A radio frequency front-end module, a radio frequency transceiver device, and an electronic device

Abstract

The present application provides a radio frequency front-end module, a radio frequency transceiver device and an electronic device, belonging to the field of communication technologies. The radio frequency front-end module includes a radio frequency switch, a radio frequency processing device and a filtering circuit. Among them, the radio frequency switch includes a first radio frequency terminal, a second radio frequency terminal and an antenna terminal. The first radio frequency terminal and the second radio frequency terminal are respectively coupled to corresponding radio frequency processing devices, and the antenna terminal is used for coupling to an antenna. The radio frequency switch is configured to: control the transmission of a first radio frequency signal between the first radio frequency terminal and the antenna terminal; or control the transmission of a second radio frequency signal between the second radio frequency terminal and the antenna terminal. The first radio frequency processing device in the radio frequency processing device is coupled to the second radio frequency terminal through the filtering circuit, and the first radio frequency processing device is a non-linear device. The embodiment of the present application improves the radiation spurious problem of the radio frequency transceiver device by arranging a filtering circuit between the non-linear device and the radio frequency terminal of the radio frequency switch.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a radio frequency front-end module, a radio frequency transceiver device, and an electronic device. Background Art

[0002] A radio frequency switch is a commonly used device in a radio frequency front-end module, which is used to realize the switching of different radio frequency signal transceivers and is widely used in radio frequency transceiver devices such as mobile phones, base stations, and satellite communications. If the isolation of the radio frequency switch is poor, radio frequency signal leakage will occur. When the leaked radio frequency signal is transmitted to a non-linear device in the radio frequency front-end module, the non-linear device will cause waveform distortion of the leaked radio frequency signal, thereby generating harmonics. The harmonics of the leaked radio frequency signal will cause the problem of radiated spurious emission (RSE) in the radio frequency transceiver device. Summary of the Invention

[0003] Embodiments of this application provide a radio frequency front-end module, a radio frequency transceiver device, and an electronic device, which are used to improve the radiated spurious problem of the radio frequency transceiver device when the isolation of the radio frequency switch is poor.

[0004] To achieve the above object, the embodiments of this application adopt the following technical solutions:

[0005] In a first aspect, a radio frequency front-end module is provided. The radio frequency front-end module includes a radio frequency switch, a radio frequency processing device, and a filtering circuit. Among them, the radio frequency switch includes a first radio frequency terminal, a second radio frequency terminal, and an antenna terminal. The first radio frequency terminal and the second radio frequency terminal are respectively coupled to corresponding radio frequency processing devices, and the antenna terminal is used to be coupled to an antenna; the radio frequency switch is configured to: control the first radio frequency signal to be transmitted between the first radio frequency terminal and the antenna terminal; or, control the second radio frequency signal to be transmitted between the second radio frequency terminal and the antenna terminal. The first radio frequency processing device in the radio frequency processing device is coupled to the second radio frequency terminal through the filtering circuit, and the first radio frequency processing device is a non-linear device; the filtering circuit is used to suppress the transmission of the first radio frequency signal to the first radio frequency processing device when the first radio frequency signal is transmitted to the second radio frequency terminal; or, when the first radio frequency signal is transmitted to the first radio frequency processing device and harmonics are generated due to distortion of the first radio frequency signal, suppress the transmission of the harmonics of the first radio frequency signal from the first radio frequency processing device to the second radio frequency terminal.

[0006] In the embodiments of the present application, by setting a wave circuit to suppress the transmission of signals in a specific frequency band, the signal intensity of the signals in the specific frequency band is greatly attenuated after passing through the filter circuit. In the case where the first radio frequency signal leaks to the second radio frequency terminal, the filter circuit suppresses the transmission of the first radio frequency signal to the first radio frequency processing device, thereby effectively reducing the harmonics generated by the first radio frequency signal exciting the first radio frequency processing device and reducing the harmonic radiation. In the case where the first radio frequency signal leaks to the first radio frequency processing device and the first radio frequency signal has excited the nonlinear device to generate harmonics, the filter circuit suppresses the transmission of the harmonics of the first radio frequency signal from the first radio frequency processing device to the second radio frequency terminal, thereby reducing the harmonic radiation. The embodiments of the present application improve the radiation spurious problem of the radio frequency transceiver device by setting a filter circuit between the nonlinear device and the radio frequency terminal of the radio frequency switch.

[0007] In some possible embodiments, the filter circuit includes a first filter circuit, and the first radio frequency processing device is coupled to the second radio frequency terminal through the first filter circuit. In the case where the first radio frequency signal is transmitted to the second radio frequency terminal, the end of the first filter circuit connected to the second radio frequency terminal can detect the leaked first radio frequency signal. The first filter circuit is used to suppress the transmission of the first radio frequency signal to the first radio frequency processing device, so that the signal intensity of the first radio frequency signal at the end of the first filter circuit connected to the first radio frequency processing device is reduced, and even the leaked first radio frequency signal cannot be detected. The transmission of the first radio frequency signal to the first radio frequency processing device to generate harmonics is reduced, and further the harmonics of the first radio frequency signal are reduced from being transmitted to the antenna, reducing the harmonic radiation and improving the radiation spurious problem of the radio frequency transceiver device.

[0008] In some possible embodiments, the frequency band of the first radio frequency signal does not overlap with the frequency band of the second radio frequency signal. Thus, the first filter circuit only suppresses the transmission of the leaked first radio frequency signal to the first radio frequency processing device, without affecting the transmission of the second radio frequency signal between the second radio frequency terminal and the first radio frequency processing device, ensuring that the second radio frequency signal can be transmitted and received through the second radio frequency terminal.

[0009] In some possible embodiments, the filter circuit includes a second filter circuit, and the first radio frequency processing device is coupled to the second radio frequency terminal through the second filter circuit. When the first radio frequency signal is transmitted to the first radio frequency processing device, the first radio frequency processing device (nonlinear device) will distort the first radio frequency signal to generate harmonics. The second filter circuit is used to suppress the transmission of the harmonics of the first radio frequency signal from the first radio frequency processing device to the second radio frequency terminal. Thus, the transmission of the harmonics of the first radio frequency signal to the antenna can be reduced or even avoided, reducing the harmonic radiation generated on the antenna, and further improving the radiation spurious problem of the radio frequency transceiver device.

[0010] In some possible embodiments, the frequency band of the harmonics of the first radio frequency signal does not overlap with the frequency band of the second radio frequency signal. As a result, the second filtering circuit only suppresses the harmonics of the first radio frequency signal transmitted from the first radio frequency processing device to the second radio frequency terminal, while also ensuring that the second radio frequency signal can be transmitted between the second radio frequency terminal and the first radio frequency processing device.

[0011] In some possible embodiments, the filtering circuit includes a first filtering circuit and a second filtering circuit, and the first radio frequency processing device is coupled to the second radio frequency terminal through the first filtering circuit and the second filtering circuit. The first filtering circuit is configured to suppress the transmission of the first radio frequency signal to the first radio frequency processing device when the first radio frequency signal is transmitted to the second radio frequency terminal. The second filtering circuit is configured to suppress the transmission of the harmonics of the first radio frequency signal from the first radio frequency processing device to the second radio frequency terminal when the first radio frequency signal is transmitted to the first radio frequency processing device and the first radio frequency signal is distorted to generate harmonics. By simultaneously providing the first filtering circuit and the second filtering circuit in the embodiments of the present application, on the one hand, the generation of harmonics caused by the transmission of the first radio frequency signal to the first radio frequency processing device is reduced. On the other hand, the second filtering circuit suppresses the transmission of the harmonics of the first radio frequency signal to the second radio frequency terminal. Thus, the harmonic radiation generated on the antenna can be significantly reduced, and the radiation spurious problem of the radio frequency transceiver device is better improved.

[0012] In some possible embodiments, a grounding circuit is further included, and the grounding circuit is coupled to the second radio frequency terminal. The first radio frequency signal transmitted to the second radio frequency terminal is output to the ground through the grounding circuit, thereby avoiding the transmission of the first radio frequency signal to the first radio frequency processing device.

[0013] In some possible embodiments, the grounding circuit is configured to ground the second radio frequency terminal and transmit the first radio frequency signal to the ground when the first radio frequency signal is transmitted to the second radio frequency terminal. Thereby, the generation of harmonics caused by the transmission of the first radio frequency signal to the first radio frequency processing device is reduced, and further, the harmonics of the first radio frequency signal are reduced from being transmitted to the antenna, the harmonic radiation is reduced, and the radiation spurious problem of the radio frequency transceiver device is improved.

[0014] In some possible embodiments, a shielding cover is further included, and the first radio frequency processing device is disposed inside the shielding cover. The shielding cover can shield the harmonic radiation generated on the first radio frequency processing device (i.e., the nonlinear device). On the one hand, the interference of the harmonic radiation to other devices inside the electronic device can be reduced, and on the other hand, the radiation spurious problem of the radio frequency transceiver device is further improved.

[0015] In a second aspect, a radio frequency transceiver device is provided. The radio frequency transceiver device includes a modem, a radio frequency chip, an antenna, and the radio frequency front-end module according to any one of the first aspect above; wherein, the modem is sequentially connected to the antenna through the radio frequency chip and the radio frequency front-end module.

[0016] In a third aspect, an electronic device is provided. The electronic device includes a processor and the radio frequency transceiver device in the second aspect above, and the processor is coupled to the radio frequency transceiver device.

[0017] It should be understood that the technical effects of the second aspect and the third aspect can refer to the technical effects of the first aspect and any of its embodiments, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic structural diagram of the electronic device provided by the embodiment of the present application;

[0019] Figure 2 Schematic structural diagram of the radio frequency transceiver device provided by the embodiment of the present application;

[0020] Figure 3 Schematic structural diagram of the related radio frequency front-end module provided by the embodiment of the present application;

[0021] Figure 4 Schematic structural diagram of a general radio frequency switch provided by the embodiment of the present application;

[0022] Figure 5 Schematic diagram of radiation spurs when the isolation of the radio frequency switch provided by the embodiment of the present application is poor;

[0023] Figure 6 Schematic structural diagram of the first radio frequency front-end module provided by the embodiment of the present application;

[0024] Figure 7 Schematic diagram of signal transmission in which the first filtering circuit in the first radio frequency front-end module provided by the embodiment of the present application suppresses the leakage of the first radio frequency signal from being transmitted to the nonlinear device;

[0025] Figure 8 Schematic structural diagram of the point-resistance filtering circuit provided by the embodiment of the present application;

[0026] Figure 9 Schematic diagram of signal transmission in which the second filtering circuit in the first radio frequency front-end module provided by the embodiment of the present application suppresses the harmonic wave from being transmitted to the radio frequency switch;

[0027] Figure 10 Schematic structural diagram of the low-pass filtering circuit provided by the embodiment of the present application;

[0028] Figure 11 Schematic structural diagram of the second radio frequency front-end module provided by the embodiment of the present application;

[0029] Figure 12 Schematic structural diagram of the third radio frequency front-end module provided by the embodiment of the present application;

[0030] Figure 13 Schematic diagram of the structure of the fourth radio frequency front-end module provided by the embodiment of the present application;

[0031] Figure 14 Signal transmission schematic diagram of the grounding circuit in the fourth radio frequency front-end module provided by the embodiment of the present application for transmitting the leaked first radio frequency information to the ground.

[0032] Reference numerals: 100, electronic device; 110, processor; 120, radio frequency transceiver device; 130, external memory interface; 140, internal memory; 150, USB interface; 160, power management module; 161, battery; 162, wireless charging coil; 170, audio module; 180, sensor module; 191, button; 192, motor; 193, indicator; 194, camera; 195, display screen; 196, SIM card interface; 210, modem; 220, radio frequency chip; 230, radio frequency front-end module; 240, antenna; 310, power amplifier; 320, low-noise amplifier; 330, duplexer; 340, radio frequency switch; 341, first transistor; 342, second transistor; 350, filtering circuit; 351, first filtering circuit; 352, second filtering circuit; 360, shielding cover; 370, grounding circuit; 400, dot resistance filter circuit; 500, low-pass filter circuit. Detailed implementation manners

[0033] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] The terms "first", "second", etc. involved in the embodiments of the present application are only used for the purpose of distinguishing the same type of features and cannot be understood as indicating relative importance, quantity, order, etc.

[0035] The terms "exemplary" or "for example" and other words involved in the embodiments of the present application are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, using the words "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0036] The terms "coupled" and "connected" involved in the embodiments of the present application should be understood in a broad sense. For example, it may refer to a direct physical connection or an indirect connection realized through electronic devices, such as a connection realized through resistors, inductors, capacitors or other electronic devices.

[0037] Embodiments of the present application provide an electronic device, which can be fixed or mobile. Additionally, the electronic device can also be referred to as a user equipment (UE), a terminal, a terminal device, a mobile station (MS), a mobile terminal (MT), an access terminal device, a vehicle-mounted terminal device, an industrial control terminal device, a mobile station, a remote station, a remote terminal device, a mobile device, a wireless communication device, a terminal agent, or a terminal device, etc. Exemplarily, the electronic device can be a mobile phone, a tablet computer (pad), a desktop computer, a laptop computer, an all-in-one computer, a vehicle-mounted terminal, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, a computing device, or other processing devices connected to a wireless modem, a wearable device, a terminal device in a future mobile communication network, or a terminal device in a future evolved public land mobile network (PLMN), etc.

[0038] Taking the electronic device as a mobile phone as an example, Figure 1Shows a possible structure of an electronic device. The electronic device 100 may include a processor 110, an external memory interface 130, an internal memory 140, a universal serial bus (USB) interface (hereinafter simply referred to as USB interface 150), a power management module 160, a battery 161, a wireless charging coil 162, a radio frequency transceiver device 120, an audio module 170, a sensor module 180, a button 191, a motor 192, an indicator 193, a camera 194, a display screen 195, and a subscriber identification module (SIM) card interface (hereinafter simply referred to as SIM card interface 196), etc.

[0039] Among them, the sensor module 180 may include a pressure sensor, a gyroscope sensor, a barometric pressure sensor, a magnetic sensor, an acceleration sensor, a distance sensor, a proximity light sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, a bone conduction sensor, etc.

[0040] It can be understood that the interface connection relationship between the modules illustrated in the embodiments of the present application is only for illustrative purposes and does not constitute a specific limitation on the electronic device 100. In other embodiments of the present application, the electronic device 100 may include more or fewer components than those shown in the figure, or combine certain components, or split certain components, or have different component arrangements. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0041] In some examples, the processor 110 may include one or more processing units. Among them, the processing units may include a field programmable gate array (FPGA), a central processing unit (CPU), an application processor (AP), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a baseband processor, and a neural-network processing unit (NPU), etc. In some examples, different processing units may be independent devices. For example, the processor 110 may be a baseband processor. In some examples, the processor 110 may also be a system on chip (SoC) integrated with multiple processing units.

[0042] A memory may also be provided in the processor 110 for storing computer instructions and data. In some embodiments, the memory in the processor 110 is a cache. This memory can save the computer instructions or data that the processor 110 has just used or recycled. If the processor 110 needs to use the computer instructions or data again, it can directly call them from the memory. This avoids repeated accesses, reduces the waiting time of the processor 110, and thus improves the efficiency of the system.

[0043] The external memory interface 130 can be used to connect an external memory card, such as a micro SanDisk (Micro SD) card, to implement the storage capacity expansion of the electronic device 100. The external memory card communicates with the processor 110 through the external memory interface 130 to implement the data storage function. For example, files such as music and videos are saved in the external memory card.

[0044] The internal memory 140 can be used to store computer-executable program codes, and the executable program codes include computer instructions. The processor 110 executes various functional applications and data processing of the electronic device 100 by running the computer instructions stored in the internal memory 140. In addition, the internal memory 140 can include high-speed random access memory and can also include non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, a universal flash storage (UFS), etc.

[0045] The memory related to the embodiments of the present application can be volatile memory or non-volatile memory, or can include both volatile and non-volatile memory. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synch link DRAM (SLDRAM), and direct ram bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include but not be limited to these and any other suitable types of memory.

[0046] The audio module 170 can include a speaker, a receiver, a microphone, and a headphone interface. The electronic device 100 can implement audio functions through the audio module 170 and the processor 110, etc., such as music playback, recording, etc.

[0047] The audio module 170 is used to convert digital audio information into an analog audio signal for output, and is also used to convert an analog audio input into a digital audio signal. In some embodiments, the audio module 170 may be disposed in the processor 110, or some functional modules of the audio module 170 may be disposed in the processor 110. The speaker, also referred to as a "loudspeaker", is used to convert an audio electrical signal into a sound signal. The receiver, also referred to as a "handset", is used to convert an audio electrical signal into a sound signal. The microphone, also referred to as a "microphone" or "transmitter", is used to convert a sound signal into an electrical signal. The electronic device 100 may be provided with at least one microphone. The headphone jack is used to connect a wired headphone. The headphone jack may be a USB interface 150, or may be a 3.5 mm open mobile terminal platform (OMTP) standard interface, or a cellular telecommunications industry association of the USA (CTIA) standard interface.

[0048] The button 191 includes a power-on button, a volume button, etc. The button 191 may be a mechanical button 191, or may be a touch button 191. The electronic device 100 can receive the input of the button 191 and generate a key signal input related to the user settings and function control of the electronic device 100. The motor 192 can generate a vibration prompt. The motor 192 can be used for incoming call vibration prompts and can also be used for touch vibration feedback. The indicator 193 may be an indicator light, which can be used to indicate the charging state, the change in battery level, and can also be used to indicate messages, missed calls, notifications, etc. The SIM card interface 196 is used to connect a SIM card. The SIM card can be inserted into or removed from the SIM card interface 196 to achieve contact and separation from the electronic device 100. The electronic device 100 may support 1 or N SIM card interfaces 196, where N is a positive integer greater than 1. The SIM card interface 196 can support Nano SIM cards, Micro SIM cards, SIM cards, etc. In some embodiments, the electronic device 100 uses an embedded SIM (eSIM) card, and the eSIM card can be embedded in the electronic device 100 and cannot be separated from the electronic device 100.

[0049] The electronic device 100 can implement a shooting function through an ISP, a camera 194, a video codec, a GPU, a display screen 195, a processor 110, etc. The ISP is used to process the data fed back by the camera 194. In some embodiments, the ISP may be disposed in the camera 194. The camera 194 is used to capture still images or videos. In some embodiments, the electronic device 100 may include 1 or N cameras 194, where N is a positive integer greater than 1.

[0050] The electronic device 100 can implement the display function through components such as the GPU, the display screen 195, and the processor 110. The GPU is a microprocessor for image processing, connected to the display screen 195 and the processor 110. The GPU is used to perform mathematical and geometric calculations for graphics rendering. The processor 110 may include one or more GPUs, which execute computer instructions to generate or change display information.

[0051] The display screen 195 is used to display images, videos, etc. The display screen 195 includes a display panel. In some embodiments, the electronic device 100 may include one or more display screens 195. In other embodiments, the touch screen in the display screen 195 may be a foldable screen.

[0052] The battery 161 may include one or more battery cells, and multiple battery cells can be connected in series, parallel, etc. to supply power to the load.

[0053] The power management module 160 is used to receive a charging input from a charger. Among them, the charger can be a wireless charger, such as a wireless charging dock, other electronic devices with reverse wireless charging function, etc. The power management module 160 can receive a wireless charging input through the wireless charging coil 162 of the electronic device 100. The charger can also be a wired charger. For example, the power management module 160 can receive a charging input from a wired charger through the USB interface 150.

[0054] The processor 110 is coupled to the radio frequency transceiver 120 to implement the 2G / 3G / 4G / 5G mobile communication and wireless communication functions of the electronic device 100. Among them, the wireless communication may include global system for mobile communications (GSM), general packet radio service (GPRS), code division multiple access (CDMA), wideband code division multiple access (WCDMA), time-division code division multiple access (TD-SCDMA), long term evolution (LTE), wireless local area networks (WLAN), bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), infrared (IR), near field communication (NFC), etc.

[0055] Figure 2 A schematic structural diagram of a radio frequency transceiver is shown. As Figure 2 shown, the radio frequency transceiver 120 includes a modem 210, a radio frequency integrated circuit (RFIC) 220, a radio frequency front-end (RFFE) 230, and an antenna (ANT) 240; among them, the modem 210 is coupled to the radio frequency chip 220, the radio frequency chip 220 is coupled to the radio frequency front-end module 230, and the radio frequency front-end module 230 is coupled to the antenna 240.

[0056] The modem 210 is used to encode and decode user data (such as voice data, text data, and video data) or control information for transmission and reception via the radio frequency transceiver 120. In some embodiments, the modem 210 may include a modulator and a demodulator. Among them, the modulator is used to modulate the low-frequency baseband signal to be transmitted into a medium-high frequency signal. The demodulator is used to demodulate the received electromagnetic wave signal into a low-frequency baseband signal and send the demodulated low-frequency baseband signal to the baseband processor 110.

[0057] The radio frequency chip 220 (which can also be referred to as a receiver, transmitter, or transceiver) may include a radio frequency transmitting end (transport, TX) and a radio frequency receiving end (receive, RX). In some embodiments, the radio frequency chip 220 may receive the baseband signal from the modem 210, process the baseband signal (such as up-conversion and digital-to-analog conversion) to obtain a radio frequency signal, and send the radio frequency signal to the radio frequency front-end module 230 through the radio frequency transmitting end. The radio frequency front-end module 230 may send the radio frequency signal to the antenna 240 to achieve the transmission of the radio frequency signal. In some embodiments, the radio frequency receiving end of the radio frequency chip 220 may receive the radio frequency signal received from the antenna 240 through the radio frequency front-end module 230. The radio frequency chip 220 may process the received radio frequency signal (such as down-conversion and analog-to-digital conversion) to obtain a baseband signal and send the baseband signal to the modem 210 to achieve the reception of the radio frequency signal.

[0058] The antenna 240 is used to transmit and receive electromagnetic wave signals. Among them, the antenna 240 may be a single antenna 240 or an antenna array composed of multiple antennas 240. Each antenna 240 can be used to cover a single or multiple frequency bands, and different antennas 240 can also be multiplexed to improve the utilization rate of the antenna 240.

[0059] As Figure 3 shown, the radio frequency front-end module 230 may include a power amplifier (PA) 310, a surface acoustic wave (SAW) filter ( Figure 3not shown), a low noise amplifier (LNA) 320, a duplexer 330, a radio frequency (RF) switch 340, etc. The RF transmitting end and the RF receiving end of the RF chip 220 are coupled to the RF end of the RF switch 340 through one or more RF processing devices for amplifying and / or filtering the RF signal (e.g., the power amplifier 310, the low noise amplifier 320, or the surface acoustic wave filter), and the antenna 240 is coupled to the antenna end of the RF switch 340. In some examples, the RF transmitting end and the RF receiving end of the RF chip 220 can be coupled to the RF end of the RF switch 340 in a one-to-one correspondence; for example, the second RF receiving end RX2 of the RF chip 220 is coupled to the second RF end RF2 of the RF switch 340. Thus, the RF end of the RF switch 340 can receive the RF signal; or transmit the RF signal. In some examples, the RF transmitting end (e.g., the first transmitting end TX1) and the RF receiving end (e.g., the first receiving end RX1) of the RF chip 220 can also share the RF end of the RF switch 340 through the duplexer 330; for example, the first RF receiving end RX1 and the first RF transmitting end TX1 of the RF chip 220 are coupled to the first RF end RF1 of the RF switch 340 through the duplexer 330. By sharing the RF end of the RF switch 340 through the duplexer 330, the shared RF end can both receive the RF signal and transmit the RF signal.

[0060] The RF switch 340 can switch between receiving and transmitting the RF signal. In some examples, the RF signal transmitted by the RF chip 220 can be input from the RF end of the RF switch 340 and output from the antenna end of the RF switch 340, so that the RF signal is transmitted to the antenna 240 to realize the transmission of the RF signal. The RF signal received by the antenna 240 can also be input from the antenna end of the RF switch 340 and output from the RF end of the RF switch 340, so that the RF signal is transmitted to the RF chip 220 to realize the reception of the RF signal.

[0061] The RF switch 340 can also switch between different RF signals. In some examples, multiple RF signals transmitted by the RF chip 220 can be input from multiple RF ends of the RF switch 340, and the RF switch 340 can switch any one of the multiple RF signals to be output from the antenna end.

[0062] Figure 4 shows a schematic structural diagram of a general RF switch. As Figure 4As shown, the RF switch 340 includes a first transistor 341 and a second transistor 342. Among them, the first end of the first transistor 341 is coupled to the first RF terminal RF1 of the RF switch 340, the first end of the second transistor 342 is coupled to the second RF terminal RF2 of the RF switch 340, and the second ends of both the first transistor 341 and the second transistor 342 are coupled to the antenna terminal ANT of the RF switch 340. Taking the transmitting scenario as an example, the RF switch 340 can choose to turn on the first RF terminal RF1 and the antenna terminal ANT to transmit and receive the first RF signal, or choose to turn on the second RF terminal RF2 and the antenna terminal ANT to transmit and receive the second RF signal.

[0063] For example, the RF switch 340 can turn on the first transistor 341 and turn off the second transistor 342 to turn on the first RF terminal RF1 and the antenna terminal ANT, so as to realize the transmission and reception of the first RF signal. The path for transmitting and receiving the first RF signal through the first RF terminal RF1 can be called the first path. However, due to the parasitic capacitance existing on the second transistor 342, the characteristic of the capacitor blocking direct current and passing alternating current will make the isolation degree of the RF switch 340 for the RF signal relatively poor. Thus, when the first RF signal is transmitted on the first path, the first RF signal can leak to the second RF terminal RF2 of the RF switch 340 through the parasitic capacitance of the second transistor 342. Similarly, the RF switch 340 can turn on the second transistor 342 and turn off the first transistor 341 to turn on the second RF terminal RF2 and the antenna terminal ANT, so as to realize the transmission and reception of the second RF signal. The path for transmitting and receiving the second RF signal through the second RF terminal RF2 can be called the second path. However, due to the parasitic capacitance existing on the first transistor 341, when the second RF signal is transmitted on the second path, the second RF signal can leak to the first RF terminal RF1 of the RF switch 340 through the parasitic capacitance of the first transistor 341.

[0064] Such as Figure 5As shown, in some examples, when the first path transmits the first radio frequency signal, due to the poor isolation of the radio frequency switch 340, the leaked first radio frequency signal will be transmitted to the second path. Since the constituent elements of the first radio frequency processing device in the radio frequency front-end module 230 include non-linear elements, these first radio frequency processing devices can be referred to as non-linear devices. For example, the constituent elements of the low-noise amplifier 320B on the second path include non-linear elements such as diodes or field effect transistors. The low-noise amplifier 320B is a non-linear device. A non-linear element refers to an element (or material) to which Ohm's law does not apply; that is, an element (or material) in which the current passing through a device is not proportional to the voltage applied across the device can be referred to as a non-linear element (or material). When the leaked first radio frequency signal is applied to the low-noise amplifier 320B (non-linear device) on the second path, the leaked first radio frequency signal will excite the non-linear device, resulting in waveform distortion. The distorted first radio frequency signal can be decomposed into the first radio frequency signal (i.e., the fundamental wave) and the harmonics of the first radio frequency signal. The frequency of the harmonics of the first radio frequency signal is higher than the frequency of the first radio frequency signal. On the one hand, the harmonics can generate harmonic radiation on the non-linear device. On the other hand, the harmonics may also be transmitted to the antenna 240, generating harmonic radiation on the antenna 240. The harmonic radiation is not within the expected operating frequency band of the radio frequency transceiver device 120, which easily leads to the problem of radiation spurs in the radio frequency transceiver device 120.

[0065] In order to improve the problem of radiation spurs caused by the poor isolation of the radio frequency switch, the radio frequency front-end module provided by the embodiment of the present application further includes a filter circuit. The first radio frequency processing device (i.e., the non-linear device) in the radio frequency processing device is coupled to the second radio frequency terminal through the filter circuit. The filter circuit can suppress the transmission of signals in a specific frequency band. Among them, suppressing the transmission of signals in a specific frequency band means that after the signals in the specific frequency band pass through the filter circuit, the signal strength (e.g., amplitude, power) will be greatly attenuated to weaken or even filter out the signals in the specific frequency band. In the case where the first radio frequency signal leaks to the second radio frequency terminal, the filter circuit is used to suppress the transmission of the first radio frequency signal to the first radio frequency processing device, thereby reducing the generation of harmonics. Or, in the case where the first radio frequency signal leaks to the first radio frequency processing device and the first radio frequency processing device causes distortion of the first radio frequency signal and generates harmonics, the filter circuit is used to suppress the transmission of the harmonics of the first radio frequency signal from the first radio frequency processing device to the second radio frequency terminal. Thereby improving the problem of radiation spurs of the radio frequency transceiver device. As described above, a non-linear device is a device whose constituent structure includes non-linear elements; for example, power amplifiers, low-noise amplifiers, or surface acoustic wave filters in the radio frequency front-end module are all non-linear devices.

[0066] As Figure 6As shown, the low-noise amplifier 320A (nonlinear device) and the power amplifier 310 on the first path can be coupled to the first end of the corresponding filter circuit 350 through the duplexer 330, and the second end of the filter circuit 350 is coupled to the first radio frequency terminal RF1 of the radio frequency switch 340. Another low-noise amplifier 320B (nonlinear device) on the second path can be directly coupled to the first end of the corresponding another filter circuit 350, and the second end of the filter circuit 350 is coupled to the second radio frequency terminal RF2 of the radio frequency switch 340.

[0067] The radio frequency signal leaked by the radio frequency switch 340 transmitted to the nonlinear device will excite the nonlinear device to generate harmonics. In the embodiments of the present application, the example that the first radio frequency signal leaks to the transceiver path of the second radio frequency signal is used for illustration. As Figure 7 shown, in some embodiments, the frequency band (which can also be referred to as the frequency range) of the first radio frequency signal does not overlap with the frequency band of the second radio frequency signal. The filter circuit 350 may include a first filter circuit 351. The low-noise amplifier 320B (nonlinear device) on the second path is coupled to the first end of the corresponding first filter circuit 351, and the second end of the first filter circuit 351 is coupled to the second radio frequency terminal RF2 of the radio frequency switch 340. In the case where the first radio frequency signal leaks to the second radio frequency terminal RF2, the first filter circuit 351 on the second path (i.e., coupled to the second radio frequency terminal RF2 of the radio frequency switch 340) can suppress the leaked first radio frequency signal from being transmitted to the low-noise amplifier 320. That is to say, for the first filter circuit 351 on the second path, the second end of the first filter circuit 351 (i.e., the end connected to the second radio frequency terminal RF2) can detect the leaked first radio frequency signal, while the signal strength of the first radio frequency signal at the first end of the first filter circuit 351 (i.e., the end connected to the low-noise amplifier 320B) is reduced, or even the leaked first radio frequency signal cannot be detected. Thus, it can effectively reduce the harmonics generated by the leaked first radio frequency signal exciting the low-noise amplifier 320B, and further reduce the harmonics of the first radio frequency signal transmitted to the antenna 240, reduce the harmonic radiation, and improve the radiation spurious problem of the radio frequency transceiver device 120.

[0068] In some embodiments, the first filter circuit 351 may be a band-stop filter circuit. Exemplarily, the stop band of the band-stop filter circuit on the second path includes the frequency band of the first radio frequency signal and does not include the frequency band of the second radio frequency signal. That is to say, the band-stop filter circuit on the second path only suppresses the transmission of the first radio frequency signal leaked to the second radio frequency terminal RF2 to the low-noise amplifier 320B on the second path, without affecting the transmission of the second radio frequency signal between the second radio frequency terminal RF2 and the low-noise amplifier 320B on the second path, ensuring that the second radio frequency signal can be transmitted and received through the second radio frequency terminal RF2.

[0069] It should be understood that when the first filter circuit 351 on the first path (i.e., coupled to the first RF terminal RF1 of the RF switch 340) is a band-stop filter circuit, the stop band of the band-stop filter circuit includes the frequency band of the second RF signal and does not include the frequency band of the first RF signal. That is to say, the band-stop filter circuit only suppresses the transmission of the second RF signal leaking to the first RF terminal RF1 to the low-noise amplifier 320A on the first path, without affecting the transmission of the first RF signal between the first RF terminal RF1 and the low-noise amplifier 320A on the first path, ensuring that the first RF signal can be transmitted and received through the first RF terminal RF1.

[0070] Specifically, as Figure 8 shown, the band-stop filter circuit can adopt a notch filter circuit 400. The first end of the notch filter circuit 400 is used to be coupled to the non-linear device, and the second end of the notch filter circuit 400 is used to be coupled to the RF terminal of the RF switch 340. Among them, the notch filter circuit 400 includes a first capacitor C1 and a first inductor L1. The first end and the second end of the notch filter circuit 400 are both coupled to the first end of the first capacitor C1. The second end of the first capacitor C1 is coupled to the first end of the first inductor L1, and the second end of the first inductor L1 is grounded to GND.

[0071] In some other embodiments, the first filter circuit 351 can also be a band-pass filter circuit. Exemplarily, the pass band of the band-pass filter circuit on the second path includes the frequency band of the second RF signal and does not include the frequency band of the first RF signal. That is to say, the band-pass filter on the second path only allows the second RF signal to be transmitted between the second RF terminal RF2 and the low-noise amplifier 320B on the second path, while suppressing the transmission of the first RF signal leaking to the second RF terminal RF2 to the low-noise amplifier 320B on the second path.

[0072] It should be understood that in other embodiments, the first filtering circuit 351 may also adopt other forms of filtering circuits, which are not limited herein in the embodiments of the present application. As an example, the first path is used for transmitting and receiving a first radio frequency signal in the B40 frequency band; wherein, the B40 frequency band ranges from 2.3 GHz to 2.39 GHz, and the center frequency is 2.35 GHz. The second path is used for receiving a second radio frequency signal in the N77 frequency band; wherein, the N77 frequency band ranges from 3.3 GHz to 4.2 GHz, and the center frequency is 3.75 GHz. The frequency band of the first radio frequency signal is lower than that of the second radio frequency signal. Therefore, the first filtering circuit 351 on the second path may adopt a high-pass filtering circuit, and the high-pass filtering circuit allows the second radio frequency signal with a higher frequency to pass through. When the first radio frequency signal leaks to the second radio frequency terminal RF2 of the radio frequency switch 340, the high-pass filtering circuit can suppress the passage of the first radio frequency signal with a lower frequency, thereby suppressing the transmission of the leaked first radio frequency signal to the low-noise amplifier 320B on the second path. On the contrary, the first filtering circuit 351 on the first path may adopt a low-pass filtering circuit, and the low-pass filtering circuit allows the first radio frequency signal with a lower frequency to pass through. When the second radio frequency signal leaks to the first radio frequency terminal RF1 of the radio frequency switch 340, the low-pass filtering circuit can suppress the passage of the second radio frequency signal with a higher frequency, thereby suppressing the transmission of the leaked second radio frequency signal to the low-noise amplifier 320A on the first path.

[0073] In some examples, there may be an overlap between the frequency bands of the first radio frequency signal transmitted and received on the first path and the second radio frequency signal on the second path. If a first filtering circuit 351 for removing the first radio frequency signal is provided on the second path, although the first filtering circuit 351 can suppress the transmission of the leaked first radio frequency signal to the nonlinear device on the second path, the first filtering circuit 351 will also suppress the transmission of the second radio frequency signal between the nonlinear device and the second radio frequency terminal RF2, affecting the transmission and reception of the second radio frequency signal on the second path. Therefore, as Figure 9As shown, in some other embodiments, the filtering circuit 350 includes a second filtering circuit 352. The low-noise amplifier 320B (nonlinear device) on the second path is coupled to the first end of the corresponding second filtering circuit 352, and the second end of the second filtering circuit 352 is coupled to the second RF terminal RF2 of the RF switch 340. When the first RF signal leaking to the second RF terminal RF2 is transmitted to the low-noise amplifier 320B coupled to the second RF terminal RF2, harmonics of the first RF signal will be generated. The second filtering circuit 352 on the second path (i.e., coupled to the second RF terminal RF2 of the RF switch 340) is used to suppress the transmission of the harmonics of the first RF signal from the low-noise amplifier 320B to the second RF terminal RF2. That is to say, for both ends of the second filtering circuit 352 on the second path, the leaked first RF signal can be detected. The end of the second filtering circuit 352 connected to the low-noise amplifier 320B can detect the harmonics of the first RF signal, and the signal strength of the harmonics of the first RF signal at the end of the second filtering circuit 352 connected to the second RF terminal RF2 is reduced, or even the harmonics of the first RF signal cannot be detected. Thus, the transmission of the harmonics of the first RF signal to the antenna 240 can be reduced or even avoided, thereby reducing the harmonic radiation generated on the antenna 240, and further improving the radiation spurious problem of the RF transceiver device 120.

[0074] Exemplarily, since the frequency of the Nth harmonic of the first RF signal is N times the frequency of the first RF signal, when the frequency band of the first RF signal coincides with the frequency band of the second RF signal, the frequency of the harmonics of the first RF signal is generally greater than the frequency of the second RF signal; that is, the frequency band of the harmonics of the first RF signal does not coincide with the frequency band of the second RF signal. Therefore, in some embodiments, the second filtering circuit 352 may be a low-pass filtering circuit. For example, the low-pass filtering circuit on the second path can effectively suppress the transmission of the harmonics (higher frequency) of the first RF signal from the low-noise amplifier 320B to the second RF terminal RF2, and at the same time can ensure that the second RF signal (lower frequency) can be transmitted between the second RF terminal RF2 and the low-noise amplifier 320B on the second path.

[0075] Specifically, as Figure 10 shown, the first end of the low-pass filtering circuit 500 is used to be coupled to the nonlinear device, and the second end of the low-pass filtering circuit 500 is used to be coupled to the RF terminal of the RF switch 340. The low-pass filtering circuit 500 includes a second capacitor C2, a second inductor L2, and a third inductor L3. Among them, the first end of the second capacitor C2 is coupled to the first end of the second inductor L2 as the first end of the low-pass filtering circuit 500, and the second end of the second capacitor C2 is grounded to GND. The second end of the second inductor L2 is coupled to the first end of the third inductor L3 as the second end of the low-pass filtering circuit 500, and the second end of the third inductor L3 is grounded to GND.

[0076] It should be understood that in other embodiments, the second filtering circuit 352 may also adopt other forms of filtering circuits; for example, a band-pass filtering circuit or a band-stop filtering circuit, etc., which are not limited herein in the embodiments of the present application.

[0077] In some embodiments, two filtering circuits 350 may be provided. The two filtering circuits 350 are respectively a first filtering circuit 351 and a second filtering circuit 352. As Figure 11 shown, on the second path, the low-noise amplifier 320B is sequentially coupled to the second radio frequency terminal RF2 through the first filtering circuit 351 and the second filtering circuit 352. On the one hand, the first radio frequency signal leaking to the second radio frequency terminal RF2 is suppressed by the first filtering circuit 351 from being transmitted to the low-noise amplifier 320B on the second path, reducing the generation of harmonics of the first radio frequency signal. On the other hand, the second filtering circuit 352 suppresses the harmonics of the first radio frequency signal transmitted by the low-noise amplifier 320B on the second path to the second radio frequency terminal RF2. Thereby, the harmonic radiation generated on the antenna 240 can be greatly reduced, and the radiation spurious problem of the radio frequency transceiver device 120 is better improved.

[0078] In addition, although not shown in the present application, those skilled in the art should understand that any radio frequency terminal of the radio frequency switch 340 may receive radio frequency signals leaked from other multiple radio frequency terminals (the frequency bands of the multiple leaked radio frequency signals may be different). Therefore, multiple filtering circuits may be provided between any radio frequency terminal of the radio frequency switch 340 and the corresponding coupled non-linear device. Among them, the multiple filtering circuits may be multiple first filtering circuits 351, or multiple second filtering circuits 352, or any combination of multiple first filtering circuits 351 and multiple second filtering circuits 352.

[0079] Furthermore, as Figure 12 shown, the radio frequency front end provided in the embodiments of the present application may further include a shielding cover 360, and part or all of the non-linear devices are disposed inside the shielding cover 360. Thereby, the harmonic radiation generated on the non-linear devices can be shielded. On the one hand, the interference of the harmonic radiation to other devices inside the electronic device 100 can be reduced, and on the other hand, the radiation spurious problem of the radio frequency transceiver device 120 is further improved.

[0080] As Figure 13 shown, in some embodiments, the radio frequency front end further includes a plurality of grounding circuits 370, and the radio frequency terminals of the radio frequency switch 340 are respectively coupled to the plurality of grounding circuits 370 in one-to-one correspondence. Specifically, the grounding circuit 370 includes a grounding transistor, the first end of the grounding transistor is coupled to the radio frequency terminal of the radio frequency switch 340, and the second end of the grounding transistor is grounded to GND. It should be understood that in other embodiments, the grounding transistor may also be integrated into the radio frequency switch 340.

[0081] As Figure 14 shown, in some examples, when the first path transmits the first RF signal through the first RF terminal RF1 of the RF switch 340, if the isolation of the RF switch 340 is poor, the first RF signal will leak to the second RF terminal RF2 of the RF switch 340. When the first path transmits the first RF signal through the first RF terminal RF1 of the RF switch 340 and the second path does not receive an RF signal, the embodiment of the present application can turn on the grounding transistor coupled to the second RF terminal RF2 of the RF switch 340, thereby transmitting the leaked first RF signal to the ground GND, and further suppressing the transmission of the leaked first RF signal to the low-noise amplifier 320B on the second path. Similarly, in other examples, when the second path transmits the second RF signal through the second RF terminal RF2 of the RF switch 340 and the first path does not transmit or receive an RF signal, the embodiment of the present application can turn on the grounding transistor coupled to the first RF terminal RF1 of the RF switch 340, thereby transmitting the leaked second RF signal to the ground GND, and further suppressing the transmission of the leaked second RF signal to the low-noise amplifier 320A on the first path.

[0082] That is to say, the embodiment of the present application can transmit the leaked RF signal to the ground GND through the grounding transistor, thereby avoiding the transmission of the leaked RF signal to the non-linear device, avoiding the harmonics generated by the leaked RF signal exciting the non-linear device, and further reducing the harmonic radiation and improving the radiation spurious problem of the RF transceiver device 120.

[0083] The embodiment of the present application further provides an electronic device, and the electronic device 100 includes a processor 110 and an RF transceiver device 120. Among them, the RF front-end module 230 in the RF transceiver device 120 is the solution of any one of the embodiments provided in the present application, or the combined solution of multiple embodiments.

[0084] It should be understood that in the embodiment of the present application, some or all of the constituent structures of the RF front-end module may be integrally integrated; or, the constituent structures of the RF front-end module may also be separately provided, and the present application does not make any restrictions on this.

[0085] In several embodiments provided in the present application, it should be understood that the disclosed radio frequency front-end module, radio frequency transceiver device, and electronic device can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of devices or modules can be in electrical, mechanical, or other forms.

[0086] As described above, the above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A radio frequency front-end module, characterized in that, It includes a radio frequency switch, radio frequency processing devices, a filtering circuit, and a shielding case; wherein, the radio frequency switch includes a first radio frequency terminal, a second radio frequency terminal, and an antenna terminal. The first radio frequency terminal and the second radio frequency terminal are respectively coupled to the corresponding radio frequency processing devices, and the antenna terminal is used to couple to an antenna; the radio frequency switch is configured to: control the transmission of a first radio frequency signal between the first radio frequency terminal and the antenna terminal; or, control the transmission of a second radio frequency signal between the second radio frequency terminal and the antenna terminal; a first radio frequency processing device in the radio frequency processing devices is coupled to the second radio frequency terminal through the filtering circuit. The first radio frequency processing device is a non-linear device and is disposed within the shielding case; the filtering circuit includes a first filtering circuit and a second filtering circuit, and the first radio frequency processing device is coupled to the second radio frequency terminal through the first filtering circuit and the second filtering circuit; the first filtering circuit is used to suppress the transmission of the first radio frequency signal to the first radio frequency processing device when the first radio frequency signal is transmitted to the second radio frequency terminal; the second filtering circuit is used to suppress the transmission of the harmonic of the first radio frequency signal from the first radio frequency processing device to the second radio frequency terminal when the first radio frequency signal is transmitted to the first radio frequency processing device and the first radio frequency signal is distorted to generate harmonics.

2. The RF front-end module according to claim 1, wherein The frequency band of the first radio frequency signal does not overlap with the frequency band of the second radio frequency signal.

3. The RF front-end module according to claim 1, characterized in that, The frequency band of the harmonic of the first radio frequency signal does not overlap with the frequency band of the second radio frequency signal.

4. The RF front-end module according to any one of claims 1-3, characterized in that It further includes a grounding circuit, and the grounding circuit is coupled to the second radio frequency terminal.

5. The radio frequency front-end module according to claim 4, wherein The grounding circuit is configured to transmit the first radio frequency signal to the ground by grounding the second radio frequency terminal when the first radio frequency signal is transmitted to the second radio frequency terminal.

6. A radio frequency transceiver device, characterized in that, It includes a modem, a radio frequency chip, an antenna, and the radio frequency front-end module according to any one of claims 1-5 above; wherein, the modem is sequentially connected to the antenna through the radio frequency chip and the radio frequency front-end module.

7. An electronic device, characterized in that, It includes a processor and the radio frequency transceiver device according to claim 6 above, and the processor is coupled to the radio frequency transceiver device.

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