas804. In the illustrated embodiment, the front-end system803includes antenna tuning circuitry810, power amplifiers (PAs)811, low noise amplifiers (LNAs)812, filters813, switches814, and signal splitting/combining circuitry815. However, other implementations are possible.

For example, the front-end system803can 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.

The antennas804can include antennas used for a wide variety of types of communications. For example, the antennas804can include antennas for transmitting and/or receiving signals associated with a wide variety of frequencies and communications standards.

The mobile device800can operate with beamforming in certain implementations. For example, the front-end system803can include amplifiers having controllable gain and phase shifters having controllable phase to provide beam formation and directivity for transmission and/or reception of signals using the antennas804. For example, in the context of signal transmission, the amplitude and phases of the transmit signals provided to the antennas804are controlled such that radiated signals from the antennas804combine 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 amplitude and phases are controlled such that more signal energy is received when the signal is arriving to the antennas804from a particular direction. In certain implementations, the antennas804include one or more arrays of antenna elements to enhance beamforming.

The baseband system801is coupled to the user interface807to facilitate processing of various user input and output (I/O), such as voice and data. The baseband system801provides the transceiver802with digital representations of transmit signals, which the transceiver802processes to generate RF signals for transmission. The baseband system801also processes digital representations of received signals provided by the transceiver802. As shown inFIG.2, the baseband system801is coupled to the memory806of facilitate operation of the mobile device800.

The memory806can be used for a wide variety of purposes, such as storing data and/or instructions to facilitate the operation of the mobile device800and/or to provide storage of user information.

The power management system805provides a number of power management functions of the mobile device800. In certain implementations, the power management system805includes a PA supply control circuit that controls the supply voltages of the power amplifiers811. For example, the power management system805can be configured to change the supply voltage(s) provided to one or more of the power amplifiers811to improve efficiency, such as power added efficiency (PAE).

As shown inFIG.2, the power management system805receives a battery voltage from the battery808. The battery808can be any suitable battery for use in the mobile device800, including, for example, a lithium-ion battery.

FIG.3is a schematic diagram of a power amplifier system860according to one embodiment. The illustrated power amplifier system860includes a baseband processor841, a transmitter/observation receiver842, a power amplifier (PA)843, a directional coupler844, front-end circuitry845, an antenna846, a PA bias control circuit847, and a PA supply control circuit848. The illustrated transmitter/observation receiver842includes an I/Q modulator857, a mixer858, and an analog-to-digital converter (ADC)859. In certain implementations, the transmitter/observation receiver842is incorporated into a transceiver.

The baseband processor841can be used to generate an in-phase (I) signal and a quadrature-phase (Q) signal, which can be used to represent a sinusoidal wave or signal of a desired amplitude, frequency, and phase. For example, the I signal can be used to represent an in-phase component of the sinusoidal wave and the Q signal can be used to represent a quadrature-phase component of the sinusoidal wave, which can be an equivalent representation of the sinusoidal wave. In certain implementations, the I and Q signals can be provided to the I/Q modulator857in a digital format. The baseband processor841can be any suitable processor configured to process a baseband signal. For instance, the baseband processor841can include a digital signal processor, a microprocessor, a programmable core, or any combination thereof. Moreover, in some implementations, two or more baseband processors841can be included in the power amplifier system860.

The I/Q modulator857can be configured to receive the I and Q signals from the baseband processor841and to process the I and Q signals to generate an RF signal. For example, the I/Q modulator857can include digital-to-analog converters (DACs) configured to convert the I and Q signals into an analog format, mixers for upconverting the I and Q signals to RF, and a signal combiner for combining the upconverted I and Q signals into an RF signal suitable for amplification by the power amplifier843. In certain implementations, the I/Q modulator857can include one or more filters configured to filter frequency content of signals processed therein.

The power amplifier843can receive the RF signal from the I/Q modulator857, and when enabled can provide an amplified RF signal to the antenna846via the front-end circuitry845.

The front-end circuitry845can be implemented in a wide variety of ways. In one example, the front-end circuitry845includes one or more switches, filters, diplexers, multiplexers, and/or other components. In another example, the front-end circuitry845is omitted in favor of the power amplifier843providing the amplified RF signal directly to the antenna846.

The directional coupler844senses an output signal of the power amplifier823. Additionally, the sensed output signal from the directional coupler844is provided to the mixer858, which multiplies the sensed output signal by a reference signal of a controlled frequency. The mixer858operates to generate a downshifted signal by downshifting the sensed output signal's frequency content. The downshifted signal can be provided to the ADC859, which can convert the downshifted signal to a digital format suitable for processing by the baseband processor841. Including a feedback path from the output of the power amplifier843to the baseband processor841can provide a number of advantages. For example, implementing the baseband processor841in this manner can aid in providing power control, compensating for transmitter impairments, and/or in performing digital pre-distortion (DPD). Although one example of a sensing path for a power amplifier is shown, other implementations are possible.

The PA supply control circuit848receives a power control signal from the baseband processor841, and controls supply voltages of the power amplifier843. In the illustrated configuration, the PA supply control circuit848generates a first supply voltage VCC1for powering an input stage of the power amplifier843and a second supply voltage VCC2for powering an output stage of the power amplifier843. The PA supply control circuit848can control the voltage level of the first supply voltage VCC1and/or the second supply voltage VCC2to enhance the power amplifier system's PAE.

The PA supply control circuit848can employ various power management techniques to change the voltage level of one or more of the supply voltages over time to improve the power amplifier's power added efficiency (PAE), thereby reducing power dissipation.

One technique for improving efficiency of a power amplifier is average power tracking (APT), in which a DC-to-DC converter is used to generate a supply voltage for a power amplifier based on the power amplifier's average output power. Another technique for improving efficiency of a power amplifier is envelope tracking (ET), in which a supply voltage of the power amplifier is controlled in relation to the envelope of the RF signal. Thus, when a voltage level of the envelope of the RF signal increases the voltage level of the power amplifier's supply voltage can be increased. Likewise, when the voltage level of the envelope of the RF signal decreases the voltage level of the power amplifier's supply voltage can be decreased to reduce power consumption.

In certain configurations, the PA supply control circuit848is a multi-mode supply control circuit that can operate in multiple supply control modes including an APT mode and an ET mode. For example, the power control signal from the baseband processor841can instruct the PA supply control circuit848to operate in a particular supply control mode.

As shown inFIG.3, the PA bias control circuit847receives a bias control signal from the baseband processor841, and generates bias control signals for the power amplifier843. In the illustrated configuration, the bias control circuit847generates bias control signals for both an input stage of the power amplifier843and an output stage of the power amplifier843. However, other implementations are possible.

Example Filter Banks for Overlapping Frequency Bands

Depending on the standard used for radio frequency communication, two or more bands used to implement the standard may have at least partially overlapping frequencies. 5G NR introduced several ENDC (E-UTRAN, New Radio, Dual Connectivity) cases.

According to 3GPP standards documents, ENDC allows user equipment to connect to an LTE enodeB that acts as a master node and a 5G gnodeB that acts as a secondary node. In effect, ENDC allows 4G LTE and 5G bandwidth to be used at the same time, and when users attempt to download content, such as a video, the speed at which that video transfers comes from both 4G LTE and 5G simultaneously. In order to implement ENDC, the user equipment front-end can connect a single antenna to two receive paths, corresponding to the frequency bands used for the LTE enodeB and 5G gnodeB wireless nodes.

One example of overlapping frequencies in 5G NR ENDC MIMO and downlink (DL) CA is DC_25_66. A design challenge for implementing radio frequency systems that support 5G NR ENDC MIMO and DL CA involves designing an integrated, low-cost solution that can handle such overlapping frequencies between different bands.

In the DC_25_66 example, there is a problem that arises due to the B25Tx band overlapping with the B3Rx band. In certain implementations of standards prior to 5G NR, a B1/3/40 penta-plexer and a B25 duplexer were used. However, due to the overlapping frequencies between the B25Tx and B3Rx bands, the penta-plexer cannot be switched combined with B25 and reused for 5G NR ENDC and DL CA implementations. In order to reuse the penta-plexer an additional external or internal B25_66 quad-plexer would also have to be added, resulting in additional cost and area penalty for the implementation. In addition to the added cost, it is challenging to fit the additional quad-plexer in an already crowded module.

Aspects of this disclosure relate to a flexible technique for reusing the B3Tx/B1Rx filter (which forms a B66 filter) with the B25 duplexer. As is described in detail below, by splitting the penta-plexer into a duplexer and a tri-plexer, aspects of this disclosure provide additional flexibility to support 5G NR ENDC MIMO and DL CA case DC_25_66, while reusing one or more of the n-plexers for other use cases. The reuse of these n-plexers provides additional flexibility, reduced the footprint of the front-end module, and reduced the cost by reducing the number of filters used to implement the same number of bands. In certain aspects, issues introduced due to the overlapping of certain frequency bands can be addressed by separating filter banks that were previously ganged together.

FIG.4is an example chart showing overlapping frequencies for two bands. With reference toFIG.4, a first band102extends over a first range of frequencies and a second band104extends of a second range of frequencies that partially overlaps the first range of frequencies. In the specific illustrated example, the first band102is band B3 Rx, which extends from 1805 MHz to 1880 MHz and the second band104is band B25 Tx which extends from 1850 MHz to 1915 Mhz. However, this is merely one example and aspects of this disclosure can be applied to other bands that at least partially overlap.

It is challenging to design an integrated low-cost solution dealing with overlapping frequencies, such as those illustrated inFIG.4. 5G NR introduced several ENDC cases, one of which is DC_25_66. The DC_25_66 ENDC case posed a problem with band B25Tx overlapping with band B3Rx. In particular, the B1/3/40 penta-plexer cannot be reused for DC_25_66 due to the overlap of band B25Tx with band B3Rx. In order to implement DC_25_66 while reusing the B1/3/40 penta-plexer, an external or internal B25_66 quad-plexer can be added as shown inFIGS.6and7. In addition to the additional cost for the added component(s), it is challenging to fit another duplexer in an already crowded front-end module.

FIG.5is an example block diagram illustrating a portion of a front-end system in accordance with aspects of this disclosure. In some implementations, the example front-end system803may implement the 4G standard. In particular, the front-end system803ofFIG.5includes a subset of filters813and switches814that may be used to implement a full front-end system803(e.g., as shown inFIG.2). With reference toFIG.5, the front-end system803includes a multichip module (MCM) including a plurality of n-plexers202,204,206,208, and210, a switch (also referred to as an antenna switch module (ASM))212, and an antenna terminal214.

The n-plexers202-212include a first duplexer202, a first penta-plexer204, a second duplexer206, a first filter208, and a third duplexer210. The first duplexer202can include a filter for the B25 Tx band and a filter for the B25 Rx band. The first penta-plexer204can include a filter for the B3 Tx band, a filter for the B1 Tx band, a filter for the B3 Rx band, a filter for the B1 Rx band, and a filter for the B40 TRx band. The second duplexer206can include a filter for the B7 Tx band and a filter for the B7 Rx band. The first filter208can be a filter for the B41F TRx band. The third duplexer210can include a filter for the B34TRx band and a filter for the B39TRx band. The above filters and bands are merely examples and other implementations can include n-plexers202-210including filters for other sets of bands without departing from aspects of this disclosure.

The duplexer202together with the penta-plexer204may be optimized for carrier aggregation performance for 4G LTE. This implementation can support band B66 by using the filters for band B3Tx and B1Rx (e.g., by extended the frequency range over 2110-2200 MHz). For example, band B66Tx can range from 1710-1780 MHz while band B66Rx can range from 2110-2200 MHz. However, this implementation may not support bands B25 and n66 internally (e.g., within the MCM200) due to the frequency loading between bands B25Tx and B3Rx.

FIG.6is an example block diagram illustrating a portion of a front-end system configured to implement 5G NR ENDC MIMO and DL CA in accordance with aspects of this disclosure. The implementation ofFIG.6builds on theFIG.5front-end system803by adding a separate quad-plexer216external to the MCM200. The n-plexers204-210, the switch212, and the antenna terminal214may be substantially similar to those discussed above in connection withFIG.5. The quad-plexer216includes a thirteenth filter for band B66 Tx, a fourteenth filter for band B66 Rx, a fifteenth filter for band B25 Tx, and a sixteenth filter for band B25 Rx. The addition of the quad-plexer216provides 5G NR ENDC MIMO and DL CA support for bands B25+n66.

FIG.7is an example block diagram illustrating a multichip module200configured to implement 5G NR ENDC MIMO and DL CA in accordance with aspects of this disclosure. The implementation ofFIG.7is similar to theFIG.6front-end system803except that the external quad-plexer216has been replaced with an internal quad-plexer218located inside the MCM200. The n-plexers204-210, the switch212, and the antenna terminal214may be substantially similar to those discussed above in connection withFIGS.5and6. The internal quad-plexer218is substantially the same as the external quad-plexer216inFIG.7. The addition of the quad-plexer216provides 5G NR ENDC MIMO and DL CA support for bands B25+n66. The embodiment ofFIG.7has an advantage over theFIG.6embodiment in that users of the MCM200do not need to implement an external quad-plexer216.

However, there are at least some drawbacks to the implementations discussed in connection withFIGS.6and7. For example, the use of an external quad-plexer216introduces certain drawbacks, including additional costs, additional size, and additional manufacturing steps. In addition, the use of an internal quad-plexer218introduces certain drawbacks, including increased manufacturing costs and the size of the filter footprint within the MCM200. Thus, it is desirable to provide an implementation that can support 5G NR ENDC MIMO and DL CA bands B25+n66 (or other overlapping bands) without introducing one or more of the above drawbacks.

Aspects of this disclosure relate to systems and techniques for implementing 5G NR ENDC MIMO and DL CA that address at least some of the above-identified drawbacks. In some implementations, the MCM200can address at least some of the drawbacks while reducing the number of required filters by two.

FIG.8is an example block diagram illustrating a multichip module200having a configurable filter bank in accordance with aspects of this disclosure. In some implementations, the configurable filter bank may be used to support 5G NR ENDC MIMO and DL CA. The implementation ofFIG.8is similar to theFIG.7MCM200. For example, the n-plexers206-210and the antenna terminal214ofFIG.8may be substantially similar to those discussed above in connection withFIGS.5-7. However, the internal quad-plexer218and the penta-plexer204may be replaced with a fourth duplexer224, a fifth duplexer226, and a tri-plexer228. The switch222may be configured to connect two or more of the n-plexers206-210,224, and226to the antenna terminal214. For example, the switch222can simultaneously connect two or more of the n-plexers206-210,224, and226to the antenna terminal214to implement a larger n-plexer comprising the filters in the two or more of the n-plexers206-210,224, and226. Aspects of this disclosure reduce the number of required filters by two, for example, from 14 filters to 12 filters. This reduction in the number of required filters necessary to implement ENDC and DL CA provides substantial savings in cost and area.

In some implementations, the fourth duplexer224includes a filter for the B25 Tx band and a filter for the B25 Rx band, the fifth duplexer226includes a filter for the B3/66 Tx bands and a filter for the B3/B66 Rx bands, and the tri-plexer228includes filter for the B3 Rx band, a filter for the B1 Tx band, and a filter for the B40 TRx band. The switch222can be configured to connect different combinations of the n-plexers206-210,224, and226to the antenna terminal214in order to implement the same combinations of filters provided by the embodiments ofFIGS.7and8. Table 1 provides an example set of states for the switch222in accordance with aspects of this disclosure.

By splitting the penta-plexer204into the fifth duplexer226and the tri-plexer228, the switch222is able to combine the filter banks of the n-plexers206-210,224, and226to form the combination of filter present in the penta-plexer204or to combine the fifth duplexer226with the fourth duplexer224. Because the fifth duplexer226is also configured to band-pass the same frequencies for the B66 Tx and Rx bands, the MCM200according to the embodiment ofFIG.8eliminates the need for an additional n66 duplexer required for ENDC MIMO and DL CA B25_n66. In other words, the switch222is able to connect both the fourth duplexer224and the fifth duplexer226to the antenna terminal214to provide the same functionality as the penta-plexer204, thereby providing an implementation for ENDC MIMO and DL CA B25_n66.

Aspects of this disclosure provide a flexible way to reuse the band B3Tx/B1Rx filters (which also form a B66 filter) in the fifth duplexer226with the band B25 filters in the fourth duplexer224. Aspects of this disclosure further provide the flexibility of forming a penta-plexer (e.g., B1TRX/3TRX/40TDD) or a quad-plexer (B25TRX/66TRX) by the selective combination of the fourth duplexer224, the fifth duplexer226, and/or the tri-plexer228. For example, the switch222can simultaneously connect two or more of the fourth duplexer224, the fifth duplexer226, and/or the tri-plexer228to the antenna terminal214to implement the penta-plexer (e.g., B1TRX/3TRX/40TDD) or the quad-plexer (B25TRX/66TRX). One advantage to these implementations is that the front-end200does not require any additional filters (e.g., internal quad-plexer218ofFIG.7) to be placed inside the module.

FIG.9illustrates a first example state of the switch222ofFIG.8. With reference toFIG.9, the switch222is simultaneously connecting the fifth duplexer226and the tri-plexer228to the antenna port214. This configuration of the switch222implements substantially the same combination of filters as the penta-plexer204ofFIGS.6and7.

FIG.10illustrates a second example state of the switch222ofFIG.8. With reference toFIG.10, the switch222is simultaneously connecting the fourth duplexer224and the fifth duplexer226. This configuration of the switch222implements substantially the same combination of filters as the external and internal quad-plexers216and218ofFIGS.6and7.

FIG.11illustrates a third example state of the switch222ofFIG.8. With reference toFIG.11, the switch222is simultaneously connecting the fourth duplexer224and the first filter208. This configuration of the switch222connects the band B25 Tx and Rx filters with the band B41F TRx filter to support bands B25+n41.

FIG.12illustrates a fourth example state of the switch222ofFIG.8. With reference toFIG.12, the switch222is simultaneously connecting the fourth duplexer224and the second duplexer206. This configuration of the switch222connects the band B25 Tx and Rx filters with the band B7 Tx and Rx filters to support bands B25+n7.

FIG.13illustrates a fifth example state of the switch222ofFIG.8. With reference toFIG.13, the switch222is simultaneously connecting the fifth duplexer226, the tri-plexer228, and the second duplexer206. This configuration of the switch222connects the bands B3/B66 Tx and Rx filters, the band B3 Rx filter, the band B1 Tx filter, the band B40 TRx filter, and the band B7 Tx and Rx filters to support the penta-plexer (e.g., penta-plexer204)+n7.

FIG.14illustrates a sixth example state of the switch222ofFIG.8. With reference toFIG.14, the switch222is simultaneously connecting the fifth duplexer226, the tri-plexer228, and the first filter208. This configuration of the switch222simultaneously connects the bands B3/B66 Tx and Rx filters, the band B3 Rx filter, the band B1 Tx filter, the band B40 TRx filter, and the band B41F TRx filter to support the penta-plexer (e.g., penta-plexer204)+n41.

FIG.15illustrates another example overlap between different bands in accordance with aspects of this disclosure. With reference toFIG.15, a first band302extends over a first range of frequencies and a second band304extends of a second range of frequencies that partially overlaps the first range of frequencies. In the specific illustrated example, the first band302is band B20 Tx, which extends from 832 MHz to 862 MHz and the second band304is band B26 Rx which extends from 850 MHz to 894 Mhz.

FIG.16illustrates yet another example overlap between different bands in accordance with aspects of this disclosure. With reference toFIG.16, a first band312extends over a first range of frequencies and a second band314extends of a second range of frequencies that partially overlaps the first range of frequencies. In the specific illustrated example, the first band312is band B28 Tx, which extends from 703 MHz to 748 MHz and the second band314is band B13 Rx which extends from 746 MHz to 756 Mhz.

WhileFIGS.4,15, and16illustrate certain example overlapping bands, there may be other overlapping bands depending on the particular radio frequency standard being implemented. For example, other example include band B20TX overlapping with B26RX, and B28TX overlapping with B13RX.

CONCLUSION

Aspects of this disclosure 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 such as packaged radio frequency modules, uplink wireless communication devices, wireless communication infrastructure, electronic test equipment, etc. Examples of the electronic devices can include, but are not limited to, a mobile phone such as a smart phone, a wearable computing device such as a smart watch or an ear piece, a telephone, a television, a computer monitor, a computer, a modem, a hand-held computer, a laptop computer, a tablet computer, a microwave, a refrigerator, a vehicular electronics system such as an automotive electronics system, a stereo system, a digital music player, a radio, a camera such as 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.

Unless the context indicates otherwise, throughout the description and the claims, the words “comprise,” “comprising,” “include,” “including” and the like are to generally 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.” Conditional language used herein, such as, among others, “can,” “could,” “might,” “may,” “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. 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.

While certain embodiments 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 resonators described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the resonators described herein may be made without departing from the spirit of the disclosure. Any suitable combination of the elements and/or acts of the various embodiments described above can be combined to provide further embodiments. 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.