A programmable impedance tuning TX module and RF circuit

Abstract

The utility model discloses a programmable impedance tuning TX module and radio frequency circuit, wherein the radio frequency input module is used to select multiple sections of radio frequency input signals; the impedance conversion circuit includes an impedance tuning circuit, and any impedance tuning circuit includes multiple impedance devices of different types and multiple switching switches, and the switching switch is used to conduct the target impedance device among the multiple impedance devices to perform impedance matching on the radio frequency input signal. In addition, the multiple conduction switches are used to realize the electrical connection between the impedance conversion circuit and the antenna input terminal, and are also used to change the circuit connection mode of the impedance tuning circuit to the impedance conversion circuit. The above-mentioned impedance tuning TX module has a high degree of integration, which reduces its layout area on the terminal device motherboard; all radio frequency circuits can reuse the above-mentioned impedance tuning TX module, which improves the utilization rate of radio frequency devices; the conduction switch and the switching switch can both control their working state through software, which shortens the time and difficulty of debugging the radio frequency circuit.

Description

Technical Field

[0001] The utility model relates to the field of integrated circuit design, in particular to a programmable impedance tuning TX module and a radio frequency circuit. Background Art

[0002] With the popularization of 5G terminal equipment, more and more functions are compatible on the motherboard of 5G terminal equipment, and the layout space reserved for RF devices on the motherboard is continuously compressed and reduced. Therefore, it is necessary to continuously improve the integration of RF devices on terminal equipment.

[0003] In addition, considering the difficulty of hardware development, the RF hardware circuit on the mainboard needs to be constantly debugged, which leads to a long development cycle of the RF hardware circuit. In order to reduce the difficulty of development and shorten the development cycle, the prior art has designed two programmable impedance-tuned TX (Transmitter) modules, one of which integrates a discrete RF circuit. The disadvantage of this circuit is that the layout area is very large and debugging is difficult. The other module integrates a TX module with fixed impedance matching and filters. The disadvantage of this circuit is that the supported frequency band is fixed and the impedance matching cannot be modified, which easily causes redundancy and waste in the design and has a low degree of customization. Utility Model Content

[0004] The purpose of the utility model is to provide a programmable impedance tuning TX module and a radio frequency circuit, to improve the integration of radio frequency devices and the customization of the impedance tuning TX module, and to reduce the development cycle of radio frequency hardware circuits.

[0005] The utility model discloses a programmable impedance tuning TX module, comprising: a radio frequency signal input module, an impedance conversion circuit and a conduction switch;

[0006] The multiple input ends of the radio frequency signal input module receive radio frequency input signals of different frequency bands respectively, and the output end is connected to the impedance conversion circuit;

[0007] The impedance transformation circuit includes an impedance tuning circuit, and any impedance tuning circuit includes a plurality of impedance devices of different types and a plurality of switching switches, wherein the switching switch is used to turn on a target impedance device among the plurality of impedance devices to perform impedance matching on the RF input signal;

[0008] The conduction switch is connected to the impedance conversion circuit and is used to realize the electrical connection between the impedance conversion circuit and the antenna input terminal, and is also used to change the circuit connection mode of the impedance tuning circuit connected to the impedance conversion circuit.

[0009] Further, the impedance conversion circuit includes: a capacitor tuning circuit and an inductor tuning circuit;

[0010] The input end of the capacitor tuning circuit is connected to the output end of the RF signal input module, the output end of the capacitor tuning circuit is electrically connected to the input end of the inductor tuning circuit through any conduction switch, and the output end of the inductor tuning circuit is electrically connected to the antenna input end through any conduction switch.

[0011] Furthermore, the capacitor tuning circuit includes a plurality of capacitors, a plurality of switching switches, a first conducting switch, a second conducting switch and a third conducting switch;

[0012] The multiple capacitors are connected in parallel with each other, one end of the capacitor is connected to the output end of the radio frequency signal input module, and the other end is connected to the input end of a switching switch.

[0013] Further, the conduction switch includes a first conduction switch, a second conduction switch and a third conduction switch;

[0014] The input end of the first conduction switch is connected to one end of the plurality of capacitors, and the output end is connected to the input end of the inductor tuning circuit;

[0015] The input end of the second conduction switch is connected to the output ends of the plurality of switching switches, and the output end is connected to the input end of the inductor tuning circuit;

[0016] The input end of the third conduction switch is connected to the output ends of the plurality of switching switches, and the output end is grounded.

[0017] Furthermore, the inductor tuning circuit includes a plurality of inductors and two sets of switching switches;

[0018] Any of the inductors is connected in series with another of the inductors via any switch in the first group of switches;

[0019] When any switch in the first group of switches is disconnected, the inductors can be connected via any switch in the second group of switches.

[0020] Furthermore, the conduction switch further includes a fourth conduction switch, a fifth conduction switch and a sixth conduction switch;

[0021] The input end of the fourth conductive switch is respectively connected to one end of the first inductor among the multiple inductors, the output end of the first conductive switch, and the first switch in the second group of switches, and the output end is respectively connected to the output end of the fifth conductive switch and the antenna input end;

[0022] The input ends of the fifth conductive switch and the sixth conductive switch are connected to the output end of the last switch in the first group of switches and the output end of the last switch in the first group of switches, the output end of the fifth conductive switch is connected to the antenna input end, and the output end of the sixth conductive switch is grounded.

[0023] Furthermore, the switching switch and the conducting switch are both double-pole double-throw switches.

[0024] Furthermore, it also includes a switch controller;

[0025] The input end of the switch controller is connected to the conduction switch and the switching switch respectively;

[0026] After receiving the external control signal, the switch controller controls the turning on and off of the conduction switch and the switching switch according to the external control signal;

[0027] The switch controller also receives a power supply voltage to power the programmable impedance tuning TX module.

[0028] Furthermore, the radio frequency signal input module is a single-pole multi-throw switch;

[0029] The multiple input ends of the single-pole multi-throw switch respectively receive radio frequency input signals of different frequency bands, and the output end is connected to the input end of the impedance tuning circuit.

[0030] The utility model also provides a radio frequency circuit, which adopts the programmable impedance tuning TX module.

[0031] Compared with the prior art, the utility model has at least the following advantages:

[0032] The programmable impedance tuning TX module disclosed in the utility model includes a radio frequency input module and an impedance conversion circuit, wherein the radio frequency input module is used to select multiple radio frequency input signals; the impedance conversion circuit includes an impedance tuning circuit, and any impedance tuning circuit includes multiple impedance devices of different types and multiple switching switches, wherein the switching switch is used to conduct the target impedance device among the multiple impedance devices to impedance match the radio frequency input signal, and in addition, the impedance tuning circuit also includes multiple conduction switches, which are used to realize the electrical connection between the impedance conversion circuit and the antenna input end, and are also used to change the circuit connection mode of the impedance tuning circuit to the impedance conversion circuit. The above-mentioned impedance tuning TX module has a high degree of integration, which reduces its layout area on the terminal device motherboard; and all radio frequency circuits can reuse the above-mentioned impedance tuning TX module, which improves the utilization rate of radio frequency devices; further, the above-mentioned conduction switch and switching switch can adjust their working state through software, which greatly shortens the time and difficulty of debugging the radio frequency circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a specific circuit diagram of a programmable impedance tuning TX module in the utility model;

[0034] Figure 2 This is a schematic diagram of the structure of a radio frequency signal input module in a programmable impedance tuning TX module in the utility model;

[0035] Figure 3 A connection diagram of a capacitor tuning circuit and a conduction switch in a programmable impedance tuning TX module of the utility model;

[0036] Figure 4 A connection diagram of an inductor tuning circuit and a conduction switch in a programmable impedance tuning TX module of the utility model;

[0037] Figure 5 The figure is a schematic diagram of the structure of a switch controller in a programmable impedance tuning TX module in the utility model. DETAILED DESCRIPTION

[0038] The following is a description of a programmable impedance tuning TX module and a radio frequency circuit of the utility model in conjunction with a schematic diagram, wherein a preferred embodiment of the utility model is shown, and it should be understood that those skilled in the art can modify the utility model described herein, and still achieve the advantageous effects of the utility model. Therefore, the following description should be understood as being widely known to those skilled in the art, and not as a limitation to the utility model.

[0039] The present invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0040] Please refer to Figure 1-Figure 5 , a programmable impedance tuning TX module provided in this embodiment includes: a radio frequency signal input module and an impedance conversion circuit.

[0041] The multiple input terminals of the RF signal input module (seven input terminals TRX1-TRX7 are shown in the figure) are used to receive RF input signals of different frequency bands respectively, and the output terminal ANT is connected to the impedance conversion circuit for selecting multiple RF input signals.

[0042] The impedance transformation circuit includes an impedance tuning circuit. Any impedance tuning circuit includes multiple impedance devices of different types and multiple switching switches. The switching switch is used to turn on a target impedance device among the multiple impedance devices to perform impedance matching on the RF input signal.

[0043] The impedance conversion circuit further includes a plurality of conduction switches, which are used to realize the electrical connection between the impedance conversion circuit and the antenna input terminal 3, and are also used to change the circuit connection mode of the impedance tuning circuit connected to the impedance conversion circuit.

[0044] Furthermore, the impedance tuning TX module also includes a switch controller 4 .

[0045] The input end of the switch controller 4 is connected to the conduction switch and the switching switch, respectively. In a specific example, the input end of the switch controller 4 is connected to the power supply voltage end (VDD end) of the conduction switch and the switching switch, respectively. When the switch controller 4 receives an external control signal from the central processing unit, it controls the turning off and on of the conduction switch and the switching switch according to the external control signal; the switch controller 4 can also receive the power supply voltage provided by the power management chip to power the programmable impedance tuning TX module. By programming the driver software, sending an external control signal to the switch controller 4, controlling the working state of the switching switch and the conduction switch in the impedance conversion circuit, the RF input signal can be efficiently impedance matched, debugged and changed, greatly reducing the development cost and development time of the RF hardware project.

[0046] Among them, the types of impedance devices, switching switches and conduction switches can be selected according to actual conditions. For example, the impedance device can be at least one of a resistor, a capacitor or an inductor. As long as the components that can achieve the impedance matching function can be used as the impedance device in this embodiment. The number of the above-mentioned electronic components can also be selected according to actual conditions. For example: according to the frequency band of the RF input signal, the number of target impedance devices is selected according to the actual impedance matching requirements, and can be any number. The number of frequency bands of the RF input signal that the RF signal input module can receive is also not limited, and can be any number. For example, the RF signal input module is a single-pole eight-throw (SP8T) switch, which is used to receive RF input signals of 8 different frequency bands.

[0047] The structure and working principle of the impedance tuning TX module will be introduced below by taking the impedance conversion circuit including the capacitor tuning circuit and the inductor tuning circuit as an example.

[0048] Please refer to Figure 1-Figure 4Specifically, the capacitor tuning circuit includes: a plurality of capacitors (as shown in the figure, C1-C7), and a plurality of switching switches (as shown in the figure, SW C1-SW C7). The plurality of capacitors are connected in parallel with each other, one end of which is connected to the output terminal ANT of the RF signal input module, and the other end of which is respectively connected to the input terminal I of a switching switch.

[0049] As can be seen from the above circuit, each switch can control the connection or disconnection of a capacitor. When any number of switches are in the on-off state, the corresponding capacitor will be connected in parallel to other parts of the circuit, or completely isolated. Since the capacitance values ​​are added when the capacitors are connected in parallel, different total capacitance values ​​can be tuned through different combinations of switch states. It can be understood that the total value of the tuned capacitance is also related to the type and number of capacitors.

[0050] In a specific example, when the number of the capacitors is 7 and the number of switching switches is also 7, the rated capacitance values ​​of the first to seventh capacitors are 0.5PF, 1PF, 2PF, 3PF, 7PF, 14PF and 28PF respectively. The total value of the tuning capacitance in the range of 0.5PF-55.5PF can be obtained by adjusting the working state of the switching switch. Every time the state of a switching switch is changed, a change of 0.5PF in the total value of the tuning capacitance can be obtained.

[0051] In another specific example, the type of the switching switch is a double-pole double-throw switch (SPST).

[0052] The inductor tuning circuit includes: a plurality of inductors (L1-L7 are shown in the figure) and two groups of switches.

[0053] Any of the inductors is connected in series with another of the inductors via any of the switches in the first group of switches (shown as SW L1 - SW L7 in the figure);

[0054] When any switch in the first group of switches is disconnected, the inductors can be connected via any switch in the second group of switches (eg, BP L1 -BP L2 as shown in the figure).

[0055] Specifically, one end of the first inductor L1 is connected to the input end I of the first switch BP L1 in the second switch group, and the output end O of the first switch BP L1 is connected to one end of the second inductor L2, and so on, until the bypass connection of the inductor is completed.

[0056] More specifically, the other end of the first inductor L1 is connected to the input end I of the first switch SWL1 in the first group of switches, the output end O of the first switch SWL1 is connected to one end of the second inductor L2, and so on, until the inductors are connected in series.

[0057] As can be seen from the above circuit, the inductors are connected in series, and any multiple switches in the first group of switches are turned on to achieve electrical connection between any multiple inductors and the RF signal input module and the antenna input terminal 3. The total value of the tuned inductor can be obtained by adding multiple inductor values. It can be understood that the total value of the tuned inductor is also related to the type and number of inductors.

[0058] In a specific example, when the number of the capacitors is 7 and the number of switching switches is also 7, the rated capacitance values ​​of the first to seventh inductors are 0.5nH, 1nH, 2nH, 3nH, 7nH, 14nH and 28nH respectively, and the total value of the tuning capacitance in the range of 0.5nH-55.5nH can be obtained by adjusting the working state of the switching switch. Every time the state of a switching switch is changed, a change of 0.5nH in the total value of the tuning inductance can be obtained.

[0059] In order to prevent the inductor tuning circuit from becoming an open circuit state when any switch in the first group of switches is disconnected, a second group of switches is added, and the inductors can be connected through any switch in the second group of switches. For example: the second switch SW L2 and the fourth switch SW L4 in the first group of switches are turned on, and all other switches in the first group of switches are turned off, then all other switches in the second group of switches except the second switch BP L2 and the fourth switch BP L4 need to be turned on, so that the turned-on inductor can be electrically connected to the RF signal input module and the antenna input terminal 3.

[0060] In a specific example, the type of the switch is a double-pole double-throw switch (SPST).

[0061] Furthermore, the conduction switch includes: a first conduction switch BP C1 , a second conduction switch BP C2 , and a third conduction switch BP C3 .

[0062] The input terminal I of the first conductive switch BP C1 is connected to one end of the multiple capacitors and the output terminal ANT of the RF signal input module, the output terminal O is connected to the input terminal of the inductor tuning circuit, and the ground terminal GND is connected to the ground terminal GND of the multiple switching switches and is grounded. The input terminal of the second conductive switch BP C2 is connected to the output terminals of the multiple switching switches, and the output terminal O is connected to the input terminal of the inductor tuning circuit. The input terminal of the third conductive switch BP C3 is connected to the output terminals O of the multiple switching switches, and the output terminal O is grounded.

[0063] In this embodiment, when the first conduction switch BP C1 is turned on, the second conduction switch BP C2 is turned off, and the third conduction switch BP C3 is turned on, the capacitor tuning circuit can be connected in parallel to the impedance conversion circuit.

[0064] When the first conduction switch BP C1 is turned off, the second conduction switch BP C2 is turned on, and the third conduction switch BP C3 is turned off, the capacitor tuning circuit can be connected in series to the impedance conversion circuit.

[0065] The conduction switches further include a fourth conduction switch L10, a fifth conduction switch S5 and a sixth conduction switch BP L12.

[0066] The input end of the fourth conductive switch L10 is respectively connected to one end of the first inductor L1 among the multiple inductors, the output end O of the first conductive switch BP C1, and the first switch BP L1 in the second group of switches, and the output end O is respectively connected to the output end O of the fifth conductive switch BP L11 and the antenna input end 3. The input end I of the fifth conductive switch BP L11 and the sixth conductive switch BP L12 are connected to the output end O of the last switch in the first group of switches (BP L7 as shown in the figure) and the output end O of the last switch in the first group of switches, the output end O of the fifth conductive switch BP L11 is connected to the antenna input end 3, and the output end O of the sixth conductive switch BP L12 is grounded.

[0067] In this embodiment, when the fourth conduction switch L10 is turned on, the fifth conduction switch BP L11 is turned off, and the sixth conduction switch BP L12 is turned on, the inductance tuning circuit can be connected to the impedance conversion circuit in parallel.

[0068] When the fourth conduction switch L10 is turned off, the fifth conduction switch BP L11 is turned on, and the sixth conduction switch BP L12 is turned off, the inductance tuning circuit can be connected to the impedance transformation circuit in series.

[0069] By adjusting the circuit connection mode of the impedance tuning circuit connected to the impedance transformation circuit, the movement direction of the radio frequency impedance on the Smith circle is changed, thereby achieving better impedance matching and further optimizing the circuit performance.

[0070] In summary, the programmable impedance tuning TX module disclosed in the utility model includes a radio frequency input module and an impedance conversion circuit, wherein the radio frequency input module is used to select multiple radio frequency input signals; the impedance conversion circuit includes an impedance tuning circuit, and any impedance tuning circuit includes multiple impedance devices of different types and multiple switching switches, wherein the switching switch is used to conduct the target impedance device among the multiple impedance devices to impedance match the radio frequency input signal, and in addition, the impedance tuning circuit also includes multiple conduction switches, which are used to realize the electrical connection between the impedance conversion circuit and the antenna input terminal, and are also used to change the circuit connection mode of the impedance tuning circuit to the impedance conversion circuit. The above-mentioned impedance tuning TX module has a high degree of integration, which reduces its layout area on the terminal device motherboard; and all radio frequency circuits can reuse the above-mentioned impedance tuning TX module, which improves the utilization rate of radio frequency devices; further, the above-mentioned conduction switch and switching switch can adjust their working state through software, which greatly shortens the time and difficulty of debugging the radio frequency circuit.

[0071] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A programmable impedance tuning TX module, characterized in that: include: RF signal input module, impedance conversion circuit and conduction switch; The multiple input ends of the radio frequency signal input module receive radio frequency input signals of different frequency bands respectively, and the output end is connected to the impedance conversion circuit; The impedance transformation circuit includes an impedance tuning circuit, and any impedance tuning circuit includes a plurality of impedance devices of different types and a plurality of switching switches, wherein the switching switch is used to turn on a target impedance device among the plurality of impedance devices to perform impedance matching on the RF input signal; The conduction switch is connected to the impedance conversion circuit and is used to realize the electrical connection between the impedance conversion circuit and the antenna input terminal, and is also used to change the circuit connection mode of the impedance tuning circuit connected to the impedance conversion circuit.

2. The programmable impedance tuning TX module according to claim 1, characterized in that: The impedance conversion circuit includes: a capacitance tuning circuit and an inductance tuning circuit; The input end of the capacitor tuning circuit is connected to the output end of the RF signal input module, the output end of the capacitor tuning circuit is electrically connected to the input end of the inductor tuning circuit through any conduction switch, and the output end of the inductor tuning circuit is electrically connected to the antenna input end through any conduction switch.

3. The programmable impedance tuning TX module according to claim 2, wherein: The capacitor tuning circuit includes a plurality of capacitors and a plurality of switching switches; The multiple capacitors are connected in parallel with each other, one end of the capacitor is connected to the output end of the radio frequency signal input module, and the other end is connected to the input end of a switching switch.

4. The programmable impedance tuning TX module according to claim 3, characterized in that: The conduction switch comprises a first conduction switch, a second conduction switch and a third conduction switch; The input end of the first conduction switch is connected to one end of the plurality of capacitors, and the output end is connected to the input end of the inductor tuning circuit; The input end of the second conduction switch is connected to the output ends of the plurality of switching switches, and the output end is connected to the input end of the inductor tuning circuit; The input end of the third conduction switch is connected to the output ends of the plurality of switching switches, and the output end is grounded.

5. The programmable impedance tuning TX module according to claim 4, characterized in that: The inductor tuning circuit includes a plurality of inductors and two sets of switching switches; Any of the inductors is connected in series with another of the inductors via any switch in the first group of switches; When any switch in the first group of switches is disconnected, the inductors can be connected via any switch in the second group of switches.

6. The programmable impedance tuning TX module according to claim 5, characterized in that: The conduction switch further comprises a fourth conduction switch, a fifth conduction switch and a sixth conduction switch; The input end of the fourth conductive switch is respectively connected to one end of the first inductor among the multiple inductors, the output end of the first conductive switch, and the first switch in the second group of switches, and the output end is respectively connected to the output end of the fifth conductive switch and the antenna input end; The input ends of the fifth conductive switch and the sixth conductive switch are connected to the output end of the last switch in the first group of switches and the output end of the last switch in the first group of switches, the output end of the fifth conductive switch is connected to the antenna input end, and the output end of the sixth conductive switch is grounded.

7. The programmable impedance tuning TX module according to claim 1, wherein: The switching switch and the conducting switch are both double-pole double-throw switches.

8. The programmable impedance tuning TX module according to claim 1, wherein: Also included is a switch controller; The input end of the switch controller is connected to the conduction switch and the switching switch respectively; After receiving the external control signal, the switch controller controls the turning on and off of the conduction switch and the switching switch according to the external control signal; The switch controller can also receive a power supply voltage to power the programmable impedance tuning TX module.

9. The programmable impedance tuning TX module according to claim 1, wherein: The radio frequency signal input module is a single-pole multi-throw switch; The multiple input ends of the single-pole multi-throw switch respectively receive radio frequency input signals of different frequency bands, and the output end is connected to the input end of the impedance tuning circuit.

10. A radio frequency circuit, characterized in that: A programmable impedance tuning TX module as described in any one of claims 1-9 is used.

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