Radio frequency front-end circuit for wireless local area network

Abstract

The invention provides a radio frequency front-end circuit for a wireless local area network. The radio frequency front-end circuit is provided with a multi-way switch, an output end and a shunt circuit. The multi-way switch is provided with an input end, a plurality of output ends and a control end. The input is coupled to the antenna for receiving a radio frequency signal from the antenna. The control end is used for coupling the input end to one of the output ends according to a switch control signal. The shunt circuit is coupled between the multi-way switch and the output end and provides a shunt path according to the switch control signal. The shunt paths correspond to varying degrees of suppression of the radio frequency signal.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a low insertion loss adaptive radio frequency (RF) front-end circuit for a wireless local area network. Background Art

[0002] The background description provided herein is intended to generally present the context of the present disclosure. The work of the presently named inventors is neither expressly nor implied to be prior art to the present invention to the extent described in this background section nor to the extent that it may not qualify as prior art at the time of filing.

[0003] In the modern era, the proliferation of wireless devices such as smartphones, laptops, and Internet of Things (IoT) devices has led to significant integration of various radio protocols including cellular, Wi-Fi, Bluetooth Low Energy (BLE), etc. This tight integration presents a significant challenge: enabling multiple radios to operate simultaneously without interfering with each other, especially when they are physically close within a device or occupy close channels in the spectrum. This phenomenon is known as wireless coexistence.

[0004] In radio frequency (RF) front-end architectures, the RF filter, usually a band-pass filter (BPF), plays a key role. It filters out strong out-of-band interferers, called interference bands, and prevents them from saturating the receiver. This is especially important for bands that are close in frequency to the desired band, called victim bands.

[0005] Figure 1The spectrum of two victim bands Bv1 and Bv2 and three interference bands Ba1-Ba3 used in a wireless device with Wi-Fi function is shown. The wireless device may have two Wi-Fi modules. One of the two Wi-Fi modules uses the victim band Bv1 to transmit and receive data and signals, and has a bandpass filter band BPF1 to filter out interference bands Ba1 and Ba2. The other Wi-Fi module uses the victim band Bv2 to transmit and receive data and signals, and has another bandpass filter band BPF2 to filter out interference band Ba3. Interference bands Ba1-Ba3 are used by one or more cellular modules (e.g., fourth generation (4G) and / or fifth generation (5G) wireless modules) of the wireless device to transmit and receive data and signals. The interference band Ba1 may include the N40 band defined in the Long Term Evolution (LTE) band, the interference band Ba2 may include the B41 and B7 bands defined in the LTE band, and the interference band Ba3 may include the N77, N78 and N79 bands defined in the 5G New Radio (5G NR) band. The frequency range of the victim band Bv1 may be between 2402MHz and 2482MHz, and the frequency range of the victim band Bv2 may be between 5150MHz and 7152MHz. The bandpass filters BPF1 and BPF2 cover the victim band Bv1 and the victim band Bv2, respectively. The frequency range of the interference band Ba1 may be between 2300MHz and 2400MHz, the frequency range of the interference band Ba2 may be between 2496MHz and 2690MHz, and the frequency range of the interference band Ba3 may be between 3300MHz and 5000MHz.

[0006] In wireless local area network (WLAN) (e.g., Wi-Fi) systems, both the transmitter (TX) and the receiver (RX) can utilize RF filters to eliminate unwanted interference bands, such as Ba1-Ba3. However, it is usually difficult to remove interference bands that are close to the victim bands (e.g., Bv1 or Bv2) in the spectrum. Therefore, the RF filters in WLAN systems are designed with a high quality factor (Q) to significantly suppress these close interferences.

[0007] As the Q of an RF filter increases, the filter's selectivity curve becomes narrower, providing higher rejection of nearby interference bands. However, this improvement comes with a trade-off: relatively high in-band insertion loss. While high-Q filters allow wireless systems to operate with significantly less interference, large amounts of insertion loss reduce the power of the transmitter's desired signal by reducing the overall front-end gain. It also impairs the receiver's sensitivity by attenuating the level of the received signal.

[0008] The design of the RF front end requires a high-Q filter with significant rejection to eliminate nearby interference bands. However, for common coexistence scenarios where the interference band is not close to the victim band in the spectrum, the high insertion loss introduced is undesirable. For example, in the case of B34 (i.e. 2010-2025MHz), it is indeed far away from the victim band Bv1. The separation frequency of about 400MHz between B34 and Bv1 usually results in high isolation, eliminating the need for a bandpass filter (BPF) to provide additional rejection. The high insertion loss of the BPF only degrades the performance of the wireless system. In addition, traditional front-end architectures usually have fixed filter positions to cope with all coexistence scenarios, regardless of whether the interference band is close to the victim band. In most cases, the interference band is not necessarily close to the victim band and high filter rejection is not required. In these cases, high-Q filters are redundant and result in additional insertion loss (1dB to 3.8dB), which degrades the performance of the transmitter and receiver. For example, at one point, the wireless device uses the victim band Bv1 and the interference band Ba3, but does not use the victim band Bv2 and the interference bands Ba1 and Ba2. Since the interference band Ba3 is far from the victim band Bv1, two bandpass filters with BPF1 and BPF2 are not required. In this case, if the bandpass filter with BPF1 is used, the victim band Bv1 will be suppressed. Therefore, the insertion loss of the RF front end of the wireless device increases and the power of the desired signal in the victim band Bv1 decreases.

[0009] Additionally, traditional WLAN radio frequency (RF) front-end designs place filters in fixed locations. Figure 2 1 is a block diagram of a transceiver of a prior art WLAN (e.g., Wi-Fi) device. The transceiver includes an antenna 10, an RF front-end circuit 14, two bandpass filters 12 and 16, four impedance matching circuits 11, 13, 15, and 17, and a Wi-Fi radio frequency integrated circuit (Wi-Fi RFIC) 40. The Wi-Fi RFIC 40 is used to process the RF signal received from the antenna 10. The bandpass filters 12 and 16 are fixed at positions P1 and P2, respectively. Two impedance matching circuits 11 and 13 are used for the bandpass filter 12 to match the impedance of the antenna 10 and the RF front-end circuit 14, and the other two impedance matching circuits 15 and 17 are used for the bandpass filter 16 to match the impedance of the RF front-end circuit 14 and the Wi-Fi RFIC 40. When the RF signal received from the antenna 10 is transmitted to the Wi-Fi RFIC 40, the received RF signal must pass through the two bandpass filters 12 and 16. Therefore, even when the transceiver is in a common coexistence scenario (eg, the interfering band is not close to the victim band in the spectrum), the received RF signal may experience insertion loss.

[0010] In some conventional WLAN RF front-end designs, the transceiver may have only one bandpass filter fixed at position P1 or P2. In this case, the transceiver also requires three impedance matching circuits. Specifically, if the bandpass filter is fixed at position P1, two impedance matching circuits 11 and 13 and an additional impedance matching circuit located between the RF front-end circuit 14 and the Wi-Fi RFIC 40 are required. If the bandpass filter is fixed at position P2, two impedance matching circuits 15 and 16 and an additional impedance matching circuit located between the RF front-end circuit 14 and the antenna 10 are required. Summary of the invention

[0011] In one embodiment of the present invention, a radio frequency (RF) front-end circuit is disclosed. The RF front-end circuit includes a multi-way switch, an output terminal and a shunt circuit. The multi-way switch includes an input terminal, multiple output terminals and a control terminal. The input terminal is connected to an antenna and configured to receive a radio frequency signal from the antenna. The control terminal is configured to connect the input terminal to one of the multiple output terminals according to a switch control signal. The shunt circuit is connected between the multi-way switch and the output terminal. When the input terminal of the multi-way switch is connected to a first output terminal among the multiple output terminals of the multi-way switch, the shunt circuit provides a first shunt path with a first suppression of the radio frequency signal between the first output terminal and the output terminal. When the input terminal of the multi-way switch is connected to a second output terminal among the multiple output terminals of the multi-way switch, the shunt circuit provides a second shunt path with a second suppression of the radio frequency signal between the second output terminal and the output terminal. The second suppression is greater than the first suppression. When the input terminal of the multi-way switch is connected to a third output terminal of the plurality of output terminals of the multi-way switch, the shunt circuit provides a third shunt path with a third suppression of the radio frequency signal between the third output terminal and the output terminal, the third suppression being greater than the second suppression.

[0012] These and other objects of the present invention will become apparent to those of ordinary skill in the art after reading the following detailed description of the preferred embodiments taken in conjunction with the figures and illustrations. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The spectra of two victim frequency bands and three interference frequency bands in a wireless device with Wi-Fi capabilities are shown.

[0014] Figure 2 is a block diagram of a transceiver of a prior art WLAN device.

[0015] Figure 3is a schematic diagram of a wireless transceiver having a radio frequency (RF) front end circuit constructed according to one embodiment of the present invention.

[0016] Figure 4 , Figure 5 , Figure 6 , Figure 7 1 is a schematic diagram of a wireless transceiver having an RF front-end circuit 100 according to various embodiments of the present invention. DETAILED DESCRIPTION

[0017] In the following detailed description, reference is made to the accompanying drawings, which show by way of example specific embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention, although different, are not necessarily mutually exclusive. For example, a particular feature, structure, or characteristic described herein in one embodiment may be implemented in other embodiments without departing from the spirit and scope of the present invention. In addition, it should be understood that the position or arrangement of the various elements in each disclosed embodiment may be modified without departing from the scope of the present invention. Therefore, the following detailed description should not be considered restrictive, and the scope of the present invention is defined solely by the appended claims and their proper interpretation, and includes all equivalent ranges that the claims should enjoy. In the accompanying drawings, the same numbers refer to the same or similar functions in multiple views.

[0018] The present invention provides various radio frequency (RF) front-end circuits in different embodiments. For a comprehensive understanding of the present invention, it is assumed that a wireless device integrates any RF front-end circuit of the present invention and uses Figure 1 Two victim bands Bv1 and Bv2 and three interference bands Ba1-Ba3 are shown. The coexistence scenarios of wireless devices using these bands can be divided into critical and non-critical scenarios. Critical scenarios include two specific situations, while all other situations are considered non-critical. The first critical scenario occurs when the wireless device uses the victim band Bv1 and at least one interference band Ba1 and Ba2. The second critical scenario occurs when the wireless device uses the victim band Bv2 and at least one interference band whose frequency is close to the victim band Bv2 (for example, the interference band Ba3). These two scenarios are considered critical because the frequency offsets between the victim band Bv1 and the interference bands Ba1 and Ba2, and between the victim band Bv2 and the interference band Ba3 are small. These two critical scenarios and non-critical scenarios will be used in the subsequent description.

[0019] Figure 31 is a schematic diagram of a wireless transceiver having a radio frequency (RF) front-end circuit 100 constructed according to an embodiment of the present invention. The wireless transceiver can be integrated in a wireless device, and includes an antenna 10, an impedance matching circuit 20, an RF front-end circuit 100, an impedance matching circuit 30, and a Wi-Fi radio frequency integrated circuit (Wi-Fi RFIC) 40. The Wi-Fi RFIC 40 is configured to process an RF signal (e.g., RF signal RF1) received from the antenna 10, and is configured to send a signal to the antenna 10 through the impedance matching circuit 30, the RF front-end circuit 100, and the impedance matching circuit 20. The impedance matching circuit 20 is used to match the impedance of the RF front-end circuit 100 with the antenna 10, and the impedance matching circuit 30 is used to match the impedance of the RF front-end circuit 100 with the Wi-Fi RFIC 40. The RF front-end circuit 100 includes a multi-way switch 110, an output terminal OT, and a shunt circuit 120. In this embodiment, the multi-way switch 110 is a three-way switch (i.e., SP3T), including an input terminal IN, three output terminals O1 to O3, and a control terminal SC. The input terminal IN is connected to the antenna 10 and is configured to receive an RF signal (e.g., RF signal RF1) from the antenna 10. The control terminal SC is configured to connect the input terminal IN to one of the output terminals O1 to O3 according to a switch control signal Sw. The switch control signal Sw can be generated by a wireless device (e.g., a smartphone, a laptop, an IoT device, etc.) in which the RF front-end circuit 100 is integrated.

[0020] The shunt circuit 120 is connected between the multi-way switch 110 and the output terminal OT. When the input terminal IN of the multi-way switch 110 is connected to the output terminal O1, the shunt circuit 120 provides a first shunt path 121 with a first suppression of the RF signal RF1 between the output terminal O1 and the output terminal OT. When the input terminal IN of the multi-way switch 110 is connected to the output terminal O2, the shunt circuit 120 provides a second shunt path 122 with a second suppression of the RF signal RF1 between the output terminal O2 and the output terminal OT. The second suppression is greater than the first suppression. In other words, if the first shunt path 121 introduces a first insertion loss of the RF signal RF1 and the second shunt path 122 introduces a second insertion loss of the RF signal RF1, the second insertion loss is greater than the first insertion loss. The power lost by the RF signal RF1 when passing through the second shunt path 122 is greater than the power lost by the RF signal RF1 when passing through the first shunt path 121.

[0021] When the input terminal IN of the multi-way switch 110 is connected to the output terminal O3, the shunt circuit 120 provides a third shunt path 123 with a third suppression of the RF signal RF1 between the output terminal O3 and the output terminal OT. The third suppression is greater than the second suppression. In other words, if the third shunt path 123 introduces a third insertion loss of the RF signal RF1, and the second shunt path 122 introduces a second insertion loss of the RF signal RF1, the third insertion loss is greater than the second insertion loss. The power lost by the RF signal RF1 when passing through the third shunt path 123 is greater than the power lost by the RF signal RF1 when passing through the second shunt path 122.

[0022] The first shunt path 121 can be used as a bypass path, so that the first suppression is extremely low (ie, almost zero). Therefore, the first shunt path 121 is suitable for non-critical scenarios. In contrast, the second shunt path 122 and the third shunt path 123 are suitable for critical scenarios.

[0023] Figure 4 1 is a schematic diagram of a wireless transceiver having an RF front-end circuit 100 according to another embodiment of the present invention. In this embodiment, the shunt circuit 120 includes a line 131, a switch SW1, a common bandpass filter 142, a line 132, a switch SW2, and a low noise amplifier (LNA) 150. The line 131 is formed on the first shunt path 121 and is used when the input terminal IN is connected to the output terminal O1. The common bandpass filter 142 is connected between the line 132 and the switch SW1. The line 132 is connected between the output terminal O2 and the common bandpass filter 142. The input terminal of the LNA 150 is connected to the output terminal O3, and the output terminal of the LNA 150 is connected to the switch SW2. When the input terminal IN is connected to the output terminal O2, the switch SW1 is turned on and the switch SW2 is turned off, so that the line 132, the common bandpass filter 142, and the switch SW1 form a second shunt path 122. When the input terminal IN is connected to the output terminal O3, both switches SW1 and SW2 are opened, so that LNA150, switch SW2, shared bandpass filter 142 and switch SW1 form a third shunt path 123. In short, in this embodiment, the first shunt path 121 (i.e., trace 131) is a bypass path. Trace 132, shared bandpass filter 142 and switch SW1 are formed on the second shunt path 122. LNA150, switch SW2, shared bandpass filter 142 and switch SW1 are formed on the third shunt path 123. In this embodiment, the first shunt path 121 is a bypass path with low insertion loss, which is suitable for non-critical scenarios. The second shunt path 122 is suitable for critical scenarios when the wireless transceiver is in transmit mode. The third shunt path 123 is suitable for critical scenarios when the wireless transceiver is in receive mode. The gain of LNA 150 can overcome the filter loss.

[0024] Figure 5 1 is a schematic diagram of a wireless transceiver having an RF front-end circuit 100 according to another embodiment of the present invention. In this embodiment, the shunt circuit 120 includes a line 131, a switch SW1, a first bandpass filter 144, a line 132, a switch SW2, a second bandpass filter 146 and a low noise amplifier (LNA) 150. The line 131 is formed on the first shunt path 121 and is used when the input terminal IN is connected to the output terminal O1. The first bandpass filter 144 is connected between the line 132 and the switch SW1. The second bandpass filter 146 is connected between the LNA 150 and the switch SW2. The input terminal of the LNA 150 is connected to the output terminal O3, and the output terminal of the LNA 150 is connected to the second bandpass filter 146. When the input terminal IN is connected to the output terminal O2, the switch SW1 is turned on and the switch SW2 is turned off, so that the line 132, the first bandpass filter 144 and the switch SW1 form the second shunt path 122. When the input terminal IN is connected to the output terminal O3, the switch SW2 is turned on and the switch SW1 is turned off, so that the LNA 150, the second bandpass filter 146 and the switch SW2 form a third shunt path 123. In short, in this embodiment, the first shunt path 121 (i.e., the wiring 131) is a bypass path. The wiring 132, the first bandpass filter 144 and the switch SW1 are formed on the second shunt path 122. The LNA 150, the second bandpass filter 146 and the switch SW2 are formed on the third shunt path 123. The first shunt path 121 is a bypass path with low insertion loss and is suitable for non-critical scenarios. The second shunt path 122 is suitable for critical scenarios when the wireless transceiver is in the transmit mode. The third shunt path 123 is suitable for critical scenarios when the wireless transceiver is in the receive mode. The gain of the LNA 150 can overcome the filter loss.

[0025] Figure 61 is a schematic diagram of a wireless transceiver having an RF front-end circuit 100 according to another embodiment of the present invention. In this embodiment, the shunt circuit 120 includes a line 131, a bandpass filter 148, a switch SW3, a switch SW1, a common bandpass filter 142, a line 132, a switch SW2, and a low noise amplifier (LNA) 150. The bandpass filter 148 is connected between the output terminal O1 and the output terminal OT through the line 131 and the switch SW3. The common bandpass filter 142 is connected between the line 132 and the switch SW1. The line 132 is connected between the output terminal O2 and the common bandpass filter 142. The input terminal of the LNA 150 is connected to the output terminal O3, and the output terminal of the LNA 150 is connected to the switch SW2. When the input terminal IN is connected to the output terminal O1, the switch SW3 is turned on, and the switches SW1 and SW2 are turned off, so that the line 131, the bandpass filter 148, and the switch SW3 form a first shunt path 121. When the input terminal IN is connected to the output terminal O2, the switch SW1 is turned on, and the switches SW2 and SW3 are turned off, so that the wiring 132, the shared bandpass filter 142 and the switch SW1 form the second shunt path 122. When the input terminal IN is connected to the output terminal O3, the switches SW1 and SW2 are turned on, and the switch SW3 is turned off, so that the LNA 150, the switch SW2, the shared bandpass filter 142 and the switch SW1 form the third shunt path 123. In short, in this embodiment, the wiring 131, the bandpass filter 148 and the switch SW3 are formed on the first shunt path 121. The wiring 132, the shared bandpass filter 142 and the switch SW1 are formed on the second shunt path 122. The LNA 150, the switch SW2, the shared bandpass filter 142 and the switch SW1 are formed on the third shunt path 123. The bandpass filter 148 may be a low Q filter, and the bandpass filter 142 may be a high Q filter. The first shunt path 121 is suitable for non-critical scenarios. The second shunt path 122 is applicable to the critical scenario when the wireless transceiver is in the transmit mode. The third shunt path 123 is applicable to the critical scenario when the wireless transceiver is in the receive mode. The gain of the LNA 150 can overcome the loss of the filter.

[0026] Figure 71 is a schematic diagram of a wireless transceiver having an RF front-end circuit 100 according to another embodiment of the present invention. In this embodiment, the multi-way switch 110 is a four-way switch (i.e., SP4T), including an input terminal IN, four output terminals O1 to O4, and a control terminal SC. The input terminal IN is connected to the antenna 10 and is configured to receive an RF signal (e.g., RF signal RF1) from the antenna 10. The control terminal SC is configured to connect the input terminal IN to one of the output terminals O1 to O4 according to a switch control signal Sw. The switch control signal Sw can be generated by a wireless device in which the RF front-end circuit 100 is integrated. The shunt circuit 120 includes a trace 131, a switch SW3, a bandpass filter 148, a trace 134, a switch SW1, a common bandpass filter 142, a trace 132, a switch SW2, and a low noise amplifier (LNA) 150. The trace 131 is connected between the output terminal O1 and the output terminal OT. The bandpass filter 148 is connected between the output terminal O4 and the output terminal OT through the wiring 134 and the switch SW3. The shared bandpass filter 142 is connected between the wiring 132 and the switch SW1. The wiring 132 is connected between the output terminal O2 and the shared bandpass filter 142. The input terminal of the LNA 150 is connected to the output terminal O3, and the output terminal of the LNA 150 is connected to the switch SW2. When the input terminal IN is connected to the output terminal O1, the switches SW1, SW2 and SW3 are closed, so that the wiring 131 serves as the first shunt path 121 (i.e., the bypass path). When the input terminal IN is connected to the output terminal O2, the switch SW1 is opened, and the switches SW2 and SW3 are closed, so that the wiring 132, the shared bandpass filter 142 and the switch SW1 form the second shunt path 122. When the input terminal IN is connected to the output terminal O3, the switches SW1 and SW2 are opened, and the switch SW3 is closed, so that the LNA 150, the switch SW2, the shared bandpass filter 142, and the switch SW1 form a third shunt path 123. When the input terminal IN is connected to the output terminal O4, the switches SW1 and SW2 are closed, and the switch SW3 is opened, so that the trace 134, the bandpass filter 148, and the switch SW3 form a fourth shunt path of the shunt circuit 120. The shared bandpass filter 142 has a first Q factor and has a fourth rejection of the RF signal RF1. The bandpass filter 148 has a second Q factor and has a fifth rejection of the RF signal RF1. In one embodiment, the second Q factor is less than the first Q factor. In another embodiment, the second Q factor is greater than the first Q factor. In one embodiment, the fourth rejection is less than the fifth rejection. In another embodiment, the fourth rejection is greater than the fifth rejection.

[0027] In summary, the present invention proposes an adaptive radio frequency (RF) front-end design suitable for wireless local area network (WLAN) systems. The design integrates the RF filter with the RF front-end circuit, providing a joint RF switching capability for different coexistence scenarios. With this adaptive switching strategy, a path through the filter can be selected in critical scenarios, while a bypass path can be selected in non-critical scenarios to reduce insertion loss. The proposed method also reduces cost and design complexity, making it a more efficient solution.

[0028] It should be understood that the terms "first", "second", "third", "fourth", etc. used in the claims and description are intended to identify and distinguish elements with the same basic name. These terms are not intended to indicate a specific order or physical orientation of the elements. Likewise, these terms are not intended to indicate a specific temporal relationship between the elements. In the claims, these terms are generally assigned in the order in which the elements are introduced, which may be different from the order assigned in the description.

[0029] Certain terms are used throughout the description and claims to refer to particular elements. As will be appreciated by those skilled in the art, electronic device manufacturers may refer to an element by different names. This document does not intend to distinguish between elements that differ in name but function. In the following description and claims, the terms "including," "comprising," and "having" are used in an open-ended manner and thus should be interpreted to mean "including but not limited to."

[0030] Directional terms such as up, down, left, right, front or back used in the following embodiments refer only to directions in the drawings. Therefore, the directional terms used in the present disclosure are for illustration only and are not intended to limit the scope of the present disclosure. It should be noted that specifically described or labeled elements may exist in various forms to the skilled person. In addition, when a layer is referred to as "on" another layer or substrate, it can be directly on the other layer or substrate, it can also be on the other layer or substrate, or include an intermediate layer between the other layers or substrates.

[0031] In addition, relative terms such as "lower" or "bottom", and "upper" or "top", "above" or "below" may be used in the embodiments to describe the relative relationship of one element labeled in the figures relative to another element. It should be understood that if the labeled device is turned upside down, the element on the "lower" side may be the element on the "upper" side.

[0032] Approximate terms such as "approximately" and "substantially" are descriptive terms used to avoid strict numerical boundaries for a specified parameter and are generally interpreted as being within a given value or range.

[0033] In the above detailed description, various inventive features are grouped together in one or more embodiments to simplify the disclosure. This disclosure method should not be interpreted as reflecting that the claimed invention requires more features than are expressly recited in each claim. On the contrary, as reflected in the claims, the novelty of the invention may lie in a portion of all features of each disclosed embodiment.

[0034] It will be readily apparent to a skilled artisan that many modifications and variations of the apparatus and methods can be made while retaining the teachings of the present invention. Therefore, the above disclosure should be limited only by the scope of the appended claims.

Claims

1. A radio frequency front-end circuit for a wireless local area network, comprising: A multi-way switch, comprising: an input terminal connected to an antenna and configured to receive a radio frequency signal from the antenna; multiple outputs; and a control terminal configured to connect the input terminal to one of the plurality of output terminals according to a switch control signal; and an output terminal; and a shunt circuit connected between the multi-way switch and the output terminal; wherein, when the input end of the multi-way switch is connected to a first output end of the plurality of output ends of the multi-way switch, the shunt circuit provides a first shunt path with a first suppression of the radio frequency signal between the first output end and the output terminal; wherein, when the input end of the multi-way switch is connected to a second output end of the plurality of output ends of the multi-way switch, the shunt circuit provides a second shunt path with a second suppression of the radio frequency signal between the second output end and the output terminal, and the second suppression is greater than the first suppression; and Wherein, when the input end of the multi-way switch is connected to the third output end among the multiple output ends of the multi-way switch, the shunt circuit provides a third shunt path with a third suppression of the radio frequency signal between the third output end and the output terminal, and the third suppression is greater than the second suppression.

2. The RF front-end circuit according to claim 1, wherein the shunt circuit comprises: a common bandpass filter having a first end connected to the output terminal; a trace connected between the second output terminal and the second terminal of the common bandpass filter; as well as A low noise amplifier is connected between the third output terminal and the second terminal of the common band pass filter.

3. The RF front-end circuit according to claim 2, wherein the shunt circuit further comprises: a first switch connected between the common bandpass filter and the output terminal; as well as A second switch is connected between the low noise amplifier and the common band pass filter.

4. The RF front-end circuit as described in claim 2, wherein the first shunt path is a bypass path, the routing and the shared bandpass filter are formed on the second shunt path, and the low noise amplifier and the shared bandpass filter are formed on the third shunt path.

5. The RF front-end circuit according to claim 2, wherein the shunt circuit further comprises: A bandpass filter is connected between the fourth output terminal of the multi-channel and the output terminal. 6 . The RF front-end circuit of claim 5 , wherein the common bandpass filter has a first Q factor, and the bandpass filter has a second Q factor that is smaller than the first Q factor. 7 . The RF front-end circuit of claim 5 , wherein the shared bandpass filter has a first Q factor, and the bandpass filter has a second Q factor greater than the first Q factor.

8. The RF front-end circuit as claimed in claim 5, wherein the common bandpass filter has a fourth suppression on the RF signal, the bandpass filter has a fifth suppression on the RF signal, and the fourth suppression is smaller than the fifth suppression.

9. The RF front-end circuit as claimed in claim 5, wherein the common bandpass filter has a fourth suppression on the RF signal, the bandpass filter has a fifth suppression on the RF signal, and the fourth suppression is greater than the fifth suppression.

10. The RF front-end circuit according to claim 5, wherein the shunt circuit further comprises: a first switch connected between the common bandpass filter and the output terminal; a second switch connected between the low noise amplifier and the common band pass filter; as well as A third switch is connected between the bandpass filter and the output terminal.

11. The RF front-end circuit of claim 10, wherein the first shunt path is a bypass path, the routing line and the shared bandpass filter are formed on the second shunt path, and the low noise amplifier and the shared bandpass filter are formed on the third shunt path.

12. The radio frequency front-end circuit according to claim 1, wherein the shunt circuit comprises: a first bandpass filter connected between the second output end and the output terminal; a low noise amplifier having an input terminal connected to the third output terminal; as well as A second bandpass filter is connected between the output end of the low noise amplifier and the output terminal.

13. The RF front-end circuit according to claim 12, wherein the shunt circuit further comprises: a first switch connected between the first bandpass filter and the output terminal; as well as A second switch is connected between the second bandpass filter and the output terminal.

14. The RF front-end circuit of claim 12, wherein the first shunt path is a bypass path, the first bandpass filter is formed on the second shunt path, and the low noise amplifier and the second bandpass filter are formed on the third shunt path.

15. The radio frequency front-end circuit according to claim 1, wherein the shunt circuit comprises: a bandpass filter connected between the first output terminal and the output terminal; a common bandpass filter having a first end connected to the output terminal; a trace connected between the second output terminal and the second terminal of the common bandpass filter; A low noise amplifier is connected between the third output terminal and the second terminal of the common band pass filter.

16. The RF front-end circuit according to claim 15, wherein the shunt circuit further comprises: a first switch connected between the common bandpass filter and the output terminal; a second switch connected between the low noise amplifier and the common bandpass filter; A third switch is connected between the bandpass filter and the output terminal.

17. The RF front-end circuit of claim 15, wherein the bandpass filter is arranged on the first shunt path, the routing line and the shared bandpass filter are arranged on the second shunt path, and the low noise amplifier and the shared bandpass filter are arranged on the third shunt path.

18. The RF front-end circuit of claim 1, wherein the first shunt path is a bypass path.

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