Signal emission circuit, wireless communication module and electronic equipment

Abstract

The invention is suitable for the technical field of communication, and provides a signal transmitting circuit, a wireless communication module and electronic equipment. The signal transmitting circuit comprises an inductance module, a switch module, a pulse excitation source and an electrode; the pulse excitation source is used for outputting a short pulse signal; the switch module is used for grounding the controlled end of the inductance module when the short pulse signal is at a high level so as to short-circuit the electrode, so that the direct-current power supply charges the inductance module; and the switch module is also used for disconnecting the controlled end of the inductance module from the ground when the short pulse signal is at a low level, so that the inductance module and the electrode form a series resonance network, and the inductance module radiates the stored electric energy outwards through the electrode. The circuit is relatively simple in structure and convenient for miniaturization design; a short pulse signal is used as an excitation signal, so that the circuit can stably emit a single-frequency signal outwards; and the resonant frequency of the series resonant network is set to be integral multiples of the frequency of the short pulse signal, so that the electric energy output efficiency of the circuit can be improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a signal transmitting circuit, a wireless communication module and an electronic device. Background Art

[0002] With the continuous development of mobile communication technology, wireless communication modules are usually configured in electronic devices such as mobile phones and tablet computers. Electronic devices can transmit wireless signals to the outside through the signal transmission circuit in the wireless communication module to achieve wireless communication with other devices, or to achieve the contact recognition function of the touch screen of the electronic device, etc. However, the structure of the signal transmission circuit in the related art is relatively complex, resulting in a large overall size of the signal transmission circuit, which is not conducive to the miniaturization design of the signal transmission circuit; in addition, the harmonic suppression level of the signal transmission circuit is low, resulting in more harmonic components in the signal it transmits, that is, the electronic device cannot stably transmit a single-frequency signal to the outside, thereby reducing the stability of the wireless communication of the electronic device, or reducing the accuracy and stability of the contact recognition of the electronic device. Summary of the invention

[0003] The embodiments of the present application provide a signal transmission circuit, a wireless communication module and an electronic device. The signal transmission circuit has a high harmonic suppression level and a high power output efficiency, and can stably transmit a single-frequency signal to the outside. The structure of the signal transmission circuit is relatively simple, which is conducive to the miniaturization design of the signal transmission circuit.

[0004] In a first aspect, an embodiment of the present application provides a signal transmission circuit, including an inductor module, a switch module, a pulse excitation source and an electrode; the first end of the inductor module is used to connect to a DC power supply, the second end of the inductor module is connected to the first end of the electrode, and the second end of the electrode is grounded; the first end of the pulse excitation source is grounded, the second end of the pulse excitation source is connected to the controlled end of the switch module, and the pulse excitation source is used to output a short pulse signal with a duty cycle less than a preset duty cycle threshold to the switch module to control the on and off of the switch module; the first conductive end of the switch module is connected to the controlled end of the inductor module, and the second conductive end of the switch module is grounded; the switch module is used to connect the controlled end of the inductor module to the ground when the short pulse signal is at a high level, so as to short-circuit the electrode and allow the DC power supply to charge the inductor module; the switch module is also used to disconnect the connection between the controlled end of the inductor module and the ground when the short pulse signal is at a low level, so that the inductor module and the electrode form a series resonant network, and the inductor module radiates the stored electrical energy outward through the electrode to realize the wireless signal transmission function.

[0005] The resonant frequency of the series resonant network is an integer multiple of the frequency of the short pulse signal. The resonant frequency of the series resonant network can be determined by the inductive reactance value of the inductor module and the capacitive reactance value of the electrode.

[0006] Exemplarily, the duty cycle of the short pulse signal may be a duty cycle measured through experiments that enables the transmission power (ie, signal energy) and power output efficiency of the signal transmission circuit to reach a relatively high level.

[0007] Optionally, the second end of the inductor module and the controlled end may be the same end.

[0008] Optionally, the second end and the controlled end of the inductor module may be different ends.

[0009] In specific applications, the electrode may also be referred to as an antenna. Exemplarily, the electrode may be a monopole electrode, a dipole electrode, or other forms of electrodes.

[0010] Exemplarily, the switch module may be a switch device of the type of triode, transistor, thyristor or relay, etc. The transistor may include, for example, a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT).

[0011] The working state of the signal transmitting circuit may include a charging state and a resonant state, and the resonant state may also be referred to as a radiation state. When the pulse signal is at a high level, the switch module is turned on, and the signal transmitting circuit works in a charging state; when the pulse signal is at a low level, the switch module is turned off, and the signal transmitting circuit works in a resonant state.

[0012] The signal transmitting circuit provided by the embodiment of the present application is configured by arranging an inductance module, a switch module, a pulse excitation source and an electrode in the signal transmitting circuit, and configuring the pulse excitation source to output a short pulse signal to the switch module to control the on and off of the switch module, and configuring the switch module to be turned on when the short pulse signal is at a high level to short-circuit the electrode so that the DC power supply charges the inductance module; and disconnected when the short pulse signal is at a low level so that the DC power supply stops charging the inductance module, and the inductance module and the electrode form a series resonant network, so that the inductance module radiates the stored electrical energy outward through the electrode to realize the wireless signal transmission function. The embodiment of the present application uses a short pulse signal to excite the switch module, so that the signal transmitting circuit can be in a resonant state for a long time, thereby improving the harmonic suppression level of the signal transmitting circuit, so that the signal transmitting circuit can stably transmit high-energy single-frequency signals outward. At the same time, since the inductor module will limit the growth rate of the current in its path during the charging process, the current flowing through the inductor module will not increase instantly, so there is no need to set a current limiting resistor in the signal transmission circuit to avoid current overload of the DC power supply. While simplifying the structure of the signal transmission circuit, it can reduce the additional loss of the signal transmission circuit on the current limiting resistor and improve the power output efficiency of the signal transmission circuit. In addition, by setting the resonant frequency of the series resonant network to an integer multiple of the frequency of the short pulse signal, the switch module can be in a soft switching state when switching from the off state to the on state, thereby reducing the power loss on the switch module and further improving the power output efficiency of the signal transmission circuit.

[0013] In an optional implementation of the first aspect, the inductor module includes a first inductor; a first end of the first inductor serves as a first end of the inductor module, and a second end of the first inductor serves as a second end and a controlled end of the inductor module.

[0014] In an optional implementation of the first aspect, the inductor module includes a first inductor and a second inductor; the first inductor and the second inductor are forward coupled; when the first end of the first inductor and the first end of the second inductor are both ends of the same name, the first end of the second inductor serves as the first end of the inductor module, the second end of the second inductor serves as the controlled end of the inductor module, the first end of the first inductor is grounded, and the second end of the first inductor serves as the second end of the inductor module; the switch module is specifically used to connect the second end of the second inductor to the ground when the short pulse signal is at a high level, so that the DC power supply charges the second inductor, and the second inductor transfers electric energy to the first inductor through coupling; the switch module is also specifically used to disconnect the connection between the second end of the second inductor and the ground when the short pulse signal is at a low level, so that the first inductor and the electrode form a series resonant network, and the first inductor radiates the stored electric energy outward through the electrode.

[0015] According to the signal transmitting circuit provided by the embodiment of the present application, by adopting the coupled first inductor and the second inductor as the inductor module, and making the second inductor work only in the charging state of the signal transmitting circuit, and not participating in the resonance process of the signal transmitting circuit, the signal transmitting circuit can realize the decoupling of the resonant frequency control and the transmission power control, and then the transmission power of the signal transmitting circuit can be adjusted by adjusting the inductive reactance value of the second inductor. In addition, since the frequency of the short pulse signal can be any integer multiple of the resonant frequency of the series resonant network, the excitation signal of the switch module has a higher degree of freedom in the selection of frequency, which expands the scope of application of the signal transmitting circuit.

[0016] In an optional implementation of the first aspect, the number of pulse excitation sources, the number of switch modules, and the number of controlled ends of the inductance module are all 2; the first end of the first pulse excitation source is grounded, the second end of the first pulse excitation source is connected to the controlled end of the first switch module, and the first pulse excitation source is used to output a first short pulse signal to the first switch module to control the on and off of the first switch module; the first conductive end of the first switch module is connected to the first controlled end of the inductance module, and the second conductive end of the first switch module is grounded; the first switch module is used to connect the first controlled end of the inductance module to the ground when the first short pulse signal is at a high level, so that the DC power supply charges the inductance module; the first switch module is also used to disconnect the connection between the first controlled end of the inductance module and the ground when the first short pulse signal is at a low level, so that the inductance module and the electrode form a series connection. The second switch module is connected to a series resonant network, and the inductor module radiates the stored electric energy outward through the electrode; the first end of the second pulse excitation source is grounded, and the second end of the second pulse excitation source is connected to the controlled end of the second switch module; the second pulse excitation source is used to output a second short pulse signal to the second switch module to control the on and off of the second switch module; the first conduction end of the second switch module is connected to the second controlled end of the inductor module, and the second conduction end of the second switch module is grounded; the second switch module is used to connect the second controlled end of the inductor module to the ground when the second short pulse signal is at a high level, so that the DC power supply charges the inductor module; the second switch module is also used to disconnect the connection between the second controlled end of the inductor module and the ground when the second short pulse signal is at a low level, so that the inductor module and the electrode form a series resonant network, and the inductor module radiates the stored electric energy outward through the electrode.

[0017] In an optional implementation of the first aspect, the inductor module includes a first inductor, a second inductor and a third inductor; the first inductor and the second inductor are forward coupled, and the first inductor and the third inductor are reverse coupled; the first end of the first inductor, the first end of the second inductor and the first end of the third inductor are all same-named ends; the first end of the second inductor and the second end of the third inductor are connected together as the first end of the inductor module, the second end of the second inductor serves as the first controlled end of the inductor module, the first end of the first inductor is grounded, the second end of the first inductor serves as the second end of the inductor module, and the first end of the third inductor serves as the second controlled end of the inductor module; the first switch module is specifically used to connect the second end of the second inductor to the ground when the first short pulse signal is at a high level, so that the DC power supply charges the second inductor. , the second inductor transfers electric energy to the first inductor by coupling; the first switch module is specifically used to disconnect the connection between the second end of the second inductor and the ground when the first short pulse signal is at a low level, so that the first inductor and the electrode form a series resonant network, and the first inductor radiates the stored electric energy outward through the electrode; the second switch module is specifically used to connect the first end of the third inductor to the ground when the second short pulse signal is at a high level, so that the DC power supply charges the third inductor, and the third inductor transfers electric energy to the first inductor by coupling; the second switch module is specifically used to disconnect the connection between the first end of the third inductor and the ground when the second short pulse signal is at a low level, so that the first inductor and the electrode form a series resonant network, and the first inductor radiates the stored electric energy outward through the electrode.

[0018] In an optional implementation of the first aspect, a coupling coefficient between the first inductor and the second inductor is equal to a coupling coefficient between the first inductor and the third inductor, and an inductive reactance value of the second inductor is equal to an inductive reactance value of the third inductor.

[0019] According to the signal transmitting circuit provided in the embodiment of the present application, by setting the inductor module as a differential coupling structure, it is possible to improve the transmission power of the signal transmitting circuit, ensure the stable output of a high-energy single-frequency signal, and enable the signal transmitting circuit to have the function of suppressing even-order harmonics, thereby further improving the harmonic suppression level of the signal transmitting circuit.

[0020] In an optional implementation of the first aspect, the electrode includes a first capacitor and a first resistor; the first end of the first capacitor serves as the first end of the electrode, the second end of the first capacitor is connected to the first end of the first resistor, and the second end of the first resistor serves as the second end of the electrode.

[0021] In an optional implementation of the first aspect, the signal transmitting circuit also includes a second capacitor; the first end of the second capacitor is used to connect to a DC power supply, and the second end of the second capacitor is grounded; the second capacitor is used to filter out an AC component in a DC signal output by the DC power supply.

[0022] This implementation method can filter out the AC component in the DC signal output by the DC power supply by setting a second capacitor capable of providing a return point for the AC signal in the signal transmitting circuit, thereby reducing unnecessary power loss and further improving the power output efficiency of the signal transmitting circuit.

[0023] In a second aspect, an embodiment of the present application provides a wireless communication module, comprising a signal transmission circuit as described in any implementation method of the first aspect above.

[0024] In a third aspect, an embodiment of the present application provides an electronic device, comprising a DC power supply and a wireless communication module as described in the second aspect above.

[0025] It can be understood that the beneficial effects of the second and third aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of an application scenario of a signal transmission circuit provided in an embodiment of the present application;

[0027] Figure 2 A schematic diagram of the structure of a signal transmission circuit provided in an embodiment of the present application;

[0028] Figure 3 A schematic diagram of the structure of a signal transmission circuit provided in another embodiment of the present application;

[0029] Figure 4 A schematic diagram of a circuit principle of a signal transmission circuit provided in an embodiment of the present application;

[0030] Figure 5 for Figure 4 The equivalent circuit diagram of the signal transmission circuit shown in different working states;

[0031] Figure 6 When a pulse signal with a duty cycle of 50% and 5% is used to stimulate the switch module in an embodiment of the present application, Figure 4 A schematic diagram showing a comparison of various performance indicators of the signal transmission circuit shown;

[0032] Figure 7 A schematic diagram of a circuit principle of a signal transmitting circuit provided in another embodiment of the present application;

[0033] Figure 8 for Figure 7 The equivalent circuit diagram of the signal transmission circuit shown in different working states;

[0034] Fig. 9When a second inductor provided in an embodiment of the present application adopts different inductance values, Figure 7 A schematic diagram showing a comparison of various performance indicators of the signal transmission circuit shown;

[0035] Fig.10 for Figure 7 A schematic diagram of various performance indicators of the signal transmission circuit shown;

[0036] Fig.11 When a short pulse signal of different frequencies is used as an excitation signal, Figure 7 A schematic diagram showing a comparison of various performance indicators of the signal transmission circuit shown;

[0037] Fig.12 A circuit structure of a signal transmitting circuit provided in yet another embodiment of the present application;

[0038] Fig.13 for Fig.12 The equivalent circuit diagram of the signal transmission circuit shown in different working states;

[0039] Fig.14 When two short pulse signals with different phases are used to stimulate the two switch modules respectively, Fig.12 A schematic diagram showing a comparison of various performance indicators of the signal transmission circuit shown;

[0040] Fig.15 A schematic diagram of the structure of a communication module provided in an embodiment of the present application;

[0041] Fig.16 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] It should be noted that the terms used in the implementation methods of the embodiments of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more than two, "at least one" and "one or more" mean one, two or more than two.

[0043] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, it is defined that the "first" and "second" features may explicitly or implicitly include one or more of the features.

[0044] References to "one embodiment" or "some embodiments" etc. described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear at different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0045] With the continuous development of mobile communication technology, wireless communication modules are usually configured in electronic devices such as mobile phones and tablet computers. Wireless communication modules usually include signal transmission circuits, and electronic devices can transmit wireless signals through the signal transmission circuit to achieve wireless communication with other devices, or to achieve the touch point recognition function of the touch screen of the electronic device.

[0046] For example, see Figure 1 , is a schematic diagram of an application scenario of a signal transmission circuit provided in an embodiment of the present application. Taking the electronic device as a mobile phone as an example, Figure 1 As shown in (a) in the near field communication (such as mobile payment or mobile identity authentication) scenario, the mobile phone can transmit wireless signals to other near field communication (NFC) devices through the signal transmission circuit to achieve point-to-point communication with other NFC devices. Figure 1 As shown in (b), in the touch point recognition scenario of the mobile phone touch screen, in order to avoid interference of factors such as water droplets on the touch point recognition, the signal transmission circuit can be set on the back panel of the mobile phone, and the mobile phone can transmit wireless signals to the outside through the signal transmission circuit on the back panel. Based on this, when the user's finger touches the mobile phone screen, the finger will conduct the wireless signal emitted by the signal transmission circuit, and the signal receiver on the mobile phone cover can receive and identify the signal conducted by the finger to realize the recognition of the finger contact.

[0047] Whether it is the above-mentioned near-field communication scenario or the touch screen contact recognition scenario, the signal transmitting circuit is required to be able to stably transmit a single-frequency signal to the outside to ensure the stability of the wireless communication of the electronic device, or to ensure the accuracy and stability of the contact recognition of the electronic device. In addition, with the miniaturization of electronic devices, the space that can be allocated to the wireless communication module in the electronic device is getting smaller and smaller, so the signal transmitting circuit is also required to have a smaller size. However, the structure of the signal transmitting circuit in the related art is relatively complex, resulting in a larger overall size of the signal transmitting circuit, which is not conducive to the miniaturization design of the signal transmitting circuit; in addition, the harmonic suppression level of the signal transmitting circuit in the related art is low, resulting in more harmonic components in the signal emitted, that is, the electronic device cannot stably transmit a single-frequency signal to the outside, thereby reducing the stability of the wireless communication of the electronic device, or reducing the accuracy and stability of the contact recognition of the electronic device.

[0048] In view of this, the embodiments of the present application provide a signal transmission circuit, a wireless communication module and an electronic device, by setting an inductance module, a switch module, a pulse excitation source and an electrode in the signal transmission circuit, and configuring the pulse excitation source to output a short pulse signal to the switch module to control the on and off of the switch module, and configuring the switch module to be turned on when the short pulse signal is at a high level to short-circuit the electrode so that the DC power supply charges the inductance module; and disconnected when the short pulse signal is at a low level so that the DC power supply stops charging the inductance module, and the inductance module and the electrode form a series resonant network, so that the inductance module radiates the stored electric energy through the electrode to realize the wireless signal transmission function. The embodiments of the present application use a short pulse signal to excite the switch module, so that the signal transmission circuit can be in a resonant state for a long time, thereby improving the harmonic suppression level of the signal transmission circuit, so that the signal transmission circuit can stably transmit a high-energy single-frequency signal to the outside. At the same time, since the inductor module will limit the growth rate of the current in its path during the charging process, the current flowing through the inductor module will not increase instantly, so there is no need to set a current limiting resistor in the signal transmission circuit to avoid current overload of the DC power supply. While simplifying the structure of the signal transmission circuit, it can reduce the additional loss of the signal transmission circuit on the current limiting resistor and improve the power output efficiency of the signal transmission circuit. In addition, by setting the resonant frequency of the series resonant network to an integer multiple of the frequency of the short pulse signal, the switch module can be in a soft switching state when switching from the off state to the on state, thereby reducing the power loss on the switch module and further improving the power output efficiency of the signal transmission circuit.

[0049] The signal transmission circuit provided in the embodiment of the present application may also be referred to as an active resonant circuit or an active integrated antenna, etc. The structure and working principle of the signal transmission circuit provided in the embodiment of the present application are described in detail below.

[0050] See also Figure 2 , is a schematic diagram of the structure of a signal transmitting circuit 10 provided in an embodiment of the present application. Figure 2 As shown, in some embodiments, the signal transmitting circuit 10 may include an inductor module 11 , a switch module 12 , a pulse excitation source 13 and an electrode 14 .

[0051] The inductor module 11 may have a first end a, a second end b and a controlled end c. The first end a of the inductor module 11 may be used to connect to the DC power supply 20, so that in some scenarios, the inductor module 11 can obtain a DC signal from the DC power supply 20 to store electrical energy; the second end b of the inductor module 11 may be connected to the first end d of the electrode 14, and the second end e of the electrode 14 may be grounded, so that in other scenarios, the inductor module 11 can form a series resonant network with the electrode 14, so that the inductor module 11 can radiate the stored electrical energy outward through the electrode 14 to realize the wireless signal transmission function.

[0052] Exemplarily, the inductor module 11 may include one or more inductor elements. For example, when the inductor module 11 includes one inductor element, the first end of the inductor element may be used as the first end a of the inductor module 11, and the second end of the inductor element may be used as the second end b or the controlled end c of the inductor module 11, that is, when the inductor module 11 includes one inductor element, the second end b and the controlled end c of the inductor module 11 may be the same end. For another example, when the inductor module 11 includes a plurality of inductor elements coupled to each other, the second end b and the controlled end c of the inductor module 11 may be different ends.

[0053] The electrode 14 may be referred to as an antenna. Exemplarily, the electrode 14 may be a monopole electrode, a dipole electrode, or other forms of electrodes. The specific form of the electrode 14 is not particularly limited in the embodiment of the present application.

[0054] The pulse excitation source 13 may have a first terminal f and a second terminal g. The first terminal f of the pulse excitation source 13 may be grounded, and the second terminal g of the pulse excitation source 13 may be connected to the controlled terminal h of the switch module 12. The pulse excitation source 13 may be used to output a pulse signal to the switch module 12 to control the on and off of the switch module 12, thereby controlling the working state of the signal transmitting circuit 10.

[0055] Exemplarily, the working state of the signal transmitting circuit 10 may include a charging state and a resonant state, etc., and the resonant state may also be referred to as a radiation state. Specifically, when the pulse signal is at a high level, the switch module 12 may be turned on, and the signal transmitting circuit 10 operates in a charging state; when the pulse signal is at a low level, the switch module 12 may be turned off, and the signal transmitting circuit 10 operates in a resonant state. In some embodiments, the pulse excitation source 13 may output a short pulse signal having a duty cycle less than a preset duty cycle threshold to the switch module 12. The preset duty cycle threshold may be set according to the actual application scenario. Exemplarily, the duty cycle of the short pulse signal may be a duty cycle measured by experiment that enables the transmission power (i.e., signal energy) and power output efficiency of the signal transmitting circuit 10 to reach a high level.

[0056] The switch module 12 may also have a first conductive end j and a second conductive end k. The first conductive end j of the switch module 12 may be connected to the controlled end c of the inductor module 11, and the second conductive end k of the switch module 12 may be grounded. The switch module 12 may be used to connect the controlled end c of the inductor module 11 to the ground when the short pulse signal is at a high level, so as to short-circuit the electrode 14, so that the DC power supply 20 charges the inductor module 11. The switch module 12 may also be used to disconnect the controlled end c of the inductor module 11 from the ground when the short pulse signal is at a low level, so that the DC power supply 20 stops charging the inductor module 11, and the inductor module 11 and the electrode 14 form a series resonant network, so that the inductor module 11 can radiate the stored electric energy outward through the electrode 14, and realize the wireless signal transmission function. It is understandable that since the inductor module 11 will limit the growth rate of the current in its path during the charging process, during the charging process of the inductor module 11, the current flowing through the inductor module 11 will not increase instantaneously, but will gradually increase according to an exponential curve. In this way, there is no need to set a current limiting resistor in the signal transmitting circuit 10 to avoid current overload of the DC power supply 20, which can not only reduce the complexity of the circuit structure, but also reduce the additional loss of the signal transmitting circuit 10 on the current limiting resistor, thereby improving the power output efficiency of the signal transmitting circuit 10.

[0057] In the embodiment of the present application, the resonant frequency of the series resonant network formed by the inductor module 11 and the electrode 14 can be an integer multiple of the frequency of the short pulse signal. This not only ensures that when the short pulse signal is at a low level, the inductor module 11 and the electrode 14 can resonate to achieve wireless signal transmission; it also enables the switch module 12 to be in a soft switching state when switching from an off state to an on state, thereby reducing the power loss on the switch module and further improving the power output efficiency of the signal transmission circuit.

[0058] The resonant frequency of the series resonant network can be determined by the inductive reactance value of the inductor module 11 and the capacitive reactance value of the electrode 14. That is, in a specific application, the resonant frequency of the series resonant network can be adjusted by adjusting the inductive reactance value of the inductor module 11 and / or the capacitive reactance value of the electrode 14, so that the resonant frequency of the series resonant network is an integer multiple of the frequency of the short pulse signal.

[0059] See also Figure 3 , is a schematic diagram of the structure of a signal transmitting circuit 10 provided in another embodiment of the present application. Figure 3 As shown, in some other embodiments, the signal transmitting circuit 10 may further include a filter capacitor 15 .

[0060] The filter capacitor 15 may have a first terminal m and a second terminal n. The first terminal m of the filter capacitor 15 may be used to connect to the DC power source 20, and the second terminal n of the filter capacitor 15 may be grounded.

[0061] The filter capacitor 15 can be used to provide a return point for the AC signal to filter out the AC component in the DC signal output by the DC power supply 20 , thereby reducing unnecessary power loss and further improving the power output efficiency of the signal transmitting circuit 10 .

[0062] See also Figure 4 , is a schematic diagram of a circuit principle of a signal transmitting circuit 10 provided in an embodiment of the present application. Figure 4 As shown, in a specific implementation, the electrode 14 may include a first resistor R ant and the first capacitor C ant The first capacitor C ant The first end of the first capacitor C ant The second end can be connected to the first resistor R ant The first end of the first resistor R ant The second end of can serve as the second end e of the electrode 14.

[0063] Exemplarily, the switch module 12 may be a switch device of the type of triode, transistor, thyristor or relay, etc. The transistor may include, for example, a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT).

[0064] For example, the switch module 12 is Figure 4Taking the relay shown as an example, the positive terminal (+) of the relay coil can be used as the controlled terminal h of the switch module 12, the negative terminal (-) of the relay coil can be connected to the normally open contact of the relay and serve as the second conduction terminal k of the switch module 12, and the common contact of the relay can serve as the first conduction terminal j of the switch module 12.

[0065] For another example, taking the switch module 12 as an NPN transistor (not shown), the base of the NPN transistor can be used as the controlled end h of the switch module 12, the collector of the NPN transistor can be used as the first conduction end j of the switch module 12, and the emitter of the NPN transistor can be used as the second conduction end k of the switch module 12.

[0066] The filter capacitor 15 may include a second capacitor C d The second capacitor C d The first end of the filter capacitor 15 can be used as the first end m of the filter capacitor 15, and the second capacitor C d The second end of can be used as the second end n of the filter capacitor 15.

[0067] In an optional implementation, the inductor module 11 may include a first inductor L res The first inductor L res The first end of the inductor module 11 can be used as the first end a of the inductor module 11. res The second end of can be used as the second end b and the controlled end c of the inductor module 11. Based on this, please refer to Figure 5 ,for Figure 4 The equivalent circuit diagram of the signal transmitting circuit 10 in different working states is shown. Figure 5 (a) in Figure 4 The equivalent circuit diagram of the signal transmitting circuit 10 in the charging state is shown in FIG. Figure 5 (b) in Figure 4 The equivalent circuit diagram of the signal transmitting circuit 10 in the resonant state is shown.

[0068] like Figure 5 As shown in (a), when the short pulse signal is at a high level, the switch module 12 is in the on state. At this time, the first inductor L res The switch module 12 is grounded so that the electrode 14 is short-circuited, and the DC power supply 20 is connected to the first inductor L res Charging is performed, that is, the signal transmitting circuit 10 is in a charging state at this time. Figure 5 As shown in (b), when the short pulse signal is at a low level, the switch module 12 is in an off state, and the electrode 14 participates in the operation of the signal transmitting circuit 10. The first inductor L res and the first capacitor C in the electrode 14 antResonance is generated and a series resonant network is formed, so that the first inductor L res The electric energy stored therein is radiated outwardly through the electrode 14, that is, the signal transmitting circuit 10 is in a resonant state at this time.

[0069] In order to further illustrate the beneficial effects of using a short pulse signal to excite the switch module 12 in the embodiment of the present application, the following takes the pulse signal duty cycle of 50% and 5% as examples to illustrate the use of pulse signals with different duty cycles to excite the switch module 12. Figure 4 The various performance indicators of the signal transmitting circuit 10 are shown.

[0070] See also Figure 6 , Figure 6 When a pulse signal with a duty cycle of 50% and 5% is used to stimulate the switch module 12, Figure 4 FIG. 1 is a schematic diagram showing a comparison of various performance indicators of the signal transmitting circuit 10 shown in FIG. Figure 6 (a), (c) and (e) are respectively the voltage V on the electrode 14 when the switch module 12 is stimulated by a pulse signal with a duty cycle of 50%. ant The waveform diagram of the current flowing through the first inductor L res The current I ind A schematic diagram of a waveform and a schematic diagram of a spectrum of the transmission power (Output Power) of the signal transmission circuit 10; Figure 6 (b), (d) and (f) are respectively the voltage V on the electrode 14 when the switch module 12 is stimulated by a pulse signal with a duty cycle of 5%. ant The waveform diagram of the current flowing through the first inductor L res The current I ind The waveform diagram of the signal transmission circuit 10 and the spectrum diagram of the transmission power. Among them, the voltage V on the electrode 14 ant It can refer to the voltage at the first end d of the electrode 14. It can be understood that since the switch module 12 in this implementation is connected in parallel at both ends of the electrode 14, the voltage V on the electrode 14 is ant It can also be regarded as the voltage on the switch module 12. The voltage on the switch module 12 may refer to the voltage of the first conduction terminal j of the switch module 12.

[0071] For example, assuming that the frequency of the pulse signal with a duty cycle of 50% and the frequency of the pulse signal with a duty cycle of 5% are both 10 MHz, the first inductor L res With the first capacitor C ant It can resonate at 10MHz. The first inductor L resThe inductive reactance value is 13.75 microhenries (μH). Then, taking the first cycle of the pulse signal (i.e., the period of 0 to 100 nanoseconds (ns)) as an example, when the duty cycle of the pulse signal is 50%, Figure 6 As shown in (a) or (c), in the period of 0 to 50 ns, the pulse signal is at a high level. At this time, the signal transmitting circuit 10 is in a charging state, the electrode 14 is short-circuited, and the DC power supply 20 is connected to the first inductor L res Due to the first inductor L res It will limit the growth rate of the current in its path, so in the period of 0 to 50ns, the current flowing through the first inductor L res The current will gradually increase with time. In the period of 50 to 100 ns, the pulse signal is at a low level. At this time, the signal transmitting circuit 10 is in a resonance state. The first inductor L res With the first capacitor C ant A series resonant network is formed, the first inductor L res To the first capacitor C ant Discharge.

[0072] like Figure 6 As shown in (a), during the period of 0 to 50 ns, since the electrode 14 is short-circuited, the voltage V on the electrode 14 is ant Always maintain 0 volts (V). In the period of 50 to 100 ns, due to the first inductor L res With the first capacitor C ant Resonance is generated, so there is a resonant voltage on the electrode 14. It can be understood that when a pulse signal with a duty cycle of 50% is used to excite the switch module 12, the signal transmission circuit 10 is in a resonant state for a short time, which will cause the voltage V on the electrode 14 to ant A truncation effect occurs, which causes the voltage V on electrode 14 to ant The waveform is as follows Figure 6 From the incomplete curve (a) shown in FIG. 1 , it can be seen that the voltage V on the electrode 14 ant There are a lot of harmonic components in the waveform. Figure 6 As can be seen from (e), using a pulse signal with a duty cycle of 50% to stimulate the switch module 12 will cause the transmission power of the signal transmission circuit 10 to appear at multiple frequency points, and the maximum transmission power is at the frequency point (i.e., near 70MHz) where the electrode 14 can independently generate resonance. Among them, the frequency point where the electrode 14 can independently generate resonance can be understood as the basic resonant frequency of the electrode 14. It can be seen that when the duty cycle of the pulse signal is 50%, the signal transmission circuit 10 cannot output a single-frequency signal.

[0073] like Figure 6 As shown in (b) or (d), when the duty cycle of the pulse signal is 5%, the pulse signal is at a high level in the period of 0 to 5ns and at a low level in the period of 5 to 100ns, so that the signal transmitting circuit 10 is only in a charging state in the period of 0 to 5ns, and in the period of 5 to 100ns, the signal transmitting circuit 10 is always in a resonant state. It can be seen that the use of a short pulse signal with a duty cycle of 5% to excite the switch module 12 can make the signal transmitting circuit 10 in a resonant state most of the time, so that a relatively complete resonant voltage can be generated on the electrode 14, that is, Figure 6 As shown in (b), the voltage V on electrode 14 ant The waveform is a relatively complete resonance curve. Figure 6 It can be seen from (f) that when the duty cycle of the pulse signal is 5%, the signal transmitting circuit 10 can achieve a transmission power of -13.7 decibel milliwatts (dBm) at a single frequency point (i.e., near 10 MHz), and the harmonic suppression level of the signal transmitting circuit 10 reaches 20.6 decibels (dB). That is to say, using a short pulse signal with a duty cycle of 5% to excite the switch module 12 can improve the harmonic suppression level of the signal transmitting circuit 10, so that the signal transmitting circuit 10 can stably transmit a single-frequency signal to the outside.

[0074] In addition, according to Figure 6 As shown in (b), when the duty cycle of the pulse signal is 5% and the frequency of the pulse signal is equal to the resonant frequency of the series resonant network, when the switch module 12 switches from the off state to the on state, the voltage V on the electrode 14 is ant The waveform of the voltage on the switch module 12 just passes through the zero point, and the voltage V on the electrode 14 ant The rate of change over time is 0, so the switch module 12 can be in a soft switching state, that is, the switching of the switch module 12 state will not cause additional power loss in the circuit, thereby further improving the power output efficiency of the signal transmission circuit 10; when the switch module 12 switches from the on state to the off state, the voltage V on the electrode 14 ant The waveform is restored to a complete resonant curve again, so that the signal transmitting circuit 10 can maintain a high level of harmonic suppression. It can be seen that the embodiment of the present application uses a short pulse signal with a duty cycle of 5% to excite the switch module 12, which not only enables the signal transmitting circuit 10 to have a high level of harmonic suppression to stably output a single-frequency signal, but also improves the power output efficiency of the signal transmitting circuit 10.

[0075] In another optional implementation, in order to further adjust the transmission power of the signal transmission circuit 10 and improve the transmission power of the signal transmission circuit 10, the embodiment of the present application also provides another implementation of the inductor module 11. Figure 7 , which is a circuit structure of a signal transmitting circuit 10 provided in another embodiment of the present application.

[0076] like Figure 7 As shown, in another optional implementation, the inductor module 11 may include a first inductor L res and the second inductor L m Among them, the first inductor L res With the second inductor L m Co-directional coupling setting, the first inductor L res With the second inductor L m The coupling coefficient may be K, and the value of K may be set according to actual requirements, for example, K may be 0.6.

[0077] For example, assuming that the second inductor L m The first end and the second inductor L m The first ends of the two inductors are the same as the first end, so the second inductor L m The first end of the inductor module 11 can be used as the first end a of the inductor module 11, and the second inductor L m The second end of the inductor module 11 can be used as the controlled end c of the inductor module 11. res The first end of the first inductor L res The second end of the second inductor L can be used as the second end b of the inductor module 11. m It can be used to store electric energy when the signal transmitting circuit 10 is in a charging state, and to couple the electric energy to the first inductor L res Transfer electrical energy. The first inductor L res It can be used to form a series resonant network with the electrode 14 when the signal transmitting circuit 10 is in a resonant state, so that the first inductor L res The stored electrical energy is radiated outward through the electrode 14 to realize the wireless signal transmission function.

[0078] For example, see Figure 8 ,for Figure 7 The equivalent circuit diagram of the signal transmitting circuit 10 in different working states is shown. Figure 8 (a) in Figure 7 The equivalent circuit diagram of the signal transmitting circuit 10 in the charging state is shown in FIG. Figure 8 (b) in Figure 7 The equivalent circuit diagram of the signal transmitting circuit 10 in the resonant state is shown.

[0079] like Figure 8As shown in (a), when the short pulse signal is at a high level, the switch module 12 is in the on state. At this time, the second inductor L m The switch module 12 is grounded, and the DC power supply 20 is connected to the second inductor L m Charging is performed, that is, at this time, the signal transmitting circuit 10 is in a charging state. res With the second inductor L m There is a coupling relationship between them, so the second inductor L m While storing electrical energy, it will be coupled to the first inductor L res transfer electrical energy, thereby making the first inductor L res It also stores electrical energy. Figure 8 As shown in (b), when the short pulse signal is at a low level, the switch module 12 is in an off state. At this time, the first inductor L res and the first capacitor C in the electrode 14 ant A series resonant network is formed so that the first inductor L res The stored electric energy is radiated outward through the electrode 14 , that is, the signal transmitting circuit 10 is in a resonant state at this time.

[0080] In this implementation, due to the second inductor L m The second inductor L only works in the charging state of the signal transmitting circuit 10 and does not participate in the resonance process of the signal transmitting circuit 10. Therefore, the second inductor L can be adjusted without affecting the series resonant network. m The inductive reactance value is used to adjust the current flowing through the second inductor L m The magnitude of the current is adjusted to adjust the transmission power of the signal transmission circuit 10. m The smaller the inductive reactance value is, the weaker its ability to limit the current growth rate of the path is, and the higher the transmission power of the signal transmitting circuit 10 is.

[0081] To further explain the transmission power of the signal transmission circuit 10 and the second inductor L m The relationship between the inductive reactance values ​​is as follows: m For example, the inductive reactance values ​​of the second inductor L m The performance indicators of the signal transmitting circuit 10 are compared when different inductive reactance values ​​are used.

[0082] See also Fig. 9 , is a second inductor L provided in an embodiment of the present application m A schematic diagram comparing various performance indicators of the signal transmission circuit 10 when different inductance values ​​are used. Fig. 9 (a) is the second inductor L m When the inductive reactance is 0.2μH, the current flowing through the second inductor Lm The current I ind Waveform diagram of ; Fig. 9 (b) is the second inductor L m When the inductive reactance is 0.05μH, the current flowing through the second inductor L m The current I ind Waveform diagram of ; Fig. 9 (c) is the second inductor L m A schematic diagram of the spectrum of the output power of the signal transmitting circuit 10 when the inductive reactance value is 0.2 μH; Fig. 9 (d) is the second inductor L m Schematic diagram of the spectrum of the transmission power of the signal transmission circuit 10 when the inductive reactance value is 0.05 μH.

[0083] like Fig. 9 As shown in (a) and (b) in FIG. m When the inductive reactance value decreases from 0.2μH to 0.05μH, the current flowing through the second inductor L m The maximum current of the second inductor L increases from 20 mA to 76 mA. m The inductive reactance value is reduced, and the second inductor L m The ability to limit the current growth rate of the path in which it is located is weakened, so that the current flowing through the second inductor L m The maximum current increases. Accordingly, if Fig. 9 As shown in (c) and (d) in FIG. m When the inductance value of the second inductor L is reduced from 0.2μH to 0.05μH, the transmission power of the signal transmitting circuit 10 at the 10MHz frequency point increases from 8.8dBm to 14.8dBm. m The inductive reactance value is reduced, and the transmission power of the signal transmission circuit 10 is improved. In addition, regardless of the second inductance L m Whether the inductance value of L is 0.2μH or 0.05μH, the signal transmitting circuit 10 can achieve a harmonic suppression level of more than 39dB. It can be seen that the introduction of the coupled inductor can enable the signal transmitting circuit 10 to decouple the resonant frequency control from the transmission power control. Therefore, by changing the second inductor L m The inductive reactance value can realize the adjustment of the transmission power of the signal transmitting circuit 10, and at the same time will not have any impact on the harmonic suppression level of the signal transmitting circuit 10.

[0084] To further illustrate the first inductor L of the coupling arrangement used in this implementation res With the second inductor L mAs the beneficial effect brought by the inductor module 11, the following assumes that the duty cycle of the short pulse signal is 5%, the frequency of the short pulse signal is 10 MHz, and the first inductor L res With the first capacitor C ant Resonance occurs at 10MHz, and the second inductor L m The inductive reactance value is 0.1μH, the first inductor L res For example, the inductive reactance value is 13.75μH. Figure 7 The various performance indicators of the signal transmitting circuit 10 are shown.

[0085] See also Fig.10 ,for Figure 7 The schematic diagram of various performance indicators of the signal transmission circuit 10 shown in FIG. Fig.10 (a) in Figure 7 The voltage V on the electrode 14 in the signal transmitting circuit 10 is shown ant Waveform diagram of ; Fig.10 (b) in Figure 7 The voltage V on the switch module 12 in the signal transmission circuit 10 shown in FIG. s Waveform diagram of ; Fig.10 (c) in Figure 7 The signal transmitting circuit 10 shown in FIG. m The current I ind Waveform diagram of ; Fig.10 (d) in Figure 7 FIG. 1 is a schematic diagram of a spectrum of the output power of the signal transmitting circuit 10 shown in FIG.

[0086] according to Fig.10 From (a) in the figure, it can be seen that without changing the first inductance L res In the case of an inductive reactance value, by placing the second inductor L m The inductive reactance value is set to 0.1μH, which can generate a resonant voltage with an amplitude of 189V on the electrode 14. Fig.10 As shown in (b), the voltage V on the switch module 12 s The maximum amplitude can be limited to 20V. It can be seen that the present implementation method is effective in increasing the voltage V on the electrode 14. ant At the same time, the voltage V on the switch module 12 will not be increased. s , thus no higher requirements are placed on the voltage resistance of the switch module 12. Fig.10 As shown in (c), with the second inductor L m The inductive reactance value is significantly reduced, and the current flowing through the second inductor L m The current I ind The transmission power of the signal transmission circuit 10 can be significantly improved. Fig.10 As can be seen from (d) in the figure, in this implementation, the signal transmitting circuit 10 can achieve a transmission power of 11.8 dBm at a single frequency point (i.e., near 10 MHz), and the harmonic suppression level of the signal transmitting circuit 10 reaches 44.9 dB. It can be seen that in this implementation, by introducing a coupled inductor, the resonant frequency control of the signal transmitting circuit 10 can be decoupled from the transmission power control, so that the control can be adjusted by adjusting the second inductor L m The transmit power of the signal transmitting circuit 10 is adjusted by adjusting the inductive reactance value.

[0087] In addition, since the frequency of the short pulse signal can be any integer multiple of the resonant frequency of the series resonant network, the excitation signal of the switch module 12 has a higher degree of freedom in the selection of the frequency, which expands the application range of the signal transmitting circuit 10. The following takes the resonant frequency of the series resonant network as 10MHz and the frequency of the short pulse signal as 1 / 4 and 1 / 10 of the resonant frequency as an example to further illustrate the influence of short pulse signals of different frequencies on various performance indicators of the signal transmitting circuit 10. Please refer to Fig.11 , is a schematic diagram for comparing various performance indicators of the signal transmitting circuit 10 when short pulse signals of different frequencies are used as excitation signals provided in an embodiment of the present application. Among them, Fig.11 (a) and (c) are respectively when the frequency of the short pulse signal is 1 / 4 of the resonant frequency, Figure 7 The voltage V on the electrode 14 in the signal transmitting circuit 10 is shown ant A schematic diagram of a waveform and a schematic diagram of a spectrum of the transmission power (Output Power) of the signal transmission circuit 10; Fig.11 (b) and (d) are respectively when the frequency of the short pulse signal is 1 / 10 of the resonant frequency, Figure 7 The voltage V on the electrode 14 in the signal transmitting circuit 10 is shown ant A waveform diagram of and a spectrum diagram of the transmission power of the signal transmission circuit 10.

[0088] according to Fig.11 From (a) and (c) in FIG. 1 , it can be seen that when the frequency of the short pulse signal is 1 / 4 of the resonant frequency (i.e., 2.5 MHz), the voltage V on the electrode 14 is ant The amplitude is 158V, the transmission power of the signal transmitting circuit 10 at the 10MHz frequency is 10.2dBm, and the signal transmitting circuit 10 has a harmonic suppression level of 34.9dB. Fig.11 From (b) and (d) in FIG. 1 , it can be seen that when the frequency of the short pulse signal is 1 / 10 of the resonant frequency (i.e., 1 MHz), the voltage V on the electrode 14 is antThe amplitude is 119V, the transmission power of the signal transmitting circuit 10 at the 10MHz frequency is 7.7dBm, and the signal transmitting circuit 10 has a harmonic suppression level of 34.7dB. It can be seen that when the frequency of the short pulse signal decreases, the transmission power of the signal transmitting circuit 10 will decrease, but the harmonic suppression level is maintained at a high level. Therefore, this implementation method only needs to ensure that the frequency of the short pulse signal is one of any integer multiples of the resonant frequency of the series resonant network, so that the signal transmitting circuit 10 can stably output a single-frequency signal with a high harmonic suppression level, thereby improving the freedom of frequency selection of the short pulse signal.

[0089] In another implementation of the present application, in order to suppress even-order harmonics and further improve the harmonic suppression level of the signal transmitting circuit 10, the present application embodiment also provides another signal transmitting circuit. Fig.12 , is a circuit structure of a signal transmitting circuit 10 provided in another embodiment of the present application. Fig.12 As shown, in another optional implementation, the number of pulse excitation sources 13 in the signal transmitting circuit 10, the number of switch modules 12, and the number of controlled terminals c of the inductor module 11 can all be 2. It should be noted that, in this implementation, the frequencies of the pulse signals output by all pulse excitation sources 13 are the same, and the duty cycles are the same, and the performances of all switch modules 12 are the same.

[0090] Each pulse excitation source 13 may have a first terminal f and a second terminal g, and each switch module 12 may have a controlled terminal h, a first conduction terminal j and a second conduction terminal k.

[0091] The first end f of the first pulse excitation source 13 can be grounded, and the second end g of the first pulse excitation source 13 can be connected to the controlled end h of the first switch module 12. The first pulse excitation source 13 can be used to output a first short pulse signal to the first switch module 12 to control the on and off of the first switch module 12.

[0092] The first conducting end j of the first switch module 12 can be connected to the first controlled end c of the inductor module 11, and the second conducting end h of the first switch module 12 can be grounded. The first switch module 12 can be used to connect the first controlled end c of the inductor module 11 to the ground when the first short pulse signal is at a high level, so that the DC power supply 20 charges the inductor module 11. The first switch module 12 can also be used to disconnect the first controlled end c of the inductor module 11 from the ground when the first short pulse signal is at a low level, so that the inductor module 11 and the electrode 14 form a series resonant network, and the inductor module 11 radiates the stored electric energy outward through the electrode 14.

[0093] The first end f of the second pulse excitation source 13 can be grounded, and the second end g of the second pulse excitation source 13 can be connected to the controlled end h of the second switch module 12. The second pulse excitation source 13 can be used to output a second short pulse signal to the second switch module 12 to control the on and off of the second switch module 12.

[0094] The first conducting end j of the second switch module 12 can be connected to the second controlled end c of the inductor module 11, and the second conducting end h of the second switch module 12 can be grounded. The second switch module 12 can be used to connect the second controlled end c of the inductor module 11 to the ground when the second short pulse signal is at a high level, so that the DC power supply 20 charges the inductor module 11; the second switch module 12 can also be used to disconnect the second controlled end c of the inductor module 11 from the ground when the second short pulse signal is at a low level, so that the inductor module 11 and the electrode 14 form a series resonant network, and the inductor module 11 radiates the stored electric energy outward through the electrode 14.

[0095] In a specific implementation, the inductor module 11 may include a first inductor L res , the second inductor L m And the third inductor L n Among them, the first inductor L res With the second inductor L m Co-directional coupling setting, the first inductor L res With the second inductor L m Reverse coupling is set, and the first inductor L res With the second inductor L m The coupling coefficient is equal to the first inductance L res With the third inductor L n The coupling coefficient of the second inductor L m The inductive reactance value is equal to the third inductor L n The inductive reactance value.

[0096] For example, assuming that the first inductor L res The first end of the second inductor L m The first end and the third inductor L n The first ends of the two inductors L m The first end of the third inductor L n The second ends of the inductor L are connected together and serve as the first end a of the inductor module 11. m The second end of the inductor module 11 can be used as the first controlled end c, and the third inductor L n The first end of the inductor module 11 can be used as the second controlled end c of the inductor module 11. res The first end of the first inductor L resThe second end of can be used as the second end b of the inductor module 11.

[0097] The first switch module 12 is specifically used for switching the second inductor L m The second end of the DC power supply 20 is connected to the ground, so that the DC power supply 20 has a direct current to the second inductor L m For charging, the second inductor L m By coupling to the first inductor L res The first switch module 12 is also specifically used to disconnect the second inductor L when the first short pulse signal is at a low level. m The second end of the first inductor L is connected to the ground. res A series resonant network is formed with the electrode 14. The first inductor L res The stored electrical energy is radiated outward through the electrodes 14 .

[0098] The second switch module 12 is specifically used for switching the third inductor L m The first end of the DC power supply 20 is connected to the ground, so that the third inductor L m For charging, the third inductor L m By coupling to the first inductor L res The second switch module 12 is also specifically used to disconnect the third inductor L when the second short pulse signal is at a low level m The first end of the first inductor L is connected to the ground so that res A series resonant network is formed with the electrode 14. The first inductor L res The stored electrical energy is radiated outward through the electrodes 14 .

[0099] See also Fig.13 ,for Fig.12 The equivalent circuit diagram of the signal transmission circuit in different working states is shown in FIG. Fig.13 (a) in Fig.12 The equivalent circuit diagram of the signal transmitting circuit 10 in the charging state is shown in FIG. Fig.13 (b) in Fig.12 The equivalent circuit diagram of the signal transmitting circuit 10 in the resonant state is shown.

[0100] like Fig.13 As shown in (a), when the short pulse signal output by the first pulse excitation source 13 is at a high level, the first switch module 12 is in the on state. At this time, the second inductor L m The second end of the first inductor L is connected to the ground through the first switch module 12, so that the DC power supply 20 has a direct current to the second inductor L mWhen the short pulse signal output by the second pulse excitation source 13 is at a high level, the second switch module 12 is in the on state. At this time, the third inductor L n The first end of the third inductor L is connected to the ground through the second switch module 12, so that the DC power supply 20 is connected to the third inductor L n Charging is performed, that is, at this time, the signal transmitting circuit 10 is in a charging state. It can be understood that due to the second inductor L m With the first inductor L res The coupling relationship is related to the third inductor L n With the first inductor L res The coupling relationship is opposite to that of the second inductor L. Therefore, when the signal transmitting circuit 10 is in the charging state, the second inductor L m and the third inductor L n The first inductor L res Generates current excitation in opposite direction.

[0101] like Fig.13 As shown in (b), when the short pulse signal output by the first pulse excitation source 13 and the short pulse signal output by the second pulse excitation source are both at low levels, the first switch module 12 and the second switch module 12 are both in the disconnected state. At this time, the first inductor L res and the first capacitor C in the electrode 14 ant A series resonant network is formed so that the first inductor L res The stored electric energy can be radiated outward through the electrode 14 , that is, the signal transmitting circuit 10 is in a resonant state at this time.

[0102] Based on this, the present implementation can adjust the phase of the pulse signal output by the first pulse excitation source 13 and / or the phase of the pulse signal output by the second pulse excitation source 13 to achieve the first inductor L res The differential excitation can enable the signal transmitting circuit 10 to have the function of suppressing even-order harmonics.

[0103] The following example illustrates the beneficial effects of this implementation method by taking the case where the frequency of the short pulse signal output by the first pulse excitation source 13 and the frequency of the short pulse signal output by the second pulse excitation source 13 are both 10MHz, the duty cycle of the short pulse signal output by the first pulse excitation source 13 and the duty cycle of the short pulse signal output by the second pulse excitation source 13 are both 5%, and the phase of the short pulse signal output by the first pulse excitation source 13 differs by 180 degrees from the phase of the short pulse signal output by the second pulse excitation source 13. Fig.14 , the figure shows that two short pulse signals with different phases are used to stimulate two switch modules respectively. Fig.12 FIG. 1 is a schematic diagram showing a comparison of various performance indicators of the signal transmitting circuit 10 shown in FIG. Fig.14(a) is when two short pulse signals with a phase difference of 180 degrees are used to stimulate the two switch modules 12 respectively. Fig.12 The voltage V on the electrode 14 in the signal transmitting circuit 10 is shown ant Waveform diagram of ; Fig.14 (b) is the voltage V on the two switch modules 12 when two short pulse signals with a phase difference of 180 degrees are used to stimulate the two switch modules 12 respectively. s (including V s1 and V s2 ) waveform diagram; Fig.14 (c) is the current I output by the DC power supply 10 when two short pulse signals with a phase difference of 180 degrees are used to excite the two switch modules 12 respectively. ind Waveform diagram of ; Fig.14 (d) is when two short pulse signals with a phase difference of 180 degrees are used to stimulate the two switch modules 12 respectively. Fig.12 FIG. 1 is a schematic diagram of a spectrum of the output power of the signal transmitting circuit 10 shown in FIG.

[0104] according to Fig.14 As shown in (a) of FIG. 1 , two short pulse signals with a phase difference of 180 degrees are used to respectively excite the two switch modules 12, which can generate a resonant voltage with an amplitude of 195V on the electrode 14. Fig.14 As shown in (b), the maximum amplitude of the voltage on the two switch modules 12 can be limited to 20V; and the voltage V s1 and V s2 The phases of the two switch modules 12 are also 180 degrees apart. In addition, when the two switch modules 12 are switched from the disconnected state to the conductive state, the voltage V s1 and V s2 The waveforms of both switches 12 just pass through the zero point, and the voltage V s1 and V s2 The rate of change over time is 0, so the two switch modules 12 can be in a soft switching state, that is, the switching of the two switch modules 12 states will not cause additional power loss in the circuit, thereby further improving the power output efficiency of the signal transmission circuit 10. At the same time, since the conduction time of the two switch modules 12 is relatively short, the short conduction of the two switch modules 12 will not affect the voltage V on the electrode 14. ant The waveform of the signal transmission circuit 10 is affected, so that the signal transmission circuit 10 can maintain a high harmonic suppression level. Fig.14 From (c) in the figure, we can see that since the first inductor L is resTwo excitations in opposite directions are performed, so two current pulses can be observed in each cycle. Fig.14 As can be seen from (d) in the figure, this implementation method can make Fig.12 The transmission power of the signal transmitting circuit 10 shown at a frequency of 10 MHz reaches 12.1 dBm, and the harmonic suppression level reaches 41.4 dB, thereby achieving complete suppression of even-order harmonics.

[0105] Based on the same inventive concept, an embodiment of the present application also provides a wireless communication module.

[0106] For example, see Fig.15 , Fig.15 This is a schematic diagram of the structure of a wireless communication module provided in an embodiment of the present application. Fig.15 As shown, the wireless communication module may include a signal transmitting circuit 10, and the signal transmitting circuit 10 may be the signal transmitting circuit in any of the above embodiments. It should be noted that the specific content of the signal transmitting circuit 10 can refer to the relevant description in the above embodiments, and will not be repeated here.

[0107] In some other embodiments, the wireless communication module may further include a signal receiving circuit.

[0108] Based on the same inventive concept, an embodiment of the present application also provides an electronic device.

[0109] For example, see Fig.16 , Fig.16 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Fig.16 As shown, the electronic device may include a DC power supply 20 and Fig.14 The wireless communication module shown.

[0110] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0111] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A signal transmitting circuit, characterized in that: It includes an inductor module, a switch module, a pulse excitation source and electrodes; The first end of the inductor module is used to connect to a DC power supply, the second end of the inductor module is connected to the first end of the electrode, and the second end of the electrode is grounded; The first end of the pulse excitation source is grounded, the second end of the pulse excitation source is connected to the controlled end of the switch module, and the pulse excitation source is used to output a short pulse signal with a duty cycle less than a preset duty cycle threshold to the switch module to control the on and off of the switch module; The first conducting end of the switch module is connected to the controlled end of the inductor module, and the second conducting end of the switch module is grounded; the switch module is used to connect the controlled end of the inductor module to the ground when the short pulse signal is at a high level, so as to short-circuit the electrode and enable the DC power supply to charge the inductor module; the switch module is also used to disconnect the connection between the controlled end of the inductor module and the ground when the short pulse signal is at a low level, so that the inductor module and the electrode form a series resonant network, and the inductor module radiates the stored electric energy outward through the electrode; wherein the resonant frequency of the series resonant network is an integer multiple of the frequency of the short pulse signal.

2. The signal transmitting circuit according to claim 1, characterized in that: The inductor module includes a first inductor; The first end of the first inductor serves as the first end of the inductor module, and the second end of the first inductor serves as the second end and the controlled end of the inductor module.

3. The signal transmitting circuit according to claim 1, characterized in that: The inductor module includes a first inductor and a second inductor; the first inductor and the second inductor are forward coupled; In the case that the first end of the first inductor and the first end of the second inductor are both the same-named ends, the first end of the second inductor serves as the first end of the inductor module, the second end of the second inductor serves as the controlled end of the inductor module, the first end of the first inductor is grounded, and the second end of the first inductor serves as the second end of the inductor module; The switch module is specifically used to connect the second end of the second inductor to the ground when the short pulse signal is at a high level, so that the DC power supply charges the second inductor, and the second inductor transfers electric energy to the first inductor through coupling; the switch module is also specifically used to disconnect the second end of the second inductor from the ground when the short pulse signal is at a low level, so that the first inductor and the electrode form a series resonant network, and the first inductor radiates the stored electric energy outward through the electrode.

4. The signal transmitting circuit according to claim 1, characterized in that: The number of the pulse excitation sources, the number of the switch modules, and the number of the controlled terminals of the inductor modules are all 2; The first end of the first pulse excitation source is grounded, the second end of the first pulse excitation source is connected to the controlled end of the first switch module, and the first pulse excitation source is used to output a first short pulse signal to the first switch module to control the on and off of the first switch module; The first conducting end of the first switch module is connected to the first controlled end of the inductor module, and the second conducting end of the first switch module is grounded; the first switch module is used to connect the first controlled end of the inductor module to the ground when the first short pulse signal is at a high level, so that the DC power supply charges the inductor module; The first switch module is further used for disconnecting the connection between the first controlled end of the inductor module and the ground when the first short pulse signal is at a low level, so that the inductor module and the electrode form a series resonant network, and the inductor module radiates the stored electric energy outward through the electrode; The first end of the second pulse excitation source is grounded, and the second end of the second pulse excitation source is connected to the controlled end of the second switch module; the second pulse excitation source is used to output a second short pulse signal to the second switch module to control the on and off of the second switch module; The first conducting end of the second switch module is connected to the second controlled end of the inductor module, and the second conducting end of the second switch module is grounded; the second switch module is used to connect the second controlled end of the inductor module to the ground when the second short pulse signal is at a high level, so that the DC power supply charges the inductor module; the second switch module is also used to disconnect the second controlled end of the inductor module from the ground when the second short pulse signal is at a low level, so that the inductor module and the electrode form a series resonant network, and the inductor module radiates the stored electric energy outward through the electrode.

5. The signal transmitting circuit according to claim 4, characterized in that: The inductor module includes a first inductor, a second inductor and a third inductor; the first inductor and the second inductor are forward coupled, and the first inductor and the third inductor are reverse coupled; the first end of the first inductor, the first end of the second inductor and the first end of the third inductor are all same-name ends; The first end of the second inductor and the second end of the third inductor are connected together as the first end of the inductor module, the second end of the second inductor serves as the first controlled end of the inductor module, the first end of the first inductor is grounded, the second end of the first inductor serves as the second end of the inductor module, and the first end of the third inductor serves as the second controlled end of the inductor module; The first switch module is specifically used for connecting the second end of the second inductor to the ground when the first short pulse signal is at a high level, so that the DC power supply charges the second inductor, and the second inductor transfers electric energy to the first inductor by coupling; the first switch module is also specifically used for disconnecting the second end of the second inductor from the ground when the first short pulse signal is at a low level, so that the first inductor and the electrode form a series resonant network, and the first inductor radiates the stored electric energy outward through the electrode; The second switch module is specifically used to connect the first end of the third inductor to the ground when the second short pulse signal is at a high level, so that the DC power supply charges the third inductor, and the third inductor transfers electric energy to the first inductor through coupling; the second switch module is also specifically used to disconnect the first end of the third inductor from the ground when the second short pulse signal is at a low level, so that the first inductor and the electrode form a series resonant network, and the first inductor radiates the stored electric energy outward through the electrode.

6. The signal transmitting circuit according to claim 5, characterized in that: The coupling coefficient between the first inductor and the second inductor is equal to the coupling coefficient between the first inductor and the third inductor, and the inductive reactance value of the second inductor is equal to the inductive reactance value of the third inductor.

7. The signal transmitting circuit according to any one of claims 1 to 6, characterized in that: The electrode includes a first capacitor and a first resistor; The first end of the first capacitor serves as the first end of the electrode, the second end of the first capacitor is connected to the first end of the first resistor, and the second end of the first resistor serves as the second end of the electrode.

8. The signal transmitting circuit according to any one of claims 1 to 6, characterized in that: The signal transmission circuit also includes a second capacitor; The first end of the second capacitor is used to connect to the DC power supply, and the second end of the second capacitor is grounded; The second capacitor is used to filter out the AC component in the DC signal output by the DC power supply.

9. A wireless communication module, characterized in that: The method comprises the signal transmitting circuit according to any one of claims 1 to 8.

10. An electronic device, characterized in that: It comprises a direct current power supply and the wireless communication module as claimed in claim 9.

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