Mobile device, low-noise amplifier, and method for amplifying radio frequency signals

Abstract

To provide a low noise amplifier (LNA) and a mobile device, capable of achieving fast biasing, accurate matching of a bias current to a reference current, smaller circuit area, and superior voltage headroom.SOLUTION: An LNA 210 includes at least one transistor 201 that amplifies a radio frequency (RF) input signal, and a bias circuit 202. The bias circuit includes a current bias circuit that generates a bias current based on a reference current, and a voltage bias circuit that generates at least one input bias voltage for the at least one transistor based on the bias current. The current bias circuit includes a first bias transistor that receives the reference current, a second bias transistor that generates the bias current, and an amplifier that controls a first bias voltage of the first bias transistor to match a second bias voltage of the second bias transistor.SELECTED DRAWING: Figure 5A

Description

[Technical Field]

[0001] Embodiments of the present invention relate to electronic systems, and more specifically to radio frequency (RF) electronic equipment. [Background technology]

[0002] A low-noise amplifier (LNA) can be used to boost the amplitude of a relatively weak radio frequency (RF) signal received through an antenna. The boosted RF signal can then be used for various purposes, including, for example, driving switches, mixers, and / or filters in an RF communication system.

[0003] Examples of RF communication systems with one or more LNAs include, but are not limited to, mobile phones, tablets, base stations, network access points, customer premises equipment (CPE), laptops, and wearable electronic devices.

[0004] LNAs can be included in RF communication systems to amplify signals over a wide range of frequencies. For example, an LNA can be used to provide low-noise amplification to RF signals in the frequency range of approximately 30 kHz to 300 GHz, such as the range of approximately 400 MHz to approximately 7.125 GHz for the 5th generation (5G) communication standard's frequency range 1 (FR1), or the range of approximately 24.250 GHz to approximately 71.000 GHz for the 5G communication standard's frequency range 2 (FR2). [Overview of the project]

[0005] In a given embodiment, the disclosure relates to a portable device. The portable device includes an antenna and a front-end system, the front-end system including a low-noise amplifier including at least one amplification transistor configured to amplify a radio frequency input signal received from the antenna, and a bias circuit, the bias circuit including a current bias circuit configured to generate a bias current based on a reference current, and a voltage bias circuit configured to generate at least one input bias voltage for the at least one amplification transistor based on the bias current. The current bias circuit includes a first bias transistor configured to receive a reference current, a second bias transistor configured to generate a bias current, and an amplifier configured to control a first bias voltage of the first bias transistor to match a second bias voltage of the second bias transistor.

[0006] In various embodiments, the current bias circuit further includes a plurality of selector switches and a plurality of current mirroring transistors, each selectable by a corresponding selector switch of the plurality of selector switches, wherein the plurality of current mirroring transistors are biased by a second bias voltage.

[0007] In some embodiments, the first bias transistor includes a drain connected to the first input of the amplifier and a gate connected to the output of the amplifier, and the second bias transistor includes a drain connected to the second input of the amplifier and a gate connected to the output of the amplifier.

[0008] In some embodiments, at least one amplifying transistor includes a common source transistor, and at least one input bias voltage includes a gate bias voltage for the common source transistor. According to some embodiments, the bias circuit includes a bias resistor and a bias resistor bypass switch, and the voltage bias circuit is configured to provide a gate bias voltage to the gate of the common source transistor via a parallel combination of the bias resistor and the bias resistor bypass switch. According to various embodiments, at least one amplifying transistor further includes a cascode transistor in series with the common source transistor, and at least one input bias voltage further includes a cascode bias voltage for the cascode transistor.

[0009] In some embodiments, the front-end system further includes a controllable current source configured to generate a reference current, the controllable current source configured to control the reference current based on a gain control signal.

[0010] In various embodiments, the voltage bias circuit further includes a first voltage bias transistor and a resistor in series between the supply voltage and the ground voltage, and a second voltage bias transistor and a third voltage bias transistor in series between the gate of the first voltage bias transistor and the ground voltage. According to certain embodiments, the voltage bias circuit is configured to generate a first input bias voltage of at least one input bias voltage based on the voltage across a resistor, and to generate a second input bias voltage of the same at least one input bias voltage based on the gate voltage of the second voltage bias transistor.

[0011] In a given embodiment, the disclosure relates to a low-noise amplifier including at least one amplification transistor configured to amplify a radio frequency input signal, a bias circuit including a current bias circuit configured to generate a bias current based on a reference current, and a voltage bias circuit configured to generate at least one input bias voltage for the at least one amplification transistor based on the bias current. The current bias circuit includes a first bias transistor configured to receive a reference current, a second bias transistor configured to generate a bias current, and an amplifier configured to control a first bias voltage of the first bias transistor to match a second bias voltage of the second bias transistor.

[0012] In various embodiments, the current bias circuit further includes a plurality of selector switches and a plurality of current mirroring transistors, each selectable by a corresponding selector switch of the plurality of selector switches, wherein the plurality of current mirroring transistors are biased by a second bias voltage.

[0013] In some embodiments, the first bias transistor includes a drain connected to the first input of the amplifier and a gate connected to the output of the amplifier, and the second bias transistor includes a drain connected to the second input of the amplifier and a gate connected to the output of the amplifier.

[0014] In some embodiments, at least one amplifying transistor includes a common source transistor, and at least one input bias voltage includes a gate bias voltage for the common source transistor. According to some embodiments, the bias circuit includes a bias resistor and a bias resistor bypass switch, and the voltage bias circuit is configured to provide a gate bias voltage to the gate of the common source transistor via a parallel combination of the bias resistor and the bias resistor bypass switch. According to some embodiments, at least one amplifying transistor further includes a cascode transistor in series with the common source transistor, and at least one input bias voltage further includes a cascode bias voltage for the cascode transistor.

[0015] In various embodiments, the low-noise amplifier further includes a controllable current source configured to generate a reference current, the controllable current source being configured to control the reference current based on a gain control signal.

[0016] In some embodiments, the voltage bias circuit includes a first voltage bias transistor and a resistor in series between a supply voltage and a ground voltage, and a second voltage bias transistor and a third voltage bias transistor in series between the gate of the first voltage bias transistor and the ground voltage. According to some embodiments, the voltage bias circuit is configured to generate a first input bias voltage of at least one input bias voltage based on the voltage across a resistor, and to generate a second input bias voltage of the same at least one input bias voltage based on the gate voltage of the second voltage bias transistor.

[0017] In a given embodiment, the present disclosure relates to a method for amplifying a radio frequency signal. The method includes amplifying a radio frequency input signal using at least one amplifying transistor of a low-noise amplifier; generating at least one input bias voltage for at least one amplifying transistor based on a bias current using a voltage bias circuit of the low-noise amplifier; generating the bias current based on a reference current using a current bias circuit of the low-noise amplifier; receiving the reference current using a first bias transistor; generating the bias current using a second bias transistor; and controlling the first bias voltage of the first bias transistor to match the second bias voltage of the second bias transistor using an amplifier.

[0018] In some embodiments, controlling the first bias voltage of the first bias transistor to match the second bias voltage of the second bias transistor includes controlling the drain-source voltage of the first bias transistor to be substantially equal to the drain-source voltage of the second bias transistor.

[0019] In some embodiments, generating at least one input bias voltage for at least one amplifying transistor includes generating a gate bias voltage for a common source transistor and generating a cascode bias voltage for a cascode transistor in series with the common source transistor. [Brief explanation of the drawing]

[0020] Embodiments of the present disclosure are described below through non-limiting examples with reference to the accompanying drawings.

[0021] [Figure 1] This is a schematic diagram of an example of a communication network. [Figure 2A] This is a schematic diagram of an example of a communication link using carrier aggregation. [Figure 2B]Figure 2A shows various examples of uplink carrier aggregation for a communication link. [Figure 2C] Figure 2A shows various examples of downlink carrier aggregation for a communication link. [Figure 3A] This is a schematic diagram of an example of a downlink channel using multi-input, multi-output (MIMO) communication. [Figure 3B] This is a schematic diagram of an example of an uplink channel using MIMO communication. [Figure 3C] This is a schematic diagram of another example of an uplink channel using MIMO communication. [Figure 4A] This is a schematic diagram of an example of a communication system that operates using beamforming. [Figure 4B] This is a schematic diagram of an example of beamforming that provides a transmit beam. [Figure 4C] This is a schematic diagram illustrating an example of beamforming that provides a receiving beam. [Figure 5A] This is a schematic diagram of one embodiment of a low-noise amplifier (LNA). [Figure 5B] This is a schematic diagram of an LNA in another embodiment. [Figure 5C] This is a schematic diagram of a bias circuit for one embodiment of an LNA. [Figure 6A] This is a schematic diagram of an LNA current bias circuit according to one embodiment. [Figure 6B] This is a schematic diagram of a servo amplifier in one embodiment for an LNA current bias circuit. [Figure 6C] This is a schematic diagram of a servo amplifier in another embodiment for an LNA current bias circuit. [Figure 7] This is a schematic diagram of a controllable reference current source according to one embodiment. [Figure 8] This is a schematic diagram of an output matching circuit for one embodiment of an LNA. [Figure 9] This is an example of a current-to-time graph for an LNA with a fast bias. [Figure 10]This is an example graph of the voltage headroom of an LNA in two implementation examples. [Figure 11] This is a schematic diagram of a portable device according to one embodiment. [Figure 12A] This is a schematic diagram of a package module according to one embodiment. [Figure 12B] This is a schematic diagram of a cross-section of a package module along the line 12B-12B in Figure 12A. [Modes for carrying out the invention]

[0022] The following detailed description of a given embodiment presents various descriptions of a particular embodiment. However, the innovation described herein can be embodied in numerous different forms defined and covered, for example, by the claims. In this specification, the same reference numeral refers to drawings showing identical or functionally similar elements. It should be understood that the elements shown in the drawings are not necessarily to scale. It should also be understood that a given embodiment may include more elements than shown in the drawings, and / or subsets of the elements shown in the drawings. Furthermore, some embodiments may also include any suitable combination of features from two or more drawings.

[0023] The International Telecommunication Union (ITU) is a specialized agency of the United Nations (UN) and is responsible for global issues concerning information and communication technologies, including the global sharing of radio frequency bands.

[0024] The Third Generation Partnership Project (3GPP®) is a collaborative project among a group of telecommunications standards organizations worldwide, including the Radio Industry Association (ARIB), the Telecommunications Technology Committee (TTC), the China Communications Standards Association (CCSA), the Telecommunications Industry Solutions Alliance (ATIS), the Telecommunications Technology Association (TTA), the European Telecommunications Standards Institute (ETSI), and the Telecommunications Standards Development Institute of India (TSDSI).

[0025] Within the scope of the ITU, 3GPP develops and maintains technical specifications for various mobile communication technologies, including, for example, second-generation (2G) technologies (e.g., Global System for Mobile Communications (GSM) (registered trademark) and Enhanced Data Rate for GSM Evolution (EDGE)), third-generation (3G) technologies (e.g., Universal Mobile Telecommunications System (UMTS) and High-Speed ​​Packet Access (HSPA)), and fourth-generation (4G) technologies (e.g., Long-Term Evolution (LTE) and LTE Advanced).

[0026] Technical specifications managed by 3GPP can be extended and revised through specification releases. These specification releases may span many years and may specify a wide range of new features and advancements.

[0027] For example, 3GPP introduced carrier aggregation (CA) for LTE in Release 10. Initially, 3GPP introduced two downlink carriers, but in Release 14, it expanded to include up to five downlink carriers and up to three uplink carriers. Other examples of new features and advancements 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).

[0028] 3GPP introduced Phase 1 of fifth-generation (5G) technology in Release 15 and Phase 2 of 5G technology in Release 16. Subsequent 3GPP releases will further evolve and expand 5G technology. Here, 5G technology is also referred to as 5G New Radio (NR).

[0029] 5GNR supports or is planned to support a variety of features such as millimeter-wave spectral communication, beamforming capability, high spectral efficiency waveforms, low latency communication, multiplex radio numerology, and / or non-orthogonal multiplex access (NOMA). Although such RF capabilities provide network flexibility and improve user data rates, there are a number of technical challenges in supporting these features.

[0030] The teachings herein are applicable to a wide variety of communication systems, including but not limited to those using advanced cellular technologies such as LTE Advanced, LTE Advanced Pro, and / or 5G NR.

[0031] Figure 1 is a schematic diagram of an example of a communication network 10. The communication network 10 includes a macrocell base station 1, a small cell base station 3, and various examples of user equipment (UEs). User equipment (UEs) include a first portable device 2a, a wirelessly connected vehicle 2b, a laptop 2c, a stationary wireless device 2d, a wirelessly connected train 2e, a second portable device 2f, and a third portable device 2g.

[0032] Although specific examples of base stations and user equipment are shown in Figure 1, the communication network may include a wide variety of types and / or numbers of base stations and user equipment.

[0033] For example, in the illustrated example, the communication network 10 includes a macrocell base station 1 and a smallcell base station 3. The smallcell base station 3 may operate with relatively lower power, shorter range, and / or fewer concurrent users compared to the macrocell base station 1. The smallcell base station 3 may also be referred to as a femtocell, picocell, or microcell. Although the communication network 10 is shown to include two base stations, the communication network 10 may be implemented to include more or fewer base stations and / or other types of base stations.

[0034] Although various examples of user devices are presented, the teachings herein are applicable to a wide variety of user devices, including but not limited to mobile phones, tablets, laptops, Internet of Things (IoT) devices, wearable electronic devices, subscriber premises equipment (CPE), wirelessly connected vehicles, wireless relays, and / or a wide variety of other communication devices. Furthermore, user devices include not only currently available communication devices operating in cellular networks, but also subsequently developed communication devices that can be easily implemented in the systems, processes, methods and devices of the present invention described herein and claimed in the claims.

[0035] The communication network 10 illustrated in Figure 1 supports communication using various cellular technologies, including, for example, 4G LTE and 5G NR. In a given implementation example, the communication network 10 is further adapted to provide a wireless local area network (WLAN) such as Wi-Fi. Although various examples of communication technologies have been given, the communication network 10 can be adapted to support a wide variety of communication technologies.

[0036] Various communication links of the communication network 10 are depicted in Figure 1. Communication links can be duplicated (duplexed) in a wide variety of ways, including, for example, using frequency division duplication (FDD) and / or time division duplication (TDD). FDD is a type of radio frequency communication that uses different frequencies for transmitting and receiving signals. FDD can offer a number of advantages, such as high data rates and low latency. In contrast, TDD is a type of radio frequency communication that uses nearly the same frequency for transmitting and receiving signals, with the transmitting and receiving communications switching over time. TDD can offer a number of advantages, such as efficient use of the spectrum and variable allocation of throughput between the transmitting and receiving directions.

[0037] In a given implementation example, user equipment can communicate with a base station using one or more of 4G LTE, 5G NR, and WiFi technologies. In a given implementation example, Enhanced License-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).

[0038] As shown in Figure 1, the communication link includes not only the communication link between the UE and the base station, but also UE-to-UE communication and base station-to-base station communication. For example, the communication network 10 can be implemented to support self-fronthaul and / or self-backhaul (such as between mobile device 2g and mobile device 2f).

[0039] Communication links can operate across a wide variety of frequencies. In a given implementation example, communication is supported using 5GNR technology over one or more frequency bands below 6 gigahertz (GHz) and / or over one or more frequency bands above 6 GHz. For example, a communication link may have frequency range 1 (FR1), frequency range 2 (FR2), or a combination thereof. In one embodiment, one or more portable devices support the HPUE power class specification.

[0040] In a given implementation example, a base station and / or user equipment communicates using beamforming. For example, beamforming can be used to converge signal strength to overcome path loss, such as the high loss associated with communication over high signal frequencies. In a given embodiment, one or more user devices, such as mobile phones, communicate using beamforming in the millimeter-wave frequency band in the range of 30 GHz to 300 GHz, and / or in the upper centimeter-wave frequencies in the range of 6 GHz to 30 GHz, more specifically 24 GHz to 30 GHz. Cellular user equipment can communicate using beamforming and / or other techniques over a wide range of frequencies, including, for example, FR2-1 (24 GHz to 52 GHz), FR2-2 (52 GHz to 71 GHz), and / or FR1 (400 MHz to 7125 MHz).

[0041] Different users of the communication network 10 can share available network resources, such as the available frequency spectrum, in a wide variety of ways.

[0042] In one example, Frequency Division Multiple Access (FDMA) is used to divide a single frequency band into multiple frequency carriers. In addition, one or more carriers are allocated 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 divides the available bandwidth into many mutually orthogonal narrowband subcarriers, which can be allocated separately to different users.

[0043] Other examples of shared access include, but are not limited to, time-division multiplexing (TDMA), where users are allocated specific time slots to use frequency resources; code-division multiplexing (CDMA), where frequency resources are shared among different users by assigning each user a unique code; spatial-division multiplexing (SDMA), where beamforming is used to provide spatially divided shared access; and non-orthogonal multiplexing (NOMA), where power domains are used for multiple access. For example, NOMA may be used to serve a large number of users at different power levels but on the same frequency, time, and / or code.

[0044] Enhanced Mobile Broadband (eMBB) refers to technologies that increase the system capacity of LTE networks. For example, eMBB may refer to communications with a peak data rate of at least 10 Gbps and a minimum of 100 Mbps per user. Ultra-High Reliability Low Latency Communications (uRLLC) refers to technologies for communications with extremely low latency, for example, less than 2 milliseconds. uRLLC can be used for mission-critical communications such as autonomous driving and / or remote surgery applications. Massive Machine-Type Communications (mMTC) refers to low-cost, low-data-rate communications associated with wireless connectivity to everyday objects, such as communications associated with Internet of Things (IoT) applications.

[0045] The communication network 10 in Figure 1 can be used to support a wide variety of advanced communication functions, including but not limited to eMBB, uRLLC, and / or mMTC.

[0046] Figure 2A is a schematic diagram of an example of a communication link using carrier aggregation. By using carrier aggregation, the bandwidth of the communication link can be increased by supporting communication across multiple frequency carriers, thereby increasing the user data rate and improving network capacity by utilizing fragmented spectral distribution.

[0047] In the illustrated example, a communication link is provided between a base station 21 and a mobile device 22. As shown in Figure 2A, the communication link includes a downlink channel (DL) used for RF communication from the base station 21 to the mobile device 22 and an uplink channel (UL) used for RF communication from the mobile device 22 to the base station 21.

[0048] Although Figure 2A shows carrier aggregation in the context of FDD communication, carrier aggregation can also be used for TDD communication.

[0049] In a given implementation example, the communication link can provide asymmetric data rates for the downlink and uplink channels. For example, the communication link can support a relatively high downlink data rate to enable high-speed streaming of multimedia content to a mobile device, while providing a relatively low data rate for data uploads from the mobile device to the cloud.

[0050] In the illustrated example, the base station 21 and the mobile device 22 communicate via carrier aggregation, which can be used to selectively increase the bandwidth of the communication link. Carrier aggregation includes continuous aggregation, in which continuous carriers are aggregated within the same operating frequency band. Carrier aggregation may be discontinuous and may include carriers whose frequencies are separated within a common band or different bands.

[0051] In the example shown in FIG. 2A, the uplink channel includes three aggregated component carriers f UL1 , f UL2 and f UL3 . Additionally, the downlink channel includes five aggregated component carriers f DL1 , f DL2 , f DL3 , f DL4 and f DL5 . Despite showing an example of component carrier aggregation, more or fewer carriers can be aggregated for the uplink and / or downlink. Further, the number of carriers to be aggregated can be changed over time to achieve the desired uplink data rate and downlink data rate.

[0052] For example, the number of carriers aggregated for uplink communication and / or downlink communication regarding a particular mobile device can change over time. For example, the number of carriers to be aggregated can change when the device moves through the communication network and / or when the network usage situation changes over time.

[0053] FIG. 2B shows various examples of uplink carrier aggregation for the communication link of FIG. 2A. FIG. 2B includes a first carrier aggregation scenario 31, a second carrier aggregation scenario 32, and a third carrier aggregation scenario 33, which schematically depict three types of carrier aggregation.

[0054] Carrier aggregation scenarios 31 - 33 include a first component carrier f UL1 , a second component carrier f UL2 , and a third component carrier f UL3This shows different spectral distributions for the given carriers. Although Figure 2B is shown in the context of aggregating three component carriers, carrier aggregation can also be used to aggregate more or fewer carriers. Furthermore, although shown in the context of uplink, the aggregation scenario is also applicable to downlink.

[0055] The first carrier aggregation scenario 31 represents continuous in-band carrier aggregation in which component carriers that are adjacent in frequency and within a common frequency band are aggregated. For example, in the first carrier aggregation scenario 31, component carrier f located continuously within the first frequency band BAND1 is aggregated. UL1 ,f UL2 and f UL3 To depict the summation of these.

[0056] Continuing to refer to Figure 2B, the second carrier aggregation scenario 32 represents an intraband discontinuous carrier aggregation in which two or more component carriers at non-adjacent frequencies but within a common frequency band are aggregated. For example, in the second carrier aggregation scenario 32, component carrier f, which is discontinuous but located within the first frequency band, is aggregated. UL1 ,f UL2 and f UL3 To depict the summation of these.

[0057] Third carrier aggregation scenario 33 represents intraband discontinuous carrier aggregation in which component carriers that are at non-adjacent frequencies and located within multiple frequency bands are aggregated. For example, in third carrier aggregation scenario 33, component carrier f of the first frequency band BAND1 UL1 and f UL2 And the component carrier f of the second frequency band BAND2 UL3 This depicts the conclusion.

[0058] Figure 2C shows various examples of downlink carrier aggregation for the communication link in Figure 2A. These examples involve the first component carrier fDL1 , second component carrier f DL2 Third component carrier f DL3 , fourth component carrier f DL4 and the 5th component carrier f DL5 Various carrier aggregation scenarios 34-38 for different spectral distributions are depicted. Although Figure 2C is shown in the context of aggregating five component carriers, carrier aggregation can also be used to aggregate more or fewer carriers. Furthermore, although shown in the context of downlink, the aggregation scenarios are also applicable to uplink.

[0059] The first carrier aggregation scenario 34 depicts the aggregation of component carriers located consecutively within the same frequency band. In addition, the second carrier aggregation scenario 35 and the third carrier aggregation scenario 36 depict two examples of aggregation where the carriers are discontinuous but located within the same frequency band. Furthermore, the fourth carrier aggregation scenario 37 and the fifth carrier aggregation scenario 38 depict two examples of aggregation where component carriers located at non-adjacent frequencies and within multiple frequency bands are aggregated. As the number of component carriers to be aggregated increases, the complexity of the possible carrier aggregation scenarios also increases.

[0060] 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 band or multiple bands. In addition, carrier aggregation is applicable to implementations where the individual component carriers have approximately the same bandwidth, and is also applicable to implementations where the individual component carriers have different bandwidths.

[0061] A designated communication network allocates a primary component carrier (PCC) or anchor carrier for uplinks and a PCC for downlinks to a specific user device. In addition, when a mobile device communicates using a single-frequency carrier for uplink or downlink, that user device communicates using a PCC. To improve bandwidth for uplink communication, an uplink PCC can be aggregated with one or more uplink secondary component carriers (SCCs). Furthermore, to improve bandwidth for downlink communication, a downlink PCC can be aggregated with one or more downlink SCCs.

[0062] In a given implementation example, the communication network provides network cells for each component carrier. In addition, the primary cell operates using PCC, while the secondary cell operates using SCC. The primary and secondary cells may have different coverage areas due to differences in carrier frequency and / or network environment.

[0063] Licensed-Assisted Access (LAA) is a downlink carrier aggregation in which licensed frequency carriers associated with a mobile network operator (i) are aggregated together with unlicensed spectrum frequency carriers such as WiFi. LAA uses downlink PCCs in the licensed spectrum to carry control and signaling information associated with the communication link, while unlicensed spectrum is aggregated for wider downlink bandwidth where available. LAA can operate to avoid and / or coexist with WiFi users through dynamic adjustment of secondary carriers. Enhanced Licensed-Assisted Access (eLAA) is an advanced form of LAA that aggregates licensed and unlicensed spectrum for both downlink and uplink. Furthermore, NR-U can operate over LAA / eLAA via the 5GHz band (5150-5925MHz) and / or the 6GHz band (5925MHz-7125MHz).

[0064] Figure 3A is a schematic diagram of an example of a downlink channel using multi-input, multi-output (MIMO) communication. Figure 3B is a schematic diagram of an example of an uplink channel using MIMO communication.

[0065] MIMO communication uses multiple antennas via a common frequency spectrum to communicate with multiple data streams simultaneously. In a given implementation, the data streams operate with different reference signals to enhance data reception at the receiver. MIMO communication benefits from a high signal-to-noise ratio (SNR), improved coding, and / or reduced signal interference due to the spatial multiplexing of the radio environment.

[0066] MIMO order refers to the number of separate data streams being transmitted or received. For example, the MIMO order of downlink communication can be described by the number of transmitting antennas at the base station and the number of receiving antennas at the UE, such as a mobile device. For instance, 2x2 DLMIMO refers to MIMO downlink communication using two base station antennas and two UE antennas. In addition, 4x4 DLMIMO refers to MIMO downlink communication using four base station antennas and four UE antennas.

[0067] In the example shown in Figure 3A, downlink MIMO communication is provided by transmitting using the M antennas 43a, 43b, 43c, ... 43m of base station 41 and receiving using the N antennas 44a, 44b, 44c, ... 44n of mobile device 42. Thus, Figure 3A shows an example of m × n DLMIMO.

[0068] Similarly, the MIMO order of uplink communication can be described by the number of transmitting antennas in the UE, such as a mobile device, and the number of receiving antennas in the base station. For example, 2x2 ULMIMO refers to MIMO uplink communication using two UE antennas and two base station antennas. In addition, 4x4 ULMIMO refers to MIMO uplink communication using four UE antennas and four base station antennas.

[0069] In the example shown in Figure 3B, uplink MIMO communication is provided by transmission using the N antennas 44a, 44b, 44c, ... 44n of the mobile device 42, and reception using the M antennas 43a, 43b, 43c, ... 44m of the base station 41. Thus, Figure 3B shows an example of n × m ULMIMO.

[0070] By increasing the MIMO level or order, the bandwidth of the uplink and / or downlink channels can be increased.

[0071] MIMO communication is applicable to various types of communication links, such as FDD and TDD communication links.

[0072] Figure 3C is a schematic diagram of another example of an uplink channel using MIMO communication. In the example shown in Figure 3C, the uplink MIMO communication is provided by transmission using the N antennas 44a, 44b, 44c, ... 44n of the mobile device 42. In addition, the first portion of the uplink transmission is received using the M antennas 43a1, 43b1, 43c1, ... 43m1 of the first base station 41a, while the second portion of the uplink transmission is received using the M antennas 43a2, 43b2, 43c2, ... 43m2 of the second base station 41b. In addition, the first base station 41a and the second base station 41b communicate with each other via wired, optical, and / or wireless links.

[0073] The MIMO scenario in Figure 3C illustrates an example of how multiple base stations cooperate to facilitate MIMO communication.

[0074] Figure 4A is a schematic diagram of an example of a communication system 110 operating by beamforming. The communication system 110 includes a transceiver 105, signal conditioning circuits 104a1, 104a2…104an, 104b1, 104b2…104bn, 104m1, 104m2…104mn, and an antenna array 102. The antenna array 102 includes antenna elements 103a1, 103a2…103an, 103b1, 103b2…103bn, 103m1, 103m2…103mn.

[0075] Communication systems that communicate using millimeter-wave carriers (e.g., 30 GHz to 300 GHz), centimeter-wave carriers (e.g., 3 GHz to 30 GHz), and / or other frequency carriers may use antenna arrays to provide beamforming and directivity for transmitting and / or receiving signals.

[0076] For example, in the illustrated embodiment, the communication system 110 includes an array 102 of m × n antenna elements, each of which is controlled by a separate signal conditioning circuit in this embodiment. As indicated by the ellipsis, the communication system 110 can implement any appropriate number of antenna elements and signal conditioning circuits.

[0077] With respect to signal transmission, the signal conditioning circuit can supply a transmission signal to the antenna array 102, thereby generating an aggregated transmission signal that exhibits beam-like quality with a strong signal intensity, where signals radiated from the antenna elements combine using constructive and destructive interference and propagate in a given direction away from the antenna array 102.

[0078] In the context of signal reception, the signal conditioning circuit processes the received signal (for example, by separately controlling the received signal phase) so that more signal energy is received when the signal reaches the antenna array 102 from a specific direction. Thus, the communication system 110 also provides directivity for signal reception.

[0079] The relative concentration of signal energy that becomes the transmit or receive beam can be increased by increasing the size of the array. For example, if there is more signal energy that is focused and becomes the transmit beam, the signal can propagate over a longer range while providing a sufficient signal level for RF communication. For instance, a signal with a large ratio of signal energy that is focused and becomes the transmit beam may exhibit high effective isotropic radiated power (EIRP).

[0080] In the illustrated embodiment, the transceiver 105 supplies a transmit signal to a signal conditioning circuit and processes the reception of a signal received from the signal conditioning circuit. As shown in Figure 4A, the transceiver 105 generates a control signal for the signal conditioning circuit. The control signal can be used for various functions, such as controlling the gain and phase of the transmit and / or receive signals to control beamforming.

[0081] Figure 4B is a schematic diagram of an example of beamforming that provides a transmit beam. Figure 4B shows a portion of a communication system including a first signal conditioning circuit 114a, a second signal conditioning circuit 114b, a first antenna element 113a, and a second antenna element 113b.

[0082] Although the communication system is shown to include two antenna elements and two signal conditioning circuits, it may include additional antenna elements and / or signal conditioning circuits. For example, Figure 4B shows one embodiment of a part of the communication system 110 of Figure 4A.

[0083] The first signal conditioning circuit 114a includes a first phase shifter 130a, a first power amplifier 131a, a first low-noise amplifier (LNA) 132a, and a switch for controlling the selection of either the power amplifier 131a or the LNA 132a. In addition, the second signal conditioning circuit 114b includes a second phase shifter 130b, a second power amplifier 131b, a second LNA 132b, and a switch for controlling the selection of either the power amplifier 131b or the LNA 132b.

[0084] Although one embodiment of a signal conditioning circuit is presented, other implementations of the signal conditioning circuit are also possible. For example, in one example, the signal conditioning circuit includes one or more bandfilters, duplexers, and / or other components.

[0085] In the illustrated embodiment, the first antenna element 113a and the second antenna element 113b are spaced apart by a distance d. In addition, Figure 4B is annotated with an angle θ. In this example, θ is approximately 90° when the transmitting beam direction is substantially perpendicular to the plane of the antenna array, and approximately 0° when the transmitting beam direction is substantially parallel to the plane of the antenna array.

[0086] A desired transmission beam angle θ can be achieved by controlling the relative phase of the transmission signal applied to antenna elements 113a and 113b. For example, the first phase shifter 130a may have a reference value of 0°, and the second phase shifter 130b may be controlled to give a phase shift of approximately -2πf(d / ν)cosθ radians, where f is the fundamental frequency of the transmission signal, d is the distance between the antenna elements, ν is the velocity of the radiated wave, and π is the mathematical constant pi.

[0087] In a given implementation example, the distance d is implemented to be approximately λ / 2, where λ is the wavelength of the fundamental component of the transmitted signal. In such an implementation, the second phase shifter 130b can be controlled to provide a phase shift of approximately -πcosθ radians in order to achieve the transmitted beam angle θ.

[0088] Therefore, the relative phases of the phase shifters 130a and 130b can be controlled to provide transmit beamforming. In a given implementation example, a baseband processor and / or transceiver (e.g., transceiver 105 in Figure 4A) controls the phase values ​​of one or more phase shifters and the gain values ​​of one or more controllable amplifiers to control beamforming.

[0089] Figure 4C is a schematic diagram of an example of beamforming that gives a receive beam. Figure 4C is similar to Figure 4B, but differs in that Figure 4C shows beamforming in the context of a receive beam rather than a transmit beam.

[0090] As shown in Figure 4C, the relative phase difference between the first phase shifter 130a and the second phase shifter 130b can be selected to be approximately equal to -2πf(d / ν)cosθ radians in order to achieve the desired receiving beam angle θ. In an implementation example where the distance d corresponds to approximately λ / 2, the phase difference can be selected to be approximately equal to -πcosθ radians in order to achieve the receiving beam angle θ.

[0091] Although various formulas have been given for phase values ​​that give beamforming, other phase selection values ​​are also possible, such as phase values ​​selected based on the antenna array implementation, the signal conditioning circuit implementation, and / or the wireless environment.

[0092] LNA and LNA bias examples

[0093] Apparatus and method for biasing an LNA are provided herein. In a given embodiment, the LNA includes at least one transistor for amplifying a radio frequency (RF) input signal and a bias circuit. The bias circuit includes a current bias circuit that generates a bias current based on a reference current and a voltage bias circuit that generates at least one input bias voltage for the at least one transistor based on the bias current. The current bias circuit includes a first bias transistor that receives the reference current, a second bias transistor that generates a bias current, and an amplifier that controls the first bias voltage of the first bias transistor to match the second bias voltage of the second bias transistor.

[0094] By implementing the LNA bias in this manner, high-speed biasing, precise matching of the bias current to the reference current, reduced circuit area, and / or excellent voltage headream are achieved.

[0095] Figure 5A is a schematic diagram of an LNA210 according to one embodiment. The LNA210 includes an amplifying transistor 201, a bias circuit 202, and a reference current source 203.

[0096] As shown in Figure 5A, the amplification transistor 201 receives the RF input signal RF IN The RF output signal is amplified and RF OUT In addition, the amplifying transistor 201 receives the bias voltage V generated by the bias circuit 202. BIAS It is biased by the RF input signal. Although it is shown to include one amplification transistor 201, the LNA210 receives the RF input signal RF IN It may include one or more additional transistors that amplify the signal. For example, in one example, the LNA210 is implemented as a cascode amplifier including a common source transistor that is biased by a first bias voltage and a cascode transistor that is biased by a second bias voltage.

[0097] The reference current source 203 supplies the reference current I to the bias circuit 202. REFThis generates the reference current source 203, which is controllable in this example. For example, in one example, the reference current I REF (RF input signal RF IN Gain control and / or trimming (adjusting the amount of amplification applied to the LNA) can be provided to digitally control variations such as process, voltage, and / or temperature (PVT) fluctuations, thereby revealing variations.

[0098] Continuing to refer to Figure 5A, the bias circuit 202 includes a current bias circuit 205 and a voltage bias circuit 206. The current bias circuit 205 is a reference current I REF Based on the bias current I BIAS While generating the bias current I, the voltage bias circuit 206 generates the bias current I BIAS Based on the bias voltage V BIAS Generates.

[0099] In a given implementation example, the current bias circuit 205 has a reference current I REF A first bias transistor that receives the signal, and a bias current I BIAS The current bias circuit 205 includes a second bias transistor that generates a bias current I, and an amplifier 207 that controls the first bias voltage of the first bias transistor to match it to the second bias voltage of the second bias transistor. BIAS Reference current I REF Precise matching is achieved. Furthermore, since such precise matching can be achieved without using a cascode transistor in the current bias circuit, excellent voltage headreme can be achieved, allowing operation in a confined area and / or at low supply voltage levels to the LNA210.

[0100] Furthermore, by including amplifier 207, LNA210 is enabled and a fast bias is applied to LNA210, and then the bias current I BIASThe system rapidly reaches a steady state level. This speed, which provides appropriate biasing, allows the LNA210 to be quickly turned on or off. This is particularly advantageous in 5G applications, which are associated with the short time window of transition between transmitted and received frames for the 5GNR TDD bandwidth.

[0101] Figure 5B is a schematic diagram of the LNA230 in another embodiment. The LNA230 includes a common-source field-effect transistor (FET) 211, a cascode FET 212, a bias circuit 213, an input matching circuit 214, a reference current source 215, a DC block capacitor 216, a degeneration inductor 217, a degeneration bypass switch 218, an output matching circuit 219, and an attenuator 220. The LNA230 is powered by a power supply voltage V DD And receive the ground voltage (ground) and the RF input signal RF IN The RF output signal is amplified and RF OUT It plays the role of generating [something].

[0102] As shown in Figure 5B, the common source FET 211 receives the RF input signal RF through the input matching circuit 214 and the DC block capacitor 216. IN Includes a gate that receives the signal. The gate voltage V of the common source FET211. G Also, the gate bias voltage V from bias circuit 213 BIAS It is biased by the following. The degeneration inductor 217 and the degeneration bypass switch 218 are connected in parallel between the source and ground of the common source FET 211 and serve to provide the common source FET 211 with a controllable amount of source degeneration (inductive degeneration). The cascode FET 212 is connected between the output matching circuit 219 and the drain of the common source FET 211 and is biased by the cascode bias voltage V generated by the bias circuit 213. CAS Includes gates that are biased by [the specified factor].

[0103] Continuing to refer to Figure 5B, the attenuator 220 applies a constant, controllable amount of attenuation to the RF signal provided by the output matching circuit 219, thereby reducing the RF output signal of the LNA 230. OUT This generates the following. In a given implementation example, the attenuator 220 is implemented as a digital step attenuator (DSA) that provides one mechanism for gain control. Although the attenuator 220 can provide some degree of gain control, other components of the LNA 230 (e.g., the reference current source 215 and / or bias circuit 213) also provide gain control. That is, multiple mechanisms may be provided to control the amount of amplification provided by the LNA 230.

[0104] In this embodiment, the reference current source 215 supplies a reference current I to the bias circuit 213. REF This generates the reference current source 215, which is controllable in this example.

[0105] In the illustrated embodiment, the bias circuit 213 includes a current bias circuit 221, a voltage bias circuit 222, a bias resistor 223, and a resistor bypass switch 224. The current bias circuit 221 controls a reference current I REF Based on the bias current I BIAS It generates a reference current I. In some implementation examples, the current bias circuit 221 generates a reference current I REF A first bias transistor that receives the signal, and a bias current I BIAS The system includes a second bias transistor that generates a voltage, and an amplifier 225 that controls the first bias voltage of the first bias transistor to match it to the second bias voltage of the second bias transistor.

[0106] Continuing to refer to Figure 5B, the voltage bias circuit 222 has a gate bias voltage V BIAS and cascode bias voltage V CAS Generates at least a gate bias voltage V BIAS The bias current I BIAS Based on the cascode bias voltage V CAS This is applied to the gate of the cascode FET212. In addition, the gate bias voltage VBIAS The gate bias voltage V is applied to the gate of the common source FET 211 via a parallel combination of bias resistor 223 and resistor bypass switch 224. In some implementation examples, the gate bias voltage V BIAS and cascode bias voltage V CAS Both sides have a bias current I BIAS It has a voltage level that changes based on the current level.

[0107] As shown in Figure 5B, the resistor bypass switch 224 is controlled by a speed control signal (SPEED) which can be selectively activated to reduce the resistance between the voltage bias circuit 222 and the gate of the common source FET 211. Therefore, the resistor-capacitor (RC) time constant associated with the charging or discharging of the gate of the common source FET 211 can be selectively reduced by activating the speed control signal. Implementing the LNA bias in this manner achieves the benefits of high-speed gate bias control and high bias isolation.

[0108] Figure 5C is a schematic diagram of a bias circuit 260 in one embodiment for an LNA such as the LNA230 in Figure 5B. The bias circuit 260 is connected to the power supply voltage V DD , ground voltage, speed control signal (SPEED), gain control signal (GAIN), and reference current I REF The bias circuit 260 receives the gate voltage V of the common source FET. G The gate bias voltage V used to control it BIAS The bias circuit 260 also generates a cascode bias voltage V used to bias the cascode FET. CAS It also generates.

[0109] In the illustrated embodiment, the bias circuit 260 includes a current bias circuit 241, a voltage bias circuit 242, a bias resistor 223, and a resistor bypass switch 224. The current bias circuit 241 is a reference current I REF Receiving bias current I BIASThe current bias circuit 241 generates the reference current I REF The first bias FET245 receives the signal, and the bias current I BIAS The system includes a second bias FET 246 that generates a first bias voltage, and a servo amplifier 247 that controls the first bias voltage Va of the first bias FET 245 to match it with the second bias voltage Vb of the second bias FET 246. In this embodiment, the first input (+) of the servo amplifier 247 receives the first bias voltage Va, the second input (-) of the servo amplifier 247 receives the second bias voltage Vb, and the output of the servo amplifier 247 controls the gates of the first bias FET 245 and the second bias FET 246, providing feedback to match the drain-source voltage of the first bias FET 245 and the drain-source voltage of the second bias FET 246 with each other.

[0110] By including the servo amplifier 247, the bias current I BIAS Reference current I REF Precise matching to is achieved. Furthermore, the current bias circuit 241 controls the power supply voltage V DD It has excellent voltage headroom, allowing it to operate at low voltage levels. Furthermore, the servo amplifier 247 provides a fast bias, allowing the LNA to turn on or off quickly, by rapidly setting the gate voltages of the first bias FET 245 and the second bias FET 246 to appropriate bias levels. This is desirable for TDD applications that have a short time window for the transition between transmit and receive frames.

[0111] Continuing to refer to Figure 5C, the current bias circuit 242 includes a voltage source 250, a first bias resistor 251, a second bias resistor 252, a first gain control switch 253, a second gain control switch 254, a first bias FET 255, a second bias FET 256, a third bias FET 257, a fourth bias FET 258, and a fifth bias FET 259. Bias current I BIASThe current flows through the first bias resistor 251 and controls the gate voltage of the first bias FET 255. The first bias FET 255 provides the current flowing through the second bias resistor 252 to create a bias voltage V BIAS Set the bias current I. BIAS Furthermore, based on the settings of the first gain control switch 253 and the second gain control switch 254 (controlled by the gain control signal GAIN), current flows through the series combination of the second bias FET 256 and the fourth bias FET 258, and / or the series combination of the third bias FET 257 and the fifth bias FET 259.

[0112] Although not depicted in Figure 5C, (I BIAS Based on the current amount (corresponding to), the voltage level of the voltage source 250 is controlled, and the gate voltages of the second bias FET 256 and the third bias FET 257 (and consequently the cascode bias voltage V) are controlled. CAS A wide variety of bias schemes (e.g., feedback schemes) can be used to set this up.

[0113] Gate bias voltage V BIAS The gate voltage V is transmitted via a parallel combination of bias resistor 223 and resistor bypass switch 224. G It is used to control the speed. The resistor bypass switch 224 is controlled by the speed control signal (SPEED).

[0114] Figure 6A is a schematic diagram of an LNA current bias circuit 330 according to one embodiment. The current bias circuit 330 includes a servo amplifier 301, a first bias FET 302, a second bias FET 303, a first selectable mirroring FET 304, a second selectable mirroring FET 305, a third selectable mirroring FET 306, a fourth selectable mirroring FET 307, a first select switch 314, a second select switch 315, a third select switch 316, and a fourth select switch 317.

[0115] As shown in Figure 6A, the first bias FET 302 is set to reference current I REFUpon receiving the signal, the second bias FET303 receives a bias current I BIAS The servo amplifier 301 generates a first bias voltage Va of the first bias FET 302 and controls it to match the second bias voltage Vb of the second bias FET 303. In addition, the first input (+) of the servo amplifier 301 receives the first bias voltage Va, and the second input (-) of the servo amplifier 301 receives the second bias voltage Vb. The output of the servo amplifier 301 controls the gates of the first bias FET 302 and the second bias FET 303, providing feedback to match the drain-source voltage of the first bias FET 302 with the drain-source voltage of the second bias FET 303.

[0116] The selectable mirroring FETs 304-307 are selectively activated by the selection switches 314-317 respectively, and the bias current I BIAS Gain control is provided by increasing the current I generated by each of the mirroring FETs 304~307. B1 , I B2 , I B3 and / or I B4 This can be selectively added to the current generated by the second bias FET 303. When the selectable mirroring FETs 304-307 are activated, they operate with the same gate-source and source-drain voltages as the second bias FET 303 due to the feedback provided by the servo amplifier 301.

[0117] In the illustrated embodiment, the servo amplifier 301 includes a first amplifier FET 321, a second amplifier FET 322, a first current source 323, and a second current source 324. However, other implementations are also possible.

[0118] Figure 6B is a schematic diagram of a servo amplifier 301 of one embodiment for an LNA current bias circuit. In the illustrated embodiment, the servo amplifier 301 includes a first amplifier FET 321, a second amplifier FET 322, a first current source 323, and a second current source 324. In this example, the first amplifier FET 321 and the second amplifier FET 322 are p-type.

[0119] FIG. 6C is a schematic diagram of a servo amplifier 350 of another embodiment for an LNA current bias circuit. The servo amplifier 350 includes a first amplifier FET 341, a second amplifier FET 342, a first current source 343, and a second current source 344. In this example, the first amplifier FET 341 and the second amplifier FET 342 are n-type. The servo amplifier 350 of FIG. 6C corresponds to a complementary implementation example of the servo amplifier 301 of FIG. 6B with the transistor polarities reversed.

[0120] FIG. 7 is a schematic diagram of a controllable reference current source 390 according to an embodiment. The controllable reference current source 390 includes a bandgap circuit 381, a trimmingable proportional to absolute temperature (PTAT) current source 382, a controllable current mirror 383, and an enable switch 384.

[0121] The bandgap circuit 381 generates a bandgap voltage V BG for biasing the trimmingable PTAT current source 382. The trimmingable PTAT current source 382 generates a PTAT current I PTAT that can be trimmed by a trimming control signal TRIM (a multi-bit digital signal in this example). The controllable current mirror 383 mirrors the PTAT current I PTAT to generate a reference current I REF . The reference current I REF is provided at the output when the enable switch 384 is activated by an enable signal EN. The controllable current mirror 383 has a controllable gain set by a gain control signal Gain (a multi-bit digital signal in this example).

[0122] FIG. 8 is a schematic diagram of an output matching circuit 410 for an LNA according to an embodiment. The output matching circuit 410 includes a tank capacitor C TANK , a tank inductor L TANK , a tuning capacitor C TUNE , a tuning switch S TUNE , and an output capacitor C OUTThe output matching circuit 410 includes a tank node TANK for connection to one or more amplification transistors of the LNA, and an output node OUT for providing the output signal.

[0123] As shown in Figure 8, the tank capacitor C TANK and tank inductor L TANK The output node OUT and the supply voltage V DD It is connected in parallel between the two. In addition, the tuning switch S TUNE When it becomes active (closed), the tuning capacitor C TUNE Tank Capacitor C TANK The amount of tank capacitance is adjusted in parallel with this. Output capacitor C OUT It is connected between the tank node TANK and the output node OUT.

[0124] Figure 9 shows an example of a current-to-time graph for an LNA with fast biasing. This graph corresponds to the LNA230 in one implementation example shown in Figure 5B. As shown in Figure 9, the bias current can be rapidly adjusted in response to changes in the bias current setting.

[0125] Figure 10 shows an example graph of the voltage headroom of LNAs for two implementation examples. The graph includes a first plot 451 showing the bias current versus headroom voltage of an LNA without the use of a servo amplifier, and a second plot 452 showing the bias current versus headroom voltage of an LNA in one implementation example with a servo amplifier. For the first plot 451, 0.86V is the maximum headroom that maintains a bias current of more than 500μA, while for the second plot 452, an adequate bias current can be maintained even with a headroom of less than 1V.

[0126] Figure 11 is a schematic diagram of a portable device 800 according to one embodiment. The portable 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.

[0127] The mobile device 800 can be used to communicate using a wide variety of communication technologies, including but not limited to 2G, 3G, 4G (LTE, LTE Advanced, and LTE Advanced Pro), 5G NR, WLAN (e.g., WiFi), WPAN (e.g., Bluetooth® and ZigBee®), WMAN (e.g., WiMAX), and / or GPS technology.

[0128] The transceiver 802 generates an RF signal for transmission and processes the incoming RF signal received from the antenna 804. It is understood that the various functions associated with transmitting and receiving RF signals can be achieved by one or more components, collectively represented as the transceiver 802 in Figure 11. In one example, a separate component (e.g., a separate circuit or die) may be provided to handle a predetermined type of RF signal.

[0129] The front-end system 803 assists in conditioning the signals transmitted to and / or received from antenna 804. In the illustrated embodiment, the front-end system 803 includes an antenna tuning circuit 810, a plurality of power amplifiers (PAs) 801, a plurality of low-noise amplifiers (LNAs) 812, a plurality of filters 813, a plurality of switches 814, and a signal splitting / coupling circuit 815. However, other implementations are possible. The LNA 812 may include one or more LNAs implemented according to the teachings herein.

[0130] The front-end system 803 can provide a certain number of functions, including, but not limited to, amplification of the transmit signal, amplification of the receive signal, filtering of the signal, switching between different bands, switching between different power modes, switching between transmit and receive modes, duplexing of the signal, multiplexing of the signal (e.g., diplexing or triplexing), or any combination thereof.

[0131] In a given implementation example, the portable device 800 supports carrier aggregation, providing flexibility to increase the peak data rate. Carrier aggregation can be used with both frequency-division duplexing (FDD) and time-division duplexing (TDD), and may be used to aggregate multiple carriers or channels. Carrier aggregation includes continuous aggregation, where continuous carriers are aggregated within the same operating frequency band. Carrier aggregation may be discontinuous and may include carriers whose frequencies are separated within a common band or different bands.

[0132] The multiple antennas 804 may include antennas used for a wide variety of types of communication. For example, antennas 804 may include antennas for transmitting and / or receiving signals associated with a wide variety of frequencies and communication standards.

[0133] In a given implementation example, antenna 804 supports MIMO communication and / or switched diversity communication. For example, MIMO communication uses multiple antennas to communicate multiplexed data streams over a single radio frequency channel. MIMO communication benefits from a high signal-to-noise ratio, improved coding, and / or reduced signal interference due to differences in the spatial multiplexing of the radio environment. Switched diversity refers to communication in which a specific antenna is selected to operate at a particular time. For example, a switch can be used to select a specific antenna from a group of antennas based on various factors such as the observed bit error rate and / or signal strength index.

[0134] The portable device 800 may operate with beamforming in a given implementation. For example, the front-end system 803 may include an amplifier with controllable gain and a phase shifter with controllable phase to provide beamforming and directivity for transmitting and / or receiving signals using antenna 804. For example, in the context of signal transmission, the amplitude and phase of the transmit signal supplied to antenna 804 are controlled so that the signal radiated from antenna 804 is coupled using constructive and destructive interference, resulting in an aggregated transmit signal exhibiting beam-like quality with strong signal intensity propagating in a given direction. In the context of signal reception, the amplitude and phase are controlled so that more signal energy is received when the signal arrives at antenna 804 from a particular direction. In a given implementation, antenna 804 includes one or more arrays of antenna elements to enhance beamforming.

[0135] The baseband system 801 is coupled to a user interface 807 that facilitates the processing of various user input / output (I / O) such as voice and data. The baseband system 801 provides a digital representation of the transmit signal to the transceiver 802, which processes this to generate the RF signal for transmission. The baseband system 801 also processes the digital representation of the receive signal provided by the transceiver 802. As shown in Figure 11, the baseband system 801 is coupled to a memory 806 to facilitate the operation of the portable device 800.

[0136] Memory 806 can be used for a wide variety of purposes, such as storing data and / or instructions, in order to facilitate the operation of the portable device 800 and / or to provide storage for user information.

[0137] The power management system 805 provides a certain number of power management functions for the portable device 800. In a given implementation example, the power management system 805 includes a PA supply control circuit that controls the supply voltage of a plurality of power amplifiers 811. For example, the power management system 805 may be configured to change the supply voltage supplied to one or more of the plurality of power amplifiers 811 in order to improve an efficiency such as power added efficiency (PAE).

[0138] As shown in Figure 11, the power management system 805 receives battery voltage from the battery 808. The battery 808 may be any suitable battery for use in the portable device 800, including, for example, a lithium-ion battery.

[0139] Figure 12A is a schematic diagram of a package module 900 according to one embodiment. Figure 12B is a schematic diagram of a cross-section of the package module 900 along the line 12B-12B in Figure 12A.

[0140] The package module 900 includes a radio frequency component 901, a semiconductor die 902, a surface mount device 903, a wire bond 908, a package substrate 920, and an encapsulation structure 940. The package substrate 920 includes a pad 906 formed from a conductor placed inside. Additionally, the semiconductor die 902 includes pins or pads 904, and the wire bond 908 is used to connect the pad 904 of the die 902 to the pad 906 of the package substrate 920.

[0141] The semiconductor die 902 includes a low-noise amplifier 945 which can be implemented according to one or more features disclosed herein.

[0142] The packaging substrate 920 is configured to accept multiple components, such as a radio frequency component 901 including, for example, a surface-mount capacitor and / or inductor, a semiconductor die 902, and a surface-mount device 903. In one packaging example, the radio frequency component 901 includes an integrated passive device (IPD).

[0143] As shown in Figure 12B, the package module 900 includes a plurality of contact pads 932. The plurality of contact pads 932 are located on the opposite side of the package module 900 from the side used to mount the semiconductor die 902. Configuring the package module 900 in this manner can assist in connecting the package module 900 to a circuit board, such as a telephone board for a mobile device. Examples of contact pads 932 can be configured to supply radio frequency signals, bias signals, and / or power (e.g., power supply voltage and ground) to the semiconductor die 902 and / or other components. As shown in Figure 12B, the electrical connection between the contact pads 932 and the semiconductor die 902 can be facilitated by a connection portion 933 via the package substrate 920. The connection portion 933 may represent an electrical path formed through the package substrate 920, such as a connection portion associated with vias and conductors of a multilayer package substrate.

[0144] In some embodiments, the package module 900 may also include one or more package structures that provide, for example, protection and / or facilitate handling. Such package structures may include an overmolding or encapsulation structure 940 formed on the package substrate 920 on which the components and dies are placed.

[0145] It should be understood that, although the package module 900 is described in the context of wire-bonded electrical connections, one or more features of this disclosure can also be implemented in other package configurations, such as a flip-chip configuration.

[0146] application

[0147] The principles and advantages of the embodiments herein can be used for any other systems or devices that require low-noise amplification. Examples of such devices include RF communication systems, which include, but are not limited to, mobile phones, tablets, base stations, network access points, customer premises equipment (CPE), laptops, and wearable electronic devices. In other words, the low-noise amplifiers herein may be included in a variety of electronic devices, including, but not limited to, consumer electronic products.

[0148] In conclusion

[0149] Unless the context explicitly requires otherwise, throughout the specification and claims, terms such as “includes,” “equip,” and so on should be interpreted in a comprehensive sense, the opposite of an exclusive or exhaustive sense, i.e., “includes but not limited to.” The term “combined,” as used herein, refers to two or more elements that can be directly connected or connected via one or more intermediate elements. Similarly, the term “connected,” as used herein, refers to two or more elements that can be directly connected or connected via one or more intermediate elements. In addition, where used in this application, the terms “here,” “above,” “below,” and similar terms refer to the entire application and not to any particular part of it. Where contextually permissible, terms in the above detailed description that use singular or plural numbers may also include plural or singular numbers. The terms “or” and “or” referring to a list of two or more items cover all of the following interpretations of the term: any of the items in the list, all of the items in the list, and any combination of the items in the list.

[0150] Furthermore, unless specifically stated or understood otherwise in the context in which they are used, conditional language used herein, in particular, such as “may,” “can,” “perhaps,” “for example,” and “like,” is generally intended to mean that a given embodiment includes a given feature, element, and / or state, while other embodiments do not. That is, such conditional language is generally not intended to imply that the feature, element, and / or state exists in any manner required for one or more embodiments, or that one or more embodiments necessarily include logic that determines, with or without the author’s input or prompt, whether or not these feature, element, and / or state are included, or should be done in any particular embodiment.

[0151] The above description of embodiments of the present invention is not intended to be exhaustive or to limit the invention to any specific form of the above disclosure. While specific embodiments and examples of the present invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as will be apparent to those skilled in the art. For example, while processes or blocks are presented in a given order, alternative embodiments may employ systems having routines or blocks with steps in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined, and / or modified. Each of these processes or blocks may be implemented in various different ways. Furthermore, while processes or blocks may be shown to be executed in series, these processes or blocks may instead be executed in parallel or at different times.

[0152] The teachings of the present invention given herein can be applied to other systems, not necessarily those described above. The elements and operations of the various embodiments described above may be combined to provide further embodiments.

[0153] While certain embodiments of the present invention have been described, these embodiments are presented only as examples and are not intended to limit the scope of this disclosure. In fact, the novel methods and systems described herein may be embodied in various other forms, and various omissions, substitutions, and modifications of the methods and systems described herein may be made without departing from the spirit of this disclosure. The appended claims and their equivalents are intended to cover forms or modifications that fall within the scope and spirit of this disclosure.

Claims

1. A mobile device, including an antenna and a front-end system, wherein the front-end system includes a low-noise amplifier including at least one amplifier transistor configured to amplify a radio frequency input signal received from the antenna, and a bias circuit, the bias circuit includes a current bias circuit configured to generate a bias current based on a reference current, and a voltage bias circuit configured to generate at least one input bias voltage for the at least one amplifier transistor based on the bias current, the current bias circuit includes a first bias transistor configured to receive the reference current, a second bias transistor configured to generate the bias current, and an amplifier configured to control a first bias voltage of the first bias transistor to match a second bias voltage of the second bias transistor, the first bias transistor includes a drain connected to a first input portion of the amplifier and a gate connected to an output portion of the amplifier, the second bias transistor includes a drain connected to a second input portion of the amplifier and a gate connected to the output portion of the amplifier, a mobile device.

2. The current bias circuit further includes a plurality of selection switches and a plurality of current mirroring transistors each selectable by a corresponding one of the plurality of selection switches, wherein the plurality of current mirroring transistors are biased by the second bias voltage, the mobile device of Claim 1.

3. The at least one amplifier transistor includes a common source transistor, wherein the at least one input bias voltage includes a gate bias voltage for the common source transistor, the mobile device of Claim 1.

4. The bias circuit includes a bias resistor and a bias resistor bypass switch, wherein the voltage bias circuit is configured to apply the gate bias voltage to the gate of the common source transistor through a parallel combination of the bias resistor and the bias resistor bypass switch, the mobile device of Claim 3.

5. The at least one amplifier transistor further includes a cascode transistor in series with the common source transistor, ​ The portable device of claim 3, wherein the at least one input bias voltage further includes a cascode bias voltage for the cascode transistor.

6. The front-end system further includes a controllable current source configured to generate the reference current, The portable device of claim 1, wherein the controllable current source is configured to control the reference current based on a gain control signal.

7. The portable device of claim 1, wherein the voltage bias circuit includes a first voltage bias transistor and a resistor in series between a supply voltage and a ground voltage, and a second voltage bias transistor and a third voltage bias transistor in series between the gate of the first voltage bias transistor and the ground voltage.

8. The portable device of claim 7, wherein the voltage bias circuit is configured to generate a first input bias voltage of the at least one input bias voltage based on a voltage across the resistor, and is configured to generate a second input bias voltage of the at least one input bias voltage based on a gate voltage of the second voltage bias transistor.

9. A low-noise amplifier, At least one amplifier transistor configured to amplify a radio frequency input signal, And a bias circuit Including, The bias circuit includes a current bias circuit configured to generate a bias current based on a reference current, and a voltage bias circuit configured to generate at least one input bias voltage for the at least one amplifier transistor based on the bias current. The current bias circuit includes a first bias transistor configured to receive the reference current, a second bias transistor configured to generate the bias current, and an amplifier configured to control a first bias voltage of the first bias transistor to match a second bias voltage of the second bias transistor. The first bias transistor includes a drain connected to a first input of the amplifier and a gate connected to an output of the amplifier. The second bias transistor includes a drain connected to a second input of the amplifier and a gate connected to the output of the amplifier. A low-noise amplifier.

10. The current bias circuit further includes a plurality of selection switches and a plurality of current mirroring transistors each selectable by a corresponding one of the plurality of selection switches, The plurality of current mirroring transistors are biased by the second bias voltage, the low-noise amplifier of claim 9. **Claim 11** The at least one amplifying transistor includes a common source transistor, The at least one input bias voltage includes a gate bias voltage for the common source transistor, the low-noise amplifier of claim 9. **Claim 12** The bias circuit includes a bias resistor and a bias resistor bypass switch, The voltage bias circuit is configured to apply the gate bias voltage to the gate of the common source transistor via a parallel combination of the bias resistor and the bias resistor bypass switch, the low-noise amplifier of claim 11. **Claim 13** The at least one amplifying transistor further includes a cascode transistor in series with the common source transistor, The at least one input bias voltage further includes a cascode bias voltage for the cascode transistor, the low-noise amplifier of claim 11. **Claim 14** Further includes a controllable current source configured to generate the reference current, The controllable current source is configured to control the reference current based on a gain control signal, the low-noise amplifier of claim 9. **Claim 15** The voltage bias circuit includes a first voltage bias transistor and a resistor in series between a supply voltage and a ground voltage, and a second voltage bias transistor and a third voltage bias transistor in series between the gate of the first voltage bias transistor and the ground voltage, the low-noise amplifier of claim 9. **Claim 16** The voltage bias circuit is configured to generate a first input bias voltage of the at least one input bias voltage based on a voltage across the resistor, and is configured to generate a second input bias voltage of the at least one input bias voltage based on a gate voltage of the second voltage bias transistor, the low-noise amplifier of claim 15. **Claim 17** A method for amplifying a radio frequency signal, comprising: Amplifying a radio frequency input signal using at least one amplifying transistor of a low-noise amplifier; Generating at least one input bias voltage for the at least one amplifying transistor based on a bias current using a voltage bias circuit of the low-noise amplifier; Generating the bias current based on a reference current using a current bias circuit of the low-noise amplifier; comprising; receiving the reference current using a first bias transistor; generating the bias current using a second bias transistor; and controlling an amplifier to match a first bias voltage of the first bias transistor to a second bias voltage of the second bias transistor; The first bias transistor includes a drain connected to a first input portion of the amplifier and a gate connected to an output portion of the amplifier; The second bias transistor includes a drain connected to a second input portion of the amplifier and a gate connected to the output portion of the amplifier, the method.

18. The generating of the at least one input bias voltage for the at least one amplifying transistor includes generating a gate bias voltage for a common source transistor and generating a cascode bias voltage for a cascode transistor in series with the common source transistor, the method of claim 17.

19. The first bias transistor further includes a source connected to a supply voltage; The second bias transistor further includes a source connected to a supply voltage, the portable device of claim 1.

20. The first bias transistor further includes a source connected to a supply voltage; The second bias transistor further includes a source connected to a supply voltage, the low-noise amplifier of claim 9.

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