Radio frequency switch circuit and radio frequency chip

Abstract

The utility model relates to wireless communication technical field provides a kind of radio frequency switch circuit and radio frequency chip, radio frequency switch circuit includes the switch bias unit, tuning switch unit and antenna tuning device connected in turn;Switch bias unit includes negative pressure generation module, positive pressure generation module, logic control module and at least two voltage drive modules;The output end of negative pressure generation module and the output end of positive pressure generation module are connected respectively the input end of logic control module;The output end of logic control module is connected respectively the input end of at least two voltage drive modules;Logic control module is used to receive negative pole bias voltage signal and positive pole bias voltage signal and generate control signal, voltage drive module is used to receive control signal and convert into drive signal, tuning switch unit receives drive signal and realizes switch switching control.The utility model's radio frequency switch circuit can optimize the switching time of tuning switch under the condition of keeping switch loss unchanged.

Description

Technical Field

[0001] This utility model relates to the field of wireless communication technology, and in particular to a radio frequency switch circuit and a radio frequency chip. Background Technology

[0002] With the rapid development of integrated circuits and wireless communication technologies, mobile phones have become necessities in people's lives. Entering the 5G era, users' demands for data transmission speed and stability are constantly increasing, leading to a continuous increase in the number of frequency bands, functions, and modes required for smartphone operation. To meet this demand, the wireless communication field generally uses CA (carrier aggregation), MIMO (multiple-input multiple-output), and new broadband 5G frequency bands to provide higher data rates, thus requiring more antennas in mobile phones. At the same time, more antennas reduce the space available for individual antennas, ultimately leading to reduced antenna efficiency. Currently, to overcome the problems caused by reduced antenna area and efficiency, the mainstream method is to use antenna tuning devices in conjunction with antenna adjustment switches to tune the antenna. A fast-responding antenna tuning switch is indispensable.

[0003] The switching time of the tuner switch directly affects the response capability of the entire system. Switching time is defined as the time required for the RF (radio frequency) output to increase to 90% (on time) or decrease to 10% (off time) when the control voltage is at 50%. Since switching time is generally inversely proportional to switching losses (IL), improving switching time without increasing switching losses is crucial for tuner switch design.

[0004] In traditional tuned switch designs, to meet the high voltage withstand requirements of applications, a series multi-stage field-effect transistor is typically used to achieve the design goal. If the application requires the tuner switch to have a power withstand capability of 48dBm, under 50 ohms conditions, this translates to a voltage of nearly 80V.

[0005] Currently, the mainstream process for RF switches has a single field-effect transistor with a withstand voltage of about 3V. Therefore, in order to meet application requirements, it is usually necessary to connect 28 stacks in series.

[0006] Typical tuner switches require very low losses. For tuner switches composed of field-effect transistors (FETs), since the FETs operate in the linear region, their on-resistance is equal to the channel resistance. Therefore, the equivalent resistance expression can be derived as follows:

[0007]

[0008] Where Ron is the equivalent on-resistance, gm is the transconductance of the transistor, and u nVx is the carrier mobility of the transistor, Cox is the gate oxide capacitance per unit area of ​​the transistor, Vgs is the gate-source voltage of the transistor, Vth is the threshold voltage of the transistor, W is the gate width of the transistor, and L is the gate length of the transistor.

[0009] In typical applications (RF port impedance R0 = 50Ω), the switching loss is expressed as:

[0010]

[0011] Combining the above expressions, we can see that the switch loss (IL) is inversely proportional to the gate width (W) and directly proportional to the gate length (L).

[0012] The switching time is essentially the process of changing the gate voltage of a field-effect transistor (FET) through charging and discharging, which is the RC time constant. R is the gate resistance, which is not involved in this parameter and can be considered a constant. C is the gate capacitance of the FET. Typically, the gate width (L) is limited by process nodes and cannot be reduced indefinitely, so a large gate width (W) is needed to meet the requirements for low power loss (IL) in applications. However, a large gate width (W) leads to a large gate capacitance in the FET, resulting in a very slow switching time. Therefore, traditional designs struggle to achieve fast switching times.

[0013] In related technologies, such as Figure 1 As shown, the tuning switch includes a switch bias unit, a switch unit, and an antenna tuning device connected in sequence. The antenna tuning device is connected to the antenna end. The switch unit includes multiple field-effect transistors connected in series. The switch bias unit includes a negative voltage generation module, a positive voltage generation module, and a logic control voltage drive module. The negative voltage generation module and the positive voltage generation module convert the power supply into negative and positive voltage signals. The logic control voltage drive module receives the positive and negative voltage signals and generates corresponding control signals to control the switch unit, thereby realizing the switching control effect of the field-effect transistor.

[0014] However, during the switching process, the control voltage is generated internally by the chip and has limited driving capability. One characteristic of tuned switches is the large number of series-connected stacks (transistor stacks) and the large switching area, resulting in a large gate capacitance C for the equivalent current i. This causes the internal voltage, which has limited driving capability, to be pulled down to a very low value during the switching process, thereby reducing the charging and discharging speed and consequently reducing the switching time, leading to greater switching losses. Utility Model Content

[0015] To address the shortcomings of the existing technology, this utility model proposes a radio frequency switch circuit and radio frequency chip to solve the problems of low charging and discharging speed and reduced switching time in existing radio frequency switch circuits.

[0016] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0017] In a first aspect, the present invention provides a radio frequency switch circuit, the radio frequency switch circuit comprising a switch bias unit, a tuning switch unit and an antenna tuning device connected in sequence;

[0018] The switching bias unit includes a negative voltage generation module, a positive voltage generation module, a logic control module, and at least two voltage drive modules. The input terminals of the negative voltage generation module and the positive voltage generation module are respectively connected to a power supply. The output terminals of the negative voltage generation module and the positive voltage generation module are respectively connected to the input terminals of the logic control module. The output terminals of the logic control module are respectively connected to the input terminals of at least two of the voltage drive modules. The negative voltage generation module generates a negative bias voltage signal, the positive voltage generation module generates a positive bias voltage signal, the logic control module receives the negative bias voltage signal and the positive bias voltage signal and generates a control signal, the voltage drive modules receive the control signal and convert it into a drive signal before outputting it, and the tuning switch unit receives the drive signal to achieve switch switching control.

[0019] The tuning switch unit includes at least two switching modules connected in series; the output terminals of the two voltage drive modules are respectively connected to the input terminals of the two switching modules, and the output terminal of one of the two switching modules is connected to the input terminal of the antenna tuning device; the output terminal of the other of the two switching modules is connected to the ground terminal of one of the switching modules, and the ground terminal of the other switching module is grounded; the output terminal of the antenna tuning device is used to connect to the antenna.

[0020] Preferably, the voltage drive module comprises N units, and the switch module comprises N units connected in series, with each of the N voltage drive modules corresponding to one of the N switch modules; wherein, N>2;

[0021] The input terminals of the first voltage driving module to the Nth voltage driving module are interconnected and jointly connected to the output terminal of the logic control module; the output terminals of the first voltage driving module to the Nth voltage driving module are respectively connected one-to-one to the input terminals of the first switch module to the Nth switch module; among the N switch modules connected in series, the output terminal of the first switch module is connected to the input terminal of the antenna tuning device, and the ground terminal of the previous switch module is connected to the output terminal of the next switch module, and the ground terminal of the Nth switch module is grounded.

[0022] Preferably, the switching module includes a transistor and a resistor; the first end of the resistor serves as the input terminal of the switching module, the second end of the resistor is connected to the gate of the transistor, the source of the transistor serves as the ground terminal of the switching module, the drain of the transistor serves as the output terminal of the switching module, the substrate terminal of the transistor is connected to the output terminal of the voltage driving module, and the output terminal of the voltage driving module is used to output a control voltage to control the substrate voltage of the transistor.

[0023] Preferably, the transistor is an NMOS transistor or a PMOS transistor.

[0024] Preferably, the antenna tuning device is a capacitor.

[0025] Secondly, this utility model embodiment provides a radio frequency chip, including the radio frequency switching circuit described above.

[0026] Compared with related technologies, in the embodiments of this utility model, the switch biasing unit, the tuning switch unit, and the antenna tuning device are electrically connected sequentially; the input terminals of the negative voltage generation module and the positive voltage generation module of the switch biasing unit are respectively connected to the power supply, and the output terminals of the negative voltage generation module and the positive voltage generation module are respectively connected to the input terminals of the logic control module; the output terminals of the logic control module are respectively connected to the input terminals of at least two voltage driving modules; the negative voltage generation module is used to generate a negative bias voltage signal, the positive voltage generation module is used to generate a positive bias voltage signal, the logic control module is used to receive the negative bias voltage signal and the positive bias voltage signal and generate a control signal, the voltage driving module is used to receive the control signal and convert it into a driving signal and output it, and the tuning switch unit receives the driving signal to realize the switching. Switching control; the tuning switch unit includes at least two switching modules electrically connected in sequence; the output terminals of the two voltage drive modules are respectively connected to the input terminals of the two switching modules; the output terminal of one of the two switching modules is connected to the input terminal of the antenna tuning device; the output terminal of the other switching module is connected to the ground terminal of one of the switching modules, and the ground terminal of the other switching module is grounded; the output terminal of the antenna tuning device is used to connect to the antenna terminal; by connecting any switching module to a voltage drive module, each part is powered by an independent voltage drive module, thus reducing the load of each voltage drive module by 1 / N. Under the same control voltage, the charging and discharging speed can be greatly accelerated, thereby improving the switching time without sacrificing switching losses. Attached Figure Description

[0027] The present invention will now be described in detail with reference to the accompanying drawings. The above and other aspects of the present invention will become clearer and easier to understand through the detailed description in conjunction with the following drawings. In the drawings:

[0028] Figure 1 A block diagram of a radio frequency switching circuit provided for related technologies;

[0029] Figure 2 A structural block diagram of the radio frequency switch circuit provided in the embodiment of this utility model.

[0030] Among them, 100 is the radio frequency switch circuit, 1 is the switch bias unit, 11 is the negative voltage generation module, 12 is the positive voltage generation module, 13 is the logic control module, 14 is the voltage drive module, 2 is the tuning switch unit, 21 is the switch module, 3 is the antenna tuning device, and 4 is the antenna end. Detailed Implementation

[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 this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0032] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] Example 1

[0035] Please see Figure 2 As shown, this utility model embodiment provides a radio frequency switch circuit 100, which includes a switch bias unit 1, a tuning switch unit 2, and an antenna tuning device 3 connected in sequence.

[0036] The switching bias unit 1 includes a negative voltage generation module 11, a positive voltage generation module 12, a logic control module 13, and at least two voltage drive modules 14. The input terminals of the negative voltage generation module 11 and the positive voltage generation module 12 are respectively connected to a power supply. The output terminals of the negative voltage generation module 11 and the positive voltage generation module 12 are respectively connected to the input terminals of the logic control module 13. The output terminals of the logic control module 13 are respectively connected to the input terminals of at least two of the voltage drive modules 14. The negative voltage generation module 11 generates a negative bias voltage signal, the positive voltage generation module 12 generates a positive bias voltage signal, and the logic control module 13 receives the negative and positive bias voltage signals and generates a control signal. The voltage drive modules 14 receive the control signal, convert it into a drive signal, and output it. The tuning switch unit 2 receives the drive signal to implement switch switching control.

[0037] The tuning switch unit 2 includes at least two switch modules 21 connected in series. The output terminals of the two voltage drive modules 14 are respectively connected to the input terminals of the two switch modules 21. The output terminal of one of the two switch modules 21 is connected to the input terminal of the antenna tuning device 3. The output terminal of the other switch module 21 is connected to the ground terminal of one of the switch modules 21, and the ground terminal of the other switch module 21 is grounded. The output terminal of the antenna tuning device 3 is used to connect to the antenna terminal 4. By connecting any switch module 21 to a voltage drive module 14, each part is powered by an independent voltage drive module 14. In this way, the load of each voltage drive module 14 is reduced by 1 / N. Under the same control voltage, the charging and discharging speed can be greatly accelerated, thereby improving the switching time without sacrificing switching losses.

[0038] In this embodiment, the voltage drive module 14 includes N units connected in series, and the switch module 21 includes N units. The N voltage drive modules 14 correspond one-to-one with the N switch modules 21; where N ≥ 2 and N is a positive integer.

[0039] The input terminals of the first voltage drive module 14 and the Nth voltage drive module 14 are interconnected and jointly connected to the output terminal of the logic control module 13. The output terminals of the first voltage drive module 14 and the Nth voltage drive module 14 are respectively connected to the input terminals of the first and Nth switch modules 21. In the N switch modules 21 connected in series, the output terminal of the first switch module 21 is connected to the input terminal of the antenna tuning device 3, and the ground terminal of the preceding switch module 21 is connected to the output terminal of the following switch module 21. The ground terminal of the Nth switch module 21 is grounded. By connecting the first switch module 21 to the first voltage drive module 14 and the Nth switch module 21 to the Nth voltage drive module 14, each segment is powered by an independent voltage drive module 14. This effectively reduces the load of each voltage drive module 14 by 1 / N, significantly accelerating the charging and discharging speed under the same control voltage, thereby improving the switching time without sacrificing switching losses.

[0040] In this embodiment, the switching module 21 includes a transistor M1 and a resistor R1. The first end of the resistor R1 serves as the input terminal of the switching module 21, the second end of the resistor R1 is connected to the gate of the transistor M1, the source of the transistor M1 serves as the ground terminal of the switching module 21, the drain of the transistor M1 serves as the output terminal of the switching module 21, and the substrate of the transistor M1 is connected to the output terminal of the voltage driving module 14. The output terminal of the voltage driving module is used to output a control voltage to control the substrate voltage of the transistor. Optionally, multiple switching modules 21 include multiple transistors (M1-Mn) and multiple resistors (R1-Rn), where n is a positive integer. In the SOI process, both the substrate and gate of the switching module 21 can be externally connected to a voltage. The output terminal of the voltage driving module 14 outputs a control voltage to control the substrate voltage of the switching module 21, achieving a switching control effect.

[0041] In this embodiment, the transistors (M1-Mn) are NMOS or PMOS transistors. NMOS or PMOS transistors facilitate the control of the switching on and off.

[0042] In this embodiment, the antenna tuning device 3 is a capacitor. Optionally, the antenna tuning device 3 can also be an inductor, with the first end of the inductor serving as the input terminal of the antenna tuning device 3 and the second end serving as the output terminal. Of course, depending on actual needs, the antenna tuning device 3 can also be designed as a combination circuit of a capacitor and an inductor.

[0043] Example 2

[0044] This embodiment of the invention provides a radio frequency (RF) chip, including the RF switch circuit 100 as described above. The technical effects produced by the RF chip are the same as those of the RF switch circuit 100 described above, and will not be described again here.

[0045] It should be noted that the various embodiments described above with reference to the accompanying drawings are only illustrative of the present invention and not intended to limit its scope. Those skilled in the art should understand that any modifications or equivalent substitutions made to the present invention without departing from its spirit and scope should be covered within the scope of the present invention. Furthermore, unless the context otherwise requires, singular terms include plural forms, and vice versa. Additionally, unless specifically stated otherwise, all or part of any embodiment may be used in conjunction with all or part of any other embodiment.

Claims

1. A radio frequency switching circuit, characterized in that, The radio frequency switch circuit includes a switch bias unit, a tuning switch unit, and an antenna tuning device that are connected in sequence. The switching bias unit includes a negative voltage generation module, a positive voltage generation module, a logic control module, and at least two voltage drive modules. The input terminals of the negative voltage generation module and the positive voltage generation module are respectively connected to a power supply. The output terminals of the negative voltage generation module and the positive voltage generation module are respectively connected to the input terminals of the logic control module. The output terminals of the logic control module are respectively connected to the input terminals of at least two of the voltage drive modules. The negative voltage generation module generates a negative bias voltage signal, the positive voltage generation module generates a positive bias voltage signal, the logic control module receives the negative bias voltage signal and the positive bias voltage signal and generates a control signal, the voltage drive modules receive the control signal and convert it into a drive signal before outputting it, and the tuning switch unit receives the drive signal to achieve switch switching control. The tuning switch unit includes at least two switching modules connected in series; the output terminals of the two voltage drive modules are respectively connected to the input terminals of the two switching modules, and the output terminal of one of the two switching modules is connected to the input terminal of the antenna tuning device; the output terminal of the other of the two switching modules is connected to the ground terminal of one of the switching modules, and the ground terminal of the other switching module is grounded; the output terminal of the antenna tuning device is used to connect to the antenna.

2. The radio frequency switching circuit according to claim 1, characterized in that, The voltage drive module comprises N units, and the switch module comprises N units connected in series, with each of the N voltage drive modules corresponding to one of the N switch modules; wherein, N>2; The input terminals of the first voltage driving module to the Nth voltage driving module are interconnected and jointly connected to the output terminal of the logic control module; the output terminals of the first voltage driving module to the Nth voltage driving module are respectively connected one-to-one to the input terminals of the first switch module to the Nth switch module; among the N switch modules connected in series, the output terminal of the first switch module is connected to the input terminal of the antenna tuning device, and the ground terminal of the previous switch module is connected to the output terminal of the next switch module, and the ground terminal of the Nth switch module is grounded.

3. The radio frequency switching circuit according to claim 1, characterized in that, The switching module includes a transistor and a resistor; the first end of the resistor serves as the input terminal of the switching module, the second end of the resistor is connected to the gate of the transistor, the source of the transistor serves as the ground terminal of the switching module, the drain of the transistor serves as the output terminal of the switching module, the substrate of the transistor is connected to the output terminal of the voltage driving module, and the output terminal of the voltage driving module is used to output a control voltage to control the substrate voltage of the transistor.

4. The radio frequency switching circuit according to claim 3, characterized in that, The transistor is an NMOS transistor or a PMOS transistor.

5. The radio frequency switching circuit according to claim 1, characterized in that, The antenna tuning device is a capacitor.

6. A radio frequency chip, characterized in that, Includes the radio frequency switching circuit as described in any one of claims 1-5.

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