Transmit-receive matching network and radio frequency front-end circuit, chip

Abstract

The application discloses a kind of transceiving matching network and radio frequency front-end circuit, chip, the transceiving matching network includes: the output matching network of transmission end, the coupled resonant switch network of receiving end and first transmission line are connected in turn;The output matching network of transmission end is used for transmission end impedance matching and provides first resonance point in receiving mode;The coupled resonant switch network of receiving end is used for receiving end impedance matching, switches transceiving mode;The first transmission line is used to provide second resonance point in receiving mode.The application embodiment effectively improves the linear output power and efficiency of front end transmission by removing the switch of transmission branch, while using coupled resonant switch structure in receiving branch to ensure that receiving has wideband, low insertion loss characteristics, and comprehensively improves the radio frequency transceiving performance of radio frequency front end.The application embodiment can be widely applied in the field of wireless communication technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication, and in particular to a transceiving matching network and a radio frequency front-end circuit and a chip. BACKGROUND

[0002] Radio frequency front-end (RF FE) is one of the key devices in a wireless communication transceiver, and its performance has a significant impact on the information transmission of the entire communication system. The radio frequency front-end in a phased array radar communication system and a time division duplex (TDD) communication system is usually composed of a power amplifier (PA), a low noise amplifier (LNA), and a transceiving switch (TR SW), wherein the TR SW connects the PA and the LNA and can multiplex an antenna (ANT), which can effectively reduce the number of system antennas. The traditional radio frequency front-end circuit architecture switches the signal path by a switch working in different modes to achieve the purpose of system transceiving signals. Therefore, to ensure that the signal has low leakage, the transceiving switch needs to have sufficient isolation to reduce the impact on the performance of the front-end transceiver.

[0003] In the related art, the insertion loss of the symmetrical switch in the radio frequency front-end architecture is high, which leads to a decrease in the output power and efficiency of the transmitting end PA and reduces the energy efficiency of the transceiver system. The radio frequency front-end integrated with an asymmetric switch considers that the signal power is small in the TDD receiving mode, and even if the isolation of the transmitting branch of the switch is low, the power of the signal leaked to the PA is not enough to damage the active device, so the transmitting branch isolation can be reduced to obtain higher transmitting end matching freedom, reduce the loss of the transmitting end matching network and the switch, and thus improve the output power and efficiency of the transmitting end PA. The asymmetric transceiving switch structure in the related art realizes high-quality radio frequency transceiving performance. However, the improvement of the asymmetric transceiving switch structure on the performance of the front-end is still limited, and it is difficult to ensure the bandwidth and low insertion loss performance of the transmitting branch while realizing the wideband and low insertion loss characteristics of the receiving switch in the performance compromise. Therefore, the switch structure in the related art leads to poor bandwidth and low insertion loss performance of the transmitting branch, which affects the transceiving performance of the radio frequency front-end. SUMMARY

[0004] In view of the problem of RF performance deterioration caused by the transmit-receive switch and matching network of the traditional RF front end, the embodiments of the present application propose a high-performance transmit-receive matching network and RF front-end circuit and chip, which effectively improves the front-end transmit linear output power and efficiency by removing the switch of the transmit branch, and at the same time, guarantees the receiving to have the characteristics of wideband and low insertion loss by using the coupled resonant switch structure in the receive branch, thereby comprehensively improving the RF transmit-receive performance of the RF front end.

[0005] To achieve the above-mentioned purpose, one aspect of the embodiments of the present application proposes a transmit-receive matching network, comprising: a transmit-end output matching network, a receive-end coupled resonant switch network and a first transmission line connected in sequence; the transmit-end output matching network is used for transmit-end impedance matching and provides a first resonance point in the receive mode; the receive-end coupled resonant switch network is used for receive-end impedance matching and switches the transmit-receive mode; and the first transmission line is used for providing a second resonance point in the receive mode. The embodiments of the present application effectively improve the front-end transmit linear output power and efficiency by removing the switch of the transmit branch, and at the same time, guarantee the receiving to have the characteristics of wideband and low insertion loss by using the coupled resonant switch structure in the receive branch, thereby comprehensively improving the RF transmit-receive performance of the RF front end.

[0006] In some embodiments, the transmit-receive matching network provided by the embodiments of the present application, the receive-end coupled resonant switch network comprises a resonance unit and a coupling unit; the number of the resonance unit is greater than or equal to 1, and the number of the coupling unit is greater than or equal to 2.

[0007] In some embodiments, the transmit-receive matching network provided by the embodiments of the present application, the receive-end coupled resonant switch network comprises a first resonance unit, a second resonance unit, a first coupling unit, a second coupling unit and a third coupling unit;

[0008] One end of the first coupling unit is connected to the low-noise amplifier, the other end of the first coupling unit is connected to one end of the second coupling unit through the first resonance unit, the other end of the second coupling unit is connected to one end of the third coupling unit through the second resonance unit, and the other end of the third coupling unit is connected to the antenna.

[0009] In some embodiments, the transmit-receive matching network provided by the embodiments of the present application, the first resonance unit comprises a second transmission line and a first switch;

[0010] One end of the second transmission line is grounded, the other end of the second transmission line is connected to the other end of the first coupling unit, and the other end of the second transmission line is also connected to one end of the second coupling unit; one end of the first switch is grounded, the other end of the first switch is connected to the other end of the first coupling unit, and the other end of the first switch is also connected to one end of the second coupling unit;

[0011] The first switch is configured to, in the off state, the radio frequency front-end circuit works in a receiving mode, the first switch and the second transmission line provide a third resonance point in the receiving mode.

[0012] In some embodiments, the transceiver matching network provided by the embodiments of the present application, the transmit end output matching network includes a fourth transmission line, a fifth transmission line, a sixth transmission line and a first capacitor:

[0013] One end of the fourth transmission line is connected to the power amplifier, one end of the fifth transmission line is grounded, and one end of the sixth transmission line is connected to the antenna; the other end of the fourth transmission line, the other end of the fifth transmission line and the other end of the sixth transmission line are connected to a first connection point; one end of the sixth transmission line is also grounded through the first capacitor.

[0014] In some embodiments, the transceiver matching network provided by the embodiments of the present application, the receiving end coupling resonance switch network includes a third resonance unit, a second capacitor and an inductor;

[0015] One end of the second capacitor is connected to the low noise amplifier, the other end of the second capacitor is connected to one end of the inductor through the third resonance unit, and the other end of the inductor is connected to the antenna.

[0016] In some embodiments, the transceiver matching network provided by the embodiments of the present application, the first coupling unit includes a seventh transmission line, the second coupling unit includes an eighth transmission line, and the third coupling unit includes a ninth transmission line.

[0017] In some embodiments, the transceiver matching network provided by the embodiments of the present application, the low noise amplifier includes a bias circuit, and the bias circuit includes the first transmission line.

[0018] To achieve the above-mentioned purpose, another aspect of the embodiments of the present application provides a radio frequency front-end circuit, including the above-mentioned transceiver matching network, the radio frequency front-end circuit further includes a power amplifier and a low noise amplifier, the power amplifier is connected to the antenna through the transceiver matching network, and the low noise amplifier is connected to the antenna through the transceiver matching network.

[0019] To achieve the above-mentioned purpose, another aspect of the embodiments of the present application provides a chip, including the above-mentioned radio frequency front-end circuit.

[0020] The embodiments of the present application at least have the following beneficial effects: first, compared with the traditional radio frequency front end, the transceiver matching network fusing the switch removes the switch of the transmitting branch, the linear output power and the efficiency of the transmitting end are improved, at the same time, the transmitting end matching network provides a resonance point in the receiving mode, and the multiplexing of the matching network can be realized. Second, compared with the existing radio frequency front end with the transmitting branch removing the switch, the transceiver matching network fusing the switch utilizes the resonant unit containing the transistor switch, connects through the coupling unit, constitutes a high-order band-pass filter structure, can realize the receiving characteristics of wide band and low noise, and ensures that the transmitting end characteristics remain unchanged. Finally, compared with the prior art, the transceiver matching network fusing the switch does not increase the area, and has high design freedom. Therefore, the transceiver matching network fusing the switch and the radio frequency front end circuit scheme provided by the present application have good application potential and prospect in the time division duplex communication system and the phased array radar system. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is an equivalent electrical schematic diagram of the transmitting mode of the embodiment one provided by the present application;

[0022] Figure 2 is an equivalent electrical schematic diagram of the transmitting mode of the embodiment one provided by the present application;

[0023] Figure 3 is an equivalent electrical schematic diagram of the receiving mode of the embodiment one provided by the present application;

[0024] Figure 4 is an equivalent electrical schematic diagram of the transmitting mode of the embodiment one provided by the present application;

[0025] Figure 5 is an equivalent electrical schematic diagram of the transmitting mode of the embodiment one provided by the present application;

[0026] Figure 6 is an equivalent electrical schematic diagram of the transmitting mode of the embodiment one provided by the present application;

[0027] Figure 7 is an equivalent electrical schematic diagram of the transmitting mode of the embodiment one provided by the present application; DETAILED DESCRIPTION

[0028] For the purpose of making the objects, technical solutions and advantages of the present application clearer, 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 not intended to limit the present application. When the following description refers to the accompanying drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with embodiments of the present application. They are merely examples of apparatuses and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0029] It can be understood that the terms "first", "second" and the like used in the present application can be used herein to describe various concepts, but unless specifically stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another concept. For example, without departing from the scope of the embodiments of the present application, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information. Depending on the context, the word "if" as used herein can be interpreted as "when" or "upon" or "in response to determining".

[0030] The terms "at least one", "multiple", "each", "any" and the like used in the present application include one, two or more than two, multiple includes two or more than two, each refers to each of the corresponding multiple, and any refers to any one of the multiple.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0032] The radio frequency front-end (RF FE) is one of the key devices in the wireless communication transceiver, and its performance has a significant impact on the information transmission of the entire communication system. The radio frequency front-end in the phased array radar communication system and the time division duplex (TDD) communication system is usually composed of a power amplifier (PA), a low noise amplifier (LNA) and a transmit / receive switch (TR SW). The TR SW connects the PA and the LNA and can multiplex an antenna (ANT), which can effectively reduce the number of system antennas. Figure 1The shown is a traditional radio frequency front-end circuit architecture, which realizes the purpose of system transceiving signals by switching the signal path under different modes. Therefore, in order to ensure that the signal has low leakage, the transceiving switch needs to have sufficient isolation to reduce the impact on the performance of the front-end transceiver.

[0033] In the related art, the insertion loss of the symmetrical switch in the radio frequency front-end architecture is high, which leads to the decline of the output power and efficiency of the transmitting end PA, and reduces the energy efficiency of the transceiver system. The radio frequency front-end integrated with the asymmetric switch considers that the signal power is small in the TDD receiving mode, and even if the isolation of the transmitting branch of the switch is low, the power of the signal leakage to the PA is not enough to damage the active device, so the isolation of the transmitting branch can be reduced to obtain higher freedom of transmitting end matching, reduce the loss of the transmitting end matching network and the switch, and thus improve the output power and efficiency of the transmitting end PA. The asymmetric transceiving switch structure in the related art realizes high-quality radio frequency transceiving performance. However, the improvement of the asymmetric transceiving switch structure on the performance of the front-end is still limited, and it is difficult to ensure the bandwidth and low insertion loss performance of the transmitting branch while realizing the wideband and low insertion loss characteristics of the receiving switch in the performance compromise. Therefore, the switch structure in the related art leads to poor bandwidth and low insertion loss performance of the transmitting branch, which affects the transceiving performance of the radio frequency front-end.

[0034] Therefore, in the embodiments of the present application, a transceiving matching network is provided to improve the transceiving performance of the radio frequency front-end.

[0035] One embodiment of the transceiving matching network provided by the embodiments of the present application comprises: a transmitting end output matching network, a receiving end coupled resonant switch network and a first transmission line connected in sequence.

[0036] The transmitting end output matching network is used for transmitting end impedance matching and providing a first resonance point in the receiving mode.

[0037] The receiving end coupled resonant switch network is used for receiving end impedance matching and switching the transceiving mode.

[0038] The first transmission line is used for providing a second resonance point in the receiving mode.

[0039] The transceiving matching network in the embodiment of the application is used for a radio frequency front-end circuit, and the specific connection relationship is as follows: the power amplifier is connected to the antenna through the transceiving matching network, and the low-noise amplifier is connected to the antenna through the transceiving matching network. One end of the transmit-end output matching network is connected to the power amplifier, and the other end of the transmit-end output matching network is connected to the antenna. One end of the receive-end coupled resonant switch network is connected to the low-noise amplifier, the other end of the receive-end coupled resonant switch network is connected to the antenna, and the other end of the receive-end coupled resonant switch network is also connected to the other end of the transmit-end output matching network. One end of the first transmission line is radio frequency grounded, the other end of the first transmission line is connected to the low-noise amplifier, and the other end of the first transmission line is also connected to one end of the receive-end coupled resonant switch network.

[0040] It can be understood that the transmit-end output matching network in the embodiment of the application is used for output matching of the power amplifier and the antenna in the transmit mode, and provides a first resonant point in the receive mode. The receive-end coupled resonant switch network is used for providing a transceiving mode switching function to reduce the power leaked to the input end of the low-noise amplifier in the transmit mode.

[0041] The scheme removes the transmit-end switch, and while ensuring transmit-end impedance matching, through multiplexing the transmit-end matching network, combining the receive-end coupled resonant switch network and the first transmission line, a high-order band-pass filter structure is formed in the receive mode, wideband impedance matching is achieved, and the radio frequency transceiving performance of the radio frequency front-end is comprehensively improved.

[0042] The transmit-end output matching network in the embodiment of the application generates at least one resonant point in the receive mode, and then performs impedance matching on the receive-mode radio frequency front-end circuit or constitutes a filter resonant unit, so as to realize wideband operation of the radio frequency front-end circuit and have certain out-of-band suppression capability. The transmit-end output matching network of the application can be designed in cooperation with the receive-end coupled resonant switch network and the first transmission line, so as to realize the input matching network of the low-noise amplifier in the receive mode, thereby fusing the transceiving switch and the matching network. Based on this, the performance of bandwidth, noise figure, linear output power and the like can be effectively improved, while the compact circuit area is maintained.

[0043] It should be noted that the transceiving matching network of the application can also be referred to as a transceiving matching circuit or a transceiving matching structure.

[0044] In some embodiments, the transceiving matching network provided by the embodiment of the application includes a receive-end coupled resonant switch network, and the receive-end coupled resonant switch network includes a resonant unit and a coupling unit. The number of resonant units is greater than or equal to 1, and the number of coupling units is greater than or equal to 2.

[0045] In some embodiments, the transceiver matching network provided by the embodiments of the present application includes a first resonant unit, a second resonant unit, a first coupling unit, a second coupling unit and a third coupling unit.

[0046] One end of the first coupling unit is connected to the low noise amplifier, the other end of the first coupling unit is connected to one end of the second coupling unit through the first resonant unit, the other end of the second coupling unit is connected to one end of the third coupling unit through the second resonant unit, and the other end of the third coupling unit is connected to the antenna.

[0047] Embodiment one:

[0048] Reference Figure 2 The electrical schematic diagram of the transceiver matching network provided by the embodiments of the present application is shown in FIG. 1. The radio frequency front-end circuit 100 includes a PA 102, a LNA 103, an antenna 101 and a transceiver matching network TRSW 104 of a fusion switch. The TRSW 104 includes a transmit end output matching network TX_OMN, a first transmission line TL1 and a receive end coupling resonant switch network RXSW. The mode switching is performed by the action of the switch (such as the first switch S1 and the second switch S2, which are located in the receive end coupling resonant switch network), so that only one amplifier is in working state in the receive / transmit mode. The first transmission line is used to provide a second resonant point in the receive mode. Exemplarily, reference is made to FIG. 2. Figure 2 As shown in FIG. 2, the first transmission line can also provide the second resonant point together with the input parasitic capacitance C in of the low noise amplifier.

[0049] In actual application, the receive end coupling resonant switch network RXSW includes at least one resonant unit and at least two coupling units, and the transmit end output matching network needs to provide at least one resonant point in the receive mode in addition to realizing the impedance matching between the PA 102 and the antenna 100 in the transmit mode. For the convenience of description, embodiment one is set to provide one resonant point.

[0050] It should be noted that the specific number of the resonant units and the coupling units in the receive end coupling resonant switch network RXSW is not limited in the present application. No matter what value the number of the resonant units and the coupling units in the RXSW takes, it all belongs to the protection scope of the present application. In addition, the number of the resonant points provided by the transmit end output matching network TX_OMN in the receive mode is also not limited in the present application. No matter what value it takes, it all belongs to the protection scope of the present application.

[0051] Exemplarily, reference is made to FIG. 3. Figure 2In one embodiment shown, the RXSW is set to two resonant units and three coupling units, including a first coupling unit J12, a second coupling unit J23, a third coupling unit J34, a first resonant unit FBR1, and a second resonant unit FBR2. The first resonant unit FBR1 includes a first switch S1 and a second transmission line TL2, and the second resonant unit FBR2 includes a second switch S2 and a third transmission line TL3.

[0052] The first transmission line TL1 has one end connected to the radio frequency ground and the other end connected to the input end of the LNA 103, and the connection point is connected to the first coupling unit J12. The first coupling unit J12 is connected to the second coupling unit J23 through the first resonant unit FBR1, the second coupling unit J23 is connected to the third coupling unit J34 through the second resonant unit FBR2, and the other end of the third coupling unit J34 is electrically connected to the transmit end output matching network TX_OMN, and the connection point is connected to the antenna 100. In addition, the first switch S1 in the first resonant unit FBR1 and one end of the second transmission line TL2 are grounded, and the other end of the first switch S1 and the second transmission line TL2 are connected in parallel in the signal path. The second switch S2 in the second resonant unit FBR2 and one end of the third transmission line TL3 are grounded, and the other end of the second switch S2 and the third transmission line TL3 are connected in parallel in the signal path.

[0053] It can be understood that by setting the above coupling units and resonant units to be connected to each other, the transceiver matching network realizes a high-order filter structure to suppress out-of-band signals. The specific working process is as follows:

[0054] When the first switch S1 and the second switch S2 are both closed, the equivalent impedance of the receive resonant coupling switch RXSW is Zrx, which matches the 50Ω impedance at the antenna 101 end to the optimal impedance Zopt of the PA 102 together with the transmit end output matching network, thereby realizing the front-end transmit mode operation. The signal amplified by the PA 102 is transmitted through the antenna 100. Since the first switch S1 and the second switch S2 are both closed at this time, signal isolation is achieved, so that the radio frequency signal leaked to the input end of the LNA 103 is low enough.

[0055] Please refer to Figure 3Figure 2 is an equivalent circuit diagram of the embodiment one in the transmitting mode. When the first switch S1 and the second switch S2 are both closed, the PA 102 works, and the radio frequency front end is in the transmitting mode. At this time, the first transmission line TL1 and the LNA 103 input equivalent capacitor Cln form a first resonant unit FBR1, and the second transmission line TL2 and the second switch S2 equivalent capacitor Cs2 form a second resonant unit FBR2. Thus, the transmitting end coupling resonant switch network RXSW forms an equivalent high-order bandpass filter in the working frequency band, and includes at least one resonant point, such as the four resonant points shown in the embodiment. Figure 3 Thus, the 50Ω antenna and the LNA 103 input are wideband impedance matched. In addition, the first transmission line TL1 can be integrated into the bias circuit of the LNA 103, reducing the circuit area. It can be understood that the present application does not limit the specific number and specific composition of the resonant units and the coupling units, Figure 2 and Figure 3 In the embodiment one shown in the above, it is only one embodiment of the resonant unit composition. Those skilled in the art can also design other resonant units with other compositions / structures to achieve the transmitting and receiving mode switching and output matching, and the present application does not make specific limitations.

[0056] From the above, the transmitting and receiving matching network integrated with the switch and the radio frequency front end circuit provided by the present application can realize the direct matching of the PA 102 to the antenna 100 due to the removal of the switch in the transmitting end, compared with the radio frequency front end with the switch in the transmitting end in the prior art, which can avoid the switch parasitic loss, reduce the overall passive loss of the transmitting end impedance matching network and the switch, and effectively improve the transmitting linear output power and efficiency performance of the radio frequency front end. In the receiving mode, the output matching network of the transmitting end is reused to generate an additional resonant point, such as the first resonant point, and the transmission line and the equivalent capacitor at the LNA input end are used to generate a second resonant point, which, in combination with the resonant points of the coupling resonant switch network itself, significantly increases the receiving bandwidth performance while ensuring the impedance matching of the LNA, so as to realize the wideband low-noise receiving performance, which has wide applicability. There is a radio frequency front end based on the post-matching architecture in the prior art. The circuit removes the switch in the transmitting end and uses a simple post-matching and lumped parameter π-type network equivalent λ / 4 transmission line structure to realize a high-performance radio frequency front end, but the λ / 4 parallel switch used in the receiving end is not designed in combination with the LNA input matching network. The transmitting and receiving matching network integrated with the switch and the radio frequency front end circuit provided by the present application not only removes the switch in the transmitting end, but also has the characteristics of reusing and integrating the amplifier matching circuit and the switch, which greatly improves the transmitting and receiving performance of the radio frequency front end.

[0057] In some embodiments, the transceiving matching network provided by the embodiments of the present application includes a first resonant unit including a second transmission line and a first switch;

[0058] One end of the second transmission line is grounded, the other end of the second transmission line is connected to the other end of the first coupling unit, and the other end of the second transmission line is also connected to one end of the second coupling unit; one end of the first switch is grounded, the other end of the first switch is connected to the other end of the first coupling unit, and the other end of the first switch is also connected to one end of the second coupling unit;

[0059] The first switch is configured to, in a disconnected state, operate the radio frequency front-end circuit in a receiving mode, and the first switch and the second transmission line provide a third resonant point in the receiving mode.

[0060] Specifically, in this scheme, the parasitic parameters of the first switch and the second transmission line form the first resonant unit. It can be understood that, referring to the embodiment shown in Figure 2 The second resonant unit includes a third transmission line TL3 and a second switch S2. The second switch is configured to, in a disconnected state, operate the radio frequency front-end circuit in a receiving mode, and the second switch and the third transmission line provide a fourth resonant point in the receiving mode. In this design, the parasitic parameters of the second switch and the third transmission line form the second resonant unit. In this embodiment, the radio frequency front-end circuit receives within a working bandwidth including four resonant points, realizing wideband operation of the radio frequency front-end receiver.

[0061] In some embodiments, the transceiving matching network provided by the embodiments of the present application includes a first resonant unit including a second transmission line and a first switch;

[0062] One end of the second transmission line is grounded, the other end of the second transmission line is connected to the other end of the first coupling unit, and the other end of the second transmission line is also connected to one end of the second coupling unit; one end of the first switch is grounded, the other end of the first switch is connected to the other end of the first coupling unit, and the other end of the first switch is also connected to one end of the second coupling unit;

[0063] Embodiment two:

[0064] Optionally, referring to Figure 4 , an electrical schematic diagram based on the transmit-end output matching network, wherein the transmit-end output matching network TX_OMN includes a fourth transmission line TL4, a fifth transmission line TL5, a sixth transmission line TL6, and a first capacitor CT.

[0065] In this embodiment, one end of the fourth transmission line TL4 is connected to the output end of the PA 102, the other end is connected to one end of the fifth transmission line TL5, and the connection point is connected to one end of the sixth transmission line TL6. The other end of the sixth transmission line TL6 is connected to one end of the first capacitor CT, and the connection point is connected to the antenna 101 and the coupling unit J34 respectively. The other end of the fifth transmission line TL5 and the other end of the first capacitor CT are both grounded. In the actual working process of the transmission end output matching network of this structure:

[0066] When the radio frequency front-end circuit is in the transmission mode, the first switch S1 and the second switch S2 are both closed, the receiving branch is equivalent to the impedance Zrx, and together with the transmission end output matching network TX_OMN, the 50Ω impedance at the end of the antenna 101 is matched to the optimal impedance Zopt of the PA 102. It is worth noting that the fourth transmission line TL4, the fifth transmission line TL5 and the sixth transmission line TL6 together form a T-shaped matching structure, which absorbs the output capacitance of the PA 102, and together with the first capacitor CT forms a bandpass filter structure with double pole tuning, that is, this network has impedance matching and bandpass filtering functions, thereby suppressing the out-of-band frequency signals at the output end of the radio frequency front-end, thereby improving the radio frequency performance of the transmission end. Further, the above-mentioned fifth transmission line TL5 can be integrated into the bias circuit of the PA 101, thereby reducing the circuit area.

[0067] When the radio frequency front-end circuit is in the receiving mode, the first switch S1 and the second switch S2 are both opened, the PA 102 does not work, and the radio frequency front-end is in the receiving mode. At this time, the equivalent impedance ZLeq of the first capacitor CT to the PA 101 in the transmission end output matching network and the first capacitor CT form a resonant network and produce a first resonance point, and the working principle of the remaining receiving branch is the same as that of the embodiment I shown in Figure 3 , which will not be described here.

[0068] Alternatively, please refer to Figure 5 , another electrical schematic diagram based on the transmission end output matching network, the transmission end output matching network TX_OMN includes the fourth transmission line TL4, the fifth transmission line TL5, the sixth transmission line TL6, the seventh transmission line TL7 and the first capacitor CT.

[0069] Among them, one end of the fourth transmission line TL4 is connected to the output end of the PA 102, the other end is connected to one end of the fifth transmission line TL5, and the connection point is connected to one end of the sixth transmission line TL6. The other end of the sixth transmission line TL6 is connected to one end of the seventh transmission line TL7, and the connection point is connected to the antenna 101 and the coupling unit J34 respectively. The other end of the seventh transmission line TL7 is connected to one end of the first capacitor CT. The other end of the fifth transmission line TL5 and the other end of the first capacitor CT are both grounded.

[0070] It should be noted that, in order to suppress the second harmonic power in the PA101 output power, improve the fundamental output power and efficiency, in the Figure 4 Corresponding embodiments provide a transmitting end output matching network TX_OMN, and a seventh transmission line TL7 is added to generate a transmission zero point with the first capacitor CT, thereby improving the transmitting end radio frequency performance.

[0071] In the actual working process of the embodiment:

[0072] When the radio frequency front-end circuit is in the transmitting mode, the first switch S1 and the second switch S2 are both closed, the receiving branch is equivalent to the impedance Zrx, and the receiving branch and the transmitting end output matching network TX_OMN together match the 50Ω impedance at the antenna 101 end to the optimal impedance Zopt of the PA102. It should be noted that, at the fundamental frequency, the added seventh transmission line TL7 is in series with the first capacitor CT to the ground, and the impedance thereof is mainly capacitive, while at the second harmonic frequency, the seventh transmission line TL7 and the first capacitor CT are resonant by reasonably setting the parameters, so that the impedance is 0, a transmission zero point is generated, and the second harmonic power is suppressed. It can be understood that the fourth transmission line TL4, the fifth transmission line TL5 and the sixth transmission line TL6 together constitute a T-shaped matching structure, absorb the output capacitance of the PA102, and at the fundamental frequency, together with the first capacitor CT, constitute a double-pole tuning band-pass filter structure, and specifically, suppress the out-of-band second harmonic signal, thereby improving the transmitting end radio frequency performance. Further, the above-mentioned fifth transmission line TL5 can be integrated into the bias circuit of the PA101, thereby reducing the circuit area.

[0073] When the radio frequency front-end circuit is in the receiving mode, the first switch S1 and the second switch S2 are both opened, and the PA102 does not work. At this time, the equivalent impedance ZLeq of the first capacitor CT in the transmitting end output matching network to the PA101 and the first capacitor CT constitute a resonant network, and a first resonant point is generated, and the working principle of the remaining receiving branch is the same as that of the embodiment one shown in Figure 3 , and details are not repeated here.

[0074] It should be noted that the transmitting end output matching network in the Figure 4 and Figure 5 of the embodiment of the application is exemplary, and can also be realized by a structure of a transmission line combined with a capacitor. The design focus is to simultaneously satisfy the generation of a resonant point in the receiving mode and complete the output matching in the transmitting mode. The application does not limit the specific composition and structure of the transmitting end output matching network.

[0075] In some embodiments, the transceiving matching network provided by the embodiment of the application includes a third resonant unit, a second capacitor and an inductor in the receiving end coupling resonant switch network;

[0076] One end of the second capacitor is connected to the low noise amplifier, the other end of the second capacitor is connected to one end of the inductor through the third resonant unit, and the other end of the inductor is connected to the antenna.

[0077] In some embodiments, the transceiving matching network provided by the embodiments of the application includes a seventh transmission line in the first coupling unit, an eighth transmission line in the second coupling unit, and a ninth transmission line in the third coupling unit.

[0078] Embodiment three:

[0079] Please refer to Figure 6 , in combination with Figure 4 the transmit end output matching network TX_OMN in embodiment two, a possible receive end coupling resonant switch RXSW structure is proposed, specifically the circuit implementation of the first to third coupling units in RXSW. Of course, in combination with the structure of the transmit end output matching network shown in Figure 5 , the application does not limit the specific combination form of the transmit end output matching network and the receive end coupling resonant switch network.

[0080] As shown in Figure 6 , the first coupling unit J12 is implemented by the seventh transmission line TL12, the second coupling unit is implemented by the eighth transmission line TL23, and the third coupling unit is implemented by the ninth transmission line TL34.

[0081] When the radio frequency front-end circuit is in the transmit mode, the working principle is the same as that of the radio frequency front-end in Figure 4 embodiment two.

[0082] When the radio frequency front-end circuit is in the receive mode, the first switch S1 and the second switch S2 are both disconnected, by adjusting the electrical length and characteristic impedance of the transmission line TL12, the transmission line TL23 and the transmission line TL34, the coupling strength between the first resonant unit and the second resonant unit, and the coupling strength between the first resonant unit and the second resonant unit and their corresponding loads is changed, so as to realize impedance matching. The working principles of the remaining elements are the same as those in Figure 4 embodiment two, which will not be described here.

[0083] Embodiment four:

[0084] Please refer to Figure 7 , in combination with Figure 4 the transmit end output matching network TX_OMN in embodiment two, a possible receive end coupling resonant switch RXSW structure is proposed.

[0085] As shown in Figure 7As shown, the receiving end coupling resonant switch RXSW includes a first switch S1, a third resonant unit FBR3 composed of a second transmission line TL2, a second capacitor C12 and an inductor L34. The second transmission line is connected at one end to the first switch S1, and the connection points are connected at one end to the inductor L34 and at one end to the second capacitor C12. The other end of the inductor L34 is connected to the antenna 101. The other end of the second capacitor C12 is connected to the input end of the LNA 103.

[0086] It should be noted that only one resonant unit is used in the receiving end coupling resonant switch RXSW in this embodiment four, thereby reducing the number of circuit elements, and the implementation of the coupling unit adopts the form of mixed lumped parameter inductors and capacitors, thereby further realizing circuit miniaturization. In actual working process:

[0087] When the radio frequency front-end circuit is in the transmitting mode, the first switch S1 is closed, and the working principle of the remaining transmitting branch is the same as that of the radio frequency front-end in the embodiment two, which will not be repeated here. Figure 4 When the radio frequency front-end circuit is in the transmitting mode, the first switch S1 is closed, and the working principle of the remaining transmitting branch is the same as that of the radio frequency front-end in the embodiment two, which will not be repeated here.

[0088] When the radio frequency front-end circuit is in the receiving mode, the first switch S1 is opened, and the PA 102 does not work. At this time, the equivalent impedance ZLeq of the first capacitor CT looking into the PA 101 in the transmitting end output matching network and the first capacitor CT form a resonant network, and a first resonant point is generated. The first transmission line and the equivalent input capacitor of the LNA 103 generate a second resonant point, and the equivalent capacitor of the first switch S1 and the second transmission line TL2 generate a third resonant point. By adjusting the parameters of the inductor L34 and the second capacitor C12, the different resonant points are distributed within the working frequency band, and the receiving wideband and low noise coefficient characteristics of the radio frequency front-end are realized.

[0089] The radio frequency front-end circuit realized based on the above embodiment scheme can be a monolithic integrated circuit (MMIC), and can also be heterogeneous or heterogeneous integrated, that is, the content of the present application should be irrelevant to the integrated circuit process and assembly method, such as CMOS, GaAs, GaN process, monolithic integration or integration on a PCB board through die wire bonding.

[0090] It should be noted that the inductors, capacitors and transmission lines mentioned above are not limited to actual electronic devices, but can also be equivalent through series, parallel and coupling electrical connection methods.

[0091] In some embodiments, the transceiving matching network provided by the embodiment of the present application includes a bias circuit, and the bias circuit includes a first transmission line.

[0092] Obviously, the design multiplexes the first transmission line to direct current bias the low noise amplifier, thereby reducing the circuit size.

[0093] Compared with the prior art, the transceiver matching network fusing a switch has certain advantages. First, compared with the traditional radio frequency front end, the transceiver matching network fusing a switch removes the switch of the transmitting branch, the linear output power and the efficiency of the transmitting end are improved, and meanwhile, the transmitting end matching network provides a resonance point in the receiving mode, so that the matching network multiplexing can be realized. Second, compared with the existing radio frequency front end removing the switch of the transmitting branch, the transceiver matching network fusing a switch utilizes the resonant unit containing a transistor switch, is connected through a coupling unit, and constitutes a high-order band-pass filter structure, so that the wideband and low-noise receiving characteristics can be realized, and the transmitting end characteristics remain unchanged. Finally, compared with the prior art, the transceiver matching network fusing a switch does not increase the area, and has high design freedom. Therefore, the transceiver matching network fusing a switch and the radio frequency front end circuit scheme have good application potential and prospect in the time division duplex communication system and the phased array radar system.

[0094] The radio frequency front end circuit provided by the embodiment of the present application also includes the transceiver matching network, the radio frequency front end circuit further includes a power amplifier and a low-noise amplifier, the power amplifier is connected to the antenna through the transceiver matching network, and the low-noise amplifier is connected to the antenna through the transceiver matching network.

[0095] In a possible design, the low-noise amplifier includes a bias circuit, the bias circuit is coupled to the receiving end coupling resonant switch network, and constitutes a common-source architecture or a common-gate architecture or a common-source and common-gate architecture.

[0096] It can be understood that the radio frequency front end elements are integrated in the same monolithic integrated circuit (MMIC) or are heterogeneously integrated in different dies and PCB boards.

[0097] It can be understood that the contents in the above transceiver matching network embodiments are all applicable to the radio frequency front end circuit embodiment, the radio frequency front end circuit embodiment specifically realizes the same functions as the above transceiver matching network embodiments, and achieves the same beneficial effects as the above transceiver matching network embodiments.

[0098] The chip provided by the embodiment of the present application also includes the radio frequency front end circuit.

[0099] It can be understood that the contents in the above transceiver matching network embodiments are all applicable to the chip embodiment, the chip embodiment specifically realizes the same functions as the above transceiver matching network embodiments, and achieves the same beneficial effects as the above transceiver matching network embodiments.

[0100] The wireless communication system provided by the embodiment of the present application also includes the chip.

[0101] It can be understood that the contents in the above-mentioned transceiving matching network embodiments are applicable to the present wireless communication system embodiment, the present wireless communication system embodiment specifically realizes the same functions as the above-mentioned transceiving matching network embodiments, and achieves the same beneficial effects as the above-mentioned transceiving matching network embodiments.

[0102] The embodiments described in the present application embodiment are for more clearly illustrating the technical solutions of the present application embodiment, and do not constitute a limitation on the technical solutions provided by the present application embodiment. Those skilled in the art can know that, with the evolution of technology and the appearance of new application scenarios, the technical solutions provided by the present application embodiment are also applicable to similar technical problems.

[0103] Those skilled in the art can understand that the technical solutions shown in the figures do not constitute a limitation on the present application embodiment, and can include more or fewer steps than the figures shown, or combine certain steps, or different steps.

[0104] The device embodiments described above are only schematic, and the units described as separate components can or can not be physically separate, that is, can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the present embodiment.

[0105] Those skilled in the art can understand that all or some steps in the above-mentioned method, the functions of the modules / units in the system and the device can be implemented as software, firmware, hardware and their appropriate combinations.

[0106] The terms "first", "second", "third", "fourth" and the like used in the description of the present application and the above-mentioned drawings (if any) are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0107] It should be understood that, in the present application, "at least one" refers to one or more, and "multiple" refers to two or more. "And / or" is used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, "A and / or B" can represent three cases of only A, only B, and A and B existing at the same time, wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it. "At least one of the following" or the like means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can represent a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, and c can be single or multiple.

[0108] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative, for example, the division of the above units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed units can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0109] The units described above as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment of the present application.

[0110] The preferred embodiments of the embodiments of the present application are described above with reference to the accompanying drawings, but this does not limit the scope of the rights of the embodiments of the present application. Any modifications, equivalent replacements and improvements made by those skilled in the art without departing from the scope and essence of the embodiments of the present application shall be within the scope of the rights of the embodiments of the present application.

Claims

1. A transceiver matching network, characterized in that, include: The transmitter output matching network, the receiver coupled resonant switch network, and the first transmission line are connected in sequence. The transmitter output matching network is used for transmitter impedance matching and provides a first resonant point in receive mode. The receiver-coupled resonant switching network is used for receiver impedance matching and switching of transmit and receive modes. The first transmission line is used to provide a second resonant point in receive mode; The receiver-coupled resonant switching network includes a first resonant unit, a second resonant unit, a first coupling unit, a second coupling unit, and a third coupling unit; One end of the first coupling unit is connected to a low-noise amplifier, the other end of the first coupling unit is connected to one end of the second coupling unit through the first resonant unit, the other end of the second coupling unit is connected to one end of the third coupling unit through the second resonant unit, and the other end of the third coupling unit is connected to an antenna. The first resonant unit includes a second transmission line and a first switch; One end of the second transmission line is grounded, and the other end of the second transmission line is connected to the other end of the first coupling unit. The other end of the second transmission line is also connected to one end of the second coupling unit. One end of the first switch is grounded, and the other end of the first switch is connected to the other end of the first coupling unit. The other end of the first switch is also connected to one end of the second coupling unit. The first switch is used to enable the RF front-end circuit to operate in receive mode when it is in the off state, and the first switch and the second transmission line provide a third resonant point in receive mode.

2. The transceiver matching network according to claim 1, characterized in that, The transmitter output matching network includes a fourth transmission line, a fifth transmission line, a sixth transmission line, and a first capacitor: One end of the fourth transmission line is connected to a power amplifier, one end of the fifth transmission line is grounded, and one end of the sixth transmission line is connected to an antenna; the other ends of the fourth, fifth, and sixth transmission lines are connected to a first connection point; one end of the sixth transmission line is also grounded through the first capacitor.

3. The transceiver matching network according to claim 1, characterized in that, The first coupling unit includes a seventh transmission line, the second coupling unit includes an eighth transmission line, and the third coupling unit includes a ninth transmission line.

4. The transceiver matching network according to claim 1, characterized in that, The low-noise amplifier includes a bias circuit, which includes the first transmission line.

5. A radio frequency front-end circuit, characterized in that, The radio frequency front-end circuit includes a transceiver matching network as described in any one of claims 1 to 4, and the radio frequency front-end circuit further includes a power amplifier and a low-noise amplifier, wherein the power amplifier is connected to an antenna through the transceiver matching network, and the low-noise amplifier is connected to the antenna through the transceiver matching network.

6. A chip, characterized in that, Includes the radio frequency front-end circuit as described in claim 5.

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