CN116868340A

CN116868340A - Radio frequency integrated circuit chip and wireless communication device

Info

Publication number: CN116868340A
Application number: CN202180093124.7A
Authority: CN
Inventors: 朱煜; 王国瑞; 汪金铭; 杨帆; 王晨
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-04-29
Filing date: 2021-04-29
Publication date: 2023-10-10
Also published as: WO2022226935A1

Abstract

The present disclosure relates to a circuit including an amplifier. The amplifier includes an amplifying tube and a limiter. The power amplifier includes a control terminal, a first terminal, and a second terminal. The amplifying tube is configured to generate an amplified signal based on an input signal received from the control terminal. The limiter is coupled between the first terminal and the second terminal and includes a first limiter circuit and a second limiter circuit. The temperature drift characteristic of the threshold value of the first clipping circuit is opposite to the temperature drift characteristic of the threshold value of the second clipping circuit. By using a clipping circuit with thresholds of opposite temperature drift characteristics, tuning of clipping of the amplifier can be achieved, so that the clipping level can be set as desired.

Description

Radio frequency integrated circuit chip and wireless communication device

Technical Field

The present disclosure relates to the field of circuits, and more particularly to radio frequency integrated circuit chips and wireless communication devices.

Background

With the development of integrated circuits, electronic devices such as wireless communication apparatuses integrate more and more chips to realize various functions. To enable wireless communication, integrated circuit components, including, for example, radio frequency front end modules, are commonly used in electronic devices to transmit signals or data. The radio frequency front end module may include chips such as radio frequency transceivers, power Amplifiers (PA), low noise amplifiers (low noise amplifier, LNA), filters, and diplexers. These chips often involve amplification of the signal during operation. For example, the input signal is amplified to different levels to meet the wireless transmission requirements of the signal. However, as power margin requirements increase, there is a problem with the reliability of the rf amplification system.

In some conventional schemes, amplification of the amplifier may be limited in order to improve reliability of the circuit. However, such designs often have limited yields on the one hand and certain limitations on the other.

Disclosure of Invention

In view of the foregoing, embodiments of the present disclosure aim to provide a circuit, a chip, a radio frequency amplifier, a radio frequency front end system, and an electronic device for improving reliability performance of the circuit.

According to a first aspect of the present disclosure, a circuit is provided that includes an amplifier. The amplifier includes an amplifying tube and a limiter. The amplifying tube includes a control terminal, a first terminal, and a second terminal. The amplifying tube is for amplifying an input signal received from the control terminal. The limiter is coupled between the first terminal and the second terminal and includes a first limiter circuit and a second limiter circuit. The first clipping circuit is different from the second clipping circuit. By using different clipping circuits, tuning of the clipping of the amplifier can be achieved, so that flexible clipping can be set as desired.

In one possible implementation, the threshold characteristics of the first clipping circuit are different from the threshold characteristics of the second clipping circuit. Tuning of the clipping threshold of the radio frequency amplifier can be achieved by using clipping circuits with different threshold characteristics, whereby the clipping threshold can be set as desired.

In one possible implementation, the first clipping circuit and the second clipping circuit are coupled in series between the first terminal and the second terminal. By coupling the first clipping circuit and the second clipping circuit in series, the range of clipping thresholds can be effectively increased and the power margin of the radio frequency amplifier can be effectively improved.

In one possible implementation, the power amplifier includes one or more transistors in series, a first terminal is a source or emitter of a transistor located at a first end of the one or more transistors, a second terminal is a drain or collector of a transistor located at a second end opposite the first end of the one or more transistors, and the control terminal is a gate or base of a transistor located at the first end of the one or more transistors. By providing the power amplifier in the form of a series transistor, the amplifying performance of the power can be effectively improved.

In one possible implementation, the first clipping circuit includes one or more gated diodes coupled in series; the second clipping circuit includes one or more body bias transistors coupled in series. The gate of the body bias transistor is coupled to the drain of the body bias transistor, and the body of the body bias transistor is for receiving a bias voltage provided by the bias circuit. Since the gated diode has a threshold characteristic of negative temperature drift and the body of the body-biased transistor is adaptive and has a threshold characteristic of positive temperature drift, the threshold characteristic of relative temperature can be achieved over a range of temperatures. The power amplifier may thus achieve a relatively stable threshold characteristic over a range of temperatures, whereby a more accurate clipping performance may be obtained.

In one possible implementation, the first clipping circuit includes one or more first transistors coupled in series, a gate of the first transistor is coupled to a drain of the first transistor, and a source of the first transistor is coupled to a body of the first transistor. The second clipping circuit includes one or more body bias transistors coupled in series, wherein a gate or base of the body bias transistor is coupled to a drain or collector of the body bias transistor and a body bias transistor body pole is for receiving a bias voltage provided by the bias circuit. Because the first transistor has the threshold characteristic of negative temperature drift and has the threshold characteristic of positive temperature drift due to the body effect of the transistor, the body pole self-adaption of the body bias transistor can be realized within a certain temperature range, so that the radio frequency amplifier has relatively stable threshold characteristic within a certain temperature range, and more accurate amplitude limiting performance can be obtained.

In one possible implementation, the radio frequency amplifier further comprises a bias circuit. A bias circuit is coupled to the volume of the body bias transistor and is configured to provide a bias voltage.

In one possible implementation, the bias circuit includes a first resistor and a second resistor coupled in series between a first supply voltage and a first reference voltage, wherein a first node between the first resistor and the second resistor is coupled to a body pole of the body bias transistor. The bias circuit provides a bias voltage to the body bias transistor, and the bias voltage is above a voltage threshold of a parasitic diode of the body bias transistor. By providing the bias voltage in the form of a voltage divider in the form of a series resistor, the bias voltage can be set as desired and can be kept stable over a certain temperature range. Thus, the power amplifier can achieve a relatively stable threshold characteristic over a range of temperatures, so that more accurate clipping performance can be obtained.

In one possible implementation, the bias circuit is configured to provide a bias voltage having a negative temperature characteristic. By providing a bias voltage with a negative temperature characteristic, the body bias transistor can be made adaptive to have a threshold characteristic of positive temperature drift. The threshold characteristic of the positive temperature drift may be cancelled out with the threshold characteristic of the negative temperature drift to obtain a stable temperature characteristic over a large temperature range.

In one possible implementation, the bias includes a third resistor and a first diode coupled in series between the first supply voltage and the first reference voltage, wherein an intermediate node between the third resistor and the first diode is coupled to the body bias transistor. The negative temperature bias voltage generator supplies a negative temperature bias voltage as a bias voltage to the body bias transistor.

In one possible implementation, the amplifier further comprises a bias resistor. The bias resistor is coupled between the body pole of the body bias transistor and the bias circuit.

In one possible implementation, the temperature drift characteristic of the threshold characteristic of the first clipping circuit is different from the temperature drift characteristic of the threshold characteristic of the second clipping circuit. By providing clipping circuits with different temperature drift characteristics, the clipping performance of the limiter can be flexibly tuned.

In one possible implementation, the threshold characteristic of the first clipping circuit decreases with increasing temperature and the threshold characteristic of the second clipping circuit increases with increasing temperature.

In one possible implementation, the clipping threshold of the limiter remains unchanged with a change in temperature. By setting the clipping threshold of the limiter to remain substantially unchanged with a change in temperature, a stable and desired clipping effect can be obtained.

In one possible implementation, the radio frequency amplifier further comprises a power limiter. The power limiter is coupled to the control terminal of the power amplifier and is configured to limit an input signal amplitude of the input signal. By providing a power limiter at the control terminal of the power amplifier, the input signal amplitude of the input signal can be effectively controlled to meet the requirements of a plurality of application scenes. In addition, the reliability of the radio frequency amplifier can be improved. For example, reliability against time-varying breakdown (time-dependent dielectric breakdown, TDDB) and hot carrier injection (hot carrier injection, HCI) is enhanced.

In one possible implementation, the power limiter comprises a second diode and a third diode. The third diode and the second diode are connected in anti-parallel between the control terminal of the power amplifier and the second terminal of the power amplifier. By providing pairs of diodes in anti-parallel connection, the power limiter can be implemented in a simple manner and the cost reduced.

In one possible implementation, the radio frequency amplifier further comprises a first inductor. The first inductor is coupled between the second terminal of the power amplifier tube and ground. By providing an inductor between the second terminal of the power amplifier tube and ground, the radio frequency signal can be effectively isolated from the dc bias.

In one possible implementation, the power limiter comprises a voltage detector and a voltage limiter. A voltage detector is coupled to the control terminal of the power amplifier and configured to detect a voltage of the input signal. A voltage limiter is coupled to the control terminal of the power amplifier and the voltage detector and is configured to limit a voltage amplitude of the input signal based on the detected voltage. By detecting the voltage of the input signal and limiting the voltage of the input signal in a suitable way, it is possible to pre-clip before amplification and to make dynamic adjustments according to the real-time voltage of the input signal to obtain good dynamic power limitation.

In one possible implementation, the voltage limiter comprises at least one limiting circuit coupled in series between the control terminal of the power amplifier and ground and comprising a regulating input terminal coupled to the voltage detector.

In one possible implementation, each of the at least one limiting circuit includes a limiting transistor. The limiting transistor is coupled in series between a control terminal of the power amplifier and ground and includes a control terminal coupled to the voltage detector. By providing limiting transistors in series, the power limiting performance can be dynamically adjusted in a simple and efficient manner.

In one possible implementation, each of the at least one limiting circuit further comprises a limiting resistor coupled between the voltage detector and the control terminal of the limiting transistor.

In one possible implementation, the circuitry is integrated into a chip. The threshold characteristic of the first clipping circuit is different from the threshold characteristic of the second clipping circuit.

According to a second aspect of the present disclosure, a chip is provided, comprising an amplifier. The amplifier includes an amplifying tube and a limiter. The amplifying tube includes a control terminal, a first terminal, and a second terminal. The power amplifier tube is for amplifying an input signal received from the control terminal. The limiter is coupled between the first terminal and the second terminal and includes a first limiter circuit and a second limiter circuit. The first clipping circuit is different from the second clipping circuit. By using circuits with different clipping, tuning of the amplifier can be achieved so that the clipping threshold can be set as desired.

According to a third aspect of the present disclosure, a radio frequency amplifier is provided. The radio frequency amplifier comprises an amplifier according to the first aspect. By using circuits with different clipping, tuning of the amplifier can be achieved so that the clipping threshold can be set as desired.

According to a fourth aspect of the present disclosure, a radio frequency front end system is provided. The radio frequency front end system comprises a circuit according to the first aspect. Tuning of the amplifier in the radio frequency front end system can be achieved by using different clipping circuits in the radio frequency front end system, whereby clipping can be set as desired.

According to a fifth aspect of the present disclosure, an electronic device is provided. The electronic device comprises a radio frequency front end system according to the fourth aspect. By using different clipping circuits in the electronic device, tuning of the amplifier in the electronic device can be achieved, whereby clipping can be set as desired.

According to a sixth aspect of the present disclosure, a method for operating a circuit is provided. The method comprises providing that an input signal is received by an amplifying tube at its control terminal and amplified, and clipping the amplified signal by a clipping device comprising a first clipping circuit and a second clipping circuit, wherein a temperature drift characteristic of a threshold value of the first clipping circuit is opposite to a temperature drift characteristic of a threshold value of the second clipping circuit. By using a limiter circuit having thresholds with opposite temperature drift characteristics, tuning of the amplifier can be achieved, so that limiting can be set as desired.

According to a seventh aspect of the present disclosure, a circuit is provided comprising an amplifier. The amplifier includes an amplifying tube and a limiter. The amplifying tube includes a control terminal, a first terminal, and a second terminal. The amplifying tube is for amplifying an input signal received from the control terminal. A limiter is coupled between the first and second terminals of the amplifying tube and includes one or more body bias transistors coupled in series. The gate of the body bias transistor is coupled to the drain of the body bias transistor and the body of the body bias transistor is for receiving a voltage provided by the bias circuit. By using body bias transistors, flexible clipping can be set as desired.

It should be understood that what is described in this summary is not intended to limit the critical or essential features of the embodiments of the disclosure nor to limit the scope of the disclosure. Other features of the present disclosure will become apparent from the following description.

Drawings

The above and other features, advantages and aspects of embodiments of the present disclosure will become more apparent by reference to the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, wherein like or similar reference numerals denote like or similar elements, in which:

fig. 1 illustrates a schematic diagram of an example wireless communication system in which embodiments of the present disclosure may be implemented;

Fig. 2 illustrates a schematic diagram of a carrier configuration of the wireless communication system in which embodiments of the present disclosure may be implemented;

fig. 3 illustrates a schematic diagram of an exemplary wireless communication device in which embodiments of the present disclosure may be implemented;

FIG. 4 illustrates a schematic diagram of an exemplary radio frequency circuit in which embodiments according to the present disclosure may be implemented;

fig. 5 shows a schematic circuit diagram of a radio frequency amplifier;

fig. 6 shows a schematic circuit diagram of another radio frequency amplifier;

fig. 7 shows a circuit schematic of a radio frequency amplifier according to one embodiment of the present disclosure;

fig. 8 shows a schematic block diagram of a limiter according to one embodiment of the present disclosure;

fig. 9 shows a schematic circuit diagram of a limiter according to one embodiment of the present disclosure;

fig. 10 shows a schematic circuit diagram of a limiter according to another embodiment of the present disclosure;

fig. 11 shows a schematic circuit diagram of a limiter according to yet another embodiment of the present disclosure;

FIG. 12 illustrates a schematic diagram of a bias circuit according to one embodiment of the present disclosure;

FIG. 13 illustrates a circuit schematic of a negative temperature bias voltage generator according to one embodiment of the present disclosure;

fig. 14 shows a circuit schematic of a radio frequency amplifier according to one embodiment of the present disclosure;

Fig. 15 shows a circuit schematic of a radio frequency amplifier according to another embodiment of the present disclosure; and

fig. 16 shows a flowchart of a method for manufacturing a circuit according to one embodiment of the present disclosure.

Detailed Description

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure have been shown in the accompanying drawings, it is to be understood that the present disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are for illustration purposes only and are not intended to limit the scope of the present disclosure.

In describing embodiments of the present disclosure, the term "comprising" and its like should be taken to be open-ended, i.e., including, but not limited to. The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first," "second," and the like, may refer to different or the same object. Other explicit and implicit definitions are also possible below.

In the following description of the specific embodiments, some repetition is not described in detail, but it should be understood that the specific embodiments have mutual references and may be combined with each other.

In a wireless communication system, devices may be classified into devices providing wireless network services and devices using wireless network services. Devices providing wireless network services are those devices that make up a wireless communication network, which may be referred to simply as network devices (network equipment), or network elements. Network devices are typically owned by an operator or infrastructure provider and are responsible for operation or maintenance by these vendors. The network devices may be further divided into radio access network (radio access network, RAN) devices and Core Network (CN) devices. A typical RAN apparatus includes a Base Station (BS).

It should be appreciated that a base station may also sometimes be referred to as a wireless Access Point (AP), or a transmitting receiving point (transmission reception point, TRP). Specifically, the base station may be a general node B (generation Node B, gNB) in a 5G New Radio (NR) system, an evolved node B (evolutional Node B, eNB) of a 4G long term evolution (long term evolution, LTE) system. Base stations may be classified as macro base stations (macro base station) or micro base stations (micro base station) depending on their physical form or transmit power. Micro base stations are sometimes also referred to as small base stations or small cells (small cells).

A device using a wireless network service may be simply referred to as a terminal (terminal). The terminal can establish connection with the network device and provide specific wireless communication service for the user based on the service of the network device. It should be appreciated that terminals are sometimes referred to as User Equipment (UE), or Subscriber Units (SU), due to their closer relationship to the user. In addition, terminals tend to move with users, sometimes referred to as Mobile Stations (MSs), relative to base stations that are typically placed at fixed locations. In addition, some network devices, such as a Relay Node (RN) or a wireless router, may be considered terminals because they have UE identities or belong to users.

Specifically, the terminal may be a mobile phone (mobile phone), a tablet computer (tablet computer), a laptop computer (laptop computer), a wearable device (such as a smart watch, a smart bracelet, a smart helmet, smart glasses), and other devices with wireless access capability, such as a smart car, various internet of things (internet of thing, IOT) devices, including various smart home devices (such as smart meters and smart home appliances), and smart city devices (such as security or monitoring devices, intelligent road transportation facilities), and the like.

For convenience of description, the technical solution of the embodiment of the present application will be described in detail by taking a base station and a terminal as examples.

Fig. 1 illustrates a schematic diagram of an example wireless communication system 100 in which embodiments of the present disclosure may be implemented. As shown in fig. 1, a wireless communication system 100 includes a terminal 101 and a base station 102. The transmission link from the terminal 101 to the base station 102 is referred to as an Uplink (UL) and the transmission link from the base station to the terminal is referred to as a Downlink (DL) according to the transmission direction. Similarly, data transmission in the uplink may be abbreviated as uplink data transmission or uplink transmission, and data transmission in the downlink may be abbreviated as downlink data transmission or downlink transmission.

In the wireless communication system, the base station 102 may provide communication coverage for a particular geographic area through an integrated or external antenna device. One or more terminals located within the communication coverage area of base station 102 can access the base station. One base station may manage one or more cells (cells). Each cell has an identification, also called cell identity (cell ID). From the radio resource point of view, one cell is a combination of downlink radio resources and (optionally) uplink radio resources paired therewith.

It should be appreciated that the wireless communication system may conform to the third generation partnership project (third generation partnership project,3 GPP) wireless communication standards, as well as to other wireless communication standards, such as the 802 family of institute of electrical and electronics engineers (Institute of Electrical and Electronics Engineers, IEEE) wireless communication standards, such as 802.11, 802.15, or 802.20. Although only one base station and one terminal are shown in fig. 1, the wireless communication system may include other numbers of terminals and base stations. The wireless communication system may further comprise other network devices, such as core network devices.

The terminal 101 and the base station 102 should be aware of predefined configurations of the wireless communication system 100, including system supported radio access technologies (radio access technology, RAT), system defined radio resource configurations, etc., such as basic configuration of frequency bands and carriers of the radio. A carrier is a range of frequencies that meets system specifications. This range of frequencies may be determined by the center frequency of the carrier (denoted carrier frequency) and the bandwidth of the carrier. These system predefined configurations may be determined as part of the standard protocols of the wireless communication system 100 or by the interaction between the terminal 101 and the base station 102. The contents of the relevant standard protocols may be pre-stored in memories of the terminal 101 and the base station 102 or embodied as hardware circuits or software codes of the terminal 101 and the base station 102.

In the wireless communication system 100, the terminal 101 and the base station 102 support one or more of the same RAT, e.g., 5g nr,4g LTE, or RAT of future evolution system. Specifically, the terminal 101 and the base station 102 employ the same air interface parameters, coding scheme, modulation scheme, and the like, and communicate with each other based on radio resources specified by the system.

Fig. 2 illustrates a schematic diagram 200 of a carrier configuration of the wireless communication system in which embodiments of the present disclosure may be implemented. In the wireless communication system 100, a base station 102 configures two carrier sets, respectively denoted as a first carrier set and a second carrier set, for a terminal 101. Wherein the first set of carriers may be used for downlink carrier aggregation (downlink carrier aggregation, DLCA) and the second set of carriers may be used for uplink carrier aggregation (uplink carrier aggregation, ULCA). The frequency ranges of the carriers comprised by the two sets of carriers may be different, such as terminals in FDD (frequency duplex division: frequency division duplex) mode; the frequency ranges of the carriers comprised by the two sets of carriers may be identical, such as terminals in TDD (time duplex division, frequency division duplex) mode.

As shown in fig. 2, the first carrier set includes 6 component carriers (component carrier, CC), which are sequentially denoted as CC 1 through CC 6. The second carrier set includes 4 component carriers, including CC 1 through CC 4. It should be understood that the number of CCs included in the first carrier set and the second carrier set is for illustration purposes only, and other numbers of CCs may be included in the first carrier set and the second carrier set in the embodiment of the present application. These CCs may be either continuous or discontinuous in the frequency domain. Different CCs may be in the same frequency band, which may correspond to intra-band carrier aggregation (intra-band CA). Different CCs may also be in different frequency bands, corresponding to inter-band carrier aggregation (inter-band CA).

It should be understood that in the present application, one component carrier may correspond to one serving cell (serving cell) of the terminal. In the chinese context, component carriers are sometimes also translated into component carriers, which may be simply referred to as carriers, and serving cells may be simply referred to as cells. Unless otherwise specified, in the present application, the terms "carrier", "component carrier", "aggregated component carrier", "serving cell", "one of PCell or SCell", "one of PCC or SCC", "aggregated carrier" may be used interchangeably.

Fig. 3 shows a schematic diagram of an exemplary wireless communication device 300, according to an embodiment of the present disclosure. The wireless communication device 300 may be a terminal 101 or a base station 102 in embodiments of the disclosure. As shown in fig. 3, the wireless communication device 300 may include an application subsystem 301, a memory 302, a mass storage (mass storage) 303, a baseband subsystem 304, radio frequency integrated circuits (radio frequency intergreted circuit, RFICs) 305A and 305B (also referred to as RFIC 1 and RFIC 2 in the figures, and may be referred to hereinafter for convenience as RFIC 305 or radio frequency chip 305), a radio frequency front end (radio frequency front end, RFFE) device 306, and an Antenna (ANT) 307, which may be coupled by various interconnection buses or other electrical connections.

In fig. 3, ant_1 denotes a first antenna, ant_n denotes an nth antenna, and N is a positive integer greater than 1. Tx denotes a transmit path, rx denotes a receive path, and different numbers denote different paths. FBRx denotes a feedback reception path, PRx denotes a main reception path, and DRx denotes a diversity reception path. HB represents high frequency, LB represents low frequency, both refer to the relative high and low frequencies. BB represents the baseband. It should be understood that the labels and components in fig. 3 are for illustrative purposes only as one possible implementation, and that other implementations are also included in the disclosed embodiments.

The radio frequency integrated circuit 305 may be further divided into a radio frequency receive path (RF receive path) and a radio frequency transmit path (RF transmit path). The rf receive path may receive rf signals via an antenna, process (e.g., amplify, filter, and downconvert) the rf signals to obtain baseband signals, and pass the baseband signals to a baseband subsystem. The rf transmit path may receive baseband signals from the baseband subsystem, rf process (e.g., up-convert, amplify, and filter) the baseband signals to obtain rf signals, and ultimately radiate the rf signals into space through the antenna. In particular, the radio frequency subsystem may include antenna switches, antenna tuners, low noise amplifiers (low noise amplifier, LNAs), power Amplifiers (PAs), mixers (mixers), local Oscillators (LOs), filters, etc., which may be integrated into one or more chips as desired. The antenna may also sometimes be considered part of the radio frequency subsystem.

The baseband subsystem 304 may extract useful information or data bits from the baseband signal or convert the information or data bits to a baseband signal to be transmitted. The information or data bits may be data representing user data or control information such as voice, text, video, etc. For example, baseband subsystem 304 may implement signal processing operations such as modulation and demodulation, encoding and decoding, and the like. For different radio access technologies, e.g. 5G NR and 4G LTE, there is often not exactly the same baseband signal processing operation. Thus, to support the convergence of multiple mobile communication modes, the baseband subsystem 304 may include multiple processing cores, or multiple HACs, simultaneously. Baseband subsystem 304 is typically integrated into one or more chips, the chips of the integrated baseband subsystem are commonly referred to as baseband processor chips (baseband intergreted circuit, BBIC), also referred to herein as baseband processing circuits.

In addition, since the radio frequency signal is an analog signal, the signal processed by the baseband subsystem 304 is primarily a digital signal, and an analog-to-digital conversion device is also required in the wireless communication device 300. The analog-to-digital conversion device includes an analog-to-digital converter (analog to digital converter, ADC) that converts the analog signal to a digital signal, and a digital-to-analog converter (digital to analog converter, DAC) that converts the digital signal to an analog signal. In the embodiment of the present application, the analog-to-digital conversion device may be disposed in the baseband subsystem 304 or may be disposed in the radio frequency subsystem.

The application subsystem 301 may be used as a main control system or a main computing system of the wireless communication device 300, and is used to run a main operating system and application programs, manage software and hardware resources of the entire wireless communication device 300, and provide a user operation interface for a user. The application subsystem 301 may include one or more processing cores. In addition, driver software associated with other subsystems (e.g., baseband subsystem) may also be included in application subsystem 301. Baseband subsystem 301 may also include one or more processing cores, as well as hardware accelerators (hardware accelerator, HACs), caches, and the like.

In the disclosed embodiments, the RF subsystem may include a separate antenna, a separate RF front end (RFFE) device, and a separate RF chip. Radio frequency chips are sometimes also referred to as receivers, transmitters or transceivers. The antenna, the radio frequency front end device and the radio frequency processing chip can all be manufactured and sold separately. Of course, the rf subsystem may also employ different devices or different integration schemes based on power consumption and performance requirements. For example, part of the devices belonging to the rf front-end are integrated in an rf chip, which may also be referred to as an rf antenna module or antenna module, and even both the antenna and the rf front-end devices are integrated in the rf chip.

Fig. 4 shows a schematic diagram of an exemplary radio frequency integrated circuit 400 according to an embodiment of the disclosure. It should be appreciated that while fig. 4 has only two transmit channels and one receive channel, the present embodiment may not be so limited and the radio frequency integrated circuit may include two or more transmit and receive channels and other channel numbers. The radio frequency receive path is generally used to process the received RF signal into an intermediate frequency signal. The radio frequency transmit path is generally used to process the intermediate frequency signal into a transmitted radio frequency signal. As shown in fig. 4, a Radio Frequency Integrated Circuit (RFIC) 400 includes a first radio frequency receive channel 401, a second radio frequency receive channel 402, and a first radio frequency transmit channel 403. The first radio frequency receive path 401 includes a first low noise amplifier (low noise amplifier, LNA 1), a first mixer (mixer 1, MIX 1), a first receive local oscillator (LO_Rx1), a first Filter (Filter 1), and a first analog to digital converter (analog to digital converter 1, ADC 1). The second radio frequency receive path 402 includes a second low noise amplifier (low noise amplifier, LNA 2), a second mixer (mixer 2, MIX 2), a second receive local oscillator (LO_Rx2), a second Filter (Filter 2), and a second analog to digital converter (analog to digital converter, ADC 2). The low noise amplifiers in the first radio frequency receiving channel 401 and the second radio frequency receiving channel 402 amplify the received radio frequency signals, and the mixer mixes the radio frequency signals amplified by the low noise amplifiers with local oscillation signals provided by the lo_rx, and intermediate frequency signals are obtained after mixing. The intermediate frequency signal is provided to the ADC after passing through the filter. The first radio frequency transmit channel 403 shown in fig. 4 includes a digital-to-analog converter (digital to analog converter, DAC), a third Filter (Filter 3), a third mixer (mixer 3, MIX 3), a transmit local oscillator (LO Tx), and a Power Amplifier (PA). The DAC in the first rf transmit channel 403 converts the digital signal into an analog signal and sends the analog signal to the filter, the filter filters the signal, the mixer mixes the analog signal after the filter with the signal provided by the local oscillator to move the analog signal to a rf signal, and the PA amplifies the rf signal. The PA and LNA may also be outside the rf channel as separate rf front-end chip devices outside the rf chip.

Fig. 5 shows a schematic circuit diagram of a radio frequency amplifier. The radio frequency amplifier may include a power limiter 2, a radio frequency amplifier tube T1, and a choke L0. The power limiter 2 receives the input signal V _IN And its power is limited as needed. A first terminal of the radio frequency amplifier T1 is coupled to the choke L0, a second terminal of the radio frequency amplifier T1 is coupled to ground GND, and a control terminal of the radio frequency amplifier T1 is coupled to the power limiter 2 to receive the limited input signal. The RF amplifying tube T1 amplifies the limited input signal to generate an amplified signal V _OUT . The choke L0 provides amplified power and forces the high frequency amplified signal into the output loop. In one embodiment, the radio frequency amplifier T1 may be a field effect transistor (MOSFET) with its gate coupled to the power limiter 2, source grounded and drain coupled to the choke L0. In one embodiment, the RF amplifier T1 is an N-type MOSFET (NMOS). It will be appreciated that P-type MOSFETs (PMOS) may also be suitable by simply transforming the circuit configuration. Alternatively, the rf amplifier transistor T1 may be a bipolar transistor. In this case, the base of the radio frequency amplifier tube T1 is coupled to the power limiter 2, the emitter is grounded and the collector is coupled to the choke L0.

Although one configuration of the radio frequency amplifier is shown in fig. 5, the radio frequency amplifier may have other configuration structures. For example, the rf amplifier T1 may include one or more transistors connected in series. The first terminal of the one or more series connected transistors is a source or emitter, the second terminal of the one or more series connected transistors is a drain or collector, and the control terminal of the one or more series connected transistors is a gate or base. By providing the power amplifier in the form of a series transistor, the amplifying performance of the power can be effectively improved. Furthermore, although not shown in fig. 5, the radio frequency amplifier may also have other components, such as a matching network.

To cope with complex and various application scenarios, the rf front-end module, especially the rf amplifier, needs to have a higher power margin. In some casesIn general, in order to improve performance, core devices are often used at the input, which are less reliable, such as TDDB and HCI. For this purpose, the power limiter 2 in fig. 5 can apply the input signal V as desired _IN The voltage amplitude of (2) is limited, but the power limiter 2 also has the problem of insertion loss. The stronger the clipping effect, the greater the insertion loss, resulting in degradation of noise figure, matching and gain performance of the radio frequency front end circuitry.

Fig. 6 shows a schematic circuit diagram of another radio frequency amplifier. The radio frequency amplifier of fig. 6 is similar to the radio frequency amplifier of fig. 5, and therefore the same or similar parts are not described in detail herein, and reference is made to the description of the corresponding parts of fig. 5. The rf amplifier of fig. 6 also adds a plurality of diodes D coupled in series between the first and second terminals of the rf amplifier tube T1 as compared to the rf amplifier of fig. 5 ₁ ……D _R Wherein R is a natural number greater than 0. In one embodiment, the diode may be a gated diode. Each diode has a threshold voltage V _TH . Therefore, the total threshold voltage of the R series diodes is R _TH . Thus, when V _OUT Higher than R _TH When R series diodes are turned on to limit the voltage amplitude of the output voltage.

However, the present inventors found through studies that the threshold voltage V of the diode _TH The fluctuation with temperature is relatively large. In other words, the threshold characteristics of the diode are not stable. In low temperature condition, threshold voltage V of diode _TH Higher. The diode size in this configuration needs to be large in order to meet the clipping requirement at low temperatures. This requires an increase in the area of the diode, which results in an increase in parasitic effects of the diode and deterioration of radio frequency performance. On the other hand, in the case of high temperature, the threshold voltage V of the diode _TH Lower, resulting in significant leakage. This adversely affects amplification efficiency and signal integrity. Furthermore, since the threshold values of the diodes connected in series cannot be tuned at the same temperature, this results in an inability to freely set the clipping threshold.

In some embodiments of the present disclosure, by providing the first clipping circuit and the second clipping circuit having different threshold characteristics between the first terminal and the second terminal of the radio frequency amplifier tube, the clipping threshold can be freely set as needed, which significantly improves the flexibility of clipping settings of the radio frequency amplifier. Furthermore, the need for the power limiter 2 for the radio frequency amplifier can be reduced.

Fig. 7 shows a circuit schematic of a radio frequency amplifier 700 according to one embodiment of the present disclosure. In one embodiment, the radio frequency amplifier 700 may be part of an integrated circuit such as a power amplifier, a low noise amplifier, and a filter, and the integrated circuit may be implemented separately as a chip. Alternatively, the integrated circuit may also include only a radio frequency amplifier. Furthermore, in some embodiments, the integrated circuit may also be integrated with other integrated circuits within a single chip to form a system on a chip (SoC). In other embodiments, the integrated circuit may also be fabricated as a die (die), and the die and other die are packaged within a single package module to form a system in package (system in a package, siP). In still other embodiments, the chip containing the integrated circuit may be assembled with other chips on a circuit board such as a printed circuit board (printed circuit board, PCB) to form an integrated circuit assembly. The above-described integrated circuits, chips, socs, sips, and integrated circuit components may be applied to various electronic devices such as terminals or base stations shown in fig. 1. It will be appreciated that embodiments of the present disclosure may also take other forms, without limitation.

The radio frequency amplifier 700 includes a power limiter 2, a radio frequency amplifier tube T1, a choke L0, and a limiter 702. The power limiter 2, the rf amplifier tube T1, and the choke L0 of the rf amplifier 700 are the same as or similar to the corresponding components in fig. 5, and thus the same or similar matters are not described herein, and reference may be made to the description of the corresponding components in fig. 5. The radio frequency amplifier 700 further comprises a limiter 702. Limiter 702 includes a first limiter circuit and a second limiter circuit not specifically shown in fig. 7. The first clipping circuit has a first threshold characteristic and the second clipping circuit has a second threshold characteristic different from the first threshold characteristic. Tuning of the clipping threshold of the radio frequency amplifier can be achieved by using clipping circuits with different threshold characteristics, whereby the clipping threshold can be set as desired. In some embodiments, the first clipping circuit and the second clipping circuit may each have one or more clipping units. The individual clipping circuits and/or clipping units may be coupled in series, parallel or other coupling combinations, so that the desired clipping threshold may be provided more flexibly.

Fig. 8 shows a schematic block diagram of a limiter according to one embodiment of the present disclosure. In one embodiment, the limiter in fig. 8 may be a specific implementation of limiter 702 in fig. 7. The limiter comprises a first limiter circuit 110 and a second limiter circuit 120 coupled in series. By means of series coupling, the limiting range of the radio frequency amplifier can be increased, and the power margin of the radio frequency amplifier can be effectively improved. The first clipping circuit 110 may have a first threshold characteristic and the second clipping circuit 120 may have a second threshold characteristic different from the first threshold characteristic. In one embodiment, the temperature drift characteristic of the first threshold characteristic is different from the temperature drift characteristic of the second threshold characteristic. By providing clipping circuits with different temperature drift characteristics, the clipping performance of the limiter can be flexibly tuned over a design temperature range.

In one embodiment, the threshold characteristic of the first clipping circuit 110 decreases with increasing temperature and the threshold characteristic of the second clipping circuit 120 increases with increasing temperature. Since the first clipping circuit 110 and the second clipping circuit 120 are coupled in series here, the threshold characteristics of the whole of the clipping device may fluctuate less with a change in temperature. By using two clipping circuits having opposite temperature drift characteristics, a temperature drift characteristic with less fluctuation can be obtained, so that a clipping threshold with less fluctuation can be obtained in a desired temperature range. In some cases, the clipping threshold of the limiter may remain unchanged with a change in temperature. By setting the clipping threshold of the limiter to remain substantially unchanged with a change in temperature, a stable and desired clipping effect can be obtained.

Although the coupling of the first clipping circuit and the second clipping circuit is shown in fig. 8 in a series coupling, this is merely illustrative and not limiting to the scope of the present disclosure. For example, the first clipping circuit and the second clipping circuit may also be connected in parallel. The limiter may further have more limiter circuits and the limiter circuits may be coupled in series, parallel or other coupling, such as star coupling or delta coupling.

Fig. 9 shows a schematic circuit diagram of a limiter according to one embodiment of the present disclosure. In one embodiment, the limiter of fig. 9 may be one implementation of the limiter of fig. 8. The first clipping circuit 111 includes N serially coupled diode D ₁ ……D _N Wherein N represents a natural number greater than 0. In one embodiment, diode D ₁ ……D _N May be a gated diode (gated diode). Each gated diode may have a voltage defined by V _TH1 The threshold characteristic represented. That is, when the voltage across the gated diode exceeds V _TH1 At this time, the gated diode is turned on. Correspondingly, when N serially coupled gated diodes D ₁ ……D _N Is N x V _TH1 At this time, the first clipping circuit 111 is turned on to clip. Alternatively, in some embodiments, the diodes may have different threshold characteristics.

The second clipping circuit 121 includes M series-coupled body bias transistors T _B1 ……T _BM Wherein M represents a natural number greater than 0, and M may be the same as or different from N. In one embodiment, body bias transistor T _B1 ……T _BM May be a metal oxide semiconductor field effect transistor (metal oxide semiconductor field effect transistor, MOSFET). In one embodiment, M series-coupled body-bias transistors T _B1 ……T _BM Are identical to each other. Taking body bias transistor TB1 as an example, body bias transistor TB1 is an NMOS, and the gate of body bias transistor TB1 is connected to the drain thereof and coupled to first clip circuit 111. Body bias crystalThe source of body transistor TB1 is coupled to the gate and drain of body bias transistor TB 2. It will be appreciated that PMOS may also be applicable by simply transforming the circuit configuration.

If the second clipping circuit 121 includes only one body bias transistor TB1, the source of the body bias transistor TB1 is coupled to the second terminal of the radio frequency amplifier transistor T1. The body of body bias transistor TB1 is coupled to receive a bias voltage. In one embodiment, the body pole of body bias transistor TB1 is coupled to generate a first bias voltage V via bias resistor RB1 _B1 Is provided. Similarly, the body pole of the body bias transistor TBM is coupled to generate an Mth bias voltage V via a bias resistor RBM _BM Is provided. Although a bias resistor is shown in fig. 9, this is merely illustrative and not limiting of the scope of the present disclosure. In some embodiments, the bias voltage may be provided via other components or directly.

Each body bias transistor may have a voltage defined by V _TH2 The same threshold characteristics are represented. That is, when the voltage across the body-bias transistor exceeds V _TH2 When the body bias transistor is turned on. Alternatively, in some embodiments, the body bias transistors may have different threshold characteristics. For a body-biased transistor configured as in fig. 9, the body effect of the MOSFET can be utilized to adaptively bias the body-biased transistor to exhibit the threshold characteristic of positive temperature drift. Specifically, when the voltage V between the body and the source of the body-biased transistor _BS When increasing, the threshold voltage V of the body bias transistor _TH2 And (3) lowering.

As described above with respect to fig. 6, serially coupled diodes D ₁ ……D _N Threshold voltage V of the diode in (3) _TH1 The fluctuation with temperature is relatively large. In other words, the threshold characteristics of the diode are not stable. In low temperature condition, threshold voltage V of diode _TH1 Higher, and under high temperature conditions, the threshold voltage V of the diode _TH1 Lower. Therefore, the first clipping circuit 111 has a threshold characteristic of negative temperature drift. In contrast, body bias coupled in seriesTransistor T _B1 ……T _BM The body bias transistor in (c) has a threshold characteristic of positive temperature drift. That is, in low temperature conditions, the threshold voltage V of the body-bias transistor _TH2 Lower, but at high temperature, the threshold voltage V of the body-bias transistor _TH2 Higher. Therefore, in the case where the first limiter circuit 111 and the second limiter circuit 121 are connected in series, the negative temperature drift characteristic of the first limiter circuit 111 and the positive temperature drift characteristic of the second limiter circuit 121 cancel each other out to some extent, so that the overall threshold characteristic of the limiter can be kept relatively small in temperature drift over a large temperature range. In some embodiments, the negative temperature drift characteristic of the first clipping circuit 111 and the positive temperature drift characteristic of the second clipping circuit 121 may substantially cancel each other, so that the overall threshold characteristic of the clipping may remain substantially stable over a large temperature range. The radio frequency amplifier can thus achieve a more accurate and defined clipping performance over a large temperature range. Further, since the number of diodes in the first limiter circuit 111 and the number of body bias transistors in the second limiter circuit 121 can be set accordingly as needed, the limiter voltage can be freely tuned.

In other embodiments, the diode in the first clipping circuit 111 and/or the body bias transistor in the second clipping circuit 121 may be connected in parallel with the switching device. When the clipping voltage needs to be increased, some switching devices may be turned off to cause the diode and body bias transistor to be added to the clipping circuit, and when the clipping voltage needs to be reduced, some switching devices may be turned on to cause the diode and body bias transistor to be shorted. Thus, the clipping performance can be dynamically adjusted during operation of the radio frequency amplifier.

Fig. 10 shows a schematic circuit diagram of a limiter according to another embodiment of the present disclosure. The limiter in fig. 10 may be one implementation of the limiter shown in fig. 8 and includes a first limiter circuit 112 and a second limiter circuit 122. The first limiter circuit 112 includes a diode D1 and a body bias transistor T _B1 . The second clipping circuit 122 includes two diodes D2 and D3 and two body biasesTransistor T _B2 And T _B3 . The diode in fig. 10 is substantially the same as the transistor in fig. 9, and the body-biased transistor in fig. 10 is also substantially the same as the body-biased transistor in fig. 9. Therefore, the diode and body bias transistor will not be described in detail herein. The limiter of fig. 10 differs from the limiter of fig. 9 in that the limiter of fig. 10 takes the form of alternating series connection of diodes and body-biasing transistors. Although the first clipping circuit 112 in fig. 10 includes only one and one body bias transistor T _B1 And the second clipping circuit 122 includes only two diodes D2 and D3 and two body bias transistors T _B2 And T _B3 This is merely illustrative and is not intended to limit the scope of the present disclosure. The first clipping circuit 112 may have a different number of devices and the second clipping circuit 122 may also have a different number of devices. It will be appreciated that the limiter arrangement of fig. 10 may also implement similar functions as described with respect to fig. 9. For example, the clipping range may be increased as needed, a relatively stable threshold characteristic may be achieved over a large temperature range, and so forth.

Fig. 11 shows a schematic circuit diagram of a limiter according to yet another embodiment of the present disclosure. The limiter may be one implementation of the limiter shown in fig. 8 and comprises a first limiter circuit 113 and a second limiter circuit 123. The configuration of the second clipping circuit 123 is substantially similar to that of the second clipping circuit 121 in fig. 9, and thus a description thereof will be omitted. The first clipping circuit 113 includes N first transistors T coupled in series _A1 ……T _AN Wherein N represents a natural number greater than 0. In one embodiment, a first transistor T _A1 ……T _AN May be substantially identical to each other, and may be, for example, MOSFETs. The gate of each first transistor is coupled to the drain of the first transistor and the source of the first transistor is coupled to the body of the first transistor. Alternatively, the first transistor may be a bipolar transistor. The first transistor may have a voltage of V _TH1 The threshold characteristic represented. That is, when the voltage across the first transistor exceeds V _TH1 When the first transistor is turned on. Correspondingly, when N series-coupled onesA transistor T _A1 ……T _AN Is N x V _TH1 At this time, the first clipping circuit 113 is turned on to clip. Alternatively, in some embodiments, the first transistor T _A1 ……T _AN May have different threshold characteristics. Similarly, the first transistor in fig. 11 has a negative temperature drift characteristic, and thus when the first limiter circuit 113 and the second limiter circuit 123 are combined in series, the limiter can achieve a threshold characteristic in which fluctuation is relatively small over a large temperature range or achieve a substantially stable threshold characteristic. Accordingly, the radio frequency amplifier has a relatively stable threshold characteristic over a range of temperatures, and more accurate clipping performance can be obtained.

Although the configuration of several clipping circuits is shown in fig. 9-11, this is merely illustrative and not limiting of the scope of the present disclosure. Other circuit configurations are also possible. For example, the first clipping circuit may be any clipping circuit having a negative temperature excursion threshold characteristic and the second clipping circuit may be any clipping circuit having a positive temperature excursion threshold characteristic.

Fig. 12 shows a schematic diagram of a bias circuit 140 according to one embodiment of the present disclosure. The bias circuit 140 may be applied to the limiters of fig. 9-11 and configured to generate a bias voltage V _B1 ……V _BM . For example, the bias resistor R in FIGS. 9-11 may be referred to _B1 ……R _BM Providing bias voltage V _B1 ……V _BM . In other embodiments, the bias circuit 140 may bias the transistor T directly to the body _B1 ……T _BM Is provided with bias voltage V _B1 ……V _BM . Alternatively, the bias circuit 140 may also bias the transistor T towards the body via other components _B1 ……T _BM Is provided with bias voltage V _B1 ……V _BM 。

The bias circuit 140 includes a first resistor R1 and a second resistor R2. The first resistor R1 and the second resistor R2 are coupled in series with a first power supply voltage and a first reference voltageBetween voltages, e.g. coupled in series to power supply V _DD And ground GND. The node between the first resistor R1 and the second resistor R2 is configured to provide a bias voltage V _B . The desired bias voltage V can be generated accordingly by adjusting the resistance values of the first resistor R1 and the second resistor R2 _B . The bias voltage V can be set according to the requirement by providing the bias voltage through a voltage divider in the form of a series resistor _B And the bias voltage V _B May remain stable over a range of temperatures, for example above the voltage threshold of the parasitic diode of the MOSFET. Alternatively, the bias voltage V _B And may be varied as desired. Thus, the radio frequency amplifier can realize a relatively stable threshold characteristic in a certain temperature range, so that more accurate clipping performance can be obtained. Although the biasing circuit is shown in the form of a voltage divider, other biasing circuits are possible.

Fig. 13 shows a circuit schematic of a negative temperature bias voltage generator 150 according to one embodiment of the present disclosure. The negative temperature bias voltage generator 150 may be applied to the limiter of fig. 9-11 and may generate the bias voltage V _B1 ……V _BM . For example, the bias resistor R in FIGS. 9-11 may be referred to _B1 ……R _BM Providing bias voltage V _B1 ……V _BM . In other embodiments, the cold bias voltage generator 150 may directly bias the transistor T toward the body _B1 ……T _BM Is provided with bias voltage V _B1 ……V _BM . Alternatively, the negative temperature bias voltage generator 150 may also bias the transistor T toward the body via other components _B1 ……T _BM Is provided with bias voltage V _B1 ……V _BM 。

The negative temperature bias voltage generator 150 includes a third resistor R3 and a first diode DB1 coupled in series between the first power supply voltage and the first reference voltage. The first power supply voltage is, for example, power supply VDD, and the first reference voltage is, for example, ground GND. A second intermediate node intermediate the third resistor R3 and the first diode DB1 is coupled to the body bias transistor such that the negative temperature bias voltage generator 150 provides a negative temperature bias voltage as a bias voltage to the body bias transistor.

Fig. 14 shows a circuit schematic of a radio frequency amplifier according to one embodiment of the present disclosure. The rf amplifier of fig. 14 has a similar structure to that of fig. 5, and thus, the description thereof will not be repeated. In contrast to the radio frequency amplifier of fig. 5, the radio frequency amplifier of fig. 14 further comprises a power limiter 22. The power limiter 22 is coupled to the control terminal of the power amplifier tube T1 and is configured to output the input signal V _IN Limiting the amplitude of the input signal. By providing a power limiter at the control terminal of the power amplifier tube T1, the power level of the input signal can be effectively controlled to meet the requirements of a plurality of application scenarios. In addition, the reliability of the radio frequency amplifier can be improved. For example, reliability against time-varying breakdown and hot carrier injection is enhanced.

The power limiter 22 includes a second diode D21 and a third diode D22. The third diode D22 and the second diode D21 are connected in anti-parallel between the control terminal of the power amplifier T1 and the second terminal of the power amplifier T1. By providing pairs of diodes in anti-parallel connection, the power limiter can be implemented in a simple manner and the cost reduced. The radio frequency amplifier further comprises a first inductor L1. The first inductor L1 is coupled between the second terminal of the power amplifier tube T1 and the ground GND. By providing the inductor L1 between the second terminal of the power amplifying tube T1 and the ground GND, the radio frequency signal can be effectively isolated from the dc bias. While fig. 14 illustrates one implementation of a power limiter in an anti-parallel fashion, this is merely illustrative and not limiting of the scope of the present disclosure. Other power limiters are possible.

Fig. 15 shows a circuit schematic of a radio frequency amplifier according to another embodiment of the present disclosure. The rf amplifier of fig. 15 has a similar structure to that of fig. 14, and thus, the description thereof will not be repeated. Another power limiter 24 is shown in fig. 15. The power limiter 24 includes voltage detection A limiter 26 and a voltage limiter 25. The voltage detector 24 is coupled to the control terminal of the power amplifier T1 and is configured to detect the input signal V _IN Is set in the above-described voltage range. A voltage limiter 25 is coupled to the control terminal of the power amplifier tube T1 and to the voltage detector 26 and is configured to limit the input signal V based on the detected voltage _IN Is set in the voltage range of (a). By detecting the voltage of the input signal and limiting the input signal V in a suitable manner _IN Can be pre-limited before amplification and can be dependent on the input signal V _IN The real-time voltage of (2) is dynamically adjusted to achieve good dynamic power limits.

The voltage limiter 25 comprises at least one limiting circuit T ₂₁ ……T _2P Wherein P is a natural number greater than 0. At least one limiting circuit is coupled in series between the control terminal of the power amplifier transistor T1 and ground GND and includes an adjustment input terminal coupled to the voltage detector 24. In one embodiment, the limiting circuit includes a limiting transistor, and the gate of the limiting transistor is the adjustment input terminal. In another embodiment, the limiting circuit further comprises at least one limiting resistor R corresponding to the at least one limiting transistor ₂₁ ……R _2P . Limiting resistor T ₂₁ ……T _2P Coupled between the voltage detector 26 and the control terminal of the corresponding limiting transistor. By providing limiting transistors in series, the power limiting performance can be dynamically adjusted in a simple and efficient manner.

Fig. 16 illustrates a flow chart of a method 1600 for circuit operation according to one embodiment of the present disclosure. Method 1600 may be performed by the circuits shown in fig. 5-15. It will thus be appreciated that the various aspects described with respect to fig. 5-15 may be applied to the method 1600. At 1602, an amplifying tube receives an input signal. At 1604, the amplifying tube amplifies the input signal. At 1606, the amplified signal is limited by a limiter comprising a first limiting circuit and a second limiting circuit, wherein a temperature drift characteristic of a threshold of the first limiting circuit is opposite to a temperature drift characteristic of the second limiting circuit. By using clipping circuits with opposite temperature drift characteristics, tuning of the amplifier can be achieved, so that the clipping level can be set as desired.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are example forms of implementing the claims.

Claims

A circuit, comprising:

an amplifier, comprising:

An amplifying tube including a control terminal, a first terminal, and a second terminal, the amplifying tube for amplifying an input signal received from the control terminal; and

and a limiter coupled between the first terminal and the second terminal, and including a first limiter circuit and a second limiter circuit, wherein a temperature drift characteristic of a threshold of the first limiter circuit is opposite to a threshold temperature drift characteristic of the second limiter sub-circuit.
The circuit of claim 1, wherein the first clipping circuit and the second clipping circuit are coupled in series between the first terminal and the second terminal.
The circuit of claim 1 or 2, wherein the amplifying transistor comprises one or more transistors in series, the first terminal of the amplifying transistor is a source or emitter of a transistor of the one or more transistors located at a first end, the second terminal of the amplifying transistor is a drain or collector of a transistor of the one or more transistors located at a second end opposite the first end, and the control terminal is a gate or base of a transistor of the one or more transistors located at the first end.
The circuit of any of claims 1-3, wherein the first clipping circuit comprises one or more gated diodes coupled in series; the second clipping circuit includes one or more body bias transistors coupled in series, wherein a gate of the body bias transistor is coupled to a drain of the body bias transistor and a body of the body bias transistor is configured to receive a bias voltage provided by a bias circuit.
The circuit of any of claims 1-4, wherein the first clipping circuit comprises one or more first transistors coupled in series, a gate of the first transistor coupled to a drain of the first transistor, and a source of the first transistor coupled to a body of the first transistor; and

the second clipping circuit includes one or more body bias transistors coupled in series, wherein a gate or base of the body bias transistor is coupled to a drain or collector of the body bias transistor and a body pole of the body bias transistor is configured to receive a bias voltage provided by the bias circuit.
The circuit of claim 4 or 5, wherein the amplifier further comprises:

A bias circuit is coupled to the body of the body bias transistor for providing the bias voltage.
The circuit of claim 6, wherein the bias circuit comprises a first resistor and a second resistor coupled in series between a first supply voltage and a first reference voltage, wherein a first node between the first resistor and the second resistor is coupled to a body pole of the body bias transistor. .
The circuit of claim 6, wherein

The bias circuit is used for providing the bias voltage with negative temperature characteristics.
The circuit of claim 8, wherein the bias circuit comprises a third resistor and a first diode coupled in series between a first supply voltage and a first reference voltage, wherein a node between the third resistor and the first diode is coupled to a body pole of the body bias transistor.
The circuit of any of claims 6-10, wherein the amplifier further comprises:

a bias resistor is coupled between the body of the body bias transistor and a bias circuit.
The circuit of any of claims 1-10, wherein a threshold characteristic of the first clipping circuit decreases with increasing temperature and a threshold characteristic of the second clipping circuit increases with increasing temperature.
The circuit of any of claims 1-11, wherein a clipping threshold of the clipping device remains unchanged with a change in temperature.
A radio frequency power amplifier comprising an amplifier according to any of claims 1-12.
A radio frequency front end system comprising:

the circuit of any one of claims 1-12.
An electronic device, comprising:

the radio frequency front end system of claim 14.