Power amplifiers with supply capacitor switching

Abstract

This invention provides a power amplifier with a supply capacitor switching capability. In some embodiments, a power amplifier system includes a power amplifier that amplifies a radio frequency (RF) signal, a power management circuit that controls a voltage level of a supply voltage of the power amplifier, a supply capacitor connected to a first terminal of the supply voltage, and an integrated bulk n-type field-effect transistor (NFET) switch. The power management circuit can operate in multiple supply control modes (e.g., an average power tracking mode and an envelope tracking mode). Furthermore, the bulk NFET switching is controlled based on the supply control mode of the power management circuit. The bulk NFET switch includes a ground NFET connected in series with a second terminal of the supply capacitor and a ground voltage, and a discharge NFET connected between the second terminal of the supply capacitor and the supply voltage.

Description

Technical Field

[0001] The embodiments of the present invention relate to electronic systems, and more specifically, to power amplifiers for radio frequency (RF) electronic devices. Prior Technology

[0002] Power amplifiers are used in radio frequency (RF) communication systems to amplify RF signals used for transmission via antennas. Managing the power of RF signal transmission to extend battery life and / or provide a suitable transmission power level can be important.

[0003] Examples of RF communication systems having one or more power amplifiers include (but are not limited to) mobile phones, tablets, base stations, network access points, laptops, and wearable electronic devices. The power amplifiers provide amplification of RF signals, which may have a frequency in the range of approximately 30 kHz to 300 GHz (e.g., for fifth-generation (5G) communication using frequency range 1 (FR1), in the range of approximately 410 MHz to approximately 7.125 GHz, or for 5G communication using frequency range 2 (FR2), in the range of approximately 24.25 GHz to 52.6 GHz). Summary of the Invention

[0004] In some embodiments, the present invention relates to a mobile device. The mobile device includes: a power amplifier configured to amplify a radio frequency signal; a power management circuit configured to control a voltage level of a supply voltage of the power amplifier and operable in a selected supply control mode selected from a plurality of supply control modes; and a front-end system including a supply capacitor connected to a first terminal of the supply voltage, an n-type field-effect transistor grounding switch connected between a second terminal of the supply capacitor and a ground voltage, and an n-type field-effect transistor discharge switch connected between the second terminal of the supply capacitor and the supply voltage. The n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch are controlled based on the selected supply control mode.

[0005] In some embodiments, the plurality of supply control modes include an average power tracking mode and an envelope tracking mode. According to several embodiments, the n-type field-effect transistor grounding switch is configured to be on in the average power tracking mode and off in the envelope tracking mode, and the n-type field-effect transistor discharge switch is configured to be off in the average power tracking mode and on in the envelope tracking mode.

[0006] In various embodiments, the n-type field-effect transistor discharge switch comprises two or more n-type field-effect transistors connected in series. According to several embodiments, the front-end system further includes a voltage divider configured to bias one of the two or more n-type field-effect transistors. According to several embodiments, the voltage divider includes a first terminal connected to one of the supply voltages and a second terminal connected to the ground voltage through a mode transistor. According to some embodiments, the plurality of supply control modes includes an average power tracking mode and an envelope tracking mode, the mode transistor being configured to be turned on in the envelope tracking mode and off in the average power tracking mode.

[0007] In several embodiments, the n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch are implemented on a semiconductor die manufactured using an integrated silicon process.

[0008] In some embodiments, the present invention relates to a packaging module. The packaging module includes: a packaging substrate; and a first die attached to the packaging substrate and comprising a power amplifier configured to amplify a radio frequency signal and receive power from a supply voltage controlled by a power management circuit. The packaging module further includes: a supply capacitor attached to the packaging substrate and having a first terminal connected to the supply voltage; and a second die attached to the packaging substrate and manufactured using an integrated silicon process. The second die includes an n-type field-effect transistor grounding switch connected between a second terminal of the supply capacitor and a ground voltage, and an n-type field-effect transistor discharge switch connected between the second terminal of the supply capacitor and the supply voltage.

[0009] In various embodiments, the power management circuit can operate in a selected supply control mode, indicating either an average power tracking mode or an envelope tracking mode, wherein the n-type MOSFET grounding switch and the n-type MOSFET discharge switch are controlled based on the selected supply control mode. According to several embodiments, the n-type MOSFET grounding switch is configured to be on in the average power tracking mode and off in the envelope tracking mode, and the n-type MOSFET discharge switch is configured to be off in the average power tracking mode and on in the envelope tracking mode.

[0010] In some embodiments, the n-type field-effect transistor discharge switch comprises two or more n-type field-effect transistors connected in series. According to various embodiments, the second die further comprises a voltage divider configured to bias one of the two or more n-type field-effect transistors. According to several embodiments, the voltage divider comprises a first terminal connected to one of the supply voltages and a second terminal connected to one of the ground voltages through a mode transistor.

[0011] In various embodiments, the package module further includes a supply pin configured to receive the supply voltage, and the power management circuit is external to the package module.

[0012] In some embodiments, the present invention relates to a power amplifier system. The power amplifier system includes: a power amplifier configured to amplify a radio frequency signal; a power management circuit configured to control a voltage level of a supply voltage of the power amplifier and operable in a selected supply control mode selected from a plurality of supply control modes; a supply capacitor having a first terminal connected to the supply voltage; an n-type field-effect transistor grounding switch connected between a second terminal of the supply capacitor and a ground voltage; and an n-type field-effect transistor discharge switch connected between the second terminal of the supply capacitor and the supply voltage. The n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch are controlled based on the selected supply control mode.

[0013] In various embodiments, the plurality of supply control modes include an average power tracking mode and an envelope tracking mode. According to several embodiments, the n-type field-effect transistor grounding switch is configured to be turned on in the average power tracking mode and off in the envelope tracking mode, and the n-type field-effect transistor discharge switch is configured to be turned off in the average power tracking mode and on in the envelope tracking mode.

[0014] In several embodiments, the n-type field-effect transistor discharge switch comprises two or more n-type field-effect transistors connected in series. According to various embodiments, the power amplifier system further includes a voltage divider configured to bias one of the two or more n-type field-effect transistors. According to various embodiments, the voltage divider includes a first terminal connected to one of the supply voltages and a second terminal connected to the ground voltage through a mode transistor. According to some embodiments, the plurality of supply control modes includes an average power tracking mode and an envelope tracking mode, the mode transistor being configured to be turned on in the envelope tracking mode and off in the average power tracking mode.

[0015] In various embodiments, the n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch are implemented on a semiconductor die manufactured using an integrated silicon process.

[0016] In some embodiments, the present invention relates to a power amplification method. The method includes amplifying a radio frequency signal using a power amplifier and controlling a voltage level of a supply voltage of the power amplifier using a power management circuit, the supply voltage being coupled to a first terminal of a supply capacitor. The method further includes operating the power management circuit in a selected supply control mode selected from a plurality of supply control modes, and controlling an n-type field-effect transistor grounding switch based on the selected supply control mode, the n-type field-effect transistor grounding switch being connected between a second terminal of the supply capacitor and a ground voltage. The method further includes controlling an n-type field-effect transistor discharge switch based on the selected supply control mode, the n-type field-effect transistor grounding switch being connected between the second terminal of the supply capacitor and the supply voltage.

[0017] In various embodiments, the plurality of supply control modes include an average power tracking mode and an envelope tracking mode. According to several embodiments, the method further includes turning on the n-type MOSFET grounding switch in the average power tracking mode and turning off the n-type MOSFET grounding switch in the envelope tracking mode. According to some embodiments, the method further includes turning off the n-type MOSFET discharge switch in the average power tracking mode and turning on the n-type MOSFET discharge switch in the envelope tracking mode. Simple Explanation of the Diagram

[0018] Figure 1 is a schematic diagram of one example of a communication network.

[0019] Figure 2A is a schematic diagram of one example of a communication link using carrier aggregation.

[0020] Figure 2B illustrates various examples of uplink carrier aggregation used in the communication link of Figure 2A.

[0021] Figure 2C illustrates various examples of downlink carrier aggregation used in the communication link of Figure 2A.

[0022] Figure 3A shows a graph of the power amplifier supply voltage versus time, one of the first examples.

[0023] Figure 3B shows a graph of the power amplifier supply voltage versus time, one of the second examples.

[0024] Figure 3C shows a graph of the power amplifier supply voltage versus time, one of the third examples.

[0025] Figure 4 is a schematic diagram of one embodiment of a power amplifier system.

[0026] Figure 5 is a schematic diagram of another embodiment of a power amplifier system.

[0027] Figure 6A is a schematic diagram of another embodiment of a power amplifier system.

[0028] Figure 6B is a curve diagram of one example of the power amplifier system in Figure 6A, showing the power mode switching waveform.

[0029] Figure 7A is a schematic diagram of one embodiment of a packaging module.

[0030] Figure 7B is a schematic cross-section of one of the packaging modules of Figure 7A obtained along line 7B-7B.

[0031] Figure 8 is a schematic diagram of one embodiment of a mobile device. Implementation

[0032] The following detailed description of certain embodiments presents various descriptions of particular embodiments. However, the innovations described herein can be embodied in a multitude of different ways, for example, as defined and covered by the claims of the invention. In this description, reference is made to the drawings, where the same element symbols may indicate the same or functionally similar elements. It will be understood that the elements drawn in the drawings are not necessarily drawn to scale. Furthermore, it will be understood that some embodiments may include more elements than are drawn in one drawing and / or a subset of the elements drawn in one drawing. In addition, some embodiments may incorporate any suitable combination of features from two or more drawings.

[0033] Figure 1 is a schematic diagram of one example of a communication network 10. The communication network 10 includes various examples of a giant cell base station 1, a small cell base station 3, and user equipment (UE), including a first mobile device 2a, a wirelessly connected car 2b, a laptop computer 2c, a fixed wireless device 2d, a wirelessly connected train 2e, a second mobile device 2f, and a third mobile device 2g.

[0034] Although specific examples of base stations and user equipment are shown in Figure 1, a communication network may include a wide variety of types and / or numbers of base stations and user equipment.

[0035] For example, in the illustrated example, communication network 10 includes a giant cell base station 1 and a small cell base station 3. Compared to the giant cell base station 1, the small cell base station 3 can operate with relatively lower power, shorter range, and / or fewer concurrent users. The small cell base station 3 may also be referred to as a microcell, a picocell, or a microcell. Although communication network 10 is illustrated as including two base stations, communication network 10 can be implemented to include more or fewer base stations and / or other types of base stations.

[0036] While various examples of user devices are shown, the teachings herein are applicable to a wide range of user devices, including (but not limited to) mobile phones, tablets, laptops, IoT devices, wearable electronics, customer premises equipment (CPE), wirelessly connected vehicles, wireless repeaters, and / or a wide variety of other communication devices. Furthermore, user devices include not only currently available communication devices operating in a cellular network, but also subsequently developed communication devices that can be readily implemented with the systems, procedures, methods, and devices of the present invention as described and claimed herein.

[0037] The communication network 10 illustrated in Figure 1 supports communication using various cellular technologies, including (e.g.) 4G LTE and 5G NR. In some implementations, the communication network 10 is further adapted to provide a wireless local area network (WLAN), such as WiFi. While various examples of communication technologies have been provided, the communication network 10 can be adapted to support a wide range of communication technologies.

[0038] Figure 1 illustrates various communication links of communication network 10. A wide variety of duplex communication links are possible, including (for example) using Frequency Division Duplex (FDD) and / or Time Division Duplex (TDD). FDD is a type of radio frequency communication that uses different frequencies for transmitting and receiving signals. FDD offers several advantages, such as high data rates and low latency. In contrast, TDD is a type of radio frequency communication that uses approximately the same frequency for transmitting and receiving signals, wherein the transmission and reception communications are switched in time. TDD offers several advantages, such as efficient use of spectrum and variable allocation of transmission capacity between the transmission and reception directions.

[0039] In some implementations, a user device may communicate with a base station using one or more of 4G LTE, 5G NR, and WiFi technologies. In some implementations, enhanced licensed assisted access (eLAA) is used to aggregate one or more licensed frequency carriers (e.g., licensed 4G LTE and / or 5G NR frequencies) with one or more unlicensed carriers (e.g., unlicensed WiFi frequencies).

[0040] As shown in Figure 1, the communication link includes not only the communication link between the UE and the base station, but also communication between UEs and between base stations. For example, the communication network 10 may be implemented to support self-forwarding and / or self-reload (e.g., between mobile device 2g and mobile device 2f).

[0041] Communication links can operate over a wide range of frequencies. In some implementations, 5G NR technology is used to support communication on one or more frequency bands below 6 GHz and / or on one or more frequency bands above 6 GHz. For example, a communication link may serve frequency range 1 (FR1), frequency range 2 (FR2), or a combination thereof. In one embodiment, one or more mobile devices support an HPUE power class specification.

[0042] In some implementations, a base station and / or user equipment uses beamforming for communication. For example, beamforming can be used to focus signal strength to overcome path loss, such as the high loss associated with communication via high signal frequencies. In some embodiments, user equipment (such as one or more mobile phones) uses beamforming to communicate in millimeter-wave bands in the range of 30 GHz to 300 GHz and / or centimeter-wave frequencies in the range of 6 GHz to 30 GHz (or more specifically, 24 GHz to 30 GHz).

[0043] Different users of the communication network 10 can share available network resources, such as available spectrum, in a wide range of ways.

[0044] In one instance, Frequency Division Multiple Access (FDMA) is used to divide a frequency band into multiple frequency carriers. Additionally, one or more carriers are assigned to a specific user. Examples of FDMA include (but are not limited to) Single-Carrier FDMA (SC-FDMA) and Orthogonal FDMA (OFDMA). OFDMA is a multi-carrier technique that subdivides the available bandwidth into multiple mutually orthogonal narrow-band subcarriers (which can be individually assigned to different users).

[0045] Other examples of shared access include (but are not limited to): Time Division Multiple Access (TDMA), in which a specific time slot for using a frequency resource is allocated to a user; Code Division Multiple Access (CDMA), in which a frequency resource is shared among different users by assigning a unique code to each user; Spatial Division Multiple Access (SDMA), in which beamforming is used to provide shared access through spatial division; and Non-Orthogonal Multiple Access (NOMA), in which a power domain is used for multiple access. For example, NOMA can be used to serve multiple users with the same frequency, time, and / or code but using different power levels.

[0046] Enhanced Mobile Broadband (eMBB) refers to technologies used to increase the system capacity of LTE networks. For example, eMBB can refer to communication with a peak data rate of at least 10 Gbps and a minimum data rate of 100 Mbps per user. Ultra-Reliable Low-Latency Communication (uRLLC) refers to a technology used for communication with very low latency (e.g., 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 Communication (mMTC) refers to low-cost and low-data-rate communication associated with wireless connectivity to everyday objects, such as low-cost and low-data-rate communication associated with Internet of Things (IoT) applications.

[0047] The communication network 10 in Figure 1 can be used to support a wide range of advanced communication features, including (but not limited to) eMBB, uRLLC and / or mMTC.

[0048] Figure 2A is a schematic diagram of one example of a communication link using carrier aggregation. Carrier aggregation can be used to widen the bandwidth of a communication link by supporting communication on multiple frequency carriers, thereby increasing user data rates and enhancing network capacity through segmented spectrum allocation.

[0049] In the illustrated example, a communication link is set between a base station 21 and a mobile device 22. As shown in Figure 2A, the communication link includes a downlink channel for RF communication from base station 21 to mobile device 22 and an uplink channel for RF communication from mobile device 22 to base station 21.

[0050] Although Figure 2A illustrates carrier aggregation in the context of FDD communication, carrier aggregation can also be used in TDD communication.

[0051] In some implementations, a communication link can provide asymmetric data rates for a downlink channel and an uplink channel. For example, a communication link can be used to support a relatively high downlink data rate to enable high-speed streaming of multimedia content to a mobile device, while providing a relatively slow data rate for uploading data from the mobile device to the cloud.

[0052] In the illustrated example, base station 21 and mobile device 22 communicate via carrier aggregation, which can be used to selectively increase the bandwidth of the communication link. Carrier aggregation includes contiguous aggregation, where consecutive carriers within the same operating frequency band are aggregated. Carrier aggregation can also be discontinuous and can include carriers with separated frequencies within a common frequency band or in different frequency bands.

[0053] In the example shown in Figure 2A, the uplink channel comprises three aggregated component carriers fUL1, fUL2, and fUL3. Additionally, the downlink channel comprises five aggregated component carriers fDL1, fDL2, fDL3, fDL4, and fDL5. While this illustrates one example of component carrier aggregation, more or fewer carriers can be aggregated for the uplink and / or downlink. Furthermore, the number of aggregated carriers can vary over time to achieve the desired uplink and downlink data rates.

[0054] For example, the number of aggregated carriers used for uplink and / or downlink communication relative to a particular mobile device may change over time. For example, the number of aggregated carriers may change as the device moves through the communication network and / or as network usage changes over time.

[0055] Figure 2B illustrates various examples of uplink carrier aggregation used in the communication link of Figure 2A. Figure 2B includes a first carrier aggregation example 31, a second carrier aggregation example 32, and a third carrier aggregation example 33, which schematically depict three types of carrier aggregation.

[0056] Carrier aggregation examples 31 to 33 illustrate different spectral allocations for a first component carrier fUL1, a second component carrier fUL2, and a third component carrier fUL3. Although Figure 2B is illustrated in the background of aggregating three component carriers, carrier aggregation can be used to aggregate more or fewer carriers. Furthermore, although illustrated in the background of the uplink, the aggregation examples are also applicable to the downlink.

[0057] First carrier aggregation example 31 illustrates the aggregation of consecutive carriers within a frequency band, wherein component carriers that are frequency-adjacent and in a common frequency band are aggregated. For example, first carrier aggregation example 31 depicts the aggregation of consecutive component carriers fUL1, fUL2, and fUL3 located within a first frequency band BAND1.

[0058] Referring again to Figure 2B, Second Carrier Aggregation Example 32 illustrates the aggregation of discontinuous carriers within a frequency band, wherein two or more component carriers that are not adjacent in frequency and are located within a common frequency band are aggregated. For example, Second Carrier Aggregation Example 32 depicts the aggregation of discontinuous component carriers fUL1, fUL2, and fUL3 located within a first frequency band BAND1.

[0059] Third carrier aggregation example 33 illustrates inter-band discontinuous carrier aggregation, wherein component carriers that are not adjacent in frequency and are in multiple frequency bands are aggregated. For example, third carrier aggregation example 33 depicts the aggregation of component carriers fUL1 and fUL2 of a first frequency band BAND1 with component carrier fUL3 of a second frequency band BAND2.

[0060] Figure 2C illustrates various examples of downlink carrier aggregation used in the communication link of Figure 2A. The examples depict various carrier aggregation cases 34 to 38 with different spectrum allocations for a first component carrier f DL1, a second component carrier f DL2, a third component carrier f DL3, a fourth component carrier f DL4, and a fifth component carrier f DL5. Although Figure 2C is illustrated in the background of aggregating five component carriers, carrier aggregation can be used to aggregate more or fewer carriers. Furthermore, although illustrated in the background of the downlink, the aggregation examples are also applicable to the uplink.

[0061] First carrier aggregation example 34 depicts the aggregation of contiguous component carriers located within the same frequency band. Second carrier aggregation example 35 and third carrier aggregation example 36 illustrate two instances of aggregation that are not contiguous but located within the same frequency band. Furthermore, fourth carrier aggregation example 37 and fifth carrier aggregation example 38 illustrate two instances of aggregation of component carriers that are not frequency-adjacent and exist in multiple frequency bands. As the number of aggregated component carriers increases, the complexity of one possible carrier aggregation case also increases.

[0062] Referring to Figures 2A to 2C, the individual component carriers used in carrier aggregation can have various frequencies, including, for example, frequency carriers in the same frequency band or in multiple frequency bands. Furthermore, carrier aggregation is applicable to embodiments where the individual component carriers have approximately the same bandwidth and embodiments where the individual component carriers have different bandwidths.

[0063] Some communication networks allocate one primary component carrier (PCC) or anchor carrier for the uplink and one PCC for the downlink to a specific user device. Additionally, when a mobile device communicates using a single frequency carrier for either the uplink or downlink, the user device uses the PCC for communication. To enhance bandwidth for uplink communication, the uplink PCC may be aggregated with one or more uplink secondary component carriers (SCCs). Similarly, to enhance bandwidth for downlink communication, the downlink PCC may be aggregated with one or more downlink SCCs.

[0064] In some implementations, a communication network provides a network cell for each component carrier. Additionally, a primary cell may use a PCC operation, while a secondary cell may use an SCC operation. For example, due to differences in carrier frequency and / or network environment, the primary and secondary cells may have different coverage areas.

[0065] Licensed Assisted Access (LAA) refers to downlink carrier aggregation where one licensed frequency carrier associated with a mobile communication operator is aggregated with one frequency carrier in unlicensed spectrum (such as WiFi). LAA uses one downlink PCC (Public Control Code) in the licensed spectrum carrying control and communication information associated with the communication link, while unlicensed spectrum, when available, is aggregated for wider downlink bandwidth. LAA can operate with dynamic adjustments to secondary carriers to avoid WiFi users and / or coexistence with WiFi users. Enhanced Licensed Assisted Access (eLAA) is an evolution of LAA that aggregates licensed and unlicensed spectrum for both downlink and uplink. [Power amplifier with capacitor switching capability]

[0066] In mobile applications such as cellular communication systems, extending battery life is crucial. This is because a significant amount of battery charge is consumed by an operating system that consumes power or amplifies RF signals for wireless transmission.

[0067] To increase efficiency and thereby extend battery life, a mobile device may include a power management circuit for controlling a voltage level of the supply voltage of a power amplifier. For example, the power management circuit may employ various power management techniques to change the voltage level of the power amplifier's supply voltage over time to improve the power-added efficiency (PAE) of the power amplifier, thereby reducing power consumption and extending battery life.

[0068] One technique for power management of a power amplifier is average power tracking (APT), in which a DC-DC converter or other suitable voltage regulator is used to generate a supply voltage for the power amplifier based on the average output power of the power amplifier. For example, when APT is provided, the supply voltage can be set to a specific voltage level (e.g., a fixed voltage level within a transmission frame) based on the average output power over a time interval.

[0069] Another technique for improving the efficiency of a power amplifier is envelope tracking (ET), in which a supply voltage of the power amplifier is controlled relative to the envelope of an RF signal. Therefore, when the voltage level of the RF signal envelope increases, the voltage level of the power amplifier's supply voltage can increase. Similarly, when the voltage level of the RF signal envelope decreases, the voltage level of the power amplifier's supply voltage can decrease to reduce power consumption.

[0070] The power amplifier system can be multi-mode and is specified to operate in a linear mode (APT mode) with a static DC supply or in a quasi-compression mode (ET mode) with a dynamically changing supply.

[0071] 4G / 5G waveforms contain amplitude modulation (AM) characteristics that cause rapidly changing current characteristics in the power amplifier. Furthermore, the finite impedance of the power amplifier supply network can lead to degradation in power amplifier linearity, and therefore, large capacitance values ​​in the supply network are expected during APT operation. Conversely, during ET operation, the power amplifier supply is designed to support high-frequency modulation and cannot tolerate large capacitance values ​​in the power amplifier supply network.

[0072] For example, a mobile device may include a shared power management circuit that can be configured in an APT mode or an ET mode, depending on the signal power level and operating characteristics (e.g., whether 3G, 4G, and / or 5G waveforms are used). In an APT mode, the power management circuit is expected to drive a large capacitor (e.g., in the range of 1 uF), while in an ET mode (especially for 5G applications), the load capacitance is expected to be limited to several hundred pF for wide envelope tracking bandwidth. For a 5G application in APT mode, a power amplifier is expected to operate with a large supply capacitor in the range of several nanofarads (nF) to meet adjacent channel power ratio (ACPR) and / or adjacent band leakage ratio (ACLR) specifications.

[0073] This document provides a power amplifier with a supply capacitor switching capability. In some embodiments, a power amplifier system includes a power amplifier that amplifies an RF signal, a power management circuit that controls a control level of a supply voltage to the power amplifier, a supply capacitor connected to a first terminal of the supply voltage, and an integrated n-type field-effect transistor (NFET) switch. The power management circuit can operate in multiple supply control modes, including, for example, an APT mode and an ET mode. Additionally, the supply control mode of the power management circuit controls the body NFET switch. The body NFET switch includes a ground NFET connected in series with a second terminal of the supply capacitor and a ground voltage, and a discharge NFET connected between the second terminal of the supply capacitor and the supply voltage.

[0074] Therefore, a power amplifier can be designed to support multiple supply control modes (such as APT and ET modes) and operate with optimal or near-optimal performance across these modes. Furthermore, the supply capacitors can be switched using a low-cost, low-complexity switching solution that utilizes only NFET devices in integrated silicon technology.

[0075] In contrast, one approach using a p-type field-effect transistor (PFET) in bulk silicon can provide isolation (e.g., using a three-well CMOS process) to avoid voltage swings below ground and / or substrate parasitic forward bias, but it can withstand the significant challenge of supporting low-voltage DC supply conditions and / or the additional well capacitance of the large PFET significantly limiting the minimum capacitance state during ET mode. In another example, an NFET switch can be connected between a supply capacitor and ground, and a charge pump can be used to bias one gate of the NFET switch above the supply voltage. However, this approach requires an additional pin interface to supply the charge pump circuitry and increases the risk of clock parasitic signals (clock spurs) disrupting the power amplifier's transmission spectrum. In yet another example, SOI technology can be used to avoid substrate effects but adds significant cost due to complex semiconductor processes.

[0076] Figure 3A shows a graph 47 of a first example of a power amplifier supply voltage versus time. Graph 47 plots the voltage of an RF signal 41, the envelope 42 of the RF signal, and a power amplifier supply voltage 43 relative to time. Graph 47 corresponds to an example of a waveform in an embodiment where the power amplifier supply voltage 43 is substantially fixed.

[0077] It is important that the power amplifier supply voltage 43 of a power amplifier has a voltage greater than that of the RF signal 41. For example, supplying a power amplifier with a power amplifier supply voltage less than that of the RF signal can clip the RF signal, thereby causing signal distortion and / or other problems. Therefore, it is important that the power amplifier supply voltage 43 is greater than the voltage of the envelope 42. However, since the region between the power amplifier supply voltage 43 and the envelope 42 can represent energy loss (which can reduce battery life and increase heat generation in a wireless device), it is desirable to reduce the voltage difference between the power amplifier supply voltage 43 and the envelope 42 of the RF signal 41.

[0078] Figure 3B shows a second example of a power amplifier supply voltage versus time curve 48. Curve 48 plots the voltage of an RF signal 41, the envelope 42 of the RF signal, and a power amplifier supply voltage 44 relative to time. Curve 48 corresponds to an example of a waveform of an embodiment in which the power amplifier supply voltage 44 is generated by envelope tracking.

[0079] Envelope tracking is a technique used to increase the power-added efficiency (PAE) of a power amplifier system by effectively controlling the voltage level of the power amplifier supply voltage relative to the envelope of an RF signal amplified by the power amplifier. Therefore, when the envelope of the RF signal increases, the voltage supplied to the power amplifier can increase. Similarly, when the envelope of the RF signal decreases, the voltage supplied to the power amplifier can decrease to reduce power consumption.

[0080] Compared to the power amplifier supply voltage 43 in Figure 3A, the power amplifier supply voltage 44 in Figure 3B changes relative to the envelope 42 of the RF signal 41. The region between the power amplifier supply voltage 44 and the envelope 42 in Figure 3B is smaller than the region between the power amplifier supply voltage 43 and the envelope 42 in Figure 3A, and therefore the curve 48 in Figure 3B can be associated with a power amplifier system with greater energy efficiency.

[0081] Figure 3C shows a third example of a power amplifier supply voltage versus time curve 49. Curve 49 plots the voltage of an RF signal 41, the envelope 42 of the RF signal, and a power amplifier supply voltage 45 relative to time. Curve 49 corresponds to an example of a waveform in an embodiment where the power amplifier supply voltage 45 is generated by average power point tracking (APT).

[0082] APT (Advanced Transmission Power) is a technique used to improve the efficiency of a power amplifier, wherein the voltage level of the power amplifier's supply voltage is controlled based on the average output power of the power amplifier. When operating with APT, the voltage level of the power amplifier's supply voltage can be substantially fixed for a specific time slot or time interval but adjusted for a subsequent time slot based on the average output power (e.g., a transmission power control level). APT can achieve an efficiency gain relative to a fixed power amplifier supply voltage, but the efficiency gain is less than that of envelope tracking. However, envelope tracking can have a higher complexity, cost, and / or additional overhead compared to APT.

[0083] Figure 4 is a schematic diagram of one embodiment of a power amplifier system 70. The power amplifier system 70 shown includes a switch 51, an antenna 52, a directional coupler 54, a power management circuit 60, a bias control circuit 61, a power amplifier 62, a transceiver 63, and a baseband processor 64.

[0084] While Figure 4 illustrates one embodiment of a power amplifier system, the teachings herein are applicable to power amplifier systems implemented in a wide variety of ways. For example, a power amplifier system may include more or fewer components, components in different configurations, and / or components implemented in different ways.

[0085] In the illustrated embodiment, transceiver 63 includes a power amplifier control circuit 66, an I / Q modulator 67, a mixer 68, and an analog-to-digital converter (ADC) 69. Although not shown in FIG4 for simplicity, transceiver 63 can also process signals received from one or more antennas (e.g., antenna 52 and / or (a number of) other antennas) via one or more receive paths. Furthermore, transceiver 63 can be implemented in other ways, including (but not limited to) different implementations using (a number of) transmit paths, (a number of) observe paths, and / or power amplifier control circuitry systems.

[0086] The baseband processor 64 can be used to generate an in-phase (I) signal and a quadrature-phase (Q) signal, which can be used to represent a sine wave or signal having a desired amplitude, frequency, and phase. For example, the I signal can be used to represent an in-phase component of a sine wave and the Q signal can be used to represent a quadrature-phase component of a sine wave, which can be an equivalent representation of a sine wave. In some embodiments, the I and Q signals can be provided to the I / Q modulator 67 in a digital format. The baseband processor 64 can be any suitable processor configured to process a baseband signal. For example, the baseband processor 64 can include a digital signal processor, a microprocessor, a programmable core, or any combination thereof. Furthermore, in some embodiments, two or more baseband processors 64 can be included in the power amplifier system 70.

[0087] I / Q modulator 67 can be configured to receive and process I and Q signals from baseband processor 64 to generate an RF signal. For example, I / Q modulator 67 may include a digital-to-analog converter (DAC) configured to convert I and Q signals to an analog format, a mixer 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 power amplifier 62. In some embodiments, I / Q modulator 67 may include one or more filters configured to filter the frequency content of the signal processed therein.

[0088] Power amplifier 62 can receive RF signals from I / Q modulator 67, and when enabled, can provide an amplified RF signal to antenna 52 via switch 51. Directional coupler 54 can be positioned between the output of power amplifier 62 and the input of switch 51, thereby allowing output power measurement of power amplifier 62 without the insertion loss of switch 51. However, other power measurement configurations are possible.

[0089] In this embodiment, switch 51 includes an antenna switch and / or a band switch. Switch 51 may further include one or more supply control switches (each connected to a corresponding supply capacitor) implemented according to the teachings herein. These supply control switches may be used in any or all stages of power amplifier 62.

[0090] In the illustrated configuration, the sensed output signal from directional coupler 54 is provided to mixer 68, which multiplies the sensed output signal by a reference signal of a controlled frequency. Mixer 68 operates to generate a down-shifted signal by down-shifting the frequency content of the sensed output signal. The down-shifted signal can be provided to ADC 69, which can convert the down-shifted signal to a digital format suitable for processing by baseband processor 64. Through a feedback path including the output of power amplifier 62 and baseband processor 64, baseband processor 64 can be configured to dynamically adjust the I and Q signals to optimize the operation of power amplifier system 70. For example, configuring power amplifier system 70 in this way can assist in controlling the PAE and / or linearity of power amplifier 62.

[0091] In the illustrated embodiment, the power management circuit 60 receives a power control signal from the transceiver 63 and controls the supply voltage of the power amplifier 62. In some embodiments, the transceiver 63 is electrically connected to the power management circuit 60 via a serial interface, and the power management circuit 60 receives the power control signal via the serial interface.

[0092] As shown in Figure 4, power management circuit 60 generates a first supply voltage VCC1 for powering one input stage of power amplifier 62 and a second supply voltage VCC2 for powering one output stage of power amplifier 62. Power management circuit 60 can control the voltage levels of the first supply voltage VCC1 and / or the second supply voltage VCC2 to enhance the power amplifier system's power efficiency (PAE). Although an embodiment with one of two controllable supply voltages is shown, a power management circuit can control more or fewer supply voltage levels. In some embodiments, a power amplifier operates with one or more controllable supply voltages and one or more substantially fixed supply voltages.

[0093] In the illustrated embodiment, the power control signal instructs the power management circuit 60 to operate in a specific supply control mode (such as an APT mode or an ET mode). Therefore, in this embodiment, the power amplifier control circuit 66 of the transceiver 63 controls the selected supply control mode.

[0094] As shown in Figure 4, the bias control circuit 61 receives a bias control signal from the transceiver 63 and generates a bias control signal for the power amplifier 62. Additionally, the bias control circuit 61 generates a bias control signal based on the bias control signal.

[0095] The bias control signal identifies the supply control mode in which the power management circuit 60 operates, and the bias control circuit 61 generates a bias control signal based on the indicated supply control mode. In some embodiments, the transceiver 63 is electrically connected to the bias control circuit 61 via a serial interface, and the bias control circuit 61 receives a control word indicating the selected supply control mode via the serial interface.

[0096] Figure 5 is a schematic diagram of another embodiment of a power amplifier system 110. The power amplifier system 110 includes a power management circuit 101, a power amplifier 102, a supply capacitor 103, and a switching chip 104.

[0097] As shown in Figure 5, power amplifier 102 receives an RF input signal RF IN and amplifies the RF input signal RF IN to generate an RF output signal RF OUT. Although depicted as comprising a single stage, power amplifier 102 may include additional stages. Power amplifier 102 receives a power amplifier supply voltage VCC from power management circuitry 101 (also referred to herein as a power management integrated circuit (PMIC)). In some embodiments, power amplifier 102 includes a bipolar transistor having a collector that receives the power amplifier supply voltage VCC through a choke inductor, or a field-effect transistor (FET) having a drain that receives the power amplifier supply voltage VCC through a choke inductor.

[0098] The power management circuit 101 controls one voltage level of the power amplifier supply voltage VCC of the power amplifier 102. The power management circuit 101 is a multi-mode power management circuit that can operate in two or more modes (which may include an APT mode and an ET mode).

[0099] As shown in Figure 5, switch die 104 includes a capacitor supply switch 105 that can be implemented according to any of the embodiments described herein. In some embodiments, switch die 104 includes one or more other components to enhance integration.

[0100] The power management circuit 101, indicated by a mode signal MODE, controls (e.g., open or closed) the capacitor switch 105.

[0101] As shown in Figure 5, the supply capacitor 103 includes a first terminal (also referred to herein as a first terminal) connected to the power amplifier supply voltage VCC and a second terminal (also referred to herein as a second terminal) connected to the supply capacitor switch 105.

[0102] By controlling one of the states of the supply capacitor switch 105, the supply capacitor 103 can be selectively included for filtering / stabilizing the power amplifier supply voltage VCC.

[0103] Figure 6A is a schematic diagram of another embodiment of a power amplifier system 210. The power amplifier system 210 includes a power management integrated circuit (PMIC) (not shown in Figure 6A) that generates a power amplifier supply voltage VCC, a power amplifier (not shown in Figure 6A) powered by the power amplifier supply voltage VCC, a bulk silicon switching die 201, a first supply capacitor C1, and a second supply capacitor C2. In this example, the bulk silicon switching die 201 is a flip-chip die, and bump inductors L1, L2, and L3 (corresponding to the inductance of the bump pads of the die) are shown for certain pads of the die 201.

[0104] In the illustrated embodiment, the bulk silicon switch die 201 includes pins or pads 202a, 202b, 202c and 202d, a first NFET M1, a second NFET M2A / M2B, a third NFET M3, gate resistors RG1 and RG2, voltage divider resistors R1 and R2, a gate capacitor CG, and an electrostatic discharge (ESD) protection circuit including a positive diode D1 and a reverse diode D2A, D2B, ..., D2M, D2N.

[0105] Pin 202b (through bump inductor L2) is connected to the supply voltage VCC and to one of the first terminals of the supply capacitor C1, while pin 202a (through bump inductor L1) is connected to the second terminal of the supply capacitor C1. Additionally, pin 202c (through bump inductor L3) is connected to ground, and pin 202d receives an APT enable signal APT_EN.

[0106] In the illustrated embodiment, NFET M1 switches the ground side of capacitor C1. This greatly simplifies the design, where the APD enable signal APT_EN can directly control the gate of the NFET switch without the need for complex circuitry (such as a charge pump) to bias the gate of the switching FET.

[0107] During ET operation, caution must be exercised because capacitor C1 can be fully charged and the low voltage supplied can force the drain of the NFET ground switch (M1) to be below the chip ground voltage and apply a positive bias to the substrate parasitic.

[0108] In the illustrated embodiment, a discharge NFET (in this example, implemented using a series combination of M2A and M2B) is activated during ET mode and shorts capacitor C1, thereby discharging capacitor C1 to a single diode voltage. Therefore, less charge remains on capacitor C1, and the low voltage transition supplying VCC does not cause a parasitic forward bias on the substrate. The discharge NFET is also referred to as a discharge switch.

[0109] In this embodiment, to increase the robustness of the discharge switch, the device is segmented and constructed in a stacked configuration M2A / M2B. Similarly, a resistor divider R1 and R2 is used to apply bias to the gate bias. This results in the division of all drain-gate, source-gate, and drain-source voltages, effectively doubling the voltage handling of the discharge switch compared to a single transistor configuration. However, the discharge switch can be implemented using more or fewer transistors.

[0110] An additional diode structure placed in parallel with the discharge switch provides an ESD protection path for this relatively small NFET structure. In this example, the NFET M1 series is large and provides self-protection through a natural foldback failure mechanism.

[0111] Using a discharge switch offers the advantage of a low-cost process technology through the use of an NFET-only switching architecture. Furthermore, the relatively small FET size and unbiased well structure provide low off-state capacitance.

[0112] Figure 6B is a curve diagram of one example of the power amplifier system in Figure 6A, showing the power mode switching waveform.

[0113] Depicts illustrative waveforms of the APT enable signal APT_EN and the supply voltage VCC. The supply voltage VCC operates with various 1 μs and 3 μs transitions, as shown.

[0114] Figure 7A is a schematic diagram of one embodiment of a packaging module 300. Figure 7B is a schematic cross-sectional view of the packaging module 300 of Figure 7A taken along line 7B-7B.

[0115] The package module 300 includes a power amplifier die 301, a switch die 302, a surface mount assembly 303, a wire bond 308, a package substrate 320, and an encapsulation structure 340. The package substrate 320 includes pads 306 formed by conductors disposed therein. Additionally, the dies 301 and 302 include pads 304, and the wire bond 308 is used to connect the pads 304 of the dies 301 and 302 to the pads 306 of the package substrate 320.

[0116] The power amplifier die 301 and the switch die 302 are implemented according to one or more features of the present invention. In some embodiments, the switch die 302 includes a supply capacitor switch connected in series with a supply capacitor formed using at least a portion of a surface-mount capacitor attached to a package substrate. To enhance integration, the switch die 302 may include an antenna switch (e.g., a transmit / receive (T / R) switch) and / or a bandgap switch. The switch die 302 may include a pin (which may be included on or outside the package module 300) for receiving a control signal indicating a supply control mode of a power management circuit.

[0117] In some implementations, dies 301 and 302 are manufactured using different processing techniques. In one example, power amplifier die 301 is manufactured using a heterojunction bipolar transistor (HBT) process and switch die 302 is manufactured using an integral silicon process.

[0118] The packaging substrate 320 can be configured to receive a plurality of components, such as dies 301, 302 and surface mount components 303 (which may include, for example, surface mount capacitors and / or inductors).

[0119] As shown in Figure 7B, the package module 300 is illustrated as comprising a plurality of contact pads 332 disposed on the side of the package module 300 opposite to the side used for mounting the chips 301, 302. This configuration of the package module 300 facilitates its connection to a circuit board, such as a telephone board for a wireless device. The exemplary contact pads 332 can be configured to provide RF signals, bias signals, (a number of) low-voltage power supplies and / or (a number of) high-voltage power supplies to the chips 301, 302 and / or the surface mount assembly 303. As shown in Figure 7B, the electrical connection between the contact pads 332 and the chip 301 can be facilitated by connections 333 through the package substrate 320. Connections 333 can represent connections formed through the package substrate 320, such as those associated with vias and conductors in a multilayer laminated package substrate.

[0120] In some embodiments, the packaging module 300 may also include one or more packaging structures for, for example, providing protection and / or facilitating the handling of the packaging module 300. Such a packaging structure may include an overlay molding or encapsulation structure 340 formed above the packaging substrate 320 and components and (a number of) dies disposed thereon.

[0121] It will be understood that although the package module 300 is described in the context of wire-bonded electrical connections, one or more features of the present invention may also be implemented in other package configurations (including, for example, flip-chip configurations).

[0122] Figure 8 is a schematic diagram of one embodiment of a mobile device 800. The mobile device 800 includes a baseband system 801, a transceiver 802, a front-end system 803, an antenna 804, a power management system 805, a memory 806, a user interface 807, and a battery 808.

[0123] While the illustration of mobile device 800 may include one example of an RF system containing one or more features of the present invention, the teachings herein are applicable to electronic systems implemented in a wide variety of ways.

[0124] Mobile device 800 can be used to communicate using a wide range of communication technologies, including (but not limited to) 2G, 3G, 4G (including LTE, LTE-Advanced and LTE-Advanced Pro), 5G, WLAN (e.g., Wi-Fi), WPAN (e.g., Bluetooth and ZigBee), WMAN (e.g., WiMax) and / or GPS technology.

[0125] Transceiver 802 generates RF signals for transmission and processes incoming RF signals received from antenna 804. It will be understood that various functionalities associated with the transmission and reception of RF signals can be achieved by one or more components collectively represented as transceiver 802 in FIG. 8. In one example, separate components (e.g., separate circuits or chips) may be provided for handling certain types of RF signals.

[0126] As shown in Figure 8, transceiver 802 is connected to front-end system 803 and power management circuitry 805 via a serial interface 809. All or part of the illustrated RF components can be controlled by serial interface 809 to configure mobile device 800 during initialization and / or when fully operational. In another embodiment, baseband processor 801 is additionally or alternatively connected to serial interface 809 and operates to configure one or more RF components, such as those of front-end system 803 and / or power management system 805.

[0127] The front-end system 803 helps regulate signals transmitted to and / or received from the antenna 804. In the illustrated embodiment, the front-end system 803 includes one or more supply capacitor switches 810, one or more power amplifiers (PAs) 811, one or more low-noise amplifiers (LNAs) 812, one or more filters 813, one or more switches 814, and one or more duplexers 815. However, other embodiments are possible.

[0128] For example, the front-end system 803 may provide several functionalities, including (but not limited to) amplifying signals for transmission, amplifying received signals, filtering signals, switching between different frequency bands, switching between different power modes, switching between transmission and reception modes, signal duplexing, signal multiplexing (e.g., duplex or triplexing), or a combination thereof.

[0129] In some implementations, the mobile device 800 supports carrier aggregation, thereby providing flexibility to increase peak data rates. Carrier aggregation can be used in both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) modes, and can be used to aggregate multiple carriers or channels. Carrier aggregation includes contiguous aggregation, where consecutive carriers within the same operating frequency band are aggregated. Carrier aggregation can also be discontinuous and can include carriers with separated frequencies within a common frequency band or in different frequency bands.

[0130] Antenna 804 may include antennas for a wide variety of types of communication. For example, antenna 804 may include antennas for transmitting and / or receiving signals associated with a wide variety of frequencies and communication standards.

[0131] In some implementations, antenna 804 supports MIMO communication and / or switchable diversity communication. For example, MIMO communication uses multiple antennas to transmit multiple data streams via a single radio frequency channel. Due to the spatial multiplexing differences in the radio environment, MIMO communication benefits from a higher signal-to-noise ratio, improved coding, and / or reduced signal interference. Switchable diversity refers to communication in which a specific antenna is selected to operate at a specific time. For example, a switch can be used to select a specific antenna from an antenna group based on various factors such as an observed bit error rate and / or a signal strength indicator.

[0132] In some embodiments, the mobile device 800 may operate using beamforming. For example, the front-end system 803 may include a phase shifter with a variable phase controlled by the transceiver 802. Additionally, the phase shifter is controlled to provide beamforming and directivity for transmitting and / or receiving signals using the antenna 804. For example, in the context of signal transmission, the phase of the transmitted signal provided to the antenna 804 is controlled such that the radiated signal from the antenna 804 uses a combination of constructive and destructive interference to produce a converged transmission signal exhibiting beamforming quality that propagates in a given direction. In the context of signal reception, the phase is controlled such that greater signal energy is received when the signal arrives at the antenna 804 from a specific direction. In some embodiments, the antenna 804 includes one or more arrays of antenna elements to enhance beamforming.

[0133] The baseband system 801 is coupled to the user interface 807 to facilitate the processing of various user inputs and outputs (I / O) (such as voice and data). The baseband system 801 provides a digital representation of the transmitted signals to a transceiver 802, which processes these digital representations to generate RF signals for transmission. The baseband system 801 also processes the digital representation of the received signals provided by the transceiver 802. As shown in Figure 8, the baseband system 801 is coupled to memory 806 to facilitate the operation of the mobile device 800.

[0134] Memory 806 can be used for a wide range of purposes, such as storing data and / or instructions to facilitate the operation of mobile device 800 and / or providing storage of user information.

[0135] The power management system 805 provides several power management functions for the mobile device 800. In some embodiments, the power management system 805 includes power amplifier (PA) supply control circuitry that controls the supply voltage of the power amplifier 811. For example, the power management system 805 can be configured to change the supply voltage(s) supplied to one or more power amplifiers 811 to improve efficiency, such as power-added efficiency (PAE).

[0136] The power management system 805 can operate in a selectable supply control mode (such as an APT mode or an ET mode). In the illustrated embodiment, the selected supply control mode of the power management system 805 is controlled by a transceiver 802. In some embodiments, the transceiver 802 uses a serial interface 809 to control the selected supply control mode. One or more supply control switches 810 open or close based on the selected supply control mode.

[0137] As shown in Figure 8, the power management system 805 receives a battery voltage from the battery 808. The battery 808 can be any suitable battery used in the mobile device 800, including, for example, a lithium-ion battery. Although the power management system 805 is depicted separately from the front-end system 803, in some embodiments, all or part of the power management system 805 (e.g., a PA supply control circuit) is integrated into the front-end system 803. [application] []

[0138] Some of the embodiments described above have been provided as examples in conjunction with wireless devices or mobile phones. However, the principles and advantages of these embodiments can be applied to any other system or device that requires a power amplifier system.

[0139] Such power amplifier systems can be implemented in a variety of electronic devices. Examples of electronic devices may include (but are not limited to) consumer electronics, parts of consumer electronics, electronic test equipment, etc. Examples of electronic devices may also include (but are not limited to) memory chips, memory modules, circuitry for optical networks or other communication networks, and disk drive circuitry. Consumer electronics may include (but are not limited to) a mobile phone, a telephone, a television, a computer monitor, a computer, a handheld computer, a digital assistant (PDA), a microwave oven, a refrigerator, a car, a stereo system, a cassette recorder or player, a DVD player, a CD player, a VCR, an MP3 player, a radio, a camcorder, a camera, a digital camera, a portable memory chip, a washing machine, a dryer, a washing machine / dryer, a copier, a fax machine, a scanner, a multi-function peripheral device, a watch, a clock, etc. In addition, electronic devices may include unfinished products. [in conclusion] []

[0140] Unless otherwise explicitly required by the background context, throughout the description and scope of the invention claim, the terms "comprise" and similar terms should be interpreted as inclusive rather than exclusive or exhaustive; that is, "including, but not limited to." As commonly used herein, the term "coupled" refers to two or more elements that can be directly connected or connected by one or more intermediate elements. Similarly, the term "connected" as commonly used herein refers to two or more elements that can be directly connected or connected by one or more intermediate elements. Furthermore, the terms "this article," "above," "below," and similar terms, when used in this application, should refer to the entirety of this application and not any specific part thereof. Where the background context permits, the use of singular or plural terms in the above embodiments may also include both singular and plural forms. The word "or" refers to one of two or more items in a list, and the word encompasses all of the following interpretations: any of the items in the list, all of the items in the list, and any combination of the items in the list.

[0141] Furthermore, unless otherwise specifically stated or understood within the context of the background used, conditional terms used herein, such as in particular "may," "can," "possibly," "able to," "for example," "likely," and the like, are generally intended to convey that certain embodiments include certain features, elements, and / or states that are not included in other embodiments. Therefore, these conditional terms are not generally intended to imply that features, elements, and / or states are required in any way in one or more embodiments, or that one or more embodiments necessarily include logic for determining whether such features, elements, and / or states are included or to be performed in any particular embodiment, with or without author input or prompting.

[0142] The detailed description of embodiments of the present invention above is not intended to be exhaustive or to limit the invention to the precise forms disclosed above. While specific embodiments and examples of the invention have been described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as will be recognized by those skilled in the art. For example, although programs or blocks are presented in a given order, alternative embodiments may execute routines with steps in a different order or employ a system with blocks, and some programs or blocks may be deleted, moved, added, subdivided, combined, and / or modified. Such programs or blocks can be implemented in various different ways. Furthermore, although programs or blocks are sometimes shown to execute sequentially, such programs or blocks may alternatively execute in parallel or at different times.

[0143] The teachings of the present invention provided herein are applicable to other systems, not necessarily those described above. Elements and actions of the various embodiments described above may be combined to provide further embodiments.

[0144] While certain embodiments of the invention have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. In fact, the novel methods and systems described herein can be embodied in various other forms; furthermore, various omissions, substitutions, and changes can be made to the form of the methods and systems described herein without departing from the spirit of the invention. The appended claims and their equivalents are intended to cover such forms or modifications that fall within the scope and spirit of the invention.

[0145] 1: Giant Community Base Station 2a: First Action Device 2b: Wireless connectivity for cars 2c: Laptop 2d: Fixed wireless devices 2e: Wireless Connectivity for Trains 2f: Second Action Device 2g: Third Action Device 3: Small-scale community base station 10: Communication Network 21:Base station 22: Mobile Devices 31: First Carrier Aggregation Case 32: Second Carrier Aggregation Case 33: Third Carrier Aggregation Case 34: First Carrier Aggregation Case 35: Second Carrier Aggregation Case 36: Third Carrier Aggregation Case 37: Case Study of Fourth Carrier Aggregation 38: Fifth Carrier Aggregation Case 41: Radio Frequency (RF) Signal 42: Envelope 43: Power amplifier supply voltage 44: Power amplifier supply voltage 45: Power amplifier supply voltage 47: Curve Graph 48: Curve Graph 49: Curve Graph 51: Switch 52: Antenna 54: Directional Coupler 60: Power Management Circuit 61: Bias control circuit 62: Power Amplifier 63: Transceiver 64: Baseband Processor 66: Power Amplifier Control Circuit 67: I / Q modulator 68: Mixer 69: Analog-to-Digital Converter (ADC) 70: Power Amplifier System 101: Power Management Circuit 102: Power Amplifier 103: Supply capacitors 104: Switching die 105: Supply capacitor switch 110: Power Amplifier System 201: Bulk Silicon Switching Diode 202a: Feet / Pads 202b: Feet / Pads 202c: Feet / Pad 202d: Feet / Pad 210: Power Amplifier System 300: Package Module 301: Power Amplifier Die 302: Switching die 303: Surface Mount Components 304: Pad 306: Pad 308: Wire Connection 320: Packaging substrate 332: Contact gasket 333: Connection 340: Encapsulation structure 800: Mobile Devices 801: Baseband System 802: Transceiver 803: Front-end System 804: Antenna 805: Power Management System 806: Memory 807: User Interface 808: Battery 809: Serial Interface 810: Supply capacitor switch 811: Power Amplifier (PA) 812: Low-noise amplifier (LNA) 813: Filter 814: Switch 815: Duplexer APT_EN: Average Power Tracking (APT) Enable Signal C1: First supply capacitor C2: Second supply capacitor CG: Gate Capacitor D1: Positive Diode D2A to D2N: Reverse Diode L1: Bump inductor L2: Bump inductor L3: Bumped inductor M1: First-body n-type field-effect transistor (NFET) M2A: Second-body n-type field-effect transistor (NFET) M2B: Second-body n-type field-effect transistor (NFET) M3: Third-body n-type field-effect transistor (NFET) MODE: Mode signal R1: Voltage divider resistor R2: Voltage divider resistor RF IN: Radio Frequency (RF) Input Signal RF OUT: Radio frequency (RF) output signal RG1: Gate resistor RG2: Gate resistor VCC: Power amplifier supply voltage VCC1: First supply voltage VCC2: Second supply voltage

Claims

1. A mobile device comprising: A power amplifier configured to amplify a radio frequency signal; a power management circuit configured to control a voltage level of a supply voltage of the power amplifier, the power management circuit being operable in a selected supply control mode selected from a plurality of supply control modes; and a front-end system comprising a supply capacitor connected to a first terminal of the supply voltage, an n-type field-effect transistor grounding switch connected between a second terminal of the supply capacitor and a ground voltage, and an n-type field-effect transistor discharge switch connected between the second terminal of the supply capacitor and the supply voltage, the n-type field-effect transistor discharge switch comprising two or more n-type field-effect transistors connected in series, the n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch being controlled based on the selected supply control mode, the front-end system further comprising a voltage divider configured to bias the two or more n-type field-effect transistors.

2. The mobile device as claimed in claim 1, wherein the plurality of supply control modes includes an average power tracking mode and an envelope tracking mode.

3. The mobile device as claimed in claim 2, wherein the n-type field-effect transistor grounding switch is configured to be on in the average power tracking mode and off in the envelope tracking mode, and the n-type field-effect transistor discharge switch is configured to be off in the average power tracking mode and on in the envelope tracking mode.

4. The mobile device of claim 1, wherein the voltage divider includes a first terminal connected to the supply voltage and a second terminal connected to the ground voltage via a mode transistor.

5. The mobile device as claimed in claim 4, wherein the plurality of supply control modes includes an average power tracking mode and an envelope tracking mode, wherein the mode transistor is configured to be turned on in the envelope tracking mode and turned off in the average power tracking mode.

6. The mobile device of claim 1, wherein the n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch are implemented on a semiconductor die manufactured using an integrated silicon process.

7. The mobile device of claim 1 further includes an antenna configured to transmit the amplified radio frequency signal provided by the power amplifier.

8. A mobile device comprising: A power amplifier configured to amplify a radio frequency signal; a power management circuit configured to control a voltage level of a supply voltage of the power amplifier, the power management circuit being operable in a selected supply control mode selected from a plurality of supply control modes; and a front-end system comprising a supply capacitor connected to a first terminal of the supply voltage, an n-type field-effect transistor grounding switch connected between a second terminal of the supply capacitor and a ground voltage, and an n-type field-effect transistor discharge switch connected between the second terminal of the supply capacitor and the supply voltage, the n-type field-effect transistor discharge switch comprising two or more n-type field-effect transistors connected in series, the n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch being controlled based on the selected supply control mode.

9. A power amplifier system comprising: A power amplifier configured to amplify a radio frequency signal; a power management circuit configured to control a voltage level of a supply voltage of the power amplifier, the power management circuit being operable in a selected supply control mode selected from a plurality of supply control modes; a supply capacitor having a first terminal connected to the supply voltage; an n-type field-effect transistor grounding switch connected between a second terminal of the supply capacitor and a ground voltage; an n-type field-effect transistor discharge switch connected between the second terminal of the supply capacitor and the supply voltage, the n-type field-effect transistor discharge switch comprising two or more n-type field-effect transistors connected in series, the n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch being controlled based on the selected supply control mode; and a voltage divider configured to bias the two or more n-type field-effect transistors.

10. The power amplifier system of claim 9, wherein the plurality of supply control modes includes an average power tracking mode and an envelope tracking mode.

11. The power amplifier system of claim 10, wherein the n-type field-effect transistor grounding switch is configured to be on in the average power tracking mode and off in the envelope tracking mode, and the n-type field-effect transistor discharge switch is configured to be off in the average power tracking mode and on in the envelope tracking mode.

12. The power amplifier system of claim 9, wherein the voltage divider includes a first terminal connected to the supply voltage and a second terminal connected to the ground voltage via a mode transistor.

13. The power amplifier system of claim 12, wherein the plurality of supply control modes includes an average power tracking mode and an envelope tracking mode, wherein the mode transistor is configured to be turned on in the envelope tracking mode and turned off in the average power tracking mode.

14. The power amplifier system of claim 9, wherein the n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch are implemented on a semiconductor die manufactured using an integrated silicon process.

15. A power amplifier system comprising: A power amplifier configured to amplify a radio frequency signal; a power management circuit configured to control a voltage level of a supply voltage of the power amplifier, the power management circuit being operable in a selected supply control mode selected from a plurality of supply control modes; a supply capacitor having a first terminal connected to a first terminal of the supply voltage; an n-type field-effect transistor grounding switch connected between a second terminal of the supply capacitor and a ground voltage; and an n-type field-effect transistor discharge switch connected between the second terminal of the supply capacitor and the supply voltage, the n-type field-effect transistor discharge switch comprising two or more n-type field-effect transistors connected in series, the n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch being controlled based on the selected supply control mode.

16. A power amplification method, the method comprising: A power amplifier is used to amplify an radio frequency signal; A power management circuit controls a voltage level of a supply voltage of the power amplifier, the supply voltage being coupled to a first terminal of a supply capacitor; the power management circuit operates in a selected supply control mode selected from a plurality of supply control modes; based on the selected supply control mode, an n-type field-effect transistor grounding switch is controlled, the n-type field-effect transistor grounding switch being connected between a second terminal of the supply capacitor and a ground voltage, an n-type field-effect transistor discharge switch comprising two or more n-type field-effect transistors connected in series; a voltage divider is used to bias the two or more n-type field-effect transistors; and based on the selected supply control mode, the n-type field-effect transistor discharge switch is controlled, the n-type field-effect transistor grounding switch being connected between the second terminal of the supply capacitor and the supply voltage.

17. The method of claim 16, wherein the plurality of supply control modes includes an average power tracking mode and an envelope tracking mode.

18. The method of claim 17, further comprising turning on the n-type field-effect transistor grounding switch in the average power tracking mode and turning off the n-type field-effect transistor grounding switch in the envelope tracking mode.

19. The method of claim 17, further comprising turning off the n-type field-effect transistor discharge switch in the average power tracking mode and turning on the n-type field-effect transistor discharge switch in the envelope tracking mode.

20. The method of claim 16, wherein the voltage divider includes a first terminal connected to one of the supply voltages and a second terminal connected to one of the ground voltages via a mode transistor.

21. The method of claim 20, wherein the plurality of supply control modes includes an average power tracking mode and an envelope tracking mode, the method further comprising turning on the mode transistor in the envelope tracking mode and turning off the mode transistor in the average power tracking mode.

22. The method of claim 16, wherein the n-type field-effect transistor grounding switch and the n-type field-effect transistor discharge switch are implemented on a semiconductor die manufactured using an integrated silicon process.

23. A power amplification method, the method comprising: A power amplifier is used to amplify an radio frequency signal; A power management circuit controls a voltage level of a supply voltage of the power amplifier, the supply voltage being coupled to a first terminal of a supply capacitor; the power management circuit operates in a selected supply control mode selected from a plurality of supply control modes; based on the selected supply control mode, an n-type field-effect transistor grounding switch is controlled, the n-type field-effect transistor grounding switch being connected between a second terminal of the supply capacitor and a ground voltage, an n-type field-effect transistor discharge switch comprising two or more n-type field-effect transistors connected in series; and based on the selected supply control mode, the n-type field-effect transistor discharge switch is controlled, the n-type field-effect transistor grounding switch being connected between the second terminal of the supply capacitor and the supply voltage.

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