Radio frequency switch circuit, radio frequency module and antenna tuner

Abstract

The application provides a radio frequency switch circuit, a radio frequency module and an antenna tuner. The radio frequency switch circuit comprises a first voltage division branch, a second voltage division branch and a switch branch. The first voltage division branch and the second voltage division branch each comprise a switch unit and a switch bias unit. The switch branch comprises N first transistors connected in series. The body of the mth first transistor is connected to the source of the ith first transistor through the switch unit in the first voltage division branch. The body of the mth first transistor is connected to the drain of the jth first transistor through the switch unit in the second voltage division branch. N, m, i and j satisfy the following relationships: 1 < m < N, 0 < i < m, m < j <= N and N >= 3. The switch bias unit can be used to intermittently provide a bias signal for the switch unit, so that the switch unit is intermittently turned on. The application can realize voltage division for the plurality of first transistors connected in series, and improve the voltage resistance performance of the radio frequency switch circuit.

Description

Technical Field

[0001] This application relates to the field of radio frequency technology, and in particular to a radio frequency switch circuit, a radio frequency module, and an antenna tuner. Background Technology

[0002] In the field of communication technology, the radio frequency (RF) switching circuit is an important component of the RF front-end module. Its function is to accurately switch the transmission path of RF signals and select the appropriate RF path. In the case of a wireless communication system sharing an antenna, it can realize the reception and transmission of RF signals.

[0003] In related technologies, radio frequency (RF) switch circuits typically need to operate in high-voltage and high-power environments and withstand large voltage fluctuations. Generally, RF switch circuits use multiple transistors stacked together to improve their voltage withstand capability. However, this stacking method can easily lead to uneven voltage distribution among the transistors, causing some transistors to withstand larger voltages, which in turn results in a lower overall voltage tolerance of the RF switch. Summary of the Invention

[0004] This application provides a radio frequency (RF) switch circuit, an RF module, and an antenna tuner, which aim to improve the uniformity of voltage distribution in the RF switch circuit.

[0005] In a first aspect, this application provides a radio frequency (RF) switch circuit, the RF switch circuit comprising:

[0006] First connection end and second connection end;

[0007] The voltage divider branch includes a first voltage divider branch and a second voltage divider branch, both of which include a switching unit and a switching biasing unit.

[0008] A switching branch includes N first transistors connected in series between the first connection terminal and the second connection terminal. The body of the m-th first transistor is connected to the source of the i-th first transistor through a switching unit in the first voltage divider branch. The body of the m-th first transistor is connected to the drain of the j-th first transistor through a switching unit in the second voltage divider branch. N, m, i, and j are all positive integers and satisfy the following relationships: 1 < m < N, 0 < i < m, m < j ≤ N, N ≥ 3.

[0009] When the first transistor is turned off, the switch biasing unit is used to intermittently provide a bias signal to the switch unit, so that the switch unit is intermittently turned on.

[0010] Secondly, this application also provides a radio frequency module, which includes the radio frequency switching circuit provided in the first aspect.

[0011] Thirdly, this application also provides an antenna tuner, which includes a plurality of parallel tuning branches, each tuning branch including a tuning component and a radio frequency switch circuit as provided in the first aspect, the radio frequency switch circuit being connected in series with the tuning component.

[0012] This application provides a radio frequency (RF) switch circuit, an RF module, and an antenna tuner. The application connects the body of the m-th first transistor to the source of the i-th first transistor via a switching unit in a first voltage divider branch, and connects the body of the m-th first transistor to the drain of the j-th first transistor via a switching unit in a second voltage divider branch. When the first transistor is off, the switching bias units in the first and second voltage divider branches can intermittently provide bias signals to the switching units, thereby intermittently turning on the switching units and achieving voltage division of the first transistors. This results in a more uniform voltage division among the multiple first transistors in the RF switch circuit, solving the problem of uneven voltage division caused by transistor stacking and improving the withstand voltage capability of the RF switch circuit. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of a radio frequency switch circuit provided in an embodiment of this application;

[0015] Figure 2 A schematic diagram of a radio frequency switch circuit provided in an embodiment of this application;

[0016] Figure 3a This is a schematic diagram of the structure of a voltage divider branch provided in an embodiment of this application;

[0017] Figure 3b This is a schematic diagram of the structure of a voltage divider branch provided in another embodiment of this application;

[0018] Figure 3c A schematic diagram of the structure of a voltage divider branch provided in another embodiment of this application;

[0019] Figure 3d A schematic diagram of the structure of a voltage divider branch provided in another embodiment of this application;

[0020] Figure 4a This is a schematic diagram of the structure of a switch biasing unit provided in an embodiment of this application;

[0021] Figure 4bThis is a schematic diagram of the structure of a switch biasing unit provided in another embodiment of this application;

[0022] Figure 4c A schematic diagram of the structure of a switch biasing unit provided in another embodiment of this application;

[0023] Figure 5 This is a schematic diagram of the structure of a voltage divider branch provided in another embodiment of this application;

[0024] Figure 6a This is a schematic diagram of the structure of a switch biasing unit provided in an embodiment of this application;

[0025] Figure 6b This is a schematic diagram of the structure of a switch biasing unit provided in another embodiment of this application;

[0026] Figure 6c A schematic diagram of the structure of a switch biasing unit provided in another embodiment of this application;

[0027] Figure 6d This is a schematic diagram of the structure of a switch biasing unit provided in another embodiment of the present application;

[0028] Figure 7 This is a schematic diagram of a radio frequency module provided in one embodiment of this application;

[0029] Figure 8 This is a schematic diagram of an antenna tuner provided in one embodiment of this application.

[0030] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0033] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0034] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a radio frequency switch circuit provided in an embodiment of this application.

[0035] like Figure 1 As shown, the RF switch circuit includes a first connection terminal 11, a second connection terminal 12, a voltage divider branch, and a switch branch 13. Specifically, the voltage divider branch includes a first voltage divider branch 141 and a second voltage divider branch 142. The first voltage divider branch 141 includes a switching unit 1411 and a switching bias unit 1412, and the second voltage divider branch 142 includes a switching unit 1421 and a switching bias unit 1422. The switching branch 13 includes N first transistors connected in series between the first connection terminal 11 and the second connection terminal 12 of the RF switching circuit. The body of the m-th first transistor Qm is connected to the source of the i-th first transistor Qi through the switching unit 1411 in the first voltage divider branch 141, and the body of the m-th first transistor Qm is connected to the drain of the j-th first transistor Qj through the switching unit 1421 in the second voltage divider branch 142. N, m, i, and j are all positive integers and satisfy the following relationships: 1 < m < N, 0 < i < m, m < j ≤ N, N ≥ 3.

[0036] It should be noted that in related technologies, the RF switch circuit improves the withstand voltage capability by connecting multiple transistors in series between the first connection terminal 11 and the second connection terminal 12 to form a stacked structure. However, in the above configuration, when the first transistor is turned off, there is a large voltage difference between the first connection terminal 11 and the second connection terminal 12. This voltage difference is distributed across the N stacked first transistors. The voltage difference between the source and drain terminals of different transistors in the stacked structure is inconsistent, that is, the voltage distribution of the RF switch circuit is uneven. This results in each transistor in the RF switch circuit bearing a different voltage, which reduces the power withstand capability of the entire RF switch circuit.

[0037] It should be understood that in the embodiments of this application, when the first transistor is turned off, the voltage difference between different first transistors enables the switch biasing unit 1412 in the first voltage divider branch 141 to intermittently provide a bias signal to the switch unit 1411, so that the switch unit 1411 is intermittently turned on; the switch biasing unit 1422 in the second voltage divider branch 142 can intermittently provide a bias signal to the switch unit 1421, so that the switch unit 1421 is intermittently turned on.

[0038] It is understandable that when all the first transistors are turned on, since the on-resistance of the first transistors is very small, the voltage difference between the first connection terminal 11 and the second connection terminal 12 is almost zero. Therefore, the switching units in the first voltage divider branch 141 and the second voltage divider branch 142 will not be turned on, thus not affecting the transmission of the radio frequency signal between the first connection terminal 11 and the second connection terminal 12.

[0039] This application connects a first transistor in an RF switching circuit to another first transistor via a first voltage divider branch 141 and / or a second voltage divider branch 142. When the first transistor is off, the switch biasing unit 1412 in the first voltage divider branch 141 can intermittently provide a bias signal to the switch unit 1411, causing the switch unit 1411 to conduct intermittently. The second voltage divider branch 142 can intermittently provide a bias signal to the switch unit 1421, causing the switch unit 1422 to conduct intermittently. This allows current to flow from the source of the i-th first transistor Qi to the body of the m-th first transistor Qm and from the body of the m-th first transistor Qm to the drain of the j-th first transistor Qj through the conducting switch units 1411 and 1421. This makes the voltage distribution of each first transistor more uniform, thereby solving the problem that some transistors in the RF switching circuit bear a large voltage.

[0040] It should be noted that, Figure 1 The diagram only shows the complete connection of the m-th first transistor Qm. The complete connections of the i-th first transistor Qi and the j-th first transistor Qj are not shown. It should be understood that the specific connection of the i-th first transistor Qi and the j-th first transistor Qj can be referred to the connection of the m-th first transistor Qm, thereby realizing voltage division of multiple first transistors.

[0041] In some embodiments, when the radio frequency signal is transmitted between the first connection terminal 11 and the second connection terminal 12 of the switch branch 13, it passes sequentially through the i-th first transistor Qi, the m-th first transistor Qm, and the j-th first transistor Qj.

[0042] For example, the i-th first transistor Qi, the m-th first transistor Qm, and the j-th first transistor Qj are connected in series in the switching branch 13 along the propagation direction of the radio frequency signal in the switching branch 13 to improve the withstand voltage capability of the radio frequency switching circuit. It should be understood that the i-th first transistor Qi, the m-th first transistor Qm, and the j-th first transistor Qj mentioned above are illustrative examples, and more first transistors may be connected in series in the switching branch 13; this application does not limit this.

[0043] like Figure 2 As shown, Figure 2 This is a schematic diagram of a radio frequency switch circuit provided in an embodiment of this application.

[0044] In some embodiments, the body of the first transistor Q1 is connected to the drain of the xth transistor Qx through the second voltage divider branch 142; the body of the Nth transistor QN is connected to the source of the yth transistor Qy through the first voltage divider branch 141, where x and y are both positive integers and satisfy the following relationship: 1 < x ≤ 5, N - 4 ≤ y < N.

[0045] For example, the first transistor Q1 indicates the first transistor adjacent to the first connection terminal 11 of the RF switching circuit, while the Nth transistor QN is the first transistor adjacent to the second connection terminal 12 of the RF switching circuit. Since there is no first transistor preceding the first transistor Q1, the body of the first transistor is connected to the drain of the xth transistor Qx through the second voltage divider branch 142. The xth transistor Qx is the first transistor following the first transistor Q1, and is less than or equal to 4 transistors away from the first transistor Q1. The first transistor is configured such that the current leaking from the body of the first transistor Q1 can flow through the second voltage divider branch 142 to the xth transistor Qx, thereby ensuring the voltage division effect of the second voltage divider branch 142. Similarly, since there is no first transistor after the Nth transistor QN, the Nth transistor QN is connected to the source of the yth transistor Qy through the first voltage divider branch 141, and the number of first transistors between the yth transistor Qy and the Nth transistor QN is less than or equal to 4, in order to ensure the voltage division effect of the first voltage divider branch 141.

[0046] In some embodiments, m, i, and j also satisfy the following relationship: mi≤4, jm≤4.

[0047] For example, since the current leaking from the body of the first transistor is small, if the two first transistors connected by the voltage divider branch are separated by a large number of first transistors, the voltage dividing effect of the voltage divider branch will be reduced. Therefore, by setting the number of first transistors between the two first transistors connected by the first voltage divider branch 141 and / or the second voltage divider branch 142 to no more than 4, the voltage dividing effect of the voltage divider branch is guaranteed, thereby improving the overall withstand voltage capability of the RF switch circuit.

[0048] In some embodiments, m, i, and j also satisfy the following relationship: mi = jm.

[0049] For example, except for the first transistor Q1 and the Nth transistor QN, the body of the remaining first transistors can be connected to the first voltage divider branch 141 and the second voltage divider branch 142 at the same time. Specifically, taking the mth first transistor Qm as an example, mi is used to indicate the number of first transistors between the mth first transistor Qm and the ith first transistor Qi, and jm is used to indicate the number of first transistors between the mth first transistor Qm and the jth first transistor Qj. By using the same number of first transistors, the uniformity of voltage division can be improved.

[0050] It should be noted that the number of first transistors separated from the first transistor connected through the first voltage divider branch 141 and the number of first transistors separated from the first transistor connected through the second voltage divider branch 142 can be the same or different, and this application does not impose any restrictions.

[0051] In some embodiments, the first voltage divider branch 141 and the second voltage divider branch 142 each include at least one second transistor Q2 and at least one capacitor C; wherein the second transistor Q2 is connected between the first end and the second end of the corresponding voltage divider branch, and the capacitor is connected between the gate of the second transistor Q2 and the first end or the second end of the corresponding voltage divider branch.

[0052] For example, both the first voltage divider branch 141 and the second voltage divider branch 142 are provided with at least one second transistor Q2 and at least one capacitor. The capacitor is connected between the controlled terminal of the second transistor Q2 and the first or second terminal of the voltage divider branch in which the second transistor Q2 is located, so as to intermittently provide a bias signal to the second transistor Q2, so that the second transistor Q2 can be intermittently turned on. The second transistor Q2 is connected between the first and second terminals of the corresponding voltage divider branch, so that when the second transistor Q2 is turned on, the current leaking from the body of the first transistor can flow through the turned-on second transistor Q2 to the source or drain of another first transistor, thereby making the voltage distribution on each first transistor more uniform.

[0053] In some embodiments, the number of second transistors Q2 in the first voltage divider branch 141 is equal to the number of second transistors Q2 in the second voltage divider branch 142, and the number of capacitors in the first voltage divider branch 141 is equal to the number of capacitors in the second voltage divider branch 142, so as to improve the convenience of circuit design and manufacturing and reduce circuit manufacturing costs.

[0054] It should be noted that the electronic components in the first voltage divider branch 141 and the second voltage divider branch 142 can be the same or different. That is, the arrangement and structure of the first voltage divider branch 141 and the second voltage divider branch 142 can be exactly the same. Alternatively, the first voltage divider branch 141 or the second voltage divider branch 142 can be adjusted according to actual needs so that the voltage dividing effect of the first voltage divider branch 141 is different from that of the second voltage divider branch 142. This application does not limit whether the first voltage divider branch 141 and the second voltage divider branch 142 are exactly the same.

[0055] Please see Figure 3a , Figure 3a This is a schematic diagram of the structure of a voltage divider branch provided in an embodiment of this application.

[0056] In some embodiments, the switching unit 1411 of the first voltage divider branch 141 is a first switching unit 14111; the first switching unit 14111 includes at least one resistor and at least one second transistor Q2, the resistor and the second transistor Q2 are connected in series between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi, and the controlled terminal of the second transistor Q2 is connected to the switching bias unit 1412 of the first voltage divider branch 141.

[0057] For example, when the switching unit 1411 of the first voltage divider branch 141 is configured as the first switching unit 14111, the first switching unit 14111 includes at least one resistor and at least one second transistor Q2. The resistor and the second transistor Q2 are connected in series between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi. The controlled terminal of the second transistor Q2 is connected to the switching bias unit 1412 of the first voltage divider branch 141, so that when the switching bias unit 1412 provides a bias signal, the second transistor Q2 is turned on, thereby realizing the voltage division of each first transistor.

[0058] In some embodiments, the first switching unit 14111 includes a second transistor Q2, and the resistor R and the second transistor Q2 are connected in series between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi to achieve voltage division of the first transistor.

[0059] Please see Figure 3b , Figure 3b This is a schematic diagram of the voltage divider branch provided in another embodiment of this application.

[0060] In another embodiment, the first switching unit 14111 includes a plurality of second transistors Q2. The plurality of second transistors Q2 are connected in series with a resistor between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi. The controlled terminals of each second transistor Q2 are interconnected so that when the switching bias unit 1412 of the first voltage divider branch 141 provides a bias signal, all the second transistors Q2 can be turned on, thereby realizing voltage division.

[0061] In one implementation, such as Figure 3b As shown, at least one resistor in the first switching unit 14111 includes a first resistor R1. The first end of the first resistor R1 is connected to the source of the i-th first transistor Qi, and the second end of the first resistor R1 is connected to the body of the m-th first transistor Qm through the second transistor Q2.

[0062] Please see Figure 3c , Figure 3c This is a schematic diagram of the structure of a voltage divider branch provided in another embodiment of this application.

[0063] In another embodiment, at least one resistor in the first switching unit 14111 includes a second resistor R2. The first end of the second resistor R2 is connected to the source of the i-th first transistor Qi through the second transistor Q2, and the second end of the second resistor R2 is connected to the body of the m-th first transistor Qm. 。

[0064] Please see Figure 3d , Figure 3d This is a schematic diagram of the voltage divider branch provided in another embodiment of this application.

[0065] In another embodiment, at least one resistor in the first switching unit 14111 includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is connected to the source of the i-th first transistor Qi. The second end of the first resistor R1 is connected to the first end of the second resistor R2 through the second transistor Q2. The second end of the second resistor R2 is connected to the body of the m-th first transistor Qm.

[0066] It should be noted that the resistor R in the first switching unit 14111 can be set in any of the three settings mentioned above, but is not limited to. Furthermore, in each of these settings, the first resistor R1 and / or the second resistor R2 can include multiple resistors. For example, at least one resistor may include multiple first resistors R1, with the multiple first resistors R1 connected in series with at least one second transistor Q2 between the source of the i-th first transistor Qi and the body of the m-th first transistor Qm. Other settings can refer to the settings for the first resistor R1, and will not be repeated here. Similarly, at least one resistor may include multiple second resistors R2, with at least one second transistor Q2 connected in series with the multiple second resistors R2 between the source of the i-th first transistor Qi and the body of the m-th first transistor Qm. Other settings can refer to the settings for the second resistor R2, and will not be repeated here. Finally, at least one resistor may include multiple first resistors R1 and multiple second resistors R2. The specific settings can refer to the settings for the first resistors R1 and second resistors R2 mentioned above, and will not be repeated here.

[0067] This application does not limit the number or specific location of resistors. Those skilled in the art can set the resistors and their number based on the voltage difference between the first connection terminal 11 and the second connection terminal 12, the number of first transistors, the voltage difference between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi, etc.

[0068] Please see Figure 4a , Figure 4a This is a schematic diagram of the structure of a switch biasing unit 1412 provided in an embodiment of this application.

[0069] In some embodiments, the switching bias unit 1412 of the first voltage divider branch 141 is a first switching bias unit 14121. The first switching bias unit 14121 includes at least one capacitor connected between the source of the i-th first transistor Qi and the body of the m-th first transistor Qm, and one end of the capacitor is connected to the controlled terminal of the second transistor Q2.

[0070] For example, a capacitor is connected between the source of the i-th first transistor Qi and the body of the m-th first transistor Qm. One end of the capacitor is also connected to the controlled terminal of the second transistor Q2, so that when the first transistor is turned off, the capacitor can intermittently provide a bias signal to the second transistor Q2, thereby causing the second transistor Q2 to be turned on intermittently, and thus achieving voltage division for different first transistors.

[0071] Please continue reading. Figure 4aIn one embodiment, the first switch bias unit 14121 includes a first capacitor C1. The first end of the first capacitor C1 is connected to the source of the i-th first transistor Qi, and the second end of the first capacitor C1 is connected to the controlled terminal of the second transistor Q2 and the body of the m-th first transistor Qm. The capacitance of the first capacitor C1 changes with the voltage difference across the first capacitor C1. That is, according to the voltage difference between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi, a bias signal is provided to the second transistor Q2 when the voltage difference changes to a certain extent, so that the second transistor Q2 is turned on.

[0072] Please see Figure 4b , Figure 4b This is a schematic diagram of the structure of a switch biasing unit 1412 provided in another embodiment of this application.

[0073] In another embodiment, such as Figure 4b As shown, the first switch bias unit 14121 also includes a second capacitor C2; the second capacitor C2 is connected in parallel with the first capacitor C1 in reverse, and the capacitance value of the second capacitor C2 changes with the voltage difference across the second capacitor C2.

[0074] In practical implementation, because the first capacitor C1 is directional and the radio frequency signal is an alternating signal, the first capacitor C1 cannot provide a bias signal to the second transistor Q2 when it is under negative voltage, resulting in a short conduction time for the second transistor Q2 within one cycle of the radio frequency signal. However, by setting a second capacitor C2 connected in reverse parallel with the first capacitor C1, the first switch bias unit 14121 can provide a bias signal to the second transistor Q2 in different states, thereby improving the voltage division effect of the circuit.

[0075] It should be noted that a transistor can be configured as a varactor diode by shorting its source and drain as one plate of the first capacitor C1, and using its gate as the other plate. This results in a variable-value, directional first capacitor C1. Taking an N-type field-effect transistor as an example, when the gate voltage is negative and the source-drain voltage is positive, the capacitance of the first capacitor C1 will change according to the voltage difference between the gate and the source-drain. Similarly, another transistor with its source and drain shorted can be used as a second capacitor C2, with a similar principle to the first capacitor C1, which will not be elaborated here.

[0076] Please see Figure 4c , Figure 4c This is a schematic diagram of the structure of a switch biasing unit 1412 provided in another embodiment of this application.

[0077] In some embodiments, the first switch biasing unit 14121 includes a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4; the first capacitor C1 and the third capacitor C3 are connected in series between the source of the i-th first transistor Qi and the body of the m-th first transistor Qm, and the connection node of the first capacitor C1 and the third capacitor C3 is connected to the controlled terminal of the second transistor Q2; the second capacitor C2 is connected in antiparallel to the first capacitor C1, and the third capacitor C3 is connected in antiparallel to the fourth capacitor C4.

[0078] It should be understood that the first switch biasing unit 14121 can also simultaneously provide a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4 to provide a bias signal to the second transistor Q2, causing the second transistor Q2 to conduct intermittently, thereby achieving voltage division for each first transistor in the switch branch 13. By providing the third capacitor C3 and the fourth capacitor C4, the first switch biasing unit 14121 can provide a bias signal to the second transistor Q2 under both positive and negative voltage conditions, causing the second transistor Q2 to conduct to divide the voltage, thereby improving the voltage division effect of the circuit and further improving the uniformity of voltage division among multiple first transistors.

[0079] It should be noted that the capacitor configuration in the first switch biasing unit 14121 can be, but is not limited to, any of the three configuration methods described above. Furthermore, in each of the above configuration methods, at least one of the first capacitor C1, second capacitor C2, third capacitor C3, and fourth capacitor C4 can be multiple. For example, at least one capacitor may include multiple first capacitors C1, connected between the source of the i-th first transistor Qi and the body of the m-th first transistor Qm. Other configuration methods can refer to the configuration method of the first capacitor C1, and will not be repeated here. Similarly, at least one resistor may include multiple second capacitors C2, connected between the source of the i-th first transistor Qi and the body of the m-th first transistor Qm. Other configuration methods can refer to the configuration method of the second capacitor C2, and will not be repeated here. Furthermore, at least one resistor may also include multiple third capacitors C3 and / or multiple fourth capacitors C4. Specific configuration methods can refer to the configuration methods of the third capacitors C3 and fourth capacitors C4 described above, and will not be repeated here.

[0080] In addition, the above Figures 4a-4c Any of the embodiments described can be applied to the foregoing Figures 3a-3d In any of the described embodiments of the switch biasing unit 1412, those skilled in the art can select the corresponding embodiment based on the voltage difference between the first connection terminal 11 and the second connection terminal 12, the number of first transistors, the voltage difference between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi, etc., and this application does not limit it.

[0081] Please see Figure 5 , Figure 5 This is a schematic diagram of the voltage divider branch provided in another embodiment of this application.

[0082] In some embodiments, the switching unit 1411 of the first voltage divider branch 141 is a second switching unit 14112. The second switching unit 14112 includes at least one third transistor Q3 and at least one third resistor R3. The third transistor Q3 is connected between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi. The controlled terminal of the third transistor Q3 is connected to the switching biasing unit 1412 of the first voltage divider branch 141 through the third resistor R3.

[0083] For example, when the switching unit 1411 of the first voltage divider branch 141 is configured as the second switching unit 14112, the second switching unit 14112 includes at least one third transistor Q3 and at least one third resistor R3. The third transistor Q3 is connected between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi, so that when it is turned on, it can divide the voltage between the m-th first transistor Qm and the i-th first transistor Qi. The controlled terminal of the third transistor Q3 is connected to the switching bias unit 1412 of the first voltage divider branch 141 through the third resistor R3, so that the switching bias unit 1412 can provide a bias signal to the third transistor Q3 to control the third transistor Q3 to be turned on.

[0084] In the specific implementation process, the switch biasing unit 1412 connected to the third resistor R3 can be, for example, the first switch biasing unit 14121 provided above, or a switch biasing unit 1412 with a different structure from the first switch biasing unit 14121.

[0085] Please see Figure 6a , Figure 6a This is a schematic diagram of the structure of a switch biasing unit 1412 provided in an embodiment of this application.

[0086] In some embodiments, the switching bias unit 1412 of the first voltage divider branch 141 is a second switching bias unit 14122. The second switching bias unit 14122 includes at least one resistor and at least one capacitor C. The resistor and capacitor C are connected in series between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi. The resistor or capacitor C is also connected to a third resistor R3.

[0087] For example, the switch biasing unit 1412 connected to the third circuit is the second switch biasing unit 14122, and the second switch biasing unit 14122 includes at least one resistor and at least one capacitor connected in series between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi, and the resistor or capacitor C is connected to the third resistor R3 to realize the connection between the second switch biasing unit 14122 and the second switch unit 14112, so that when the second switch biasing unit 14122 provides a bias signal, the second switch unit 14112 is turned on, thereby realizing the voltage division of the first transistor.

[0088] It should be noted that the second switch bias unit 14122 can also be connected to the first switch unit 14111 to provide a bias signal to the first switch unit 14111, so that the first switch unit 14111 is turned on.

[0089] It should be understood that the capacitor in the second switch biasing unit 14122 plays the same role as the capacitor in the first switch biasing unit 14121, and will not be described again here.

[0090] For example, the resistor R in the second switch bias unit 14122 may be configured as described in one of the following embodiments.

[0091] Please continue reading. Figure 6a In some embodiments, at least one resistor in the second switch bias unit 14122 includes a fourth resistor R4, the first end of which is connected to the source of the i-th first transistor Qi, and the second end of which is connected to the body of the third resistor R3 and the m-th first transistor Qm via a capacitor.

[0092] Please see Figure 6b , Figure 6b This is a schematic diagram of the structure of a switch biasing unit 1412 provided in another embodiment of this application.

[0093] In another embodiment, at least one resistor in the second switch bias unit 14122 includes a fifth resistor R5, the first end of the fifth resistor R5 is connected to the source of the i-th first transistor Qi through a capacitor C, and the second end of the fifth resistor R5 is connected to the body of the third resistor R3 and the m-th first transistor Qm.

[0094] Please see Figure 6c , Figure 6c This is a schematic diagram of the structure of a switch biasing unit 1412 provided in another embodiment of this application.

[0095] In another embodiment, at least one resistor in the second switch bias unit 14122 includes a fourth resistor R4 and a fifth resistor R5. The first end of the fourth resistor R4 is connected to the source of the i-th first transistor Qi. The second end of the fourth resistor R4 is connected to the first end of the fifth resistor R5 through a capacitor. The second end of the fifth resistor R5 is connected to the body of the m-th first transistor Qm. The second end of the fifth resistor R5 is also connected to a third resistor R3.

[0096] It should be noted that the number of fourth resistor R4 and / or fifth resistor R5 in the above embodiments can be one or more. This application does not limit the specific number of fourth resistor R4 and fifth resistor R5.

[0097] Please see Figure 6d , Figure 6d This is a schematic diagram of the structure of a switch biasing unit 1412 provided in another embodiment of this application.

[0098] In some embodiments, the capacitors in the second switch biasing unit 14122 include a fifth capacitor C5 and a sixth capacitor C6 connected in reverse parallel.

[0099] It should be understood that the fifth capacitor C5 and the sixth capacitor C6 are similar to the first capacitor C1 and the second capacitor C2 mentioned above, and are directional. By setting the fifth capacitor C5 and the sixth capacitor C6 in reverse parallel, when the first transistor is turned off, regardless of whether the RF signal is in the positive or negative voltage range, the switching bias unit can intermittently provide a bias signal to the first switching unit 14111 or the second switching unit 14112, so that the first switching unit 14111 or the second switching unit 14112 is intermittently turned on. Then, the first switching unit 14111 or the second switching unit 14112 is turned on to achieve voltage division of the first transistor, so that the voltage division of the multiple stacked first transistors in the RF switching circuit is more uniform.

[0100] In one embodiment, the switching unit 1421 of the second voltage divider branch 142 is a third switching unit. The third switching unit includes at least one resistor and at least one fourth transistor. The resistor and the fourth transistor are connected in series between the body of the m-th first transistor Qm and the drain of the j-th first transistor Qj. The controlled terminal of the fourth transistor is connected to the switching bias unit 1422 of the second voltage divider branch 142.

[0101] For example, the switching unit 1421 of the second voltage divider branch 142 includes a fourth transistor, and the resistor and the fourth transistor are connected in series between the body of the m-th first transistor Qm and the drain of the j-th first transistor Qj; or the switching unit 1421 of the second voltage divider branch 142 includes multiple fourth transistors, and the multiple fourth transistors are connected in series with the resistor between the body of the m-th first transistor Qm and the drain of the j-th first transistor Qj, and the controlled terminals of each fourth transistor are interconnected.

[0102] For example, at least one resistor in the switching unit 1421 of the second voltage divider branch 142 includes a sixth resistor, the first end of which is connected to the drain of the j-th first transistor Qj, and the second end of which is connected to the body of the m-th first transistor Qm via a fourth transistor; or at least one resistor includes a seventh resistor, the first end of which is connected to the drain of the j-th first transistor Qj via a fourth transistor, and the second end of which is connected to the body of the m-th first transistor Qm; or at least one resistor includes a sixth resistor and a seventh resistor, wherein the sixth resistor, the fourth transistor, and the seventh resistor are connected in series between the drain of the j-th first transistor Qj and the body of the m-th first transistor Qm. For example, the first end of the sixth resistor is connected to the drain of the j-th first transistor Qj, the second end of the sixth resistor is connected to the first end of the seventh resistor via the fourth transistor, and the second end of the seventh resistor is connected to the body of the m-th first transistor Qm. It should be understood that one or more of the above-mentioned sixth and seventh resistors may be provided, and this is not limited here.

[0103] In the case of the switching unit 1421 of the second voltage divider branch 142 as described above, the switching bias unit 1422 of the second voltage divider branch 142 is a third switching bias unit. The third switching bias unit includes at least one capacitor connected between the drain of the j-th first transistor Qj and the body of the m-th first transistor Qm, and one end of the capacitor is connected to the controlled terminal of the fourth transistor.

[0104] For example, the switching bias unit 1422 of the second voltage divider branch 142 includes a seventh capacitor. The first end of the seventh capacitor is connected to the drain of the j-th first transistor Qj, and the second end of the seventh capacitor is connected to the controlled terminal of the fourth transistor and the body of the m-th first transistor Qm. The capacitance value of the seventh capacitor changes with the voltage difference across the seventh capacitor.

[0105] For example, the switching bias unit 1422 of the second voltage divider branch 142 also includes an eighth capacitor, which is connected in reverse parallel with the seventh capacitor, and the capacitance value of the eighth capacitor varies according to the voltage difference across the eighth capacitor.

[0106] For example, the switching bias unit 1422 of the second voltage divider branch 142 includes a seventh capacitor, an eighth capacitor, a ninth capacitor, and a tenth capacitor; the seventh capacitor and the ninth capacitor are connected in series between the body of the m-th first transistor Qm and the drain of the j-th first transistor Qj, and the connection node of the seventh capacitor and the ninth capacitor is connected to the controlled terminal of the fourth transistor; the eighth capacitor is connected in antiparallel to the seventh capacitor, and the ninth capacitor is connected in antiparallel to the tenth capacitor.

[0107] In another embodiment, the switching unit 1421 of the second voltage divider branch 142 includes at least one fifth transistor and at least one eighth resistor. The fifth transistor is connected between the body of the m-th first transistor Qm and the drain of the j-th first transistor Qj. The controlled terminal of the fifth transistor is connected to the switching bias unit of the second voltage divider branch 142 through the eighth resistor.

[0108] In the embodiment described above, where the switching unit 1421 of the second voltage divider branch 142 is the switching bias unit 1422, the switching bias unit 1422 of the second voltage divider branch 142 is the fourth switching bias unit. The structure of the fourth switching bias unit can be the same as that of the second switching bias unit, except that the fourth switching bias unit is connected between the body of the m-th first transistor Qm and the drain of the j-th first transistor Qj. That is, the switching bias unit 1422 of the second voltage divider branch 142 includes at least one resistor and at least one capacitor, which are connected in series between the body of the m-th first transistor Qm and the drain of the j-th first transistor Qj. The resistor or capacitor is also connected to the eighth resistor.

[0109] For example, at least one resistor in the fourth switch biasing unit includes a ninth resistor, the first end of which is connected to the drain of the j-th first transistor Qj, and the second end of which is connected to the eighth resistor and the body of the m-th first transistor Qm via a capacitor; or, at least one resistor in the fourth switch biasing unit includes a tenth resistor, the first end of which is connected to the drain of the j-th first transistor Qj via a capacitor, and the second end of which is connected to the eighth resistor and the body of the m-th first transistor Qm; or, at least one resistor in the fourth switch biasing unit includes a ninth resistor and a tenth resistor, the first end of which is connected to the drain of the j-th first transistor Qj, the second end of which is connected to the first end of the tenth resistor via a capacitor, and the second end of the tenth resistor is connected to the eighth resistor and the body of the m-th first transistor Qm.

[0110] For example, the capacitors in the switching bias unit 1422 of the second voltage divider branch 142 include an eleventh capacitor and a twelfth capacitor connected in reverse parallel.

[0111] It should be understood that the above Figures 6a-6d The corresponding embodiments can all be applied to Figure 5In the corresponding voltage divider branch, those skilled in the art can select any of the above embodiments based on the voltage difference between the first connection terminal 11 and the second connection terminal 12, the number of first transistors, the voltage difference between the body of the m-th first transistor Qm and the source of the i-th first transistor Qi, etc., and this application does not limit it.

[0112] It should be noted that the switching unit 1411 and the switching bias unit 1412 in the second voltage divider branch 142 in the preceding embodiments can be configured with reference to the configuration of the switching unit 1411 and the switching bias unit 1412 in the first voltage divider branch 141. For example, the switching unit 1411 in the second voltage divider branch 142 can have the same circuit structure as the switching unit in the first voltage divider branch 141, and the connection relationship between these two switching units can be symmetrically arranged with the body pole of the m-th first transistor Qm as the center. For example, the switching bias unit 1412 in the second voltage divider branch 142 can have the same circuit structure as the switching bias unit in the first voltage divider branch 141, and the connection relationship between these two switching bias units can be symmetrically arranged with the body pole of the m-th first transistor Qm as the center.

[0113] In some embodiments, the nth to zth first transistors are not connected to the voltage divider branch, where n and z are both positive integers and satisfy the following relationship: 0.25N < n < z < 0.75N.

[0114] It should be noted that, due to the characteristics of the stacked structure formed by multiple series-connected first transistors in the switching branch 13, when the number of first transistors is large, the voltage division unevenness of the first transistors near the two ends of the switching branch 13 will be more obvious, while the voltage division unevenness between the first transistors located in the middle part of the switching branch 13 is less severe. Therefore, the first transistors in the middle part can be left unconnected to the voltage divider branch to save on the hardware cost of the RF switching circuit.

[0115] For example, the nth to zth first transistors are not connected to the voltage divider branch. The number of first transistors before the nth first transistor Qn is not less than one-quarter of the total number of first transistors. Similarly, the number of first transistors after the zth first transistor is not less than one-quarter of the total number of first transistors. This ensures that the first transistors near both ends of the switch branch 13 can achieve voltage division more uniformly. Furthermore, setting the first transistors in the middle part to not be connected to the voltage divider branch simplifies the structure of the RF switch circuit and reduces manufacturing costs.

[0116] Furthermore, both the first transistor and the second transistor Q2 mentioned above are field-effect transistors, and the size of the first transistor is larger than the size of the second transistor Q2.

[0117] In some embodiments, the first connection terminal 11 of the RF switch circuit is used to connect to the antenna through the tuning component, and the second connection terminal 12 of the RF switch circuit is used to ground or connect to the RF front-end module.

[0118] In the specific implementation process, the first connection terminal 11 of the RF switch circuit is also used to connect the antenna through the tuning component, and the second connection terminal 12 of the RF switch circuit is also used to ground or connect the RF front-end module to realize the reception and transmission of RF signals, and can also realize antenna impedance tuning to improve antenna efficiency.

[0119] The RF switching circuit provided in the above embodiment connects the body of the m-th first transistor Qm to the source of the i-th first transistor Qi through a first voltage divider branch 141, and connects the body of the m-th first transistor Qm to the drain of the j-th first transistor Qj through a second voltage divider branch 142. Both the first voltage divider branch 141 and the second voltage divider branch 142 include a switching unit 1411 and a switching bias unit 1412. When the first transistor is turned off, the switching bias unit 1412 can transmit a bias signal to the switching unit 1411, causing the switching unit 1411 to intermittently... The circuit is turned on, allowing the current at the source of the i-th first transistor Qi to flow through the switched unit 1411 in the first voltage divider branch 141 to the drain of the j-th first transistor Qj, and the current leaking from the body of the m-th first transistor Qm to flow through the switched unit 1411 in the second voltage divider branch 142 to the drain of the j-th first transistor Qj. This achieves voltage division of the first transistors in the RF switching circuit, reduces the voltage that some of the first transistors need to withstand, makes the voltage distribution of the RF switching circuit more uniform, and thus improves the withstand voltage capability of the RF switching circuit.

[0120] Please see Figure 7 , Figure 7 This is a schematic diagram of a radio frequency module provided in an embodiment of this application.

[0121] This application also provides a radio frequency (RF) module, wherein the RF module includes the RF switch circuit 10 provided in any of the embodiments above; the RF module can be applied to electronic devices, for example, electronic devices include smartphones, tablets, smartwatches and other devices with communication functions, and the above electronic devices can all communicate with the outside world through the RF module.

[0122] Please see Figure 8 , Figure 8 This is a schematic diagram of an antenna tuner provided in one embodiment of this application.

[0123] This application also provides an antenna tuner, wherein the antenna tuner includes multiple parallel tuning branches, each tuning branch including a tuning component and a radio frequency switch circuit 10 as provided in any of the embodiments above. The radio frequency switch circuit 10 is connected in series with the tuning component. The operating state of the antenna tuner can be adjusted through the radio frequency switch circuit 10 to realize the transmission and reception of radio frequency signals and eliminate unnecessary resonance, thereby improving the performance of the antenna. Specifically, the antenna tuner can be applied to the above-mentioned electronic devices. For example, when applied to a mobile terminal, the antenna can be tuned through the antenna tuner to achieve more optimized performance over a wider frequency range.

[0124] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0125] It should also be understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. It should be noted that, herein, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0126] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above descriptions are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A radio frequency switching circuit, characterized in that, include: First connecting end and second connecting end; The voltage divider branch includes a first voltage divider branch and a second voltage divider branch, both of which include a switching unit and a switching biasing unit. A switching branch includes N first transistors connected in series between the first connection terminal and the second connection terminal. The body of the m-th first transistor is connected to the source of the i-th first transistor through a switching unit in the first voltage divider branch, and the body of the m-th first transistor is connected to the drain of the j-th first transistor through a switching unit in the second voltage divider branch. N, m, i, and j are all positive integers and satisfy the following relationship: ; When all N first transistors are turned off, the switch biasing unit in each voltage divider branch is used to intermittently provide a bias signal to the switch unit in the same voltage divider branch, so that the switch unit is intermittently turned on.

2. The radio frequency switching circuit as described in claim 1, characterized in that, The body of the first transistor is connected to the drain of the xth transistor through the second voltage divider branch; the body of the Nth transistor is connected to the source of the yth transistor through the first voltage divider branch, where x and y are both positive integers and satisfy the following relationship: 1 < x ≤ 5, N - 4 ≤ y < N.

3. The radio frequency switching circuit as described in claim 2, characterized in that, N, m, i, j, x, and y also satisfy the following relationships: x-1=jm, Ny=mi.

4. The radio frequency switching circuit as described in claim 1, characterized in that, m, i, and j also satisfy the following relationship: mi≤4, jm≤4.

5. The radio frequency switching circuit as described in claim 1, characterized in that, m, i, and j also satisfy the following relationship: mi = jm.

6. The radio frequency switching circuit according to any one of claims 1-5, characterized in that, Both the first voltage divider branch and the second voltage divider branch include at least one second transistor and at least one capacitor; The second transistor is connected between the first and second ends of the corresponding voltage divider branch, and the capacitor is connected between the gate of the second transistor and the first or second end of the corresponding voltage divider branch.

7. The radio frequency switching circuit according to claim 6, wherein the number of second transistors in the first voltage divider branch is equal to the number of second transistors in the second voltage divider branch, and the number of capacitors in the first voltage divider branch is equal to the number of capacitors in the second voltage divider branch.

8. The radio frequency switching circuit according to any one of claims 1-5, characterized in that, The switching unit of the first voltage divider branch is a first switching unit; the first switching unit includes at least one resistor and at least one second transistor, the resistor and the second transistor are connected in series between the body of the m-th first transistor and the source of the i-th first transistor, and the controlled terminal of the second transistor is connected to the switching bias unit of the first voltage divider branch. and / or The switching unit of the second voltage divider branch is a third switching unit, which includes at least one resistor and at least one fourth transistor. The resistor and the fourth transistor are connected in series between the body of the m-th first transistor and the drain of the j-th first transistor. The controlled terminal of the fourth transistor is connected to the switching bias unit of the second voltage divider branch.

9. The radio frequency switching circuit as described in claim 8, characterized in that, The first switching unit includes a second transistor, and the resistor and the second transistor are connected in series between the body of the m-th first transistor and the source of the i-th first transistor; or, the first switching unit includes a plurality of second transistors, and the plurality of second transistors are connected in series with the resistor between the body of the m-th first transistor and the source of the i-th first transistor, and the controlled terminals of each second transistor are interconnected. And / or, The third switching unit includes a fourth transistor, and the resistor and the fourth transistor are connected in series between the body of the m-th first transistor and the drain of the j-th first transistor; or, the switching unit of the second voltage divider branch includes multiple fourth transistors, and the multiple fourth transistors and the resistor are connected in series between the body of the m-th first transistor and the drain of the j-th first transistor, and the controlled terminals of each of the fourth transistors are interconnected.

10. The radio frequency switching circuit as described in claim 9, characterized in that, At least one resistor in the first switching unit includes a first resistor, the first end of which is connected to the source of the i-th first transistor, and the second end of which is connected to the body of the m-th first transistor through the second transistor. Alternatively, at least one resistor in the first switching unit includes a second resistor, the first end of which is connected to the source of the i-th first transistor via the second transistor, and the second end of which is connected to the body of the m-th first transistor. Alternatively, at least one resistor in the first switching unit includes a first resistor and a second resistor, the first end of the first resistor is connected to the source of the i-th first transistor, the second end of the first resistor is connected to the first end of the second resistor through the second transistor, and the second end of the second resistor is connected to the body of the m-th first transistor. And / or, At least one resistor in the third switching unit includes a sixth resistor, the first end of which is connected to the drain of the j-th first transistor, and the second end of which is connected to the body of the m-th first transistor through the fourth transistor. Alternatively, at least one resistor in the third switching unit includes a seventh resistor, the first end of which is connected to the drain of the j-th first transistor through the fourth transistor, and the second end of which is connected to the body of the m-th first transistor. Alternatively, at least one resistor in the third switching unit includes a sixth resistor and a seventh resistor, the first end of the sixth resistor is connected to the drain of the j-th first transistor, the second end of the sixth resistor is connected to the first end of the seventh resistor through the fourth transistor, and the second end of the seventh resistor is connected to the body of the m-th first transistor.

11. The radio frequency switching circuit as described in claim 8, characterized in that, The switching bias unit of the first voltage divider branch is a first switching bias unit, which includes at least one capacitor connected between the source of the i-th first transistor and the body of the m-th first transistor, and one end of the capacitor is connected to the controlled terminal of the second transistor; and / or The switching bias unit of the second voltage divider branch is a third switching bias unit. The third switching bias unit includes at least one capacitor. The capacitor is connected between the drain of the j-th first transistor and the body of the m-th first transistor, and one end of the capacitor is connected to the controlled terminal of the fourth transistor.

12. The radio frequency switching circuit as described in claim 11, characterized in that, The first switch biasing unit includes a first capacitor, a first terminal of which is connected to the source of the i-th first transistor, and a second terminal of which is connected to the controlled terminal of the second transistor and the body of the m-th first transistor; wherein the capacitance value of the first capacitor changes with the voltage difference across the first capacitor; and or, The third switch bias unit includes a seventh capacitor. The first end of the seventh capacitor is connected to the drain of the j-th first transistor, and the second end of the seventh capacitor is connected to the controlled terminal of the fourth transistor and the body of the m-th first transistor. The capacitance of the seventh capacitor changes with the voltage difference across the seventh capacitor.

13. The radio frequency switching circuit as described in claim 12, characterized in that, The first switch biasing unit further includes a second capacitor; the second capacitor is connected in reverse parallel with the first capacitor, and the capacitance value of the second capacitor changes with the voltage difference across the second capacitor; and / or, The third switch bias unit also includes an eighth capacitor, which is connected in parallel with the seventh capacitor in reverse, and the capacitance value of the eighth capacitor changes with the voltage difference across the eighth capacitor.

14. The radio frequency switching circuit as described in claim 11, characterized in that, The first switch bias unit includes a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor; the first capacitor and the third capacitor are connected in series between the source of the i-th first transistor and the body of the m-th first transistor, and the connection node of the first capacitor and the third capacitor is connected to the controlled terminal of the second transistor; the second capacitor is connected in antiparallel to the first capacitor, and the third capacitor is connected in antiparallel to the fourth capacitor. And / or, The third switch bias unit includes a seventh capacitor, an eighth capacitor, a ninth capacitor, and a tenth capacitor; the seventh capacitor and the ninth capacitor are connected in series between the body of the m-th first transistor and the drain of the j-th first transistor, and the connection node of the seventh capacitor and the ninth capacitor is connected to the controlled terminal of the fourth transistor. The eighth capacitor is connected in anti-parallel with the seventh capacitor, and the ninth capacitor is connected in anti-parallel with the tenth capacitor.

15. The radio frequency switching circuit as described in claim 1, characterized in that, The switching unit of the first voltage divider branch is a second switching unit. The second switching unit includes at least one third transistor and at least one third resistor. The third transistor is connected between the body of the m-th first transistor and the source of the i-th first transistor. The controlled terminal of the third transistor is connected to the switching bias unit of the first voltage divider branch through the third resistor. and / or The switching unit of the second voltage divider branch is a fourth switching unit, which includes at least one fifth transistor and at least one eighth resistor. The fifth transistor is connected between the body of the m-th first transistor and the drain of the j-th first transistor. The controlled terminal of the fifth transistor is connected to the switching bias unit of the second voltage divider branch through the eighth resistor.

16. The radio frequency switching circuit as described in claim 15, characterized in that, The switching bias unit of the first voltage divider branch is a second switching bias unit. The second switching bias unit includes at least one resistor and at least one capacitor. The resistor and the capacitor are connected in series between the body of the m-th first transistor and the source of the i-th first transistor. The resistor or the capacitor is also connected to the third resistor. and / or The switching bias unit of the second voltage divider branch is a fourth switching bias unit. The fourth switching bias unit includes at least one resistor and at least one capacitor. The resistor and the capacitor are connected in series between the body of the m-th first transistor Qm and the drain of the j-th first transistor Qj. The resistor or the capacitor is also connected to the eighth resistor.

17. The radio frequency switching circuit as described in claim 16, characterized in that, At least one resistor in the second switch bias unit includes a fourth resistor, the first end of which is connected to the source of the i-th first transistor, and the second end of which is connected to the third resistor and the body of the m-th first transistor through the capacitor; Alternatively, at least one resistor in the second switch bias unit includes a fifth resistor, the first end of which is connected to the source of the i-th first transistor through the capacitor, and the second end of which is connected to the third resistor and the body of the m-th first transistor. Alternatively, at least one resistor in the second switch bias unit includes a fourth resistor and a fifth resistor, the first end of the fourth resistor is connected to the source of the i-th first transistor, the second end of the fourth resistor is connected to the first end of the fifth resistor through the capacitor, the second end of the fifth resistor is connected to the body of the m-th first transistor, and the second end of the fifth resistor is also connected to the third resistor; and / or At least one resistor in the fourth switch bias unit includes a ninth resistor, the first end of which is connected to the drain of the j-th first transistor, and the second end of which is connected to the eighth resistor and the body of the m-th first transistor through the capacitor. Alternatively, at least one resistor in the fourth switch bias unit includes a tenth resistor, the first end of which is connected to the drain of the j-th first transistor through the capacitor, and the second end of which is connected to the eighth resistor and the body of the m-th first transistor. Alternatively, at least one resistor in the fourth switch bias unit includes a ninth resistor and a tenth resistor, the first end of the ninth resistor is connected to the drain of the j-th first transistor, the second end of the ninth resistor is connected to the first end of the tenth resistor through a capacitor, and the second end of the tenth resistor is connected to the eighth resistor and the body of the m-th first transistor.

18. The radio frequency switching circuit as described in claim 16 or 17, characterized in that, The capacitors in the second switch biasing unit include a fifth capacitor and a sixth capacitor connected in reverse parallel; and / or, the capacitors in the fourth switch biasing unit include an eleventh capacitor and a twelfth capacitor connected in reverse parallel.

19. The radio frequency switching circuit according to any one of claims 1-5, characterized in that, The first transistors from the nth to the zth are not connected to the voltage divider branch, where n and z are both positive integers and satisfy the following relationship: 0.25N < n < z < 0.75N.

20. The radio frequency switching circuit according to any one of claims 1-5, characterized in that, When the radio frequency signal is transmitted between the first connection terminal and the second connection terminal of the switch branch, it passes through the i-th first transistor, the m-th first transistor, and the j-th first transistor in sequence.

21. The radio frequency switch circuit according to any one of claims 1-5, wherein the first connection terminal of the radio frequency switch circuit is used to connect to an antenna through a tuning component, and the second connection terminal of the radio frequency switch circuit is used to ground or connect to a radio frequency front-end module.

22. A radio frequency module, characterized in that, The radio frequency module includes the radio frequency switching circuit as described in any one of claims 1-21.

23. An antenna tuner, characterized in that, It includes multiple parallel tuning branches, each tuning branch including a tuning component and a radio frequency switch circuit as described in any one of claims 1-21, wherein the radio frequency switch circuit is connected in series with the tuning component.

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