Front-end circuit with amplifier protection

Abstract

Methods and apparatus for providing amplifier protection for a radio frequency (RF) front-end circuit. Example RF front-end circuits generally include an amplifier having a gain, a first sensor configured to sense a first power (or voltage) of a first node coupled to an input of the amplifier, a second power (or voltage) configured to sense a second node coupled to an output of the amplifier a second sensor; and logic coupled to the first sensor and the second sensor. The logic component is generally configured to determine that the second power (or voltage) is outside of range based on the gain and the first power (or voltage), and to take action to protect the amplifier based on the determination. By utilizing the techniques and apparatus described herein, protection can be provided to the amplifier in an RF front-end circuit without significantly affecting the performance of the RF front-end circuit.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application Ser. No. 17 / 808,040, filed on Jun. 21, 2022, which is hereby incorporated by reference herein. Technical Field

[0003] Certain aspects of the present disclosure relate generally to electronic circuits, and more particularly to techniques and apparatus for providing amplifier protection for radio frequency front end circuits. Background Art

[0004] Wireless communication devices are widely deployed to provide various communication services, such as telephony, video, data, messaging, broadcast, etc. Such wireless communication devices may send and / or receive radio frequency (RF) signals via any of a variety of suitable radio access technologies (RATs), including but not limited to 5G New Radio (NR), Long Term Evolution (LTE), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Wideband CDMA (WCDMA), Global System for Mobile (GSM), Bluetooth, Bluetooth Low Energy (BLE), ZigBee, Wireless Local Area Network (WLAN) RATs (e.g., WiFi), etc.

[0005] A wireless communication network may include multiple base stations that can support communications for multiple mobile stations. A mobile station (MS) may communicate with a base station (BS) via a downlink and an uplink. A downlink (or forward link) refers to a communication link from a base station to a mobile station, and an uplink (or reverse link) refers to a communication link from a mobile station to a base station. A base station may send data and control information to a mobile station on a downlink, and / or may receive data and control information from a mobile station on an uplink. A base station and / or a mobile station may include a power amplifier (PA) that can be used to amplify a radio frequency (RF) signal before the RF signal is sent by one or more antennas. Summary of the invention

[0006] The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable characteristics. Without limiting the scope of the present disclosure as expressed by the claims that follow, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description," it will be understood how the features of the present disclosure provide advantages including providing protection to amplifiers in radio frequency (RF) front-end circuits without significantly affecting the performance of the RF front-end circuits.

[0007] Certain aspects of the present disclosure provide a radio frequency front-end circuit. The radio frequency front-end circuit generally includes: a power amplifier configured to amplify an input signal with a gain; a first sensor coupled to a first node and configured to sense at least one of a first power or a first voltage of the first node, the first node being coupled to the input of the power amplifier; a second sensor coupled to a second node and configured to sense at least one of a second power or a second voltage of the second node, the second node being coupled to the output of the power amplifier; and a logic component coupled to the first sensor and the second sensor. The logic component is generally configured to determine that the second power or the second voltage is out of range based on the gain and the at least one of the first power or the first voltage, and to take action based on the determination to protect the power amplifier.

[0008] Certain aspects of the present disclosure provide a method of wireless communication. The method generally includes: operating a power amplifier with a gain; sensing at least one of a first power or a first voltage of a first node coupled to an input of the power amplifier; and sensing at least one of a second power or a second voltage of a second node coupled to an output of the power amplifier. The method generally also includes determining, based on the gain and the at least one of the first power or the first voltage, that the at least one of the second power or the second voltage is out of range, and taking action to protect the power amplifier based on the determination.

[0009] Certain aspects of the present disclosure provide an apparatus for wireless communication. The apparatus generally includes: a means for amplifying a signal with a gain; a first means for sensing at least one of a first power or a first voltage of a first node coupled to an input of the means for amplification; and a second means for sensing at least one of a second power or a second voltage of a second node coupled to an output of the means for amplification. The apparatus generally also includes: a means for determining that the at least one of the second power or the second voltage is out of range based on the gain and the at least one of the first power or the first voltage; and a means for taking action based on the determination to protect the means for amplification.

[0010] To achieve the foregoing and related ends, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail some illustrative features of one or more aspects. However, these features are merely indicative of some of the various ways in which the principles of the various aspects may be employed, and this specification is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to be able to understand in detail the manner in which the above-mentioned features of the present disclosure are achieved, a more specific description briefly summarized above may be obtained by reference to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only certain typical aspects of the present disclosure and are therefore not to be considered as limiting the scope thereof, as the specification may admit to other equally effective aspects.

[0012] Figure 1 is an illustration of an example wireless communication network in which aspects of the present disclosure may be practiced.

[0013] Figure 2 is a block diagram conceptually illustrating designs of example base stations (BSs) and user equipment (UEs) in which aspects of the present disclosure may be practiced.

[0014] Figure 3 is a block diagram of an example radio frequency (RF) transceiver in which aspects of the present disclosure may be practiced.

[0015] Figure 4A An example RF front-end circuit with amplifier protection circuit according to certain aspects of the present disclosure is illustrated.

[0016] Figure 4B Another example RF front-end circuit with amplifier protection circuitry according to certain aspects of the present disclosure is illustrated.

[0017] Figure 5 is a flow chart of example operations for providing amplifier operations in accordance with certain aspects of the present disclosure.

[0018] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation. DETAILED DESCRIPTION

[0019] Certain aspects of the present disclosure relate to techniques and apparatus for providing amplifier protection for radio frequency (RF) front-end circuits. Such techniques and apparatus relate to protection circuits for detecting input and output conditions and implementing protective measures on the amplifier for certain conditions.

[0020] The various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure can be embodied in many different forms, and should not be construed as being limited to any specific structure or function presented throughout the present disclosure. Instead, these aspects are provided so that the present disclosure will be thorough and complete, and the protection scope of the present disclosure will be fully conveyed to those skilled in the art. Based on the teachings of this article, it should be understood by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the disclosure disclosed herein, whether it is implemented independently or in combination with any other aspect of the present disclosure. For example, any number of aspects set forth herein may be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such devices or methods implemented using other structures, functionality, or structures and functionality in addition to or different from the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the present invention.

[0021] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.

[0022] As used herein, the term "connected with" in various tenses of the verb "connect" may mean that element A is directly connected to element B or that other elements may be connected between element A and element B (i.e., element A is indirectly connected to element B). In the context of electronic components, the term "connected with" may also be used herein to mean that wires, traces, or other conductive materials are used to electrically connect element A and element B (and any components electrically connected therebetween).

[0023] Example Wireless System

[0024] Figure 1 An example wireless communication network 100 in which aspects of the present disclosure may be practiced is illustrated. For example, the wireless communication network 100 may be a New Radio (NR) system (e.g., a fifth generation (5G) NR network), an Evolved Universal Terrestrial Radio Access (E-UTRA) system (e.g., a fourth generation (4G) network), a Universal Mobile Telecommunications System (UMTS) (e.g., a second generation / third generation (2G / 3G) network), or a Code Division Multiple Access (CDMA) system (e.g., a 2G / 3G network), or may be configured for communication according to IEEE standards such as one or more of the 802.11 standards.

[0025] like Figure 1As shown in , the wireless communication network 100 may include several base stations (BSs) 110a to 110z (each also individually referred to as BS 110 or collectively referred to as BS 110 herein) and other network entities. A BS may also be referred to as an access point (AP), an evolved Node B (eNodeB or eNB), a next generation Node B (gNodeB or gNB) or some other terminology.

[0026] BS 110 may provide communication coverage for a particular geographic area (sometimes referred to as a "cell"), which may be stationary or may move depending on the location of mobile BS 110. In some examples, BS 110 may be interconnected with each other and / or connected to one or more other BSs or network nodes (not shown) in wireless communication network 100 through various types of backhaul interfaces (e.g., direct physical connections, wireless connections, virtual networks, etc.) using any suitable transport network. Figure 1 In the example shown, BSs 110a, 110b, and 110c may be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for pico cell 102x. BSs 110y and 110z may be femto BSs for femto cells 102y and 102z, respectively. A BS may support one or more cells.

[0027] The BS 110 communicates with one or more user equipment (UE) 120a to 120y (each also individually or collectively referred to herein as UE 120) in the wireless communication network 100. A UE may be fixed or mobile, and may also be referred to as a user terminal (UT), a mobile station (MS), an access terminal, a station (STA), a client, a wireless device, a mobile device, or some other terminology. A user terminal may be a wireless device such as a cellular phone, a smart phone, a personal digital assistant (PDA), a handheld device, a wearable device, a wireless modem, a laptop computer, a tablet computer, a personal computer, etc.

[0028] BS 110 is considered a transmitting entity for downlink and a receiving entity for uplink. UE 120 is considered a transmitting entity for uplink and a receiving entity for downlink. As used herein, a "transmitting entity" is an independently operated device or apparatus capable of transmitting data via a frequency channel, and a "receiving entity" is an independently operated device or apparatus capable of receiving data via a frequency channel. In the following description, the subscript "dn" indicates a downlink, and the subscript "up" indicates an uplink. N may be selected. up UEs are used for simultaneous transmission on the uplink, N dn UEs are used for simultaneous transmission on the downlink. up May or may not be equal to Ndn , and N up and N dn It may be a static value or may change for each scheduling interval.Beam steering or some other spatial processing technique may be used at the BS 110 and the UE 120.

[0029] UEs 120 (e.g., 120x, 120y, etc.) may be dispersed throughout the wireless communication network 100, and each UE 120 may be stationary or mobile. The wireless communication network 100 may also include a relay station (e.g., relay station 110r) (also referred to as a repeater, etc.) that receives transmissions of data and / or other information from an upstream station (e.g., BS 110a or UE 120r) and transmits transmissions of data and / or other information to a downstream station (e.g., UE 120 or BS 110), or relays transmissions between UEs 120 to facilitate communication between devices.

[0030] BS 110 may communicate on the downlink and uplink with one or more UEs 120 at any given moment. The downlink (i.e., forward link) is the communication link from BS 110 to UE 120, while the uplink (i.e., reverse link) is the communication link from UE 120 to BS 110. A UE 120 may also communicate peer-to-peer with another UE 120.

[0031] The wireless communication network 100 may use multiple transmit antennas and multiple receive antennas to transmit data on the downlink and uplink. The BS 110 may be equipped with several (N ap A group of (N) antennas can be used to implement transmit diversity for downlink transmission and / or receive diversity for uplink transmission. u Each UE 120 may receive downlink transmissions and send uplink transmissions. Each UE 120 may send user-specific data to and / or receive user-specific data from BS 110. Typically, each UE 120 may be equipped with one or more antennas. u The UEs 120 may have the same or different numbers of antennas.

[0032] The wireless communication network 100 may be a time division duplex (TDD) system or a frequency division duplex (FDD) system. For a TDD system, the downlink and uplink share the same frequency band. For an FDD system, the downlink and uplink use different frequency bands. The wireless communication network 100 may also utilize a single carrier or multiple carriers for transmission. Each UE 120 may be equipped with a single antenna (e.g., to reduce costs) or multiple antennas (e.g., where additional costs can be supported).

[0033] The network controller 130 (sometimes also referred to as a "system controller") may communicate with a set of BSs 110 and provide coordination and control (e.g., via backhaul) for these BSs 110. In some cases (e.g., in a 5G NR system), the network controller 130 may include a centralized unit (CU) and / or a distributed unit (DU). In some aspects, the network controller 130 may communicate with a core network 132 (e.g., a 5G core network (5GC)), which provides various network functions such as access and mobility management, session management, user plane functions, policy control functions, authentication server functions, unified data management, application functions, network open functions, network repository functions, network slice selection functions, etc.

[0034] In certain aspects of the present disclosure, BS 110 and / or UE 120 may include RF front-end circuitry with amplifier protection, as described in greater detail herein.

[0035] Figure 2 1 and 120a (eg, from a BS 110a) in which various aspects of the present disclosure may be implemented. Figure 1 Example components of a wireless communication network 100).

[0036] On the downlink, at BS 110a, the transmit processor 220 may receive data from the data source 212, control information from the controller / processor 240, and / or possibly other data (e.g., from the scheduler 244). Various types of data may be transmitted on different transport channels. For example, control information may be designated for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), etc. Data may be designated for a physical downlink shared channel (PDSCH), etc. A medium access control (MAC)-control element (MAC-CE) is a MAC layer communication structure that may be used for the exchange of control commands between wireless nodes. The MAC-CE may be carried in a shared channel such as a PDSCH, a physical uplink shared channel (PUSCH), or a physical sidelink shared channel (PSSCH).

[0037] The processor 220 may process (e.g., encode and symbol map) data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a PBCH demodulation reference signal (DMRS), and a channel state information reference signal (CSI-RS).

[0038] The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., pre-decoding) on ​​data symbols, control symbols, and / or reference symbols where applicable, and may provide an output symbol stream to a modulator (MOD) in a transceiver 232a-232t. Each modulator 232a-232t in the transceiver may process a respective output symbol stream (e.g., for orthogonal frequency division multiplexing (OFDM) or the like) to obtain an output sample stream. Each transceiver 232a-232t may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signals from the transceivers 232a-232t may be transmitted via antennas 234a-234t, respectively.

[0039] At UE 120a, antennas 252a-252r may receive downlink signals from BS110a and may provide received signals to transceivers 254a-254r, respectively. Transceivers 254a-254r may condition (e.g., filter, amplify, downconvert, and digitize) the corresponding received signals to obtain input samples. Each demodulator (DEMOD) in transceivers 232a-232t may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 may obtain received symbols from all demodulators in transceivers 254a-254r, perform MIMO detection on the received symbols (where applicable), and provide detected symbols. Receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 120a to data sink 260, and provide decoded control information to controller / processor 280.

[0040] On the uplink, at the UE 120a, a transmit processor 264 may receive and process data from a data source 262 (e.g., for a physical uplink shared channel (PUSCH)) and control information from a controller / processor 280 (e.g., for a physical uplink control channel (PUCCH)). The transmit processor 264 may also generate reference symbols for reference signals (e.g., for a sounding reference signal (SRS)). The symbols from the transmit processor 264 may be pre-decoded by a TX MIMO processor 266 (if applicable), further processed by a modulator (MOD) in the transceivers 254a to 254r (e.g., for single carrier frequency division multiplexing (SC-FDM), etc.), and transmitted to the BS 110a. At BS 110a, the uplink signal from UE 120a may be received by antenna 234, processed by demodulators in transceivers 232a-232t, detected by MIMO detector 236 (if applicable), and further processed by receive processor 238 to obtain decoded data and control information transmitted by UE 120a. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller / processor 240.

[0041] Memories 242 and 282 may store data and program codes for BS 110a and UE 120a, respectively. Memories 242 and 282 may also interface with controllers / processors 240 and 280, respectively. Scheduler 244 may schedule UEs for data transmission on the downlink and / or uplink.

[0042] The antennas 252, processors 258, 264, 266 and / or controller / processor 280 of the UE 120a and / or the antennas 234, processors 220, 230, 238 and / or controller / processor 240 of the BS 110a may be used to perform the various techniques and methods described herein.

[0043] In certain aspects of the present disclosure, transceiver 232 and / or transceiver 254 may include RF front-end circuitry with amplifier protection, as described in greater detail herein.

[0044] Example RF Transceiver

[0045] Figure 3is a block diagram of an example RF transceiver circuit 300 according to certain aspects of the present disclosure. The RF transceiver circuit 300 includes at least one transmit (TX) path 302 (also referred to as a transmit chain) for transmitting signals via one or more antennas 306 and at least one receive (RX) path 304 (also referred to as a receive chain) for receiving signals via one or more antennas 306. When the TX path 302 and the RX path 304 share an antenna 306, these paths can be connected to the antenna via an interface 308, which can include any of a variety of suitable RF devices, such as switches, duplexers, diplexers, multiplexers, switch converters, etc.

[0046] Receiving in-phase (I) and / or quadrature (Q) baseband analog signals from a digital-to-analog converter (DAC) 310, the TX path 302 may include a baseband filter (BBF) 312, a mixer 314, a driver amplifier (DA) 316, and a power amplifier (PA) 318. The BBF 312, the mixer 314, the DA 316, and the PA 318 may be included in a radio frequency integrated circuit (RFIC). For certain aspects, the PA 318 may be external to the RFIC.

[0047] For certain aspects, the TX path 302 may be implemented with an amplifier protection circuit to protect at least one amplifier (eg, PA 318, DA 316) in the TX path 302, as described in more detail below.

[0048] The BBF 312 filters the baseband signal received from the DAC 310, and the mixer 314 mixes the filtered baseband signal with a transmit local oscillator (LO) signal to convert the baseband signal of interest to a different frequency (e.g., upconvert from baseband to radio frequency). This frequency conversion process produces sum and difference frequencies between the LO frequency and the frequency of the baseband signal of interest. The sum and difference frequencies are referred to as "beat frequencies." The beat frequencies are typically in the RF range, so that the signal output by the mixer 314 is typically an RF signal, which may be amplified by the DA 316 and / or by the PA 318 before being transmitted by the antenna 306. Although one mixer 314 is illustrated, several mixers may be used to upconvert the filtered baseband signal to one or more intermediate frequencies and thereafter upconvert the intermediate frequency (IF) signal to a frequency for transmission.

[0049] The RX path 304 may include a low noise amplifier (LNA) 324, a mixer 326, and a baseband filter (BBF) 328. The LNA 324, the mixer 326, and the BBF 328 may be included in one or more RFICs, which may be the same RFIC as the RFIC that includes the TX path components, or may be a different RFIC. The RF signal received via the antenna 306 may be amplified by the LNA 324, and the mixer 326 mixes the amplified RF signal with a receive local oscillator (LO) signal to convert the RF signal of interest to a different baseband frequency (e.g., down-convert). The baseband signal output by the mixer 326 may be filtered by the BBF 328 before being converted to a digital I and / or Q signal by an analog-to-digital converter (ADC) 330 for digital signal processing.

[0050] Some transceivers may employ a frequency synthesizer with a variable frequency oscillator (e.g., a voltage controlled oscillator (VCO) or a digitally controlled oscillator (DCO)) to generate a stable, tunable LO with a specific tuning range. Thus, the transmit LO may be generated by the TX frequency synthesizer 320, which may be buffered or amplified by the amplifier 322 before being mixed with the baseband signal in the mixer 314. Similarly, the receive LO may be generated by the RX frequency synthesizer 332, which may be buffered or amplified by the amplifier 334 before being mixed with the RF signal in the mixer 326. For certain aspects, a single frequency synthesizer may be used for both the TX path 302 and the RX path 304. In certain aspects, the TX frequency synthesizer 320 and / or the RX frequency synthesizer 332 may include a frequency multiplier (such as a doubler) driven by an oscillator (e.g., a VCO) in the frequency synthesizer.

[0051] Controller 336 (eg, Figure 2 Controller / processor 240 or 280 in the RF transceiver circuit 300 may direct the operation of the RF transceiver circuit 300, such as transmitting signals via TX path 302 and / or receiving signals via RX path 304. Controller 336 may be a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof. Memory 338 (e.g., Figure 2 The memory 242 or 282 in the controller 336 may store data and / or program codes for operating the RF transceiver circuit 300. The controller 336 and / or the memory 338 may include control logic (eg, complementary metal oxide semiconductor (CMOS) logic).

[0052] Although Figures 1 to 3Wireless communications in which certain aspects of the present disclosure may be implemented are provided as an example application to facilitate understanding, but certain aspects described herein may be used to provide amplifier protection in any of a variety of other suitable systems, such as audio systems or other electronic systems utilizing amplifiers.

[0053] Example RF front-end circuit with amplifier protection circuit

[0054] A power amplifier (PA, such as PA 318) is designed to transmit power in certain operating bands (e.g., within a specified band) where the impedance (as well as voltage and current) has been designed to ensure reliability and durability of the PA. The design of the PA ensures that even a large voltage standing wave ratio (VSWR) at the output of the PA can be maintained in the operating band of the PA. Outside the operating band of the PA, the PA is typically used with filters or duplexers that present very extreme and rapidly changing impedances (e.g., very high or very low impedance) in order to achieve PA isolation and rejection specifications or targets.

[0055] Generally speaking, these out-of-band impedances may not pose a challenge to the PA when transmitting signals within the desired operating band (e.g., within the specified band). However, in some cases, strong input signals outside the desired operating band (e.g., outside the specified band) may be present in the PA for a variety of reasons. For example, the presence of a strong input signal outside the desired operating band may be the result of oscillations of the stages driving the PA. The combination of such out-of-band signals and out-of-band impedances present at the PA may generate large voltages and currents that may severely damage or even destroy the PA.

[0056] In order to improve the durability of amplifiers in RF front-end circuits and protect these amplifiers, certain aspects of the present disclosure provide techniques and devices for providing amplifier protection. Such protection may include an amplifier protection circuit that is configured to detect input and output conditions and implement protective measures for the amplifier when certain risk conditions are detected. Risk conditions may include out-of-band high-power input signals in the presence of extreme impedances at the PA output due to filter or duplexer impedance characteristics. For example, if a high input signal is detected at the input of the PA, but the output of the PA does not reach the expected level associated with the known gain of the PA, the amplifier may be exposed to risk conditions that may cause damage. Another risk condition may be that a post-PA component (e.g., a switch, such as a band select switch, an antenna switch module, etc.) is not properly turned on, is damaged or fails, and therefore the output of the PA is followed by a disconnected switch. Disconnection, damage or failure of the PA post-component may be caused during assembly and / or programming of the RF front-end circuit.

[0057] Certain aspects of the present invention provide techniques and apparatus for providing protection to amplifiers in RF front-end circuits without significantly affecting the performance of the RF front-end circuits. For example, the techniques and apparatus described herein can provide amplifier protection without introducing substantial losses, limiting the magnitude of some of the parameters of the RF front-end circuits, or introducing undesirable complexity.

[0058] Figure 4A An example RF front-end circuit 400A with an amplifier protection circuit (e.g., protection circuit 420) according to certain aspects of the present disclosure is illustrated. According to certain aspects, the RF front-end circuit 400A can be included in a TX path (e.g., TX path 302) of an RF transceiver circuit (e.g., RF transceiver circuit 300).

[0059] For certain aspects, RF front end circuit 400A may include node 402, impedance matching circuit 406A, PA 318, impedance matching circuit 406B, node 408, antenna 306, and interface 308. Figure 4A Not shown, but Figure 4A The PA 318 in FIG. 314 may be replaced by a driver amplifier (e.g., DA 316) connected in series with the PA 318. For ease of description, only the PA 318 in FIG. 314 will be described below. Figure 4A The PA 318 is described. The PA 318 can be coupled to a power supply (PS) 422 via a power rail and can have specified gain parameters. In some aspects, the RF front end circuit 400A can also include a protection circuit 420. The protection circuit 420 can include one or more sensors 416A, 416B and a logic component 418.

[0060] For certain aspects, node 402 may be coupled to an input of an impedance matching circuit 406A, and impedance matching circuit 406A may have an output coupled to an input of PA 318. In some aspects, additional circuitry may be present between node 402 and impedance matching circuit 406A. The output of PA 318 may be coupled to an input of impedance matching circuit 406B, and the output of impedance matching circuit 406B may be coupled to node 408. Either or both of impedance matching circuits 406A, 406B may be tunable. In such cases, the impedance of the tunable impedance matching circuit may be adjusted by a controller (e.g., controller 336).

[0061] Node 408 may be coupled to antenna 306 via interface 308. Interface 308 may include any of a variety of suitable RF devices, such as a switch, a duplexer, a diplexer, a multiplexer, a switchplexer, etc. In some aspects, additional circuitry may be present between impedance matching circuit 406B and node 408. For example, RF front end circuit 400A may include a band select switch coupled to an output of impedance matching circuit 406B, and the band select switch can be used to couple to one or more sets of filters or duplexers.

[0062] For certain aspects, sensor 416A of protection circuit 420 may be coupled to node 402, and sensor 416B of protection circuit 420 may be coupled to node 408. Logic component 418 may be coupled to sensors 416A, 416B, and PS 422 of PA 318 (and in some cases, configured to control at least one). Logic component 418 may also be coupled to PA 318 and configured to control the PA. In such cases, logic component 418 of protection circuit 420 may be part of a controller (e.g., controller 336) for RF front end circuit 400A.

[0063] For certain aspects, the PA 318 may be configured to amplify an RF input signal (labeled “RFIN”) to the RF front end circuit 400A with a gain. The gain may be a specified gain parameter associated with the PA 318. The sensors 416A, 416B may be configured to allow detection of the presence of a strong out-of-band signal in the PA 318. For example, the sensor 416A may be configured to sense at least one of a first power or a first voltage at the node 402, and the sensor 416B may be configured to sense at least one of a second power or a second voltage at the node 408. In some scenarios, the input power and the output power and / or voltage detected by the sensors 416A, 416B may be related by a gain parameter of the PA 318. In other scenarios, the input power and the output power and / or voltage detected by the sensors 416A, 416B may not be related by a gain parameter of the PA 318.

[0064] For certain aspects, the logic component 418 may determine whether a risk condition is detected by using at least one sensor 416A, 416B. Determining whether a risk condition is detected may include comparing voltages or powers at two nodes in the RF front-end circuit 400A to determine whether the output signal is within an expected range. The logic component 418 may determine whether the output signal is within an expected range by determining whether the second power and / or the second voltage is outside the expected range based on (i) known gain parameters of the PA 318 and (ii) the first power and / or the first voltage.

[0065] For example, when (i) sensor 416A detects a high input signal to PA 318 and (ii) the output signal of PA 318 detected by sensor 416B does not reach an expected level based on the known gain of PA 318, PA 318 may be exposed to a risk condition that may damage PA 318. In another example, when (i) sensor 416A detects a high input signal to PA 318 and (ii) the output signal of PA 318 detected by sensor 416B reaches an expected level based on the known gain of PA 318, PA 318 may be considered not to be exposed to a risk condition that may damage PA 318. In some aspects, logic component 418 may be programmed with the known gain of PA 318 and may calculate the expected range at the output of PA 318 based on the known gain and the location of sensor 416B in RF front end circuit 400A. Other known parameters of RF front end circuit 400A may also be used to determine the expected range.

[0066] For certain aspects, when logic component 418 has detected the presence of a risk condition, logic component 418 can be configured to output an indication based on the determination. In some aspects, logic component 418 can take at least one action based on the detection to protect PA 318. The at least one action can include reducing the PA 318 bias, reducing the voltage of a power rail (e.g., a voltage common collector (VCC) rail) of PA 318, engaging an attenuator ( Figure 4A Not shown, but see Figure 4B ) or reduce the amplitude of the RFIN signal. In some aspects, the at least one action can include powering off the PA 318.

[0067] Figure 4B An example RF front-end circuit 400B with an amplifier protection circuit (e.g., protection circuit 420) according to certain aspects of the present disclosure is illustrated. According to certain aspects, the RF front-end circuit 400B can be included in a TX path (e.g., TX path 302) of an RF transceiver circuit (e.g., RF transceiver circuit 300).

[0068] For certain aspects, the RF front-end circuit 400B may include a node 402, an attenuator 404, a DA 316, an impedance matching circuit 406A, a PA 318, an impedance matching circuit 406B, a node 408, a filter or duplexer 410, a switch converter 412, a node 414, an antenna 306, and an interface 308. In some aspects, the DA 316 may be removed and replaced with a short component or another component. In some aspects, the attenuator 404 may be included in the DA 316. The RF front-end circuit 400B may also include a protection circuit 420. The protection circuit 420 may include one or more sensors 416A, 416B, 416C and a logic component 418. Note that the RF front-end circuit 400B is a reference example of an RF front-end circuit that may include an amplifier protection circuit, and the RF front-end circuit 400 may include different components. For example, in some aspects, the RF front-end circuit 400B may not include the attenuator 404. Therefore, the optional attenuator 404 is shown with a dashed box.

[0069] For certain aspects, node 402 may be selectively coupled to an input of attenuator 404 or an input of DA 316 via switch 430. The output of attenuator 404 may be coupled to the input of DA 316. For other aspects, switch 430 and / or attenuator 404 may be eliminated, and in these aspects, node 402 may be connected to the input of DA 316 or coupled to the input of DA 316 via one or more other components. The output of DA 316 may be coupled to the input of impedance matching circuit 406A, and impedance matching circuit 406A may have an output coupled to the input of PA 318. The output of PA 318 may be coupled to the input of impedance matching circuit 406B, and the output of impedance matching circuit 406B may be coupled to node 408. Node 408 may be coupled to the input of filter or duplexer 410, and the output of filter or duplexer 410 may be coupled to the input of switching converter 412. The output of the switching converter 412 can be coupled to the node 414. The node 414 can be coupled to the antenna 306 via the interface 308, as described above. In some aspects, the RF front-end circuit 400B may also include a band selection switch coupled to the output of the impedance matching circuit 406B and to the input of the filter or duplexer 410, and may also include additional filter banks or duplexer banks. For some aspects, the switching converter 412 and / or the filter or duplexer 410 may be eliminated and may be replaced by one or more other components in some such cases.

[0070] For certain aspects, sensor 416A of protection circuit 420 may be coupled to node 402, sensor 416B of protection circuit 420 may be coupled to node 408, and sensor 416C of protection circuit 420 may be coupled to node 414. For other aspects, sensor 416C may be coupled to another node in the circuit path between the output of impedance matching circuit 406B and antenna 306 (e.g., a node between filter or duplexer 410 and switching converter). Logic component 418 may be coupled to sensors 416A, 416B, 416C, and PS 422 (and in some cases, configured to control one or more of these sensors). In some aspects, logic component 418 may also be coupled to and configured to control at least one of PA 318, DA 316, attenuator 404, or switch 430. For certain aspects, one or more of sensors 416A, 416B, 416C may include one or more rectifiers to generate a direct current (DC) voltage or power proportional to an alternating current (AC) voltage or power measured at a node (e.g., node 402, node 408, node 414) for use by logic component 418 (e.g., in determining whether an output signal of PA 318 is within an expected range).

[0071] For certain aspects, the PA 318 may be configured to amplify the RFIN signal to the RF front end circuit 400B with a gain. The gain may be a specified gain parameter associated with the PA 318. The sensors 416A, 416B, 416C may allow for the detection of the presence of a strong out-of-band signal in at least one of the DA 316 or the PA 318. For example, the sensor 416A may be configured to sense at least one of a first power or a first voltage at the node 402, the sensor 416B may be configured to sense at least one of a second power or a second voltage at the node 408, and the sensor 416C may be configured to sense at least one of a third power or a third voltage at the node 414. In some scenarios, the input power and the output power and / or voltage detected by the sensors 416A, 416B, 416C may be related by a gain parameter of the PA 318. In other scenarios, the input power and output power and / or voltage detected by the sensors 416A, 416B, 416C may not be related via a gain parameter of the PA 318 .

[0072] For certain aspects, logic component 418 may determine whether a risk condition is detected by using at least one sensor 416A, 416B, 416C. Determining whether a risk condition is detected may include comparing the voltage or power at node 402 and node 408 (and / or node 414) in RF front-end circuit 400B to determine whether the output signal is within an expected range. Logic component 418 may determine whether the output signal is within an expected range by determining whether at least one of the second (or third) power or the second (or third) voltage is outside the range based on (i) the known gain of DA 316 plus PA 318 and (ii) at least one of the first power or the first voltage.

[0073] For example, when (i) sensor 416A detects a high input signal to DA 316 (or to PA 318) and (ii) the output signal of PA 318 detected by sensor 416B does not reach the expected level based on the known gain of DA 316 plus PA 318, DA 316 and / or PA 318 may be exposed to a risk condition that may damage at least one of PA 318 or DA 316. Such an example may be the result of a post-PA component (e.g., a switch, such as a band select switch, an antenna switch module, etc.) not being properly turned on, being damaged, or malfunctioning. As a result of such a defective post-PA component, the output of PA 318 may be followed by an open switch, causing the output of PA 318 to be lower than the expected output based on the known combined gain of the DA and PA.

[0074] In another example, when (i) sensor 416A detects a high input signal to DA 316 (or PA 318) and (ii) the output signal of PA 318 detected by sensor 416B reaches an expected level based on the known combined gain of the DA and PA, DA 316 and PA 318 may be considered not to be exposed to a risk condition that may damage at least one of DA 316 or PA 318. In certain aspects, logic component 418 may be programmed with the known gain of DA 316 and PA 318 (or with the combined gain of DA and PA) and may calculate the expected range at the output of PA 318 based on the known gain and information received from sensor 416B (and / or sensor 416C) in RF front end circuit 400B. Other known parameters of RF front end circuit 400B may also be used to determine the expected range.

[0075] For certain aspects, determining whether a risk condition is detected may include comparing voltages or powers at nodes 402 and 414 in RF front end circuit 400B using sensors 416A, 416C to determine whether the output signal is within an expected range. Logic component 418 may determine whether at least one of the third power or the third voltage is outside the range based on (i) a known gain of PA 318 and (ii) at least one of the first power or the first voltage.

[0076] For example, when (i) sensor 416A detects a high input signal to DA 316 (or PA 318) and (ii) the output signal of PA 318 detected by sensor 416C does not reach the expected level based on the known combined gain of DA 316 and PA 318, the DA and / or PA may be exposed to a risk condition that may damage at least one of DA 316 or PA 318. Such an example may be the result of an out-of-band high power RFIN signal in the presence of extreme impedance (e.g., due to the impedance characteristics of filter or duplexer 410) at the output of PA 318, causing the output of PA 318 to be lower than the expected output based on the known combined gain of DA 316 and PA 318. Additionally, such an example may be the result of a post-PA component not being properly turned on, being damaged, or malfunctioning. As mentioned, as a result of such a defective post-PA component, the output of the PA may be followed by an open switch, causing the output of PA 318 to be lower than the expected output based on the known combined gain of DA and PA. In another example, when (i) sensor 416A detects a high input signal to DA 316 (or PA 318) and (ii) the output signal of PA 318 detected by sensor 416C reaches an expected level based on the known gain of PA 318, PA 318 can be considered not to be exposed to risk conditions that could damage at least one of PA 318 or DA 316.

[0077] For certain aspects, when logic component 418 has detected the presence of a risk condition, logic component 418 can be configured to output an indication based on the determination. In some aspects, logic component 418 can take at least one action based on the detection to protect PA 318 and / or DA 316. The at least one action can include reducing PA 318 bias, reducing the voltage of a power rail (e.g., VCC) of PA 318, engaging an attenuator (e.g., attenuator 404, routing the RFIN signal through the attenuator by controlling an associated switch 430), or reducing the amplitude of the RFIN signal. In certain aspects, the at least one action can include at least one of powering off PA 318 or powering off DA 316.

[0078] Example protection operation

[0079] Figure 5 is a flow chart of example operations 500 for providing amplifier (e.g., driver amplifier (DA) 316 and / or power amplifier (PA) 318) protection according to certain aspects of the present disclosure. Operations 500 may be performed by RF front-end circuits, such as Figure 4A or Figure 4B In some aspects, the RF front-end circuit 400A, 400B may include a protection circuit 420.

[0080] Operations 500 may generally include operating a power amplifier (PA, such as PA 318, alone or in combination with DA 316) at a gain at block 502. The gain may be a specified gain parameter associated with the PA, which may be stored in a memory (e.g., memory 338) and / or set by a controller (e.g., controller 336).

[0081] According to certain aspects, operations 500 may also include sensing at least one of a first power or a first voltage of a first node (e.g., node 402) coupled to an input of the power amplifier at block 504. In some aspects, the sensing may be performed by a first sensor (e.g., sensor 416A).

[0082] According to certain aspects, operation 500 may also include sensing at least one of a second power or a second voltage of a second node (e.g., node 408 or node 414) coupled to the output of the power amplifier at block 506. In some aspects, the sensing may be performed by a second sensor (e.g., sensor 416B or sensor 416C).

[0083] According to certain aspects, operation 500 may also include determining, at block 508, that at least one of the second power or the second voltage is outside of a range (e.g., an expected range) based on (i) the gain and (ii) at least one of the first power or the first voltage. In some aspects, the determination may be performed by a logic component (e.g., logic component 418), which may be part of a controller (e.g., controller 336). In certain aspects, the logic component may be programmed with a known gain of the PA and may calculate an expected range at the output of the PA based on the known gain and the received sensor information, the expected range depending on the location of the sensor.

[0084] According to certain aspects, operations 500 may also include, at block 510, taking at least one action based on the determination to protect the PA. In some aspects, taking the at least one action may include reducing a bias of the power amplifier, reducing a power supply voltage of the power amplifier (e.g., a voltage at PS 422), and / or engaging an attenuator (e.g., attenuator 404) having an output coupled to an input of the power amplifier. Figure 4B As shown, the attenuator may be engaged by the logic component via operation of a switch (e.g., switch 430). Additionally or alternatively in some aspects, taking the action may include reducing the amplitude of an RF input signal (e.g., RFIN signal) of the power amplifier. Additionally or alternatively, in some aspects, taking the action may include powering down at least one of the power amplifier or the driver amplifier (e.g., DA 316). In some aspects, the at least one action may be performed by the logic component.

[0085] According to certain aspects, operation 500 may also include sensing (e.g., via a first sensor) at least one of a third power or a third voltage of a first node coupled to an input of the power amplifier. In this case, operation 500 may also include sensing (e.g., via a second sensor) at least one of a fourth power or a fourth voltage of a second node (e.g., node 408 or node 414) coupled to an output of the power amplifier. In this case, operation 500 may also include determining that at least one of the fourth power or the fourth voltage is within another range based on (i) the gain and (ii) at least one of the third power or the third voltage. In some aspects, the determination may be performed by a logic component. In this case, operation 500 may also include reversing an action taken to protect the power amplifier (e.g., an action taken at block 510) based on the determination within another range. In some aspects, the reversal action may be performed by a logic component.

[0086] Example aspects

[0087] In addition to the above-mentioned aspects, specific combinations of the aspects are also within the scope of the present disclosure, and the details of some of the specific combinations are as follows:

[0088] Aspect 1: A radio frequency front-end circuit, comprising: a power amplifier, the power amplifier being configured to amplify an input signal with a gain; a first sensor, the first sensor being coupled to a first node and being configured to sense at least one of a first power or a first voltage of the first node, the first node being coupled to an input end of the power amplifier; a second sensor, the second sensor being coupled to a second node and being configured to sense at least one of a second power or a second voltage of the second node, the second node being coupled to an output end of the power amplifier; and a logic component, the logic component being coupled to the first sensor and the second sensor and being configured to: determine that the second power or the second voltage is out of range based on the gain and the at least one of the first power or the first voltage; and take action based on the determination to protect the power amplifier.

[0089] Aspect 2: The RF front-end circuit according to Aspect 1, wherein when taking the action, the logic component is configured to control a reduction in the bias of the power amplifier.

[0090] Aspect 3: The RF front-end circuit according to Aspect 1 or 2, wherein when taking the action, the logic component is configured to control the reduction of the power supply voltage of the power amplifier.

[0091] Aspect 4: The RF front-end circuit according to any one of Aspects 1 to 3 further includes an attenuator having an output terminal selectively coupled to the input terminal of the power amplifier, wherein when the action is taken, the logic component is configured to control the engagement of the attenuator.

[0092] Aspect 5: The RF front-end circuit according to any one of Aspects 1 to 4, wherein when taking the action, the logic component is configured to control the reduction of the amplitude of the input signal of the power amplifier.

[0093] Aspect 6: The RF front-end circuit according to Aspect 1, wherein when taking the action, the logic component is configured to control powering off the power amplifier.

[0094] Aspect 7: The RF front-end circuit according to any one of the preceding aspects, wherein the logic component is configured to output an indication based on the determination.

[0095] Mode 8: The RF front-end circuit according to any one of the preceding aspects further includes a driving amplifier having an input terminal coupled to the first node and the first sensor, and having an output terminal coupled to the input terminal of the power amplifier.

[0096] Aspect 9: The RF front-end circuit according to any one of the preceding aspects further includes an impedance matching circuit, wherein the impedance matching circuit has an input end coupled to the output end of the power amplifier and has an output end coupled to the second node and the second sensor.

[0097] Aspect 10: The RF front-end circuit according to any one of the preceding aspects further includes a filter or a duplexer, wherein the filter or the duplexer has an input coupled to the output end of the power amplifier, the second node, and the input end of the second sensor.

[0098] Aspect 11: The RF front-end circuit according to Aspect 10 further includes a third sensor coupled to a third node, the third node being coupled to an output end of the filter or the duplexer, the third sensor being configured to sense at least one of a third power or a third voltage of the third node, wherein the logic component is coupled to the third sensor.

[0099] Aspect 12: The RF front-end circuit according to any one of the preceding aspects further includes a switching converter having an input terminal coupled to the output terminal of the power amplifier, the second node, and the second sensor.

[0100] Aspect 13: The RF front-end circuit according to Aspect 12 further includes a third sensor coupled to a third node, the third node being coupled to the output end of the switching converter, the third sensor being configured to sense at least one of a third power or a third voltage of the third node, wherein the logic component is coupled to the third sensor.

[0101] Aspect 14: An RF front-end circuit according to any one of the preceding aspects, wherein the first node is an input end of a first impedance matching circuit, the first impedance matching circuit having an output end coupled to the input end of the power amplifier, and wherein the second node is an output end of a second impedance matching circuit, the second impedance matching circuit having an input end coupled to the output end of the power amplifier.

[0102] Aspect 15: A method of wireless communication, the method comprising: operating a power amplifier with a gain; sensing at least one of a first power or a first voltage at a first node coupled to an input terminal of the power amplifier; sensing at least one of a second power or a second voltage at a second node coupled to an output terminal of the power amplifier; determining that the second power or at least one of the second voltage is out of range based on the gain and the at least one of the first power or the first voltage; and taking action to protect the power amplifier based on the determination.

[0103] Aspect 16: The method of aspect 15, wherein taking the action comprises reducing a bias of the power amplifier.

[0104] Aspect 17: The method according to aspect 15 or 16, wherein taking the action comprises reducing a supply voltage of the power amplifier.

[0105] Aspect 18: The method of any one of aspects 15 to 17, wherein taking the action comprises engaging an attenuator having an output coupled to the input of the power amplifier.

[0106] Aspect 19: The method according to any one of aspects 15 to 18, wherein taking the action comprises reducing the amplitude of the input signal of the power amplifier.

[0107] Aspect 20: The method according to aspect 15, wherein taking the action includes powering off the power amplifier.

[0108] Aspect 21: The method according to any one of Aspects 15 to 19 further includes: sensing at least one of a third power or a third voltage of the first node coupled to the input end of the power amplifier; sensing at least one of a fourth power or a fourth voltage of the second node coupled to the output end of the power amplifier; determining that the at least one of the fourth power or the fourth voltage is within another range based on the gain and at least one of the third power or the third voltage; and reversing the action taken to protect the power amplifier based on the determination within the other range.

[0109] Aspect 22: An apparatus for wireless communication, the apparatus comprising: a component for amplifying a signal with a gain; a first component for sensing at least one of a first power or a first voltage of a first node coupled to an input terminal of the component for amplifying; a second component for sensing at least one of a second power or a second voltage of a second node coupled to an output terminal of the component for amplifying; a component for determining that at least one of the second power or the second voltage is out of range based on the gain and the at least one of the first power or the first voltage; and a component for taking action to protect the component for amplifying based on the determination.

[0110] Additional considerations

[0111] The above description provides examples, but does not limit the scope, applicability or examples set forth in the claims. Without departing from the scope of the present disclosure, the functions and arrangements of the elements discussed may be changed. Each example may ignore, replace or add each procedure or component as appropriate. For example, the method described may be performed in a different order than described, and various steps may be added, omitted or combined. In addition, the features described for some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such devices or methods practiced using other structures, functional functions or structures and functionality in addition to or different from the various aspects of the present disclosure given herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the present invention. The word "exemplary" is used herein to mean "used as an example, instance, or illustration". Any aspect described herein as "exemplary" is not necessarily interpreted as being preferred or having advantages over other aspects.

[0112] The various operations of the above methods may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs), or processors. In general, where there are operations illustrated in the accompanying drawings, these operations may have corresponding corresponding means plus functional components. For example, a means for amplifying a signal with a gain may include a PA, such as Figure 3 , Figure 4A or Figure 4B The first and second components for sensing at least one of the first power or the first voltage may include at least one sensor such as Figure 4A or Figure 4B The means for determining that at least one of the second power or the second voltage is out of range based on the gain of the PA and at least one of the first power or the first voltage and the means for taking action may include a logic component, such as Figure 4A or Figure 4B Logic component 418.

[0113] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items (including single members). As an example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0114] The methods disclosed herein include one or more steps or actions for implementing the described methods. The steps and / or actions of the methods may be interchangeable with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0115] It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A radio frequency front-end circuit, the radio frequency front-end circuit comprising: a power amplifier configured to amplify an input signal with a gain; a first sensor coupled to a first node and configured to sense at least one of a first power or a first voltage at the first node, the first node being coupled to an input of the power amplifier; a second sensor coupled to a second node and configured to sense at least one of a second power or a second voltage at the second node, the second node being coupled to an output of the power amplifier; as well as a logic component coupled to the first sensor and the second sensor and configured to: determining that the at least one of the second power or the second voltage is out of range based on the gain and the at least one of the first power or the first voltage; as well as Action is taken based on the determination to protect the power amplifier. 2 . The RF front-end circuit according to claim 1 , wherein when taking the action, the logic component is configured to control a reduction in the bias of the power amplifier. 3 . The RF front-end circuit according to claim 1 , wherein when taking the action, the logic component is configured to control reducing the power supply voltage of the power amplifier.

4. The RF front-end circuit according to claim 1, further comprising an attenuator having an output terminal selectively coupled to the input terminal of the power amplifier, wherein when taking the action, the logic component is configured to control the engagement of the attenuator. 5 . The RF front-end circuit according to claim 1 , wherein when taking the action, the logic component is configured to control reducing the amplitude of the input signal of the power amplifier. 6 . The RF front-end circuit according to claim 1 , wherein when taking the action, the logic component is configured to control the power amplifier to be powered off. 7 . The RF front end circuit of claim 1 , wherein the logic component is configured to output an indication based on the determination.

8. The RF front-end circuit according to claim 1, further comprising a driver amplifier having an input terminal coupled to the first node and the first sensor, and having an output terminal coupled to the input terminal of the power amplifier.

9. The RF front-end circuit according to claim 1, further comprising an impedance matching circuit, the impedance matching circuit having an input coupled to the output of the power amplifier and having an output coupled to the second node and the second sensor.

10. The RF front-end circuit according to claim 1, further comprising a filter or a duplexer, wherein the filter or the duplexer has an input coupled to the output terminal of the power amplifier, the second node, and the second sensor.

11. The RF front-end circuit according to claim 10, further comprising a third sensor coupled to a third node, the third node being coupled to an output end of the filter or the duplexer, the third sensor being configured to sense at least one of a third power or a third voltage of the third node, wherein the logic component is coupled to the third sensor.

12. The RF front-end circuit of claim 1, further comprising a switching converter having an input coupled to the output of the power amplifier, the second node, and the second sensor.

13. The RF front-end circuit according to claim 12, further comprising a third sensor coupled to a third node, the third node being coupled to the output end of the switching converter, the third sensor being configured to sense at least one of a third power or a third voltage of the third node, wherein the logic component is coupled to the third sensor.

14. The RF front-end circuit of claim 1 , wherein the first node is an input of a first impedance matching circuit having an output coupled to the input of the power amplifier, and wherein the second node is an output of a second impedance matching circuit having an input coupled to the output of the power amplifier.

15. A method of wireless communication, the method comprising: operating the power amplifier with a gain; sensing at least one of a first power or a first voltage of a first node coupled to an input of the power amplifier; sensing at least one of a second power or a second voltage of a second node coupled to an output terminal of the power amplifier; determining that the at least one of the second power or the second voltage is out of range based on the gain and the at least one of the first power or the first voltage; as well as Action is taken based on the determination to protect the power amplifier. The method of claim 15 , wherein taking the action comprises reducing a bias of the power amplifier.

17. The method of claim 15, wherein taking the action comprises reducing a supply voltage of the power amplifier.

18. The method of claim 15, wherein taking the action comprises engaging an attenuator having an output coupled to the input of the power amplifier.

19. The method of claim 15, wherein taking the action comprises reducing the amplitude of an input signal to the power amplifier.

20. The method of claim 15, wherein taking the action comprises powering off the power amplifier.

21. The method according to claim 15, further comprising: sensing at least one of a third power or a third voltage of the first node coupled to the input of the power amplifier; sensing at least one of a fourth power or a fourth voltage of the second node coupled to the output terminal of the power amplifier; determining, based on the gain and at least one of the third power or the third voltage, that the at least one of the fourth power or the fourth voltage is within another range; as well as Action taken to protect the power amplifier is reversed based on the determination within the other range.

22. An apparatus for wireless communication, the apparatus comprising: A means for amplifying a signal by a gain; first means for sensing at least one of a first power or a first voltage at a first node coupled to an input of the means for amplifying; second means for sensing at least one of a second power or a second voltage at a second node coupled to the output of the means for amplifying; means for determining that the at least one of the second power or the second voltage is out of range based on the gain and the at least one of the first power or the first voltage; as well as Means for taking action based on the determination to protect the means for amplifying.

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