Multi-mode wideband matching circuit, printed circuit board, antenna and electronic device

Abstract

The application provides a multi-mode broadband matching circuit, a printed circuit board, an antenna and an electronic device. The multi-mode broadband matching circuit comprises a direct current power supply module, a broadband matching module, a first signal shunt module and a second signal shunt module. The direct current power supply module is connected with the broadband matching module. An input end of the broadband matching module is connected with the antenna, and is used for performing broadband impedance matching and amplification on an electromagnetic signal received by the antenna. Output ends of the broadband matching module are connected with the first signal shunt module and the second signal shunt module respectively. The first signal shunt module is connected with an FM back-end module, and is used for transmitting an FM signal to the FM back-end module. The second signal shunt module is connected with a cellular back-end module, and is used for transmitting a cellular communication signal to the cellular back-end module. The broadband matching module can provide broadband input impedance matching and high signal gain, and can simultaneously support FM broadcast and cellular communication through the first signal shunt module and the second signal shunt module.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a multi-mode broadband matching circuit, a printed circuit board, an antenna, and electronic equipment. Background Technology

[0002] With the development of mobile communication technology, the space available for antennas within communication devices is becoming increasingly limited. Using a single antenna to perform multiple functions allows for the reuse of the same physical space, improving integration. FM radio, which achieves low-cost, wide-area signal coverage without base stations or the internet, is an internationally recognized emergency backup solution and enjoys a large audience base and market demand in emerging markets. Cellular communication, as a crucial component of mobile communication technology, is an indispensable infrastructure of modern society, supporting mobile internet, data transmission, and IoT applications for billions of people worldwide.

[0003] Currently, mobile phones use wired headphone cables as FM receiving antennas, but this is not very portable. With wired headphones gradually being replaced, current mobile phones use built-in FM receiving antennas. However, built-in mobile phone antennas are electrically small antennas in the FM band (88-108MHz), severely limiting their bandwidth. Traditional impedance matching methods suffer from low efficiency and poor stability, making current solutions far less effective than wired headphones.

[0004] Active matching circuits based on a single field-effect transistor can overcome the limitations of electrically small antennas to achieve broadband matching, and they are simple in structure and highly stable. Current achievements are concentrated at the circuit board level, lacking system-level applications in practical engineering scenarios and complex electromagnetic environments. How to apply this broadband matching technology to mobile phones to overcome the challenge of high-quality FM signal reception, and on this basis, be compatible with cellular communication functions to achieve highly integrated antenna multiplexing, is a technological gap that urgently needs to be filled in this field. Summary of the Invention

[0005] This application provides a multi-mode broadband matching circuit, a printed circuit board, an antenna, and an electronic device to solve at least some of the problems in the related art.

[0006] In a first aspect, embodiments of this application provide a multi-mode broadband matching circuit, including: a DC power supply module, a broadband matching module, a first signal splitting module, and a second signal splitting module; the broadband matching module, the first signal splitting module, and the second signal splitting module each include an input terminal and an output terminal; The DC power supply module is connected to the broadband matching module and is used to supply power to the broadband matching module. The input terminal of the broadband matching module is connected to the antenna and is used to perform broadband impedance matching and amplification on the electromagnetic signals received by the antenna. The output terminal of the broadband matching module is connected to the input terminal of the first signal splitting module and the input terminal of the second signal splitting module, respectively. The output of the first signal splitter module is connected to the FM back-end module for transmitting FM signals to the FM back-end module; The output of the second signal splitter module is connected to the cellular back-end module and is used to transmit cellular communication signals to the cellular back-end module.

[0007] Optionally, the broadband matching module includes: a field-effect transistor, a first bias decoupling module, a second bias decoupling module, a third bias decoupling module, and a fourth bias decoupling module; the field-effect transistor includes a drain, a source, and a gate; The gate of the field-effect transistor is connected to the antenna; The first bias decoupling module is connected between the DC power supply module and the drain of the field-effect transistor; The second bias decoupling module is connected between the source of the field-effect transistor and ground; The third bias decoupling module is connected between the gate of the field-effect transistor and ground; The fourth bias decoupling module is connected between the drain of the field-effect crystal and the input terminals of the first signal splitter module and the second signal splitter module.

[0008] Optionally, the first bias decoupling module includes a first resistor, a first inductor, and a first capacitor; the first resistor and the first inductor are connected in series and placed between the DC power supply module and the drain of the field-effect transistor; the first resistor is connected to the DC power supply module, and the first inductor is connected to the drain of the field-effect transistor; the first capacitor is connected between the power supply path of the DC power supply module and ground, one end of the first capacitor is grounded, and the other end is connected between the DC power supply module and the first resistor; and / or The second bias decoupling module includes a second resistor and a second capacitor, which are connected in parallel between the source of the field-effect transistor and ground; and / or The third bias decoupling module includes a third resistor connected between the gate of the field-effect transistor and ground; and / or The fourth bias decoupling module includes a third capacitor, which is connected between the drain of the field-effect transistor and the input terminals of the first signal splitter module and the second signal splitter module.

[0009] Optionally, the first bias decoupling module, the second bias decoupling module, the third bias decoupling module, and the fourth bias decoupling module are configured to operate the field-effect transistor in the linear variable resistance region, thereby utilizing the characteristics of the field-effect transistor in the linear variable resistance region to achieve broadband input impedance matching.

[0010] Optionally, the first signal splitting module includes a first filter network composed of inductors and capacitors, the first filter network being used to allow FM signals to pass through while isolating cellular signals; and / or The second signal splitting module includes a second filter network composed of inductors and capacitors, which allows cellular signals to pass through while isolating FM signals.

[0011] Optionally, the first signal splitting module includes a second inductor, a fourth capacitor, a third inductor, a fifth capacitor, a fourth inductor, and a sixth capacitor; the second inductor, the fourth capacitor, the fourth inductor, and the sixth capacitor are connected in series sequentially; the second inductor is connected to the broadband matching module, and the sixth capacitor is connected to the FM back-end module; the third inductor and the fifth capacitor are connected in parallel, with one end of the third inductor and the fifth capacitor grounded, and the other end connected between the fourth capacitor and the fourth inductor; and / or The second signal splitting module includes a fifth inductor, a seventh capacitor, a sixth inductor, an eighth capacitor, a seventh inductor, and a ninth capacitor; the fifth inductor, the seventh capacitor, the seventh inductor, and the ninth capacitor are connected in series in sequence, the fifth inductor is connected to the broadband matching module, and the ninth capacitor is connected to the cellular back-end module; the sixth inductor and the eighth capacitor are connected in parallel, one end of the sixth inductor and the eighth capacitor is grounded, and the other end is connected between the seventh capacitor and the seventh inductor.

[0012] Optionally, the multi-mode broadband matching circuit supports at least two operating modes, including a first mode and a second mode: When the multi-mode broadband matching circuit is in the first mode, the antenna connected to the broadband matching module is in the FM band. The broadband matching module matches the antenna connected to it that is operating in the zero-mode and outputs the FM broadcast signal through the first signal splitting module. When the multi-mode broadband matching circuit is in the second mode, the antenna connected to the broadband matching module is in the cellular frequency band. The broadband matching module matches the antenna connected to it that is operating in the first mode or a higher mode, and outputs the cellular network signal through the second signal splitting module.

[0013] Secondly, embodiments of this application provide a printed circuit board including the multi-mode broadband matching circuit as described in the first aspect.

[0014] Thirdly, embodiments of this application provide an antenna, including an electrically small antenna and a multi-mode broadband matching circuit as described in the first aspect, wherein the electrically small antenna is connected to the broadband matching module of the multi-mode broadband matching circuit.

[0015] Fourthly, embodiments of this application provide an electronic device, including: Printed circuit boards as described in the second aspect; and / or The antenna as described in the third aspect.

[0016] The multi-mode broadband matching circuit provided in this application offers broadband input impedance matching and high signal gain, overcoming the physical limitations of passive antenna matching. This allows electronic devices to receive FM signals without external wired headphones, while also improving the number of stations and sound quality. Furthermore, through the design of a first and second signal splitter module, a single antenna and matching circuit can simultaneously support FM broadcasting and cellular communication. Thus, the multi-mode broadband matching circuit boasts high integration, low cost, and achieves high-quality FM signal reception and multi-mode communication compatibility.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] Figure 1 This is a system architecture block diagram of the multi-mode broadband matching circuit provided in the first embodiment of this application; Figure 2 This is a modular exploded view of the broadband matching module of the multi-mode broadband matching circuit provided in the second embodiment of this application; Figure 3 This is a schematic diagram of the specific circuit structure of the broadband matching module of the multi-mode broadband matching circuit provided in the third embodiment of this application; Figure 4 This is a schematic diagram of the specific circuit structure of the broadband matching module and signal splitting module of the multi-mode broadband matching circuit provided in the fourth embodiment of this application; Figure 5 This is a comparison diagram of the reflection coefficients of the antenna provided in this application, with and without the broadband matching module. Figure 6 This is a diagram of the FM band reflection coefficients of the signal provided in this application after passing through the first signal splitting module; Figure 7 This is a comparison diagram of the FM band gain of the antenna provided in this application example, with and without a broadband matching module. Figure 8 This is a cellular band reflection coefficient diagram of the signal provided in this application after passing through the second signal splitting module; Figure 9 This is a comparison diagram of the cellular band gain of the antenna provided in this application example, with and without a broadband matching module. Figure 10 This is a diagram showing the coupling coefficients between the first signal splitter module and the second signal splitter module provided in this application example.

[0020] Figure label: 1-Antenna; 2-DC power supply module; 3-Broadband matching module; 30-Field effect transistor; 31-First bias decoupling module; 311-First resistor; 312-First inductor; 313-First capacitor; 32-Second bias decoupling module; 321-Second resistor; 322-Second capacitor; 33-Third bias decoupling module; 331-Third resistor; 34-Fourth bias decoupling module; 341-Third capacitor; 4-First signal splitter module; 41-Second inductor; 42-Fourth capacitor; 43-Third inductor; 44-Fifth capacitor; 45-Fourth inductor; 46-Sixth capacitor; 5-Second signal splitter module; 51-Fifth inductor; 52-Seventh capacitor; 53-Sixth inductor; 54-Eighth capacitor; 55-Seventh inductor; 56-Ninth capacitor; 6-FM back-end module; 7-Cellular back-end module. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0022] Electrically small antennas (EMS) are antennas with a maximum geometric dimension less than 0.1λ, where λ is the wavelength of the electromagnetic wave at the operating frequency of the EMS. The small radiation resistance and large reactance of EMS reduce their radiation gain and bandwidth performance. Impedance matching can improve the performance of EMS. Non-Foster circuits can compensate for the large reactance of EMS, breaking the limits of gain-bandwidth theory, improving the impedance characteristics of EMS, broadening the antenna's bandwidth, and increasing its gain. This enables the use of EMS in broadband communication systems, reducing the antenna size in communication equipment. However, non-Foster circuits have a complex circuit structure, including multiple transistors, which leads to higher power consumption.

[0023] Therefore, in the face of the problem of high power consumption in the matching circuit of electrically small antennas in the prior art, this application, through inventive research, proposes to reduce the power consumption of the matching circuit of electrically small antennas and improve the impedance characteristics of electrically small antennas. This requires reducing the number of active components and ensuring that the electrically small antenna can be impedance matched with the transmission line through the matching circuit. Therefore, this application proposes a multi-mode broadband matching circuit, a printed circuit board, an antenna, and electronic equipment.

[0024] To better understand the technical solution of this application, the multi-mode broadband matching circuit, printed circuit board, antenna, and electronic equipment of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features in the following embodiments and implementations can be combined with each other.

[0025] See Figure 1 As shown, an embodiment of this application provides a multi-mode broadband matching circuit, which can be a multi-mode broadband matching circuit for electrically small antennas. The multi-mode broadband matching circuit may include: a DC power supply module 2, a broadband matching module 3, a first signal splitter module 4, and a second signal splitter module 5. The broadband matching module 3, the first signal splitter module 4, and the second signal splitter module 5 each include an input terminal and an output terminal.

[0026] The DC power supply module 2 is connected to the broadband matching module 3, and the DC power supply module 2 supplies power to the broadband matching module 3 and all modules of the entire circuit. The input terminal of the broadband matching module 3 is connected to the antenna 1, and is used to perform broadband impedance matching and amplification on the electromagnetic signal received by the antenna 1. Optionally, the antenna 1 can be an electrically small antenna. Electrically small antennas are used to receive electromagnetic wave signals and can be various antenna types such as patch antennas, dipole antennas, and monopole antennas.

[0027] The output of the broadband matching module 3 is connected to the input of the first signal splitter module 4 and the input of the second signal splitter module 5, respectively. The output of the first signal splitter module 4 is connected to the FM back-end module 6 to process FM broadcast signals and transmit FM signals to the FM back-end module 6. The output of the second signal splitter module 5 is connected to the cellular back-end module 7 to process cellular signals and transmit cellular communication signals to the cellular back-end module 7.

[0028] The multi-mode broadband matching circuit provided in this application offers broadband input impedance matching and high signal gain, overcoming the physical limitations of passive antenna matching. This allows electronic devices to receive FM signals without external wired headphones, while also improving the number of stations and sound quality. Furthermore, through the design of a first and second signal splitter module, a single antenna and matching circuit can simultaneously support FM broadcasting and cellular communication. Thus, the multi-mode broadband matching circuit boasts high integration, low cost, and achieves high-quality FM signal reception and multi-mode communication compatibility.

[0029] In some optional implementations, the multi-mode broadband matching circuit supports at least two operating modes, including a first mode and a second mode.

[0030] When the multi-mode broadband matching circuit is in the first mode, the antenna 1 connected to the broadband matching module 3 operates in the FM band (88-108MHz). The broadband matching module 3 matches the antenna 1, which is operating in zero-order mode, and outputs an FM broadcast signal through the first signal splitter module 4. Understandably, in the first mode, because the physical size of antenna 1 is much smaller than the operating wavelength, the resonance condition is not met. At this time, the antenna operates in zero-order mode (i.e., a non-resonant electrically small antenna mode), exhibiting extremely low radiation resistance and extremely high capacitive reactance. The broadband matching module 3 biases the field-effect transistor in the linear variable resistance region (ohmic region) to perform broadband impedance matching and signal amplification on the antenna operating in zero-order mode, and outputs an FM broadcast signal through the first signal splitter module 4.

[0031] When the multi-mode broadband matching circuit is in the second mode, the antenna 1 connected to the broadband matching module 3 operates in the cellular frequency band (e.g., 690-960MHz). The broadband matching module 3 matches the antenna 1 connected to it, which operates in a first-order mode or a higher-order mode, and outputs the cellular network signal through the second signal splitter module 5. It is understood that in the second mode, the physical size of the antenna 1 is close to a quarter wavelength of the operating electromagnetic wave or an integer multiple thereof, and the antenna operates as a resonant antenna. At this time, the antenna operates in a first-order mode (e.g., the fundamental mode of quarter-wavelength resonance) or a second-order mode (e.g., a higher-order resonant mode). The broadband matching module 3 performs impedance matching on the antenna operating in the first-order or second-order mode and outputs the cellular network signal through the second signal splitter module 5.

[0032] Through the above architecture, this embodiment uses the broadband matching module 3 to replace the low-noise amplifier and complex passive matching network in the traditional technology, which not only reduces the circuit cost and board area, but also realizes dual support for FM and cellular signals by a single antenna.

[0033] See Figure 2 As shown, in some optional embodiments, the broadband matching module 3 includes: a field-effect transistor 30, a first bias decoupling module 31, a second bias decoupling module 32, a third bias decoupling module 33, and a fourth bias decoupling module 34. The field-effect transistor 30 includes a drain, a source, and a gate.

[0034] The gate of the field-effect transistor 30 is connected to the antenna 1. The field-effect transistor 30 amplifies the signal input to the electrically small antenna and performs broadband impedance matching and amplification on the electromagnetic signal received by the antenna 1. The first bias decoupling module 31 is connected between the DC power supply module 2 and the drain of the field-effect transistor 30. The second bias decoupling module 32 is connected between the source of the field-effect transistor 30 and ground. The third bias decoupling module 33 is connected between the gate of the field-effect transistor 30 and ground. The fourth bias decoupling module 34 is connected between the drain of the field-effect transistor and the input terminals of the first signal splitter module 4 and the second signal splitter module 5. Optionally, the field-effect transistor 30 can be an NMOS (N-Metal-Oxide-Semiconductor), HEMT (High Electron Mobility Transistor), etc.

[0035] Understandably, the gate of the field-effect transistor 30 is connected to antenna 1 and grounded through the third bias decoupling module 33, which is used to set the gate bias. The source of the field-effect transistor 30 is grounded through the second bias decoupling module 32, which is used to set the source potential and AC bypass. The drain of the field-effect transistor 30 is connected to a T-node, and then upwards to the first bias decoupling module 31, and further to the DC power supply module 2, introducing drain power supply, filtering out noise and interference signals on the power path and preventing radio frequency signals from entering the DC power supply module 2. The drain of the field-effect transistor 30 is connected to the fourth bias decoupling module 34 to the right, which is used to isolate DC signals and allow only AC radio frequency signals to pass through.

[0036] With this modular layout, the circuit structure is simple. The multi-mode broadband matching circuit in this embodiment can flexibly adjust the impedance characteristics of each port to ensure stable operation of the transistor in both FM and cellular frequency bands. Through the synergistic effect of the above components, the first bias decoupling module 31, the second bias decoupling module 32, the third bias decoupling module 33, and the fourth bias decoupling module 34 configure the field-effect transistor 30 to operate in the linear variable resistance region (ohmic region), ensuring impedance matching of the field-effect transistor. The ohmic region is also called the variable resistance region or the non-saturation region. Broadband input impedance matching is achieved by utilizing the characteristics of the field-effect transistor 30 in the linear variable resistance region. By biasing the field-effect transistor 30 in the ohmic region, the signal input to the electrically small antenna can be amplified. The output impedance of the field-effect transistor can be a preset value and has broadband stability, enabling broadband impedance matching and amplification of the electromagnetic signal received by antenna 1, thereby improving the radiation gain and radiation bandwidth of the electrically small antenna and broadening its radiation bandwidth to a wide frequency band. Besides the DC power supply module 2, the circuit contains only one active device, the field-effect transistor 30. The field-effect transistor 30 can be biased in the ohmic region, resulting in low DC power consumption. In summary, the proposed solution features a simple structure for the electrically small antenna broadband matching circuit and reduces its power consumption.

[0037] In this embodiment, the gate of the field-effect transistor 30 serves as the RF input terminal of the broadband matching circuit for the electrically small antenna, and the drain of the field-effect transistor 30 serves as the RF output terminal of the broadband matching circuit for the electrically small antenna. The electrically small antenna is used to receive electromagnetic wave signals and can convert the received electromagnetic wave signals into voltage signals that are input to the broadband matching module 3. That is, the electrically small antenna inputs the converted voltage signal to the gate of the field-effect transistor 30. Here, since the equivalent capacitance of the field-effect transistor 30 and the equivalent capacitance of the electrically small antenna itself divide the voltage signal converted by the electrically small antenna, the voltage signal output by the electrically small antenna is not completely input to the field-effect transistor 30. However, the field-effect transistor 30 is DC biased in the ohmic region by the first bias decoupling module 31, the second bias decoupling module 32, the third bias decoupling module 33, and the fourth bias decoupling module 34. Therefore, the field-effect transistor 30 can amplify the voltage signal and output it from the drain, thereby offsetting the voltage division loss of the electrically small antenna itself and improving the radiation gain of the electrically small antenna. Meanwhile, the output impedance of the field-effect transistor 30 has a broadband and stable characteristic, enabling impedance matching over a wide frequency band and reducing output signal echo reflection. Therefore, it can broaden the radiation bandwidth of the electrically small antenna. The multi-mode broadband matching circuit provided in this embodiment, through output impedance matching of the field-effect transistor, is suitable for antennas of various sizes and types, reducing the limitations and complexity of electrically small antenna design. In summary, in this embodiment, the broadband matching circuit has a simple structure and can reduce the power consumption of the electrically small antenna matching circuit.

[0038] See Figure 3 As shown, in some optional embodiments, the first bias decoupling module 31 includes a first resistor 311, a first inductor 312, and a first capacitor 313. The second bias decoupling module 32 includes a second resistor 321 and a second capacitor 322. The third bias decoupling module 33 includes a third resistor 331, and the fourth bias decoupling module 34 includes a third capacitor 341.

[0039] The first resistor 311 and the first inductor 312 are connected in series and placed between the DC power module 2 and the drain of the field-effect transistor 30. The first resistor 311 is connected to the DC power module 2, and the first inductor 312 is connected to the drain of the field-effect transistor 30. The first capacitor 313 is connected between the power supply path of the DC power module 2 and ground. One end of the first capacitor 313 is grounded, and the other end is connected between the DC power module 2 and the first resistor 311. The second resistor 321 and the second capacitor 322 are connected in parallel between the source of the field-effect transistor 30 and ground. The third resistor 331 is connected between the gate of the field-effect transistor 30 and ground. The third capacitor 341 is connected between the drain of the field-effect transistor 30 and the input terminals of the first signal splitter module 4 and the second signal splitter module 5.

[0040] Understandably, the specific connection relationships of the above circuit components are as follows: The gate of the field-effect transistor 30 is connected to the antenna 1 and to the first terminal of the third resistor 331, and the second terminal of the third resistor 331 is grounded. The source of the field-effect transistor 30 is connected to the first terminal of the second resistor 321 and the first terminal of the second capacitor 322, and the second terminals of the second resistor 321 and the second terminal of the second capacitor 322 are both grounded. The drain of the field-effect transistor 30 is connected to the first terminal of the first inductor 312, the second terminal of the first inductor 312 is connected to the first terminal of the first resistor 311, the second terminal of the first resistor 311 is connected to the DC power supply module 2, the first terminal of the first capacitor 313 is connected between the second terminal of the first resistor 311 and the DC power supply module 2, and the second terminal of the first capacitor 313 is grounded. The drain of the field-effect transistor 30 is also connected to the first terminal of the third capacitor 341, and the second terminal of the third capacitor 341 serves as the output terminal of the broadband matching module 3, and is connected to the subsequent first signal splitting module 4 and second signal splitting module 5, respectively. The circuit structure is simple and easy to integrate and miniaturize.

[0041] The functions of the above circuit components are as follows: The first resistor 311, the second resistor 321, and the third resistor 331 together form a DC bias network. Their resistance values ​​are configured according to the voltage of the DC power supply module 2, and are used to set the DC operating point of the field-effect transistor 30 in the linear variable resistance region (ohmic region). The first inductor 312 acts as an RF choke, using its inductive reactance to prevent the RF signal output from the drain from leaking into the DC power supply module 2. The first capacitor 313 is used to filter out noise and interference signals on the power path. The second capacitor 322 acts as a bypass capacitor, providing a low-impedance AC ground path for the RF signal, preventing negative feedback from the source resistor to the AC signal, thereby ensuring circuit gain. The third capacitor 341 acts as a DC blocking capacitor, used to isolate the DC bias voltage of the drain, allowing only valid RF signals to be transmitted to the downstream signal splitter module.

[0042] Thus, through the synergistic effect of the aforementioned components, the first bias decoupling module 31, the second bias decoupling module 32, the third bias decoupling module 33, and the fourth bias decoupling module 34 configure the field-effect transistor 30 to operate in the linear variable resistance region (ohmic region), utilizing the characteristics of the field-effect transistor 30 in the linear variable resistance region to achieve broadband input impedance matching. This embodiment utilizes the characteristics of the field-effect transistor in the ohmic region to achieve broadband impedance matching for the front-end antenna.

[0043] See Figure 4As shown, in some optional embodiments, the first signal splitting module 4 includes a first filter network composed of inductors and capacitors, which is used to allow FM signals to pass through and isolate cellular signals.

[0044] Optionally, the first signal splitting module 4 includes a second inductor 41, a fourth capacitor 42, a third inductor 43, a fifth capacitor 44, a fourth inductor 45, and a sixth capacitor 46. The second inductor 41, the fourth capacitor 42, the fourth inductor 45, and the sixth capacitor 46 are connected in series. The second inductor 41 is connected to the broadband matching module 3, and the sixth capacitor 46 is connected to the FM back-end module 6. The third inductor 43 and the fifth capacitor 44 are connected in parallel, with one end grounded and the other end connected between the fourth capacitor 42 and the fourth inductor 45.

[0045] Understandably, the first signal splitter module 4 adopts an LC filter network structure, including a second inductor 41 and a fourth capacitor 42 connected in series in the signal path, a third inductor 43 and a fifth capacitor 44 connected in parallel to ground, and a fourth inductor 45 and a sixth capacitor 46 connected in series in the signal path. Specifically, the first end of the second inductor 41 is connected to the input terminal of the first signal splitter module 4, and the second end is connected to the first end of the fourth capacitor 42. The second end of the fourth capacitor 42 is connected to a common node. At this common node, the third inductor 43 and the fifth capacitor 44 are connected in parallel and grounded together. This common node is also connected to the first end of the fourth inductor 45. The second end of the fourth inductor 45 is connected to the first end of the sixth capacitor 46, and the second end of the sixth capacitor 46 serves as the output terminal of the first signal splitter module 4, connected to the FM back-end module 6. This combined filter network only allows FM band signals to pass through and be transmitted to the FM back-end module 6, isolating high-frequency cellular signals.

[0046] In some alternative implementations, the second signal splitting module 5 includes a second filter network composed of inductors and capacitors, which allows cellular signals to pass through while isolating FM signals.

[0047] Optionally, the second signal splitting module 5 includes a fifth inductor 51, a seventh capacitor 52, a sixth inductor 53, an eighth capacitor 54, a seventh inductor 55, and a ninth capacitor 56. The fifth inductor 51, the seventh capacitor 52, the seventh inductor 55, and the ninth capacitor 56 are connected in series. The fifth inductor 51 is connected to the broadband matching module 3, and the ninth capacitor 56 is connected to the cellular back-end module 7. The sixth inductor 53 and the eighth capacitor 54 are connected in parallel, with one end of each inductor grounded and the other end connected between the seventh capacitor 52 and the seventh inductor 55.

[0048] Understandably, the second signal splitter module 5 also employs an LC filter network structure, including a fifth inductor 51 and a seventh capacitor 52 connected in series in the signal path, a sixth inductor 53 and an eighth capacitor 54 connected in parallel to ground, and a seventh inductor 55 and a ninth capacitor 56 connected in series in the signal path. Specifically, the first end of the fifth inductor 51 is connected to the input terminal of the second signal splitter module 5, and the second end is connected to the first end of the seventh capacitor 52. The second end of the seventh capacitor 52 is connected to a common node. At this common node, the sixth inductor 53 and the eighth capacitor 54 are connected in parallel and grounded together. This common node is also connected to the first end of the seventh inductor 55. The second end of the seventh inductor 55 is connected to the first end of the ninth capacitor 56, and the second end of the ninth capacitor 56 serves as the output terminal of the second signal splitter module 5, connected to the cellular back-end module 7. This combined filter network only allows high-frequency cellular signals to pass through and be transmitted to the cellular back-end module 7, isolating low-frequency FM broadcast signals.

[0049] By combining the two sets of filtering networks, the first signal splitting module 4 and the second signal splitting module 5 together form a duplexer structure at the output of the broadband matching module 3, enabling a single broadband matching module to simultaneously drive two back-end loads of different frequency bands, and realize multi-mode concurrent operation under a single antenna and a single matching circuit.

[0050] The following describes the multi-mode broadband matching circuit of this application through a specific embodiment.

[0051] This example uses a monopole antenna with a total length of 60 mm and dielectric parameters of relative permittivity 4.4 and loss tangent 0.02. The bias decoupling modules in broadband matching module 3 are adjusted so that the field-effect transistors in broadband matching module 3 operate in the ohmic region, with a drain-source port voltage VDS = 0.36V and a drain current ID = 14mA. At this point, the output impedance is approximately 50 ohms. The signal splitter module circuit structure in this example is the same. Figure 4 In the first signal splitting module 4, the values ​​of the second inductor 41 and the fourth inductor 45 are 440nH, the values ​​of the fourth capacitor 42 and the sixth capacitor 46 are 6pF, the value of the third inductor 43 is 18nH, and the value of the fifth capacitor 44 is 150pF; in the second signal splitting module 5, the values ​​of the fifth inductor 51 and the seventh inductor 55 are 20nH, the values ​​of the seventh capacitor 52 and the ninth capacitor 56 are 1.7pF, the value of the sixth inductor 53 is 2.4nH, and the value of the eighth capacitor 54 is 15pF.

[0052] exist Figure 5In the frequency range of 50MHz to 1000MHz, the reflection coefficient of the unmatched antenna is close to 0dB; after passing through the broadband matching module of this application, its reflection coefficient is significantly reduced in the wide frequency band and remains below -10dB, achieving excellent broadband impedance matching.

[0053] exist Figure 6 The reflection coefficient results after passing through the first signal splitter module show that the reflection coefficient of the filter network remains below -10dB in the FM band, achieving excellent impedance matching and very steep out-of-band suppression.

[0054] exist Figure 7 In the FM band, unmatched antennas have extremely low gain, approximately -55dBi to -50dBi, because their size is much smaller than the operating wavelength. After being matched with a broadband module, the gain is significantly improved to around -25dBi to -15dBi, with a gain improvement of up to 30dB, which greatly enhances the signal reception capability of the FM band.

[0055] exist Figure 8 The reflection coefficient results after passing through the second signal splitting module show that the filtering network also has a good matching effect in the cellular band, with the reflection coefficient remaining below -10dB and the deepest in-band reaching -23dB, effectively ensuring the stable passage of broadband cellular signals, and the out-of-band suppression is very steep.

[0056] exist Figure 9 In the cellular band, the gain of an unmatched antenna is approximately -15dBi to -11dBi; after passing through the broadband matching module, the gain is significantly improved to approximately -5dBi to -1dBi, an improvement of about 10dB, ensuring high-quality transmission of cellular communication.

[0057] exist Figure 10 The coupling coefficient results between the ports of the two signal splitting modules show that the coupling coefficient between the ports is less than -80dB throughout the entire test frequency band, that is, the isolation is greater than 80dB, which proves that the dual-path filtering network of this application has extremely strong isolation performance.

[0058] from Figures 5 to 10 The data shows that, after passing through the multi-mode broadband matching circuit, the antenna in this application not only achieves a significant reduction in reflection coefficient and a significant improvement in radiation gain over an extremely wide frequency band, but also perfectly achieves efficient separation of FM broadcast signals and cellular communication signals. This demonstrates that the multi-mode broadband matching circuit provided in this application has extremely high stability and excellent multi-mode concurrent operation performance.

[0059] Embodiments of this application also provide a printed circuit board, which includes the multi-mode broadband matching circuit described in the above embodiments and implementation methods. Optionally, the multi-mode broadband matching circuit may be an electrically small antenna multi-mode broadband matching circuit.

[0060] The broadband matching module, utilizing a multi-mode broadband matching circuit, provides broadband input impedance matching and high signal gain, overcoming the physical limitations of passive antenna matching. This allows electronic devices to receive FM signals without external wired headphones, while also improving the number of stations and sound quality. Furthermore, through the design of a first and second signal splitter module, a single antenna and matching circuit can be compatible with both FM broadcasting and cellular communication. Thus, the multi-mode broadband matching circuit achieves high integration, low cost, and enables high-quality FM signal reception and multi-mode communication compatibility.

[0061] Embodiments of this application also provide an antenna, including an electrically small antenna and the multi-mode broadband matching circuit described in the above embodiments and implementations, wherein the electrically small antenna is connected to the broadband matching module of the multi-mode broadband matching circuit. Optionally, the antenna can be an electrically small antenna. The electrically small antenna is used to receive electromagnetic wave signals and can be of various antenna types such as patch antennas, dipole antennas, and monopole antennas.

[0062] The broadband matching module, utilizing a multi-mode broadband matching circuit, provides broadband input impedance matching and high signal gain, overcoming the physical limitations of passive antenna matching. This allows electronic devices to receive FM signals without external wired headphones, while also improving the number of stations and sound quality. Furthermore, through the design of a first and second signal splitter module, a single antenna and matching circuit can be compatible with both FM broadcasting and cellular communication. Thus, the multi-mode broadband matching circuit achieves high integration, low cost, and enables high-quality FM signal reception and multi-mode communication compatibility.

[0063] Embodiments of this application also provide an electronic device, which includes the aforementioned antenna and may also include the aforementioned printed circuit board. The electronic device can be a mobile phone, tablet computer (PAD), or other communication device. The electronic device receives FM broadcast signals through the broadband matching module and the electrically small antenna, and is compatible with cellular communication functions. The aforementioned multi-mode broadband matching circuit and antenna can replace traditional built-in FM antennas, low-noise amplifiers, and complex passive matching networks, effectively reducing manufacturing costs while reducing device size. Using the aforementioned antenna can reduce the space occupied by the antenna in the electronic device. With reduced antenna space, the electronic device can have more usable space to accommodate more components and achieve more functions. Alternatively, with reduced antenna space, the size of the electronic device can be reduced, making it more portable.

[0064] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A multi-mode broadband matching circuit, characterized in that, include: The system includes a DC power supply module, a broadband matching module, a first signal splitter module, and a second signal splitter module; each of the broadband matching module, the first signal splitter module, and the second signal splitter module includes an input terminal and an output terminal. The DC power supply module is connected to the broadband matching module and is used to supply power to the broadband matching module. The input terminal of the broadband matching module is connected to the antenna and is used to perform broadband impedance matching and amplification on the electromagnetic signals received by the antenna. The output terminal of the broadband matching module is connected to the input terminal of the first signal splitting module and the input terminal of the second signal splitting module, respectively. The output of the first signal splitter module is connected to the FM back-end module for transmitting FM signals to the FM back-end module; The output of the second signal splitter module is connected to the cellular back-end module and is used to transmit cellular communication signals to the cellular back-end module.

2. The multi-mode broadband matching circuit according to claim 1, characterized in that, The broadband matching module includes: a field-effect transistor, a first bias decoupling module, a second bias decoupling module, a third bias decoupling module, and a fourth bias decoupling module; the field-effect transistor includes a drain, a source, and a gate; The gate of the field-effect transistor is connected to the antenna; The first bias decoupling module is connected between the DC power supply module and the drain of the field-effect transistor; The second bias decoupling module is connected between the source of the field-effect transistor and ground; The third bias decoupling module is connected between the gate of the field-effect transistor and ground; The fourth bias decoupling module is connected between the drain of the field-effect crystal and the input terminals of the first signal splitter module and the second signal splitter module.

3. The multi-mode broadband matching circuit according to claim 2, characterized in that, The first bias decoupling module includes a first resistor, a first inductor, and a first capacitor; the first resistor and the first inductor are connected in series and placed between the DC power supply module and the drain of the field-effect transistor; the first resistor is connected to the DC power supply module, and the first inductor is connected to the drain of the field-effect transistor; the first capacitor is connected between the power supply path of the DC power supply module and ground, one end of the first capacitor is grounded, and the other end is connected between the DC power supply module and the first resistor; and / or The second bias decoupling module includes a second resistor and a second capacitor, which are connected in parallel between the source of the field-effect transistor and ground; and / or The third bias decoupling module includes a third resistor connected between the gate of the field-effect transistor and ground; and / or The fourth bias decoupling module includes a third capacitor, which is connected between the drain of the field-effect transistor and the input terminals of the first signal splitter module and the second signal splitter module.

4. The multi-mode broadband matching circuit according to claim 2, characterized in that, The first bias decoupling module, the second bias decoupling module, the third bias decoupling module, and the fourth bias decoupling module configure the field-effect transistor to operate in the linear variable resistance region, and utilize the characteristics of the field-effect transistor in the linear variable resistance region to achieve broadband input impedance matching.

5. The multi-mode broadband matching circuit according to claim 1, characterized in that, The first signal splitting module includes a first filter network composed of inductors and capacitors, which allows FM signals to pass through while isolating cellular signals; and / or The second signal splitting module includes a second filter network composed of inductors and capacitors, which allows cellular signals to pass through while isolating FM signals.

6. The multi-mode broadband matching circuit according to claim 5, characterized in that, The first signal splitter module includes a second inductor, a fourth capacitor, a third inductor, a fifth capacitor, a fourth inductor, and a sixth capacitor; the second inductor, the fourth capacitor, the fourth inductor, and the sixth capacitor are connected in series sequentially; the second inductor is connected to the broadband matching module, and the sixth capacitor is connected to the FM back-end module; the third inductor and the fifth capacitor are connected in parallel, with one end of the third inductor and the fifth capacitor grounded, and the other end connected between the fourth capacitor and the fourth inductor; and / or The second signal splitting module includes a fifth inductor, a seventh capacitor, a sixth inductor, an eighth capacitor, a seventh inductor, and a ninth capacitor; the fifth inductor, the seventh capacitor, the seventh inductor, and the ninth capacitor are connected in series in sequence, the fifth inductor is connected to the broadband matching module, and the ninth capacitor is connected to the cellular back-end module; the sixth inductor and the eighth capacitor are connected in parallel, one end of the sixth inductor and the eighth capacitor is grounded, and the other end is connected between the seventh capacitor and the seventh inductor.

7. The multi-mode broadband matching circuit according to claim 1, characterized in that, The multi-mode broadband matching circuit supports at least two operating modes, including a first mode and a second mode: When the multi-mode broadband matching circuit is in the first mode, the antenna connected to the broadband matching module is in the FM band. The broadband matching module matches the antenna connected to it that is operating in the zero-mode and outputs the FM broadcast signal through the first signal splitting module. When the multi-mode broadband matching circuit is in the second mode, the antenna connected to the broadband matching module is in the cellular frequency band. The broadband matching module matches the antenna connected to it that is operating in the first mode or a higher mode, and outputs the cellular network signal through the second signal splitting module.

8. A printed circuit board, characterized in that, Includes the multi-mode broadband matching circuit as described in any one of claims 1-7.

9. An antenna, characterized in that, It includes an electrically small antenna and a multi-mode broadband matching circuit as described in any one of claims 1-7, wherein the electrically small antenna is connected to the broadband matching module of the multi-mode broadband matching circuit.

10. An electronic device, characterized in that, include: The printed circuit board as described in claim 8; and / or The antenna as described in claim 9.

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