WO2022226935A1 - Radio-frequency integrated circuit chip and wireless communication apparatus - Google Patents

Abstract

The present disclosure relates to a circuit, comprising an amplifier. The amplifier comprises an amplifier transistor and a clipper. The power amplifier transistor comprises a control terminal, a first terminal and a second terminal. The amplifier transistor is configured to generate an amplification signal on the basis of an input signal received from the control terminal. The clipper is coupled between the first terminal and the second terminal, and the clipper comprises a first clipping circuit and a second clipping circuit. The temperature drift characteristics of a threshold of the first clipping circuit is opposite to the temperature drift characteristics of a threshold of the second clipping circuit. By means of using clipping circuits that have thresholds of opposite temperature drift characteristics, the clipping of the amplifier can be tuned, so that the clipping level can be set as needed.

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 technique

With the development of integrated circuits, electronic devices such as wireless communication devices integrate more and more chips to realize various functions. To enable wireless communication, integrated circuit components, such as radio frequency front-end modules, are typically used in electronic devices to transmit signals or data. The RF front-end module may include chips such as RF transceiver, power amplifier (PA), low noise amplifier (LNA), filter and duplexer. These chips often involve signal amplification during their operation. For example, amplifying the input signal to different levels to meet the wireless transmission requirements of the signal. However, with the improvement of power tolerance requirements, there are certain problems in the reliability of the radio frequency amplification system.

In some conventional solutions, in order to improve the reliability of the circuit, the amplification of the amplifier may be limited. However, this design often brings limited benefits on the one hand and certain limitations on the other.

SUMMARY OF THE INVENTION

In view of the above problems, the 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 the reliability performance of the circuit.

According to a first aspect of the present disclosure, there is provided a circuit including an amplifier. Amplifiers include amplifier tubes and limiters. The amplifying tube includes a control terminal, a first terminal and a second terminal. The amplifier tube is used to amplify the input signal received from the control terminal. A limiter is coupled between the first terminal and the second terminal, and the limiter includes a first limiter circuit and a second limiter circuit. The first clipping circuit is different from the second clipping circuit. By using different limiter circuits, the tuning of the limiter of the amplifier can be achieved, so that the flexible limiter can be set as required.

In a possible implementation manner, the threshold characteristic of the first clipping circuit is different from the threshold characteristic of the second clipping circuit. By using limiter circuits with different threshold characteristics, the tuning of the limiter threshold of the radio frequency amplifier can be achieved, so that the limiter threshold can be set as required.

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 the clipping threshold can be effectively increased and the power tolerance of the radio frequency amplifier can be effectively improved.

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

In a possible implementation manner, the first limiter circuit includes one or more gate-controlled diodes coupled in series; the second limiter circuit includes one or more body-bias transistors coupled in series. The gate of the body-biased transistor is coupled to the drain of the body-biased transistor, and the body of the body-biased transistor is used to receive a bias voltage provided by the bias circuit. Since the gated diode has the threshold characteristic of negative temperature drift and the body of the body bias transistor is adaptive and has the threshold characteristic of positive temperature drift, the threshold characteristic relative to temperature can be achieved within a certain temperature range. The power amplifier can thus achieve a relatively stable threshold characteristic within a certain temperature range, so that more accurate limiting performance can be obtained.

In one possible implementation, the first clipping circuit includes one or more first transistors coupled in series, the gate of the first transistor is coupled to the drain of the first transistor, and the source of the first transistor is coupled to body of the first transistor. The second clipping circuit includes one or more body-biased transistors coupled in series, wherein the gate or base of the body-biased transistor is coupled to the drain or collector of the body-biased transistor, and the body of the body-biased transistor is to receive the bias voltage provided by the bias circuit. Since the first transistor has a threshold characteristic of negative temperature drift, and has a threshold characteristic of positive temperature drift due to the body effect of the transistor, the body electrode adaptation of the body bias transistor can be realized within a certain temperature range, so that the RF amplifier can be It has relatively stable threshold characteristics within a certain temperature range, so that more accurate limiting performance can be obtained.

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

In one possible implementation, the bias circuit includes a first resistor and a second resistor coupled in series between the first supply voltage and the first reference voltage, where the first resistor and the second resistor are located between the first and second resistors. A first node between is coupled to the body of the body-biased transistor. The bias circuit provides a bias voltage to the body-bias transistor, and the bias voltage is higher than the voltage threshold of the parasitic diode of the body-bias transistor. The bias voltage is provided by a voltage divider in the form of a series resistor, which can be set as desired and is stable over a range of temperature. Therefore, the power amplifier can achieve a relatively stable threshold characteristic within a certain temperature range, so that more accurate limiting performance can be obtained.

In a possible implementation, the bias circuit is used to provide a bias voltage with negative temperature characteristics. By providing a bias voltage with a negative temperature characteristic, the body bias transistor can be adapted to have a threshold characteristic with a positive temperature drift. The threshold characteristic of positive temperature drift can be mutually eliminated with the threshold characteristic of negative temperature drift to obtain stable temperature characteristics in a wide temperature range.

In one possible implementation, the biasing includes a third resistor and a first diode coupled in series between the first supply voltage and the first reference voltage, wherein the third resistor and the first diode are located The intermediate node between is coupled to the body-biased transistor. The negative temperature bias voltage generator provides the body bias transistor with a negative temperature bias voltage as a bias voltage.

In one possible implementation, the amplifier also includes a bias resistor. A bias resistor is coupled between the body of the body bias transistor and the bias circuit.

In a possible implementation manner, 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. The limiting performance of the limiter can be flexibly tuned by providing limiting circuits with different temperature drift characteristics.

In a possible implementation manner, the threshold characteristic of the first clipping circuit decreases as the temperature increases, and the threshold characteristic of the second clipping circuit increases as the temperature increases.

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

In a possible implementation, the radio frequency amplifier further includes a power limiter. A power limiter is coupled to the control terminal of the power amplifier tube and is configured to limit the input signal amplitude of the input signal. By providing a power limiter at the control terminal of the power amplifier tube, the input signal amplitude of the input signal can be effectively controlled to meet the needs of multiple application scenarios. In addition, the reliability of the RF amplifier can be improved. For example, enhanced reliability against time-dependent dielectric breakdown (TDDB) and hot carrier injection (HCI).

In one possible implementation, the power limiter includes a second diode and a third diode. The third diode and the second diode are connected in antiparallel between the control terminal of the power amplifying tube and the second terminal of the power amplifying tube. By arranging anti-parallel paired diodes, a power limiter can be implemented in a simple manner and reduce costs.

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

In one possible implementation, the power limiter includes a voltage detector and a voltage limiter. A voltage detector is coupled to the control terminal of the power amplifier tube and is configured to detect the voltage of the input signal. A voltage limiter is coupled to the control terminal of the power amplifier tube and the voltage detector and is configured to limit the 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 an appropriate way, it can be pre-limited before amplification, and can be dynamically adjusted according to the real-time voltage of the input signal to obtain good dynamic power limiting.

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

In one possible implementation, each of the at least one limiting circuit includes a limiting transistor. A limiting transistor is coupled in series between the control terminal of the power amplifier tube and ground and includes a control terminal coupled to a voltage detector. By providing limiting transistors in series, the power limiting performance can be dynamically adaptively tuned simply and efficiently.

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

In one possible implementation, the circuit is integrated into the 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, there is provided a chip including an amplifier. Amplifiers include amplifier tubes and limiters. The amplifying tube includes a control terminal, a first terminal and a second terminal. The power amplifier tube is used to amplify the input signal received from the control terminal. A limiter is coupled between the first terminal and the second terminal, and the limiter 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. A radio frequency amplifier includes 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 includes a circuit according to the first aspect. By using different limiter circuits in the RF front-end system, the amplifier in the RF front-end system can be tuned, so that the limiter can be set as required.

According to a fifth aspect of the present disclosure, there is provided an electronic device. The electronic device includes the radio frequency front end system according to the fourth aspect. By using circuits with different limiters in the electronic equipment, the tuning of the amplifiers in the electronic equipment can be achieved, so that the limiter can be set as required.

According to a sixth aspect of the present disclosure, there is provided a method for operating a circuit. The method includes receiving an input signal by an amplifier tube at its control terminal and amplifying the input signal, and limiting the amplified signal by a limiter including a first limiter circuit and a second limiter circuit, wherein the first limiter circuit The temperature drift characteristic of the threshold value of the limiter circuit is opposite to the temperature drift characteristic of the threshold value of the second limiter circuit. Tuning of the amplifier can be achieved by using a limiter circuit with thresholds with opposite temperature drift characteristics, so that the limiter can be set as desired.

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

It should be understood that the matters described in this Summary section are not intended to limit key or critical features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become apparent from the following description.

Description of drawings

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

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

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

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

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

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

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

FIG. 7 shows a schematic circuit diagram of a radio frequency amplifier according to an embodiment of the present disclosure;

8 shows a schematic block diagram of a limiter according to an embodiment of the present disclosure;

9 shows a schematic circuit diagram of a limiter according to an embodiment of the present disclosure;

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 shows a schematic diagram of a bias circuit according to an embodiment of the present disclosure;

13 shows a schematic circuit diagram of a negative temperature bias voltage generator according to an embodiment of the present disclosure;

FIG. 14 shows a schematic circuit diagram of a radio frequency amplifier according to an embodiment of the present disclosure;

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

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

Detailed ways

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 are shown in the drawings, it should 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 rather are provided for the purpose of A more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes, and are not intended to limit the protection scope of the present disclosure.

In the description of embodiments of the present disclosure, the term "comprising" and the like should be understood as open-ended inclusion, ie, "including but not limited to". The term "based on" should be understood as "based at least in part on". The terms "one embodiment" or "the embodiment" should be understood to mean "at least one embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

It should be understood that the technical solutions provided by the embodiments of the present application, in the introduction of the following specific embodiments, some repeated parts may not be repeated, but it should be considered that these specific embodiments have been referred to each other and can be combined with each other.

In a wireless communication system, devices can be divided into devices that provide wireless network services and devices that use wireless network services. The devices that provide wireless network services refer to those devices that make up a wireless communication network, which can be referred to as network equipment or network elements for short. Network equipment is usually owned by operators or infrastructure providers, who are responsible for operation or maintenance. Network devices can be further classified into radio access network (RAN) devices and core network (core network, CN) devices. A typical RAN device includes a base station (BS).

It should be understood that a base station may also sometimes be referred to as a wireless access point (AP), or a transmission reception point (TRP). Specifically, the base station may be a general node B (generation Node B, gNB) in a 5G new radio (new radio, NR) system, or an evolutional Node B (evolutional Node B, eNB) in a 4G long term evolution (long term evolution, LTE) system. ). Base stations can be classified into macro base stations or micro base stations according to their physical form or transmit power. Micro base stations are also sometimes referred to as small base stations or small cells.

A device using a wireless network service may be referred to as a terminal for short. The terminal can establish a connection with the network device, and provide the user with specific wireless communication services based on the service of the network device. It should be understood that because the terminal has a closer relationship with the user, it is sometimes also referred to as user equipment (user equipment, UE), or subscriber unit (subscriber unit, SU). In addition, as opposed to base stations, which are usually placed in fixed locations, terminals tend to move with users and are sometimes referred to as mobile stations (mobile stations, MSs). In addition, some network devices, such as relay nodes (relay nodes, RNs) or wireless routers, can sometimes be regarded as terminals because they have UE identity or belong to users.

Specifically, the terminal may be a mobile phone, a tablet computer, a laptop computer, a wearable device (such as a smart watch, smart bracelet, smart helmet, smart glasses), and other Devices with wireless access capabilities, such as smart cars, various Internet of things (IOT) devices, including various smart home devices (such as smart meters and smart home appliances) and smart city devices (such as security or monitoring equipment, intelligent road transport facilities), etc.

For ease of expression, the present application will take the base station and the terminal as examples to describe the technical solutions of the embodiments of the present application in detail.

1 shows 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 , the wireless communication system 100 includes a terminal 101 and a base station 102 . According to different transmission directions, the transmission link from the terminal 101 to the base station 102 is marked as an uplink (uplink, UL), and the transmission link from the base station to the terminal is marked as a downlink (downlink, DL). 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 can provide communication coverage for a specific geographical area through an integrated or external antenna device. One or more terminals located within the communication coverage of the base station 102 can access the base station. A base station can manage one or more cells. Each cell has an identification, which is also called a cell identity (cell ID). From the perspective of radio resources, a cell is a combination of downlink radio resources and paired uplink radio resources (optional).

It should be understood that the wireless communication system may comply with the wireless communication standard of the third generation partnership project (3GPP), or may comply with other wireless communication standards, such as the Institute of Electrical and Electronics Engineers (IEEE) ) of the 802 series (such as 802.11, 802.15, or 802.20) wireless communication standards. Although only one base station and one terminal are shown in FIG. 1 , the wireless communication system may also include other numbers of terminals and base stations. In addition, the wireless communication system may further include other network devices, such as core network devices.

The terminal 101 and the base station 102 should know the predefined configuration of the wireless communication system 100, including the radio access technology (RAT) supported by the system and the wireless resource configuration specified by the system, such as the basic configuration of the radio frequency band and carrier . A carrier is a frequency range that conforms to system regulations. This frequency range can be determined by the center frequency of the carrier (referred to as the carrier frequency) and the bandwidth of the carrier. These system pre-defined configurations may be part of the standard protocols of the wireless communication system 100 or determined through interaction between the terminal 101 and the base station 102. The content of the relevant standard protocol may be pre-stored in the memory 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 RATs, such as 5G NR, 4G LTE, or RATs of future evolution systems. Specifically, the terminal 101 and the base station 102 use the same air interface parameters, coding scheme, modulation scheme, etc., and communicate with each other based on radio resources specified by the system.

FIG. 2 shows 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, the base station 102 configures two carrier sets for the terminal 101, which are respectively denoted as a first carrier set and a second carrier set. The first carrier set may be used for downlink carrier aggregation (DLCA), and the second carrier set may be used for uplink carrier aggregation (ULCA). The frequency ranges of the carriers included in the two carrier sets may be different, such as terminals in the FDD (frequency duplex division: frequency division duplex) mode; the frequency ranges of the carriers included in the two carrier sets may be the same, such as in TDD ( time duplex division, the terminal in frequency division duplex) mode.

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

It should be understood that in this application, one component carrier may correspond to one serving cell (serving cell) of the terminal. In the Chinese context, a component carrier is sometimes translated as a component carrier, which may be referred to as a carrier for short, and a serving cell may be referred to as a cell for short. Unless otherwise specified, in this application, the terms "carrier", "component carrier", "aggregated carrier", "aggregated component carrier", "serving cell", "cell", "one of PCell or SCell", "One of PCC or SCC" and "aggregated carrier" can be used interchangeably.

FIG. 3 shows a schematic structural diagram of an exemplary wireless communication device 300 according to an embodiment of the present disclosure. The wireless communication device 300 may be the terminal 101 or the base station 102 in the embodiment of the present disclosure. As shown in FIG. 3 , the wireless communication device 300 may include an application subsystem 301, a memory 302, a mass storage 303, a baseband subsystem 304, and a radio frequency integrated circuit (RFIC) 305A and 305B (also referred to as RFIC 1 and RFIC 2 in the figure, here for convenience, may be collectively referred to as RFIC 305 or radio frequency chip 305), a radio frequency front end (radio frequency front end, RFFE) device 306, and an antenna (antenna, ANT ) 307, these devices may be coupled through various interconnection buses or other electrical connections.

In FIG. 3 , ANT_1 represents the first antenna, ANT_N represents the Nth antenna, and N is a positive integer greater than 1. Tx represents the transmit path, Rx represents the receive path, and different numbers represent different paths. FBRx represents the feedback receiving path, PRx represents the primary receiving path, and DRx represents the diversity receiving path. HB means high frequency, LB means low frequency, both refer to the relative high and low frequency. BB stands for baseband. It should be understood that the labels and components in FIG. 3 are for illustrative purposes only, and are only used as a possible implementation manner, and the embodiments of the present disclosure also include other implementation manners.

The radio frequency integrated circuit 305 can be further divided into a radio frequency receive path (RF receive path) and a radio frequency transmit path (RF transmit path). The RF receive channel can receive the RF signal through the antenna, process the RF signal (eg, amplify, filter and down-convert) to obtain the baseband signal, and transmit it to the baseband subsystem. The RF transmit channel can receive the baseband signal from the baseband subsystem, perform RF processing (such as up-conversion, amplification and filtering) on the baseband signal to obtain the RF signal, and finally radiate the RF signal into space through the antenna. Specifically, the radio frequency subsystem may include an antenna switch, an antenna tuner, a low noise amplifier (LNA), a power amplifier (PA), a mixer (mixer), a local oscillator (LOO) ), filters and other electronic devices, which can be integrated into one or more chips as required. Antennas can also sometimes be considered part of the RF subsystem.

Baseband subsystem 304 may extract useful information or data bits from the baseband signal, or convert the information or data bits into a baseband signal to be transmitted. These 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. Different radio access technologies, such as 5G NR and 4G LTE, tend to have different baseband signal processing operations. Therefore, in order to support the convergence of multiple mobile communication modes, the baseband subsystem 304 may simultaneously include multiple processing cores, or multiple HACs. The baseband subsystem 304 is generally integrated into one or more chips, and the chip integrating the baseband subsystem is generally referred to as a baseband processor chip (baseband intergreted circuit, BBIC), also referred to herein as a baseband processing circuit.

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

The application subsystem 301 can be used as the main control system or the main computing system of the wireless communication device 300 to run the main operating system and application programs, manage the hardware and software resources of the entire wireless communication device 300, and provide users with a user interface . Application subsystem 301 may include one or more processing cores. In addition, the application subsystem 301 may also include driver software related to other subsystems (eg, baseband subsystem). The baseband subsystem 301 may also include one or more processing cores, as well as hardware accelerators (HACs), caches, and the like.

In the embodiment of the present disclosure, the radio frequency subsystem may include an independent antenna, an independent radio frequency front end (RF front end, RFFE) device, and an independent radio frequency chip. A radio frequency chip is also sometimes referred to as a receiver, transmitter, or transceiver. Antennas, RF front-end devices, and RF processing chips can all be manufactured and sold separately. Of course, the RF subsystem can also use different devices or different integration methods based on power consumption and performance requirements. For example, some devices belonging to the radio frequency front-end are integrated into the radio frequency chip, and even the antenna and the radio frequency front-end device are integrated into the radio frequency chip, and the radio frequency chip can also be called a radio frequency antenna module or an antenna module.

FIG. 4 shows a schematic diagram of an exemplary radio frequency integrated circuit 400 according to an embodiment of the present disclosure. It should be understood that although FIG. 4 has only two receiving channels and one transmitting channel, this embodiment may be more than this, and the radio frequency integrated circuit may include two or more transmitting channels and receiving channels and other channel numbers. The RF receive channel is generally used to process the received RF signal into an intermediate frequency signal. The radio frequency transmit channel is generally used to process the intermediate frequency signal into the transmitted radio frequency signal. As shown in FIG. 4 , a radio frequency integrated circuit (RFIC) 400 includes a first radio frequency receiving channel 401 , a second radio frequency receiving channel 402 and a first radio frequency transmitting channel 403 . The first radio frequency receiving channel 401 includes a first low noise amplifier (low noise amplifier1, LNA1), a first mixer (mixer 1, MIX1), a first receiving local oscillator (LO_Rx1), a first filter (Filter1), The first analog to digital converter (analog to digital converter 1, ADC1). The second radio frequency receiving channel 402 includes a second low noise amplifier (low noise amplifier 2, LNA2), a second mixer (mixer 2, MIX2), a second receiving local oscillator (LO_Rx2), and a second filter (Filter2) , the second analog-to-digital converter (analog to digital converter 2, ADC2). 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 signal, and the mixer mixes the radio frequency signal amplified by the low noise amplifier with the local oscillator signal provided by LO_RX, The intermediate frequency signal is obtained after mixing. The IF signal is filtered and supplied to the ADC. The first radio frequency transmit channel 403 shown in FIG. 4 includes a digital to analog converter (DAC), a third filter (Filter3), a third mixer (mixer3, MIX3), a transmit local oscillator (LO_Tx) ) and a power amplifier (PA). The DAC in the first radio frequency transmission channel 403 converts the digital signal into an analog signal and sends it to the filter, the filter performs filtering processing on the signal, and the mixer mixes the analog signal after the filter with the signal provided by the local oscillator. It is transferred into a radio frequency signal, and the PA then performs power amplification on the radio frequency signal. The PA and LNA can also be used as separate RF front-end chip devices outside the RF channel.

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 coil L0. The power limiter 2 receives the input signal V _IN and limits its power as required. The first terminal of the RF amplifier tube T1 is coupled to the choke coil L0, the second terminal of the RF amplifier tube T1 is coupled to the ground GND, and the control terminal of the RF amplifier tube T1 is coupled to the power limiter 2 to receive the limited input signal . The RF amplifier tube T1 amplifies the limited input signal to generate the amplified signal V _OUT . Choke LO 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), and the gate of the field effect transistor is coupled to the power limiter 2, the source is grounded and the drain is coupled to the choke coil L0. In one embodiment, the radio frequency amplifier tube T1 is an N-type MOSFET (NMOS). It is understood that a P-type MOSFET (PMOS) can also be applied by simply changing the circuit configuration. Alternatively, the radio frequency amplifier tube 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 coil L0.

Although one configuration of the radio frequency amplifier is shown in FIG. 5, the radio frequency amplifier may have other configurations. For example, the RF amplifier tube T1 may include one or more transistors connected in series. The first terminal of the one or more transistors in series is the source or emitter, the second terminal of the one or more transistors in series is the drain or collector, and the control terminal of the one or more transistors in series is the gate or base. The power amplification performance can be effectively improved by providing the power amplifying tube in the manner of connecting transistors in series. Furthermore, although not shown in Figure 5, the radio frequency amplifier may also have other components, such as a matching network.

In order to cope with complex and various application scenarios, RF front-end modules, especially RF amplifiers, need to have higher power tolerance. In some cases, in order to improve performance, a core device is usually used at the input side, and its reliability is relatively weak, such as TDDB and HCI. To this end, the power limiter 2 in FIG. 5 can limit the voltage amplitude of the input signal V _IN as required, but the power limiter 2 also has the problem of insertion loss. The stronger the clipping effect, the greater the insertion loss, resulting in degraded noise figure, matching, and gain performance of the RF front-end circuit.

FIG. 6 shows a schematic circuit diagram of another radio frequency amplifier. The radio frequency amplifier in FIG. 6 is similar to the radio frequency amplifier in FIG. 5 , so the same or similar parts are not repeated here, and reference may be made to the description of the corresponding components in FIG. 5 . Compared with the radio frequency amplifier in FIG. 5 , the radio frequency amplifier in FIG. 6 also adds a plurality of diodes D ₁ . . . DR coupled in series between the first terminal and the second terminal of the radio frequency amplifier tube T1 , where _R is greater than A natural number of 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*V _TH . Therefore, when V _OUT is higher than R*V _TH , the R series diodes conduct to limit the voltage magnitude of the output voltage.

However, the inventors found through research that the threshold voltage V _TH of the diode fluctuates greatly with temperature. In other words, the threshold characteristic of the diode is not stable. In low temperature conditions, the threshold voltage _VTH of the diode is higher. To meet the clipping requirements at low temperatures, the diode size in this configuration needs to be large. This requires an increase in the area of the diode, which results in increased diode parasitics and degraded RF performance. On the other hand, under high temperature conditions, the threshold voltage V _TH of the diode is lower, resulting in significant leakage. This adversely affects amplification efficiency and signal integrity. Furthermore, since the thresholds of the diodes connected in series cannot be tuned at the same temperature, the clipping threshold cannot be freely set.

In some embodiments of the present disclosure, by arranging a first limiter circuit and a second limiter circuit with different threshold characteristics between the first terminal and the second terminal of the radio frequency amplifier tube, the limiter can be freely set as required threshold, which significantly increases the flexibility of the limiter setting of the RF amplifier. In addition, the requirement of the power limiter 2 for the radio frequency amplifier can also be reduced.

FIG. 7 shows a schematic circuit diagram 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 radio frequency amplifiers. 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, and the die and other dies are packaged in a single package module to form a 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 (PCB), to form an integrated circuit assembly. The above-described integrated circuits, chips, SoCs, SiPs, and integrated circuit components can be applied to various electronic devices, such as the terminal or base station shown in FIG. 1 . It can be understood that the embodiments of the present disclosure may also have other forms, which are not limited herein.

The radio frequency amplifier 700 includes a power limiter 2 , a radio frequency amplifier tube T1 , a choke coil L0 and a limiter 702 . The power limiter 2 , the radio frequency amplifier tube T1 and the choke coil L0 of the radio frequency amplifier 700 are the same or similar to the corresponding components in FIG. 5 , so the same or similar parts will not be repeated here, and reference may be made to the description of the corresponding components in FIG. 5 . . The radio frequency amplifier 700 also includes a limiter 702 . The 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. By using limiter circuits with different threshold characteristics, the tuning of the limiter threshold of the radio frequency amplifier can be achieved, so that the limiter threshold can be set as required. In some embodiments, the first clipping circuit and the second clipping circuit may each have one or more clipping units. Each clipping circuit and/or clipping unit can be coupled in series, in parallel or in other coupling manners, so that the required clipping threshold can 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 the limiter 702 in FIG. 7 . The limiter includes a first limiter circuit 110 and a second limiter circuit 120 coupled in series. Through the series coupling, the limiting range of the radio frequency amplifier can be improved and the power tolerance 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 limiting circuits with different temperature drift characteristics, the limiting performance of the limiter can be flexibly tuned over the 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 limiter circuit 110 and the second limiter circuit 120 are coupled in series here, the overall threshold characteristic of the limiter will have less fluctuation with temperature. By using two clipping circuits with opposite temperature drift characteristics, a less fluctuating temperature drift characteristic can be obtained, and thus a less fluctuating clipping threshold within a desired temperature range. In some cases, the clipping threshold of the clipper may remain constant over temperature. By setting the clipping threshold of the clipper to remain substantially constant with changes in temperature, a stable and desired clipping effect can be obtained.

Although the coupling manner of the first clipping circuit and the second clipping circuit is shown in a series coupling manner in FIG. 8 , this is for illustration only and does not limit the scope of the present disclosure. For example, the first limiter circuit and the second limiter circuit may also be connected in parallel. In addition, the limiter may also have more limiter circuits, and each limiter circuit may be coupled in series, in parallel or in other coupling manners, 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 in FIG. 9 may be an implementation of the limiter in FIG. 8 . The first limiter circuit 111 includes N diodes D ₁ . . . D _N coupled in series, where N represents a natural number greater than zero. In one embodiment, the diodes D ₁ . . . _DN may be gated diodes. Each gated diode may have a threshold characteristic represented by V _TH1 . That is, when the voltage across the gated diode exceeds V _TH1 , the gated diode is turned on. Correspondingly, when the voltages at both ends of the _N gated diodes D ₁ . . . DN coupled in series are N*V _TH1 , the first clipping circuit 111 is turned on to perform clipping. Alternatively, in some embodiments, the diodes may have different threshold characteristics.

The second clipping circuit 121 includes M body-biased transistors T _B1 . . . T _BM coupled in series, where M represents a natural number greater than 0, and M may be the same as or different from N. In one embodiment, the body bias transistors T _B1 . . . T _BM may be metal oxide semiconductor field effect transistors (MOSFETs). In one embodiment, each of the M series coupled body-bias transistors T _B1 . . . T _BM are identical to each other. Taking the body-bias transistor TB1 as an example, the body-bias transistor TB1 is an NMOS, and the gate of the body-bias transistor TB1 is connected to the drain thereof, and is coupled to the first limiter circuit 111 . The source of body-biased transistor TB1 is coupled to the gate and drain of body-biased transistor TB2. It will be understood that PMOS can also be applied by simply changing the circuit configuration.

If the second limiter 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 tube T1. The body of body bias transistor TB1 is coupled to receive a bias voltage. In one embodiment, the body of body bias transistor TB1 is coupled via bias resistor _RB1 to a bias circuit that generates a first bias voltage VB1. Similarly, the body of the body bias transistor TBM is coupled via a bias resistor RBM to a bias circuit that generates the Mth bias voltage V _BM . Although bias resistors are shown in Figure 9, this is for illustration only and does not limit the scope of the present disclosure. In some embodiments, the bias voltage may be provided via other components or directly.

Each body-biased transistor may have the same threshold characteristic represented by V _TH2 . That is, when the voltage across the body-bias transistor exceeds V _TH2 , the body-bias transistor is turned on. Alternatively, in some embodiments, the body-biased transistors may have different threshold characteristics. For a body-biased transistor as configured in Figure 9, the body-effect of the MOSFET can be exploited to make the body-biased transistor adaptively biased to exhibit a threshold characteristic of positive temperature drift. Specifically, as the voltage V _BS between the body and source of the body-biased transistor increases, the threshold voltage V _TH2 of the body-biased transistor decreases.

As described above with respect to FIG. 6 , the threshold voltage _{V TH1} of the diodes in series coupled diodes D ₁ . . . DN fluctuates considerably with temperature. In other words, the threshold characteristic of the diode is not stable. In the low temperature condition, the threshold voltage V _TH1 of the diode is high, and in the high temperature condition, the threshold voltage V _TH1 of the diode is low. Therefore, the first limiter circuit 111 has a threshold characteristic of negative temperature drift. In contrast, the body-biased transistors in series coupled body-biased transistors T _B1 . . . T _BM have a threshold characteristic of positive temperature drift. That is, in the case of low temperature, the threshold voltage V _TH2 of the body-biased transistor is lower, and in the case of high temperature, the threshold voltage V _TH2 of the body-biased transistor is higher. Therefore, when 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 to a certain extent , so that the overall threshold characteristic of the limiter can maintain relatively small temperature drift over a large temperature range. In some embodiments, the negative temperature drift characteristic of the first limiter circuit 111 and the positive temperature drift characteristic of the second limiter circuit 121 may substantially cancel each other, so that the overall threshold characteristic of the limiter may be over a wide temperature range remain basically stable. The RF amplifier can thus achieve more accurate and deterministic clipping performance over a wide temperature range. Furthermore, since the number of diodes in the first clipping circuit 111 and the number of body bias transistors in the second clipping circuit 121 can be set accordingly as required, the clipping 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 can be turned off so that the diodes and body-bias transistors are added to the clipping circuit, and when the clipping voltage needs to be reduced, some switching devices can be closed so that the diodes and body-biased transistors are short circuit. In this way, the clipping performance can be dynamically adjusted during the operation of the RF 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 an implementation of the limiter shown in FIG. 8 and includes a first limiter circuit 112 and a second limiter circuit 122 . The first clipping 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 bias transistors 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 diodes and body-biased transistors are not described in detail here. The difference between the limiter of FIG. 10 and the limiter of FIG. 9 is that in FIG. 10 , diodes and body bias transistors are alternately connected in series. 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 only It is intended to be illustrative and not 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 configuration in FIG. 10 may also perform similar functions as described with respect to FIG. 9 . For example, the clipping range can be increased as needed, a relatively stable threshold characteristic can be achieved over a wide temperature range, and so on.

FIG. 11 shows a schematic circuit diagram of a limiter according to yet another embodiment of the present disclosure. The limiter may be an implementation of the limiter shown in FIG. 8 and includes a first limiter circuit 113 and a second limiter circuit 123 . The configuration of the second limiter circuit 123 is basically similar to that of the second limiter circuit 121 in FIG. 9 , and thus will not be described again. The first limiter circuit 113 includes N first transistors T _A1 . . . T _AN coupled in series, where N represents a natural number greater than 0. In one embodiment, the first transistors T _A1 . . . T _AN may be substantially the same as each other, eg, may be 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 also be a bipolar transistor. The first transistor may have a threshold characteristic represented by V _TH1 . That is, when the voltage across the first transistor exceeds V _TH1 , the first transistor is turned on. Correspondingly, when the voltages at both ends of the N series-coupled first transistors T _A1 . . . T _AN are N*V _TH1 , the first clipping circuit 113 is turned on for clipping. Alternatively, in some embodiments, the first transistors T _A1 . . . T _AN may have different threshold characteristics. Similarly, the first transistor in FIG. 11 has negative temperature drift characteristics, so when the first limiter circuit 113 and the second limiter circuit 123 are combined in series, the limiter can achieve a threshold value with relatively small fluctuation in a wide temperature range characteristic or achieve a substantially stable threshold characteristic. Correspondingly, the RF amplifier has a relatively stable threshold characteristic within a certain temperature range, and more accurate limiting performance can be obtained.

Although several clipping circuit configurations are shown in FIGS. 9-11 , this is for illustration only and does not limit 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 drift threshold characteristic, and the second clipping circuit may be any clipping circuit having a positive temperature drift threshold characteristic.

FIG. 12 shows a schematic diagram of a bias circuit 140 according to one embodiment of the present disclosure. Bias circuit 140 may be applied to the limiters of FIGS. 9-11 and is configured to generate bias voltages V _B1 . . . V _BM . For example, bias voltages V _B1 . . . V _BM may be provided to bias resistors _RB1 . . . R _BM in FIGS. 9-11 . In other embodiments, the bias circuit 140 may directly provide the bias voltages V _B1 . . . V _BM to the bodies of the body-biased transistors T _B1 . . . T _BM . Alternatively, bias circuit 140 may also provide bias voltages V _B1 . . . V _BM to the bodies of body bias transistors T _B1 . . . T _BM via other components.

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 between the first power supply voltage and the first reference voltage, eg, between the power supply V _DD and the ground GND. The node between the first resistor R1 and the second resistor R2 is configured to provide the bias voltage V _B . The desired bias voltage _VB can be correspondingly generated by adjusting the resistance values of the first resistor R1 and the second resistor R2. The bias voltage, V _B , is provided by a voltage divider in the form of a series resistor, which can be set as desired and is stable over _a temperature range, such as higher than that of the MOSFET. Voltage threshold of parasitic diodes. Alternatively, the bias voltage _VB can also be changed as required. Therefore, the RF amplifier can achieve a relatively stable threshold characteristic within a certain temperature range, so that more accurate limiting performance can be obtained. Although the bias circuit is shown in the form of a voltage divider, other bias circuits are possible.

FIG. 13 shows a schematic circuit diagram 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 limiters of FIGS. 9-11 and may generate bias voltages V _B1 . . . V _BM . For example, bias voltages V _B1 . . . V _BM may be provided to bias resistors _RB1 . . . R _BM in FIGS. 9-11 . In other embodiments, the negative temperature bias voltage generator 150 may directly provide the bias voltages V _B1 . . . V _BM to the bodies of the body-biased transistors T _B1 . . . T _BM . Alternatively, the negative temperature bias voltage generator 150 may also provide bias voltages V _B1 . . . V _BM to the bodies of the body bias transistors T _B1 . . . T _BM via other components.

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

FIG. 14 shows a schematic circuit diagram of a radio frequency amplifier according to an embodiment of the present disclosure. The radio frequency amplifier of FIG. 14 has a similar structure to the radio frequency amplifier shown in FIG. 5 , so the similarities are not repeated here. Compared to the radio frequency amplifier of FIG. 5 , the radio frequency amplifier of FIG. 14 further includes a power limiter 22 . The power limiter 22 is coupled to the control terminal of the power amplifier tube T1 and is configured to limit the amplitude of the input signal of the input signal V _IN . 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 needs of multiple application scenarios. In addition, the reliability of the RF amplifier can be improved. For example, enhanced reliability against time-varying breakdown and hot carrier injection.

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 antiparallel between the control terminal of the power amplifier tube T1 and the second terminal of the power amplifier tube T1. By arranging anti-parallel paired diodes, a power limiter can be implemented in a simple manner and reduce costs. The radio frequency amplifier also includes 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 arranging the inductor L1 between the second terminal of the power amplifier tube T1 and the ground GND, the radio frequency signal can be effectively isolated from the DC bias. Although FIG. 14 shows one implementation of a power limiter in anti-parallel, this is for illustration only and does not limit the scope of the present disclosure. Other power limiters are possible.

FIG. 15 shows a schematic circuit diagram of a radio frequency amplifier according to another embodiment of the present disclosure. The radio frequency amplifier shown in FIG. 15 has a similar structure to the radio frequency amplifier shown in FIG. 14 , so the similarities will not be repeated here. Another power limiter 24 is shown in FIG. 15 . The power limiter 24 includes a voltage detector 26 and a voltage limiter 25 . The voltage detector 24 is coupled to the control terminal of the power amplifier tube T1 and is configured to detect the voltage of the input signal V _IN . The voltage limiter 25 is coupled to the control terminal of the power amplifier tube T1 and the voltage detector 26 and is configured to limit the voltage amplitude of the input signal V _IN based on the detected voltage. By detecting the voltage of the input signal and limiting the voltage of the input signal V _IN in a suitable way, it can be pre-limited before amplification, and can be dynamically adjusted according to the real-time voltage of the input signal V _IN for good dynamic power limiting.

The voltage limiter 25 includes at least one limiter circuit T ₂₁ . . . T _2P , where P is a natural number greater than zero. At least one limiting circuit is coupled in series between the control terminal of power amplifier tube T1 and ground GND and includes a regulation input terminal coupled to voltage detector 24 . In one embodiment, the limiting circuit includes a limiting transistor, and the gate of the limiting transistor is an adjustment input terminal. In another embodiment, the limiting circuit further includes at least one limiting resistor R ₂₁ . . . R _2P corresponding to the at least one limiting transistor. Limiting resistors _T21 ... _T2P are coupled between the voltage detector 26 and the control terminals of the corresponding limiting transistors. By providing limiting transistors in series, the power limiting performance can be dynamically adaptively tuned simply and efficiently.

FIG. 16 shows a flowchart 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 FIGS. 5-15. It will thus be appreciated that various aspects described with respect to FIGS. 5-15 may apply to method 1600 . At 1602, an amplifier tube receives an input signal. At 1604, the amplifier tube amplifies the input signal. At 1606, the amplified signal is clipped by a clipper including a first clipping circuit and a second clipping circuit, wherein a temperature drift characteristic of a threshold of the first clipping circuit is related to a temperature drift of the second clipping circuit The characteristics are opposite. Tuning of the amplifier is achieved by using a clipping circuit with opposite temperature drift characteristics, allowing the clipping level to be set as desired.

Although the subject matter has been described in language specific to structural features and/or logical acts of method, 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 merely example forms of implementing the claims.

Claims (15)

1. A circuit comprising:

   Amplifier, including:

   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

   a limiter coupled between the first terminal and the second terminal, and the limiter includes a first limiter circuit and a second limiter circuit, wherein a threshold of the first limiter circuit is The temperature drift characteristic is opposite to the threshold temperature drift characteristic of the second limiting sub-circuit.
2. 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.
3. The circuit of claim 1 or 2, wherein the amplifier tube comprises one or more transistors connected in series, and the first terminal of the amplifier tube is at the first end of the one or more transistors The source or emitter of the transistor, the second terminal of the amplifying tube is the drain or collector of the transistor located at the second end opposite to the first end among the one or more transistors , and the control terminal is the gate or base of a transistor at the first end of the one or more transistors.
4. 3. The circuit of any one of claims 1-3, wherein the first clipping circuit comprises one or more gated diodes coupled in series; the second clipping circuit comprises one or more blocks coupled in series A bias transistor, wherein 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 used to receive a bias circuit to provide a bias voltage.
5. 4. The circuit of any of claims 1-4, wherein the first clipping circuit comprises one or more first transistors coupled in series, the gates of the first transistors being coupled to the first transistors and the source of the first transistor is coupled to the body of the first transistor; and

   The second clipping circuit includes one or more body-biased transistors coupled in series, wherein the gate or base of the body-biased transistor is coupled to the drain or collector of the body-biased transistor, and the The body of the body bias transistor is used for receiving the bias voltage provided by the bias circuit.
6. The circuit of claim 4 or 5, wherein the amplifier further comprises:

   A bias circuit, coupled to the body of the body bias transistor, provides the bias voltage.
7. 7. The circuit of claim 6, wherein 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 the first resistor and A first node between the second resistors is coupled to the body of the body-biased transistor. .
8. The circuit of claim 6, wherein

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

    A bias resistor coupled between the body of the body bias transistor and a bias circuit.
11. 11. The circuit of any one 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 temperature increase and increase.
12. 11. The circuit of any one of claims 1-11, wherein a clipping threshold of the clipper remains constant with temperature.
13. A radio frequency power amplifier, comprising the amplifier according to any one of claims 1-12.
14. A radio frequency front-end system, comprising:

    A circuit according to any of claims 1-12.
15. An electronic device comprising:

    The radio frequency front-end system of claim 14 .

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