CN112436848B

CN112436848B - Tuning circuit, radio frequency circuit and electronic equipment

Info

Publication number: CN112436848B
Application number: CN202011414139.2A
Authority: CN
Inventors: 彭致勇
Original assignee: Realme Mobile Telecommunications Shenzhen Co Ltd
Current assignee: Realme Mobile Telecommunications Shenzhen Co Ltd
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2022-08-05
Anticipated expiration: 2040-12-04
Also published as: CN112436848A

Abstract

The embodiment of the application discloses a tuning circuit, a radio frequency circuit and electronic equipment. The tuning circuit includes: the circuit comprises a first capacitor, a second capacitor, a first tuning module and a second tuning module. The first capacitor comprises a first input end and a first output end, and the first input end is used for being connected with a signal source; the second capacitor comprises a second input end and a second output end, the second input end is connected with the first output end, and the second output end is used for connecting the antenna radiator; the first tuning module is connected with a first input end and the first output end; the second tuning module is connected with the first output end; the first tuning module and the second tuning module are used for outputting radio frequency signals in different frequency ranges to the antenna radiating body. Through this tuned circuit, promoted the radiation performance of antenna radiator.

Description

Tuning circuit, radio frequency circuit and electronic equipment

Technical Field

The application relates to the technical field of communication, in particular to a tuning circuit, a radio frequency circuit and electronic equipment.

Background

In the prior art, an antenna is required for the electronic equipment to transmit or receive electromagnetic waves. The application scenes of radio communication, broadcasting, television, radar, navigation and the like need to utilize electromagnetic waves to transfer information. With the iterative development of communication technology, an antenna needs to carry more and more frequency-band signal transmission, and meanwhile, the power carried by the antenna is also greater and greater, and when the power carried by the antenna is greater, the withstand voltage value of the antenna is exceeded, so that the radiation performance of the antenna is reduced.

Disclosure of Invention

The embodiment of the application provides a tuning circuit, a radio frequency circuit and electronic equipment.

In a first aspect, a tuning circuit provided in an embodiment of the present application includes:

the first capacitor comprises a first input end and a first output end, and the first input end is used for being connected with a signal source;

the second capacitor comprises a second input end and a second output end, the second input end is connected with the first output end, and the second output end is used for connecting an antenna radiator;

a first tuning module connected to the first input terminal and the first output terminal;

the second tuning module is connected with the first output end;

the first tuning module and the second tuning module are used for outputting radio frequency signals in different frequency ranges to the antenna radiator.

In a second aspect, an embodiment of the present application provides a radio frequency circuit, including a signal source, a tuning circuit, and an antenna radiator, where the signal source, the tuning circuit, and the antenna radiator are connected in sequence;

the signal source is used for generating radio frequency signals;

the tuning circuit is used for tuning the radio frequency signal, and the tuning circuit is the tuning circuit provided by the embodiment of the application;

the antenna radiator is used for transmitting the tuned radio frequency signal to the outside.

In a third aspect, an embodiment of the present application provides an electronic device, which includes a housing and a radio frequency circuit disposed inside the housing, where the radio frequency circuit is the radio frequency circuit provided in the embodiment of the present application

In an embodiment of the present application, there is provided a tuning circuit including: the circuit comprises a first capacitor, a second capacitor, a first tuning module and a second tuning module. The first capacitor comprises a first input end and a first output end, and the first input end is used for being connected with a signal source; the second capacitor comprises a second input end and a second output end, the second input end is connected with the first output end, and the second output end is used for connecting the antenna radiator; the first tuning module is connected with a first input end and the first output end; the second tuning module is connected with the first output end; the first tuning module and the second tuning module are used for outputting radio frequency signals in different frequency ranges to the antenna radiating body. Through this tuned circuit, promoted the radiation performance of antenna radiator.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an electronic device provided in an embodiment of the present application.

Fig. 2 is a first circuit diagram of a radio frequency circuit provided in an embodiment of the present application.

Fig. 3 is a second circuit diagram of a radio frequency circuit provided in an embodiment of the present application.

Fig. 4 is a third circuit diagram of a radio frequency circuit provided in an embodiment of the present application.

Fig. 5 is a circuit diagram of a first tuning module provided in an embodiment of the present application.

Fig. 6 is a fourth circuit diagram of a radio frequency circuit provided in an embodiment of the present application.

Fig. 7 is a first circuit diagram of a second tuning module provided in an embodiment of the present application.

Fig. 8 is a second circuit diagram of a second tuning module provided in an embodiment of the present application.

Fig. 9 is a graph illustrating an operation of the rf circuit according to the embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, terms such as "first", "second", are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined by terms such as "first," "second," etc., may explicitly or implicitly include one or more of the recited features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

The following disclosure provides many different embodiments or examples for implementing different features of the application. To simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Further, the present application may repeat reference numerals and/or reference letters in the various examples for simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or arrangements discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

The embodiment of the application provides electronic equipment. The electronic device may be a smart phone, a tablet computer, or other devices, and may also be a game device, an AR (Augmented Reality) device, an automobile, a data storage device, an audio playing device, a video playing device, a notebook, a desktop computing device, or other devices.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure.

The electronic device 100 includes a display 40, a housing 50, a circuit board 60, and a battery 70.

The display screen 40 is disposed on the casing 50 to form a display surface of the electronic device 100, and is used for displaying information such as images and texts. The Display 40 may include a Liquid Crystal Display (LCD) or an Organic Light-Emitting Diode (OLED) Display.

It will be appreciated that the display screen 40 may include a display surface and a non-display surface opposite the display surface. The display surface is a surface of the display screen 40 facing a user, i.e. a surface of the display screen 40 visible to the user on the electronic device 100. The non-display surface is a surface of the display screen 40 facing the inside of the electronic device 100. The display surface is used for displaying information, and the non-display surface does not display information.

It is understood that a cover plate may be disposed on the display screen 40 to protect the display screen 40 from being scratched or damaged by water. The cover may be a transparent glass cover, so that a user can observe contents displayed on the display screen 40 through the cover. It will be appreciated that the cover plate may be a glass cover plate of sapphire material.

The housing 50 is used to form an outer contour of the electronic apparatus 100 so as to accommodate electronic devices, functional components, and the like of the electronic apparatus 100, while forming a sealing and protecting function for the electronic devices and functional components inside the electronic apparatus. For example, functional components of the electronic apparatus 100 such as a camera, a circuit board, a vibration motor, etc. may be disposed inside the housing 50. It will be appreciated that the housing 50 may include a center frame and a rear cover.

The middle frame may have a thin plate-like or sheet-like structure, or may have a hollow frame structure. The middle frame is used for providing a supporting function for the electronic devices or functional components in the electronic device 100 so as to mount the electronic devices or functional components of the electronic device 100 together. For example, the middle frame may be provided with a groove, a protrusion, or the like, so as to facilitate installation of the electronic device or the functional component of the electronic apparatus 100. It is understood that the material of the middle frame may include metal or plastic.

The rear cover is connected with the middle frame. For example, the rear cover may be attached to the middle frame by an adhesive such as a double-sided tape to achieve connection with the middle frame. The rear cover is used for sealing the electronic devices and functional components of the electronic device 100 inside the electronic device 100 together with the middle frame and the display screen 40, so as to protect the electronic devices and functional components of the electronic device 100. It will be appreciated that the battery cover may be integrally formed. In the forming process of the rear cover, structures such as a rear camera mounting hole can be formed on the rear cover. It is understood that the material of the rear cover may also include metal or plastic.

A circuit board 60 is disposed inside the housing 50. For example, the circuit board 60 may be mounted on a middle frame of the case 50 to be fixed, and the circuit board 60 is sealed inside the electronic device by a battery cover. Specifically, the circuit board may be installed at one side of the loading plate, and the display screen is installed at the other side of the loading plate. The circuit board 60 may be a main board of the electronic device 100. One or more of functional components such as a processor, a camera, an earphone interface, an acceleration sensor, a gyroscope, and a motor may also be integrated on the circuit board 60. Meanwhile, the display screen 40 may be electrically connected to the circuit board 60 to control the display of the display screen 40 by a processor on the circuit board 60.

The battery 70 is disposed inside the case 50. For example, the battery 70 may be mounted on a middle frame of the case 50 to be fixed, and the battery 70 is sealed inside the electronic device by a battery cover. Meanwhile, the battery 70 is electrically connected to the circuit board 60 to enable the battery 70 to power the electronic device 100. Among them, the circuit board 60 may be provided with a power management circuit thereon. The power management circuit is used to distribute the voltage provided by the battery 70 to the various electronic devices in the electronic apparatus 100.

In this embodiment, the electronic device 100 is further provided with a radio frequency circuit. The radio frequency circuitry is disposed inside a housing of the electronic device 100. The radio frequency circuit is used for transmitting radio frequency signals to the outside and receiving radio frequency signals from the outside. For example, the radio frequency circuitry may be used to transmit radio frequency signals to a base station or other electronic device, and to receive radio frequency signals transmitted by a base station or other electronic device. Thus, communication of the electronic device with the base station and other electronic devices can be achieved. The radio frequency signal may include one of a cellular network signal, a Wireless Fidelity (Wi-Fi) signal, a positioning signal, and the like.

Referring to fig. 2, fig. 2 is a first circuit diagram of a radio frequency circuit according to an embodiment of the present disclosure.

The radio frequency circuit includes a signal source 10, a tuning circuit 20, and an antenna radiator 30.

In some embodiments, the signal source 10, the tuning circuit 20, and the antenna radiator 30 are connected in series, and the signal source 10 is used to generate a radio frequency signal. The radio frequency signal generated by the signal source 10 may be radio frequency signals of multiple frequency bands, such as a long term evolution LTE signal, a WiFi signal, a 5G signal, and the like.

The LTE signal is a long term evolution LTE signal transmitted based on a UMTS (Universal Mobile Telecommunications System) technical standard established by The 3GPP (The 3rd Generation Partnership Project) organization, and is used for accessing a wireless communication network to implement wireless communication. The LTE signal of long term evolution may be divided into a Low Band (LB), a Medium Band (MB), and a High Band (HB), where the LB includes a frequency range of 700MHz to 960MHz, the MB includes a frequency range of 1710MHz to 2170MHz, and the HB includes a frequency range of 2300MHz to 2690 MHz; the Wi-Fi signals are signals which are wirelessly transmitted based on a Wi-Fi technology and are used for accessing a wireless local area network to realize network communication, and the Wi-Fi signals comprise Wi-Fi signals with the frequency of 2.4GHz and 5 GHz; the 5G signal is used for accessing a wireless communication network to realize wireless communication, and the 5G signal includes radio frequency signals of frequency bands of N1, N3, N41, N78, N79, and the like.

The tuning circuit 20 is used for tuning the radio frequency signal, and when the type of the radio frequency signal output by the signal source 10 is different, different tuning modules in the tuning circuit 20 may be used for tuning. For example, if the signal type output by the signal source 10 is a Wi-Fi signal, tuning the Wi-Fi signal by using the tuning module a; if the signal type output by the signal source 10 is a 5G signal, the tuning module B is used to tune the 5G signal.

In some embodiments, the tuning circuit 20 includes a first capacitor 210, a second capacitor 220, a first tuning module 230, and a second tuning module 240.

The first capacitor 210 includes a first output terminal a2 and a first input terminal a1, and the second capacitor 220 includes a second output terminal B2 and a second input terminal B1. The first input terminal a1 is connected to the signal source 10, the first output terminal a2 is connected to the second input terminal B1, and the second output terminal B2 is connected to the antenna radiator 30.

The first tuning module 230 has one end connected to the first input terminal a1 and the other end of the second tuning module 240 connected to the first output terminal a 2. That is, the input terminal of the first tuning module 230 is connected to the signal source 10, and the output terminal of the first tuning module 230 is connected to the first output terminal a 2.

One end of the second tuning module 240 is connected to the first output terminal a2 and the other end of the second tuning module 240 is connected to the system ground G. That is, the second tuning module 240 is connected in parallel between the first capacitor 210 and the second capacitor 220.

In some embodiments, the first tuning module 230 can tune at least one frequency band of radio frequency signals, and the second tuning module 240 can tune at least three different frequency bands of radio frequency signals. So that the radio frequency circuit can radiate radio frequency signals of at least four different frequency bands. Thereby improving the communication capability of the electronic device.

In some application scenarios, the second capacitor 220 is not disposed in the rf circuit, and only the first capacitor 210 is disposed. That is, the first input terminal a1 of the first capacitor 210 is connected to the signal source 10, and the first multiple output terminal of the first capacitor 210 is connected to the antenna radiator 30. If The signal source 10 is located close to The radiation end of The entire antenna radiator 30, when The first tuning module 230 and The second tuning module 240 are both in a disconnected state, The signal source 10 outputs a radio frequency signal, and The entire radio frequency circuit may exceed a voltage withstanding value, which may cause a voltage of The node 270 to be too high, thereby generating a Radiation Stray (RSE) problem, resulting in a performance degradation of The ota (over The air) of The antenna radiator 30. Node 270 may be understood to be the first output a2 to which first tuning module 230 and second tuning module 240 need to be connected.

In order to reduce the voltage at the node 270, in the embodiment of the present application, the second capacitor 220 is connected in series between the first capacitor 210 and the antenna radiator 30, so that the second capacitor 220 can perform a voltage division function, so as to reduce the voltage at the node 270. It is also possible to reduce the voltage value of the entire rf circuit under the path when the first tuning module 230 and the second tuning module 240 are disconnected, thereby solving the problem of radiation stray and improving the OTA performance of the antenna radiator 30.

Wherein the voltage value at node 270 depends on the ratio of the first capacitance 210 and the second capacitance 220. For example, when the voltage value input by the signal source 10 is 3 volts, and the ratio of the value of the first capacitor 210 to the value of the second capacitor 220 is 1:2, the voltage value of the first capacitor 210 and the voltage value of the second capacitor 220 are 2: 1. The voltage at node 270 is now 1 volt. The voltage at node 270 drops due to the voltage division of second capacitor 220. When the antenna radiator 30 receives and transmits radio frequency signals, it can have better radiation performance.

Referring to fig. 3, fig. 3 is a second circuit diagram of the rf circuit according to the embodiment of the present disclosure.

The tuning circuit 20 is further provided with a serial switch 250 and a parallel switch 260, the serial switch 250 is arranged between the first output terminal a2 and the first tuning module 230, and the serial switch 250 is used for controlling the connection condition of the first tuning module 230 and the radio frequency circuit. When the serial switch 250 is connected, at this time, the first tuning module 230 is electrically connected to the radio frequency circuit, a signal transmitted by the signal source 10 enters the first tuning module 230 for tuning, the first tuning module 230 outputs a tuned radio frequency signal to the antenna radiator 30, and the antenna radiator 30 radiates the tuned radio frequency signal to the outside. When the string switch 250 is turned off, the first tuning module 230 cannot tune in the rf circuit.

The parallel switch 260 is used to control the connection of the second tuning module 240 to the rf circuit. When the parallel switch 260 is connected, at this time, the second tuning module 240 is electrically connected to the radio frequency circuit, the signal transmitted by the signal source 10 enters the second tuning module 240 for tuning, the second tuning module 240 outputs the tuned radio frequency signal to the antenna radiator 30, and the antenna radiator 30 radiates the tuned radio frequency signal to the outside. When the combination switch 260 is turned off, the second tuning module 240 cannot perform tuning function in the rf circuit.

In some embodiments, the serial switch 250 and the parallel switch 260 may be in a connected state at the same time. The first tuning module 230 and the second tuning module 240 may operate simultaneously, and at this time, the first tuning module 230 and the second tuning module 240 may tune radio frequency signals of different frequency bands, respectively. For example, the first tuning module 230 may be used to tune Wi-Fi signals, while the second tuning module 240 may be used to tune cellular network signals.

In some embodiments, the string switch 250 and the parallel switch 260 may be in different states at the same time. For example, the serial switch 250 is in a connected state and the serial switch 260 is in an open state, and the first tuning module 230 is used for tuning the rf signal, while the second tuning module 240 does not perform the tuning function. When the parallel switch 260 is in the connected state and the serial switch 250 is in the disconnected state, the second tuning module 240 is used for tuning the rf signal, and the first tuning module 230 does not perform the tuning function.

Referring to fig. 4, fig. 4 is a third circuit diagram of the rf circuit according to the embodiment of the present disclosure.

Wherein the radio frequency circuit further comprises a third capacitor 230, the third capacitor 230 may be connected in series between the first capacitor 210 and the second capacitor 220. That is, the input terminal of the third capacitor 230 is connected to the first output terminal a2 of the first capacitor 210, and the output terminal of the third capacitor 230 is connected to the input terminal of the second capacitor 220.

At this time, the node 270 is between the third capacitance 230 and the first capacitance 210. The third capacitor 230 may also perform a voltage division function, and the voltage value at the node 270 may be adjusted by adjusting a ratio of the first capacitor 210, the second capacitor 220, and the third capacitor 230, so that the voltage value at the node 270 may not be too high. Therefore, the voltage values of the serial switch 250 and the parallel switch 260 are not too high, and the reduction of the radiation performance of the antenna radiator 30 caused by the abnormal operation of the tuning circuit 20 due to the too high voltage is avoided.

Referring to fig. 5, fig. 5 is a circuit diagram of a first tuning module 230 according to an embodiment of the present disclosure.

The first tuning module 230 includes a fourth capacitor 231, a first switch 232, a second switch 233, and a first ground point 234. The fourth capacitor 231 includes a fourth input terminal C1 and a fourth output terminal C2, and the fourth input terminal C1 is connected to the first input terminal a1 of the first capacitor 210.

The first switch 232 is connected in series between the fourth output terminal C2 and the first output terminal a2, and when the first switch 232 is connected, the tuning circuit 20 can output the radio frequency signal in the first frequency range through the tuning function of the first tuning module 230.

In some embodiments, a second switch 233 is connected in parallel between the first switch 232 and the first capacitor 210. One end of the second switch 233 is connected between the first switch 232 and the first capacitor 210, and the other end of the second switch 233 is connected to a first ground point 234.

When the first tuning module 230 does not need to operate, the first switch 232 may be opened, thereby opening the first tuning module 230. However, when the first switch 232 is turned off, the first switch 232 may have parasitic capacitance, which may cause the first tuning module 230 to interfere with the normal operation of the entire tuning circuit 20. At this time, the parasitic capacitance existing when the first switch 232 is turned off can be eliminated by putting the second switch 233 in a connected state and connecting the second switch 233 to the first grounding point 234.

Referring to fig. 6, fig. 6 is a fourth circuit diagram of a radio frequency circuit according to an embodiment of the present disclosure.

In some embodiments, the second tuning module 240 includes a first tuning sub-module 241, a second tuning sub-module 242, and a third tuning sub-module 243. Wherein the first tuning sub-module 241, the second tuning sub-module 242, and the third tuning sub-module 243 are connected in parallel between the first capacitor 210 and the second capacitor 220. That is, the inputs of the first tuning submodule 241, the second tuning submodule 242 and the third tuning submodule 243 are connected to the first output a2, and the outputs of the first tuning submodule 241, the second tuning submodule 242 and the third tuning submodule 243 are connected to the system ground G.

In some embodiments, the first tuning sub-module 241, the second tuning sub-module 242, and the third tuning sub-module 243 may operate simultaneously, and the first tuning sub-module 241, the second tuning sub-module 242, and the third tuning sub-module 243 may tune radio frequency signals of different frequency bands, respectively.

Referring to fig. 7, fig. 7 is a first circuit diagram of the second tuning module 240 according to an embodiment of the present application.

The first tuning submodule 241 includes a second ground point 2413, a third switch 2411, and a first inductor 2412.

The first inductor 2412 includes a first terminal D1 and a second terminal D2, and the third switch 2411 is connected in series between the first output terminal a2 and the first terminal D1 of the first capacitor 210. The second terminal D2 is connected to a second ground point 2413. When the third switch 2411 is in a connected state, the first tuning sub-module 241 may be used to tune the radio frequency signal. At this time, due to the tuning function of the first tuning sub-module 241, the tuning circuit 20 may be used to output the radio frequency signal of the second frequency range. Such as a 4G signal.

Second tuning submodule 242 includes a fourth ground point 2423, a second inductance 2422, and a fifth switch 2421. The second inductor 2422 comprises a third terminal E1 and a fourth terminal E2, and the fifth switch 2421 is connected in series between the first output terminal a2 and the third terminal E1 of the first capacitor 210. The fourth end E2 is connected to a fourth ground 2423. When the fifth switch 2421 is in the on state, the second tuning sub-module 242 may be used to tune the radio frequency signal. At this time, the tuning circuit 20 may be used to output the radio frequency signal in the third frequency range due to the tuning action of the second tuning sub-module 242. Such as a 5G signal.

The third tuning submodule 243 includes a sixth ground point 2433, a third inductor 2432, and a seventh switch 2431. The third inductor 2432 includes a fifth terminal F1 and a sixth terminal F2, and the seventh switch 2431 is connected in series between the first output terminal a2 and the fifth terminal F1 of the first capacitor 210. The sixth terminal F2 is connected to a sixth ground point 2433. When the seventh switch 2431 is in the on state, the third tuning sub-module 243 may be used to tune the radio frequency signal. At this time, the tuning circuit 20 may be used to output the radio frequency signal of the fourth frequency range due to the tuning function of the third tuning sub-module 243. Such as Wi-Fi signals.

Referring to fig. 8, fig. 8 is a second circuit diagram of the second tuning module 240 according to an embodiment of the present disclosure.

Wherein first tuning submodule 241 further comprises a fourth switch 2414 and a third ground point 2415.

The fourth switch 2414 is connected in parallel between the third switch 2411 and the first inductor 2412, and the other end of the fourth switch 2414 is connected to the third ground point 2415. When the tuning circuit 20 does not need the first tuning submodule 241 to operate, at this time, the third switch 2411 is in an open state, but there may still be a parasitic capacitance across the third switch 2411, and the fourth switch 2414 is closed to connect to the third ground point 2415, so as to eliminate the parasitic capacitance, thereby reducing the interference of the parasitic capacitance to the radio frequency circuit.

Second tuning submodule 242 also includes a sixth switch 2424 and a fifth ground point 2425.

A sixth switch 2424 is connected in parallel between the fifth switch 2421 and the second inductor 2422, and the other end of the sixth switch 2424 is connected to a fifth ground point 2425. When the second tuning submodule 242 is not required to operate in the tuning circuit 20, at this time, the fifth switch 2421 is in an open state, but parasitic capacitance may still exist across the fifth switch 2421, and the parasitic capacitance is eliminated by closing the sixth switch 2424 to connect the fifth grounding point 2425, so as to reduce interference of the parasitic capacitance on the radio frequency circuit.

Third tuning submodule 243 further includes an eighth switch 2434 and a seventh ground point 2435.

The eighth switch 2434 is connected in parallel between the seventh switch 2431 and the third inductor 2432, and the other end of the eighth switch 2434 is connected to a seventh grounding point 2435. When the third tuning submodule 243 of the tuning circuit 20 is not required to operate, at this time, the seventh switch 2431 is in an open state, but a parasitic capacitance may still exist across the seventh switch 2431, and the parasitic capacitance is eliminated by closing the eighth switch 2434 to connect the fifth grounding point 2425, so as to reduce the interference of the parasitic capacitance to the radio frequency circuit.

Referring to fig. 9, fig. 9 is a graph illustrating an operation of a radio frequency circuit according to an embodiment of the present disclosure.

The curve corresponding to the coordinate point 1 is a graph of the rf circuit without the second capacitor 220 connected in series. The capacitance of the first capacitor 210 is 0.8pF, and the voltage at the coordinate point 1 is 70.637V. That is, the voltage value carried at node 270 at this time is too high.

The curve corresponding to the coordinate point 2 is a graph of voltage division performed by the second capacitor 220 connected in series in the rf circuit. At this time, the capacitance of the first capacitor 210 is 4pF, the capacitance of the second capacitor 220 is 1pF, and the voltage value at the coordinate point 2 is 56.68V. The voltage value at node 270 at this time drops significantly.

The abscissa of the coordinate point 1 is the same as the abscissa of the coordinate point 2, that is, the input frequency is the same, and the frequency value is 0.85263 GHz. At this time, the first tuning module 230 and the second tuning module 240 are not connected to the radio frequency circuit, and only a path formed by sequentially connecting the signal source 10, the first capacitor 210, the second capacitor 220, and the antenna radiator 30 remains.

The voltage at the node 270 is reduced by about 20% by dividing the voltage by the second capacitor 220 connected in series, so that the first tuning module 230 and the second tuning module 240 can have a proper operating voltage when they are turned on, thereby improving the radiation performance of the antenna radiator 30.

In an embodiment of the present application, there is provided a tuning circuit 20 including: a first capacitor 210, a second capacitor 220, a first tuning module 230, and a second tuning module 240. The first capacitor 210 comprises a first input terminal a1 and a first output terminal a2, the first input terminal a1 is used for connecting the signal source 10; the second capacitor 220 includes a second input end B1 and a second output end B2, the second input end B1 is connected to the first output end a2, and the second output end B2 is used for connecting the antenna radiator 30; the first tuning module 230 is connected to the first input a1 and the first output a 2; the second tuning module 240 is connected to the first output terminal a 2; the first tuning module 230 and the second tuning module 240 are configured to output radio frequency signals with different frequency ranges to the antenna radiator 30. By means of the tuning circuit 20, the radiation performance of the antenna radiator 30 is improved.

The tuning circuit, the radio frequency circuit, and the electronic device provided in the embodiments of the present application are described in detail above, and specific examples are applied in the present application to explain the principles and implementations of the present application, and the description of the above embodiments is only used to help understand the method and the core idea of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. A tuning circuit, wherein when the types of radio frequency signals output by signal sources are different, different tuning modules in the tuning circuit are used for tuning, and the tuning circuit comprises:

the first capacitor comprises a first input end and a first output end, and the first input end is used for connecting a signal source;

a first tuning module connected to the first input and the first output, comprising: a fourth capacitor, wherein the fourth capacitor comprises a fourth input end and a fourth output end, and the fourth input end of the fourth capacitor is connected with the first input end; a first switch connected in series between the fourth output terminal and the first output terminal, the tuning circuit operable to output a radio frequency signal in a first frequency range when the first switch is on; a second switch connected in parallel between the first switch and the fourth capacitor; a first ground point connected to the second switch;

the second tuning module is connected with the first output end;

2. The tuning circuit of claim 1, further comprising:

a third capacitor connected in series between the first capacitor and the second capacitor.

3. The tuning circuit of claim 1, wherein the second tuning module comprises:

the first tuning submodule is connected with the first output end;

the second tuning submodule is connected with the first output end;

a third tuning sub-module connected to the first output terminal.

4. The tuning circuit of claim 3, wherein the first tuning submodule comprises:

a second ground point;

a first inductor comprising a first terminal and a second terminal, the second terminal being connected to the second ground point;

a third switch connected in series between the second terminal and the first output terminal, the tuning circuit operable to output radio frequency signals of a second frequency range when the third switch is on.

5. The tuning circuit of claim 4, wherein the second tuning sub-module comprises:

a fourth switch connected in parallel between the third switch and the first inductor;

a third ground point connected to the fourth switch.

6. The tuning circuit of claim 3, wherein the second tuning sub-module comprises:

a fourth ground point;

a second inductor comprising a third terminal and a fourth terminal, the fourth terminal being connected to the fourth ground point;

and the fifth switch is connected between the third end and the first output end in series, and when the fifth switch is connected, the tuning circuit can be used for outputting radio-frequency signals in a third frequency range.

7. The tuning circuit of claim 6, wherein the third tuning sub-module further comprises:

a sixth switch connected in parallel between the fifth switch and the second inductor;

a fifth ground point connected to the sixth switch.

8. The tuning circuit of claim 3, wherein the third tuning sub-module comprises:

a sixth ground point;

a third inductor comprising a fifth terminal and a sixth terminal, the sixth terminal being connected to the sixth ground point;

a seventh switch connected in series between the fifth terminal and the first output terminal, the tuning circuit operable to output a radio frequency signal in a fourth frequency range when the seventh switch is on.

9. The tuning circuit of claim 8, wherein the third tuning sub-module further comprises:

an eighth switch connected in parallel between the seventh switch and the third inductor;

a seventh ground point connected to the eighth switch.

10. A radio frequency circuit is characterized by comprising a signal source, a tuning circuit and an antenna radiator, wherein the signal source, the tuning circuit and the antenna radiator are sequentially connected;

the signal source is used for generating radio frequency signals;

the tuning circuit is used for tuning the radio frequency signal, and the tuning circuit is the tuning circuit in any one of claims 1 to 9;

11. An electronic device comprising a housing and radio frequency circuitry disposed inside the housing, the radio frequency circuitry being as claimed in claim 10.