Radio frequency interference suppression circuit and communication equipment

Abstract

The invention relates to a radio frequency interference suppression circuit and communication equipment, and the circuit comprises an impedance matching module, a first end is used for connecting an antenna, and the impedance matching module is also provided with a plurality of second ends which are used for matching the impedance of the antenna and a main frequency band of a radio frequency path; the plurality of first ends of the antenna tuning module are connected with one second end of the impedance matching module in a one-to-one correspondence manner, and the second end of the antenna tuning module is used for being connected with a radio frequency path and used for adjusting matching parameters of the impedance matching module; the first end of the second harmonic suppression module is connected with the first end of the impedance matching module and used for being connected with an antenna, and the second end of the second harmonic suppression module is connected with the first end of the line tuning module and used for suppressing frequency band interference of second harmonics of the preset frequency band of the radio frequency path on GPS path antenna connection. Therefore, the interference of the second harmonic of the radio frequency path on the GPS path can be suppressed, and the influence of insertion loss on the main radio frequency performance can be reduced.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a radio frequency interference suppression circuit and communication equipment. Background Art

[0002] In the RF signal processing systems of wireless communication devices, the B13 band operates in the uplink frequency range of 777-787 MHz, generating a second harmonic frequency in the 1554-1574 MHz range. This second harmonic frequency is very close to the 1575 MHz signal band of the GPS (Global Positioning System), making it highly susceptible to interference with GPS reception. Interference from the B13 band's second harmonic often degrades the performance of Assisted Global Positioning Systems (AGPS), manifesting as reduced positioning accuracy and stability for communication devices.

[0003] To solve the above-mentioned harmonic interference problem, relevant technologies suppress the second harmonic by connecting a series-parallel resonant circuit (Notch circuit) or a low-pass filter (LPF) in the RF path, or setting a Notch circuit between the GPS antenna and the pre-surface acoustic wave filter (Pre-SAW) to avoid the second harmonic interference caused by the excitation of the main frequency signal.

[0004] However, during the implementation process, the applicant discovered that the related technology still has at least the problem of increased insertion loss in the signal path due to second harmonic suppression. Summary of the Invention

[0005] Based on this, the purpose of this application is to solve at least one of the above-mentioned technical defects, especially the technical defect of suppressing the second harmonic in the prior art to increase the insertion loss. This application provides a radio frequency interference suppression circuit and communication equipment.

[0006] In a first aspect, the present application provides a radio frequency interference suppression circuit, which is applied to a communication device, wherein the communication device includes an antenna, a radio frequency path, and a GPS path; the radio frequency interference suppression circuit includes:

[0007] An impedance matching module, having a first end for connecting to an antenna and a plurality of second ends for matching the impedance of the antenna and the main frequency band of the radio frequency path;

[0008] An antenna tuning module, wherein the plurality of first ends are connected to a second end of the impedance matching module in a one-to-one correspondence, and the second end of the antenna tuning module is used to connect to the radio frequency path and to adjust the matching parameters of the impedance matching module;

[0009] The second harmonic suppression module has a first end connected to the first end of the impedance matching module and is used to connect to the antenna. The second end of the second harmonic suppression module is connected to the first end of the tuning module to suppress the second harmonic of the preset frequency band of the radio frequency path from interfering with the frequency band of the GPS path connected to the antenna.

[0010] In one embodiment, the impedance matching module includes a multi-channel impedance matching unit;

[0011] The first ends of the multi-path impedance matching units are connected in common and used to be connected to the antenna;

[0012] The second end of each anti-matching unit is correspondingly connected to a first end of the antenna tuning module.

[0013] In one embodiment, a first end of the second harmonic suppression module is connected to a first end of one of the impedance matching units, and a second end of the second harmonic suppression module is connected to a second end of the impedance matching unit.

[0014] In one embodiment, the second harmonic suppression module includes a series resonance unit and a parallel resonance unit;

[0015] The first end of the series resonance unit is used to connect to the antenna, and the second end of the series resonance unit is connected to the first end of one of the impedance matching units;

[0016] The first end of the parallel resonance unit is connected to the first end of the series resonance unit and is used to connect to the antenna. The second end of the parallel resonance unit is respectively connected to the second end of the impedance matching unit and the first end of the antenna tuning module.

[0017] In one embodiment, the series resonant unit includes an inductor unit;

[0018] The first end of the inductor is connected to the first end of the parallel resonance unit and is used to connect to the antenna.

[0019] In one embodiment, the parallel resonant unit includes a capacitor unit;

[0020] The first end of the capacitor unit is connected to the first end of the series resonant unit and is used to connect to the antenna;

[0021] The second end of the capacitor unit is connected to the second end of the impedance matching unit and the first end of the impedance matching unit respectively.

[0022] In one embodiment, the second harmonic suppression module includes a harmonic suppression integrated component;

[0023] The first end of the harmonic suppression integrated component is connected to the first end of the harmonic suppression integrated component and is used to connect to the antenna;

[0024] The second terminal of the harmonic suppression integrated component is used for grounding.

[0025] In one embodiment, the radio frequency interference suppression circuit further includes:

[0026] A GPS signal quality monitoring module, wherein a first end is connected to the GPS path, and a second end of the GPS signal quality monitoring module is connected to a second end of the antenna tuning module;

[0027] The antenna tuning module is used to adjust the matching parameters of the impedance matching module and the second harmonic suppression module based on the signal quality monitored by the GPS signal quality monitoring module, so as to adjust the frequency band interference intensity of the second harmonic.

[0028] In one embodiment, the radio frequency path includes a B13 frequency band path, and the second harmonic of the preset frequency band is the second harmonic of the B13 frequency band; the radio frequency interference suppression circuit further includes:

[0029] A B13 signal strength detection module, a first end of which is connected to the B13 frequency band path, and a second end of which is connected to the second end of the antenna tuning module;

[0030] The antenna tuning module is used to adjust the matching parameters of the impedance matching module and the second harmonic suppression module based on the signal strength monitored by the B13 signal strength detection module, so as to adjust the frequency band interference intensity of the second harmonic.

[0031] In a second aspect, the present application further provides a communication device, the communication device comprising:

[0032] antenna;

[0033] RF pathway;

[0034] GPS access;

[0035] Such as the radio frequency interference suppression circuit mentioned above.

[0036] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0037] The radio frequency interference suppression circuit and communication equipment provided in the present application add a second harmonic suppression module to the impedance matching module of the antenna tuning module. In this way, the antenna impedance can be adjusted through the antenna tuning module so that it presents a high impedance in a preset second harmonic frequency band, that is, the second harmonic frequency band is in a mismatched state, which can reduce the second harmonic radiation efficiency and suppress the second harmonic frequency band. Therefore, while suppressing the interference of the second harmonic of the radio frequency path on the GPS path, it can reduce the impact of the insertion loss on the main radio frequency performance, and can optimize the complexity of the circuit layout, with the effects of effectively suppressing interference, reducing insertion loss, improving positioning accuracy and stability, and simplifying the circuit design and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0039] Figure 1 A schematic diagram of the structure of a radio frequency interference suppression circuit provided in an embodiment of the present application;

[0040] Figure 2 A schematic diagram of the specific structure of an impedance matching module in a radio frequency interference suppression circuit provided by an embodiment of the present application;

[0041] Figure 3 A schematic diagram of the specific structure of a second harmonic suppression module in a radio frequency interference suppression circuit provided in an embodiment of the present application;

[0042] Figure 4 This is a schematic diagram of the specific structure of a radio frequency interference suppression circuit provided in this application.

[0043] Reference numerals:

[0044] 1. Communication equipment; 10. Radio frequency interference suppression circuit; 20. Antenna; 30. Radio frequency path; 40. GPS path;

[0045] 110 - impedance matching module; 120 - antenna tuning module; 130 - second harmonic suppression module; 111 - impedance matching unit; 121 - antenna tuner; 131 - parallel resonance unit; 132 - series resonance unit. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0048] It will be understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor without departing from the scope of this application. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0049] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if there is transmission of electrical signals or data between the connected circuits, modules, units, etc.

[0050] It is understood that “at least one” may refer to one or more, “a plurality” may refer to two or more, and “at least a portion of an element” may refer to a portion or all of an element.

[0051] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include," "comprising," "having," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Furthermore, the term "and / or" as used in this specification includes any and all combinations of the relevant listed items.

[0052] In existing radio frequency communication systems, the second harmonic of the mainband signal interferes with the GPS band. For example, the B13 band's uplink second harmonic, covering 1554-1574 MHz, overlaps with the GPS band's 1575 MHz frequency. Traditional solutions, by adding band-stop filters or low-pass filters to the RF path, can suppress harmonics but increase insertion loss, impacting the mainband signal quality. They also require additional layout space and increase hardware design complexity. In compact communication devices, such solutions struggle to balance performance and space constraints.

[0053] Based on this, the present application provides a radio frequency interference suppression circuit and communication equipment. By adding a second harmonic suppression module to the impedance matching module of the antenna tuning module, the antenna impedance can be adjusted through the antenna tuning module so that it presents a high impedance in a preset second harmonic frequency band, that is, the second harmonic frequency band is in a mismatched state, which can reduce the second harmonic radiation efficiency and suppress the second harmonic frequency band, thereby suppressing the interference of the second harmonic of the radio frequency path on the GPS path while reducing the impact of the insertion loss on the main radio frequency performance, and optimizing the complexity of the circuit layout, with the effects of effectively suppressing interference, reducing insertion loss, improving positioning accuracy and stability, and simplifying the circuit design and reducing costs.

[0054] In an exemplary embodiment, Figure 1 A schematic diagram of a radio frequency interference suppression circuit provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the radio frequency interference suppression circuit 10 is applied to a communication device 1, which includes an antenna 20, a radio frequency path 30, and a GPS path 40; the radio frequency interference suppression circuit 10 includes:

[0055] The impedance matching module 110 has a first end for connecting to the antenna 20 and a plurality of second ends for matching the impedance of the main frequency band of the antenna 20 and the RF path 30 .

[0056] The impedance matching module 110 may refer to a circuit unit composed of a multi-way parallel matching network, which may be implemented by an adjustable inductor array or a varactor diode network, and is used to maintain impedance matching between the antenna 20 and the RF path 30 in different frequency bands.

[0057] The antenna tuning module 120 has multiple first ends connected to a second end of the impedance matching module 110 in a one-to-one correspondence. The second end of the antenna tuning module 120 is used to connect to the RF path 30 to adjust the matching parameters of the impedance matching module 110.

[0058] The antenna tuning module 120 may refer to a tuning circuit including a digital control interface. Specifically, it may be implemented using a microcontroller driving an adjustable capacitor matrix to optimize signal transmission efficiency by adjusting matching network parameters. The antenna tuning module 120 may be an antenna 20 tuner.

[0059] The second harmonic suppression module 130 has a first end connected to the first end of the impedance matching module 110 and is used to connect to the antenna 20. The second end of the second harmonic suppression module 130 is connected to the first end of the tuning module to suppress the second harmonic of the preset frequency band of the RF path 30 from interfering with the frequency band connected to the GPS path 40.

[0060] The second harmonic suppression module 130 may refer to a filter structure with frequency selection characteristics, which may be implemented by combining a series resonant circuit and a parallel resonant circuit, and suppressing harmonic energy in a specific frequency band by setting a resonance point.

[0061] For example, the first end of the impedance matching module 110 can be connected to the antenna 20, and the multiple second ends of the impedance matching module 110 can be connected one-to-one with the multiple first ends of the antenna tuning module 120. The impedance matching module 110 can be used to match the impedance of the main frequency band of the antenna 20 and the RF path 30. The second end of the antenna tuning module 120 is used to connect to the RF path 30 and can be used to adjust the matching parameters of the impedance matching module 110.

[0062] The impedance matching module 110 can be directly connected to the impedance matching module 110. In this way, the position of the impedance matching module 110 can be increased in the matching network of the antenna 20 tuner, which can avoid adding filter matching on the RF path 30, reduce the RF path 30 loss, optimize the RF transmission performance, and save the reserved position of the notch / LPF on the RF path 30, saving the space for ornaments and facilitating the early RF routing.

[0063] Specifically, when the antenna 20 receives or transmits a radio frequency signal, the impedance matching module 110 can select a corresponding matching path according to the current operating frequency band to reduce signal reflection loss. The antenna tuning module 120 can monitor the status of the radio frequency path 30 in real time and dynamically adjust the matching network parameters to compensate for the impedance mismatch caused by environmental changes. The second harmonic suppression module 130 can act directly on the antenna 20 end to filter out the second harmonic components of a preset frequency band before the signal enters the radio frequency path 30. For example, the second harmonic suppression module 130 can form a band-stop characteristic through the series resonance unit 132, and the parallel resonance unit 131 can provide a low-impedance path for high-frequency harmonics. The dual effects suppress the coupling of target harmonics to the GPS path 40.

[0064] Compared with the existing technology, the traditional solution inserts a filter in the RF path 30, resulting in an increase in the insertion loss of the main signal. However, this embodiment pre-positions the harmonic suppression function to the antenna 20 end, that is, a notch circuit can be added to the matching network of the antenna tuning module 120 to avoid affecting the integrity of the main path signal. In addition, the conventional band-stop filter needs to be fixedly arranged near the RF chip. This embodiment, through the combination of a distributed impedance matching network and an independent harmonic suppression module, can be flexibly configured in an area with ample space in the device structure. In addition, the dynamic tuning mechanism replaces the fixed filtering parameters and can adaptively compensate for performance changes caused by factors such as temperature and frequency offset.

[0065] In this embodiment, the above-described structural arrangement effectively suppresses interference from the second harmonic of the RF signal on the GPS frequency band, while also preventing signal quality degradation caused by increased insertion loss in the main RF path 30. The coordinated operation of the impedance matching module 110 and the harmonic suppression module limits the harmonic energy in a specific frequency band to a safe threshold while maintaining the transmission efficiency of the main path. The dynamic adjustment function of the antenna tuning module 120 enhances the system's adaptability to changes in the operating environment and addresses the performance limitations of traditional fixed filtering solutions in complex application scenarios.

[0066] In an exemplary embodiment, Figure 2 This is a schematic diagram of the specific structure of an impedance matching module in a radio frequency interference suppression circuit provided in an embodiment of the present application.

[0067] like Figure 2 As shown, the impedance matching module 110 includes a multi-channel impedance matching unit 111 .

[0068] The first ends of the multi-path impedance matching units 111 are connected in common and are used to connect to the antenna 20 .

[0069] The second end of each anti-matching unit is correspondingly connected to a first end of the antenna tuning module 120 .

[0070] Among them, the multi-channel impedance matching unit 111 may refer to a plurality of independently set impedance matching circuits. For example, it can be implemented by using a combination of capacitors with different capacitance values ​​or inductors with different inductance values. Each unit corresponds to the impedance matching requirements of different main frequency bands in the RF path 30. Common connection may refer to the input ends of multiple impedance matching units 111 being combined into the same electrical node through a physical connection point. For example, it can be implemented by using a star topology or a parallel structure to ensure that the antenna 20 signal can be input to each matching unit at the same time. Respective corresponding connection may refer to the output end of each impedance matching unit 111 forming a one-to-one mapping relationship with the input end of the antenna tuning module 120. For example, it can be implemented by directly connecting with a wire or indirectly connecting through a filter element, so that the signal of each frequency band is independently transmitted to the tuning module.

[0071] Exemplarily, the multi-channel impedance matching unit 111 can form a signal transmission channel with the antenna 20 in a common connection manner, and each multi-channel impedance matching unit 111 can perform impedance matching for different main frequency bands in the RF path 30. For example, when the RF path 30 contains multiple communication frequency bands, each impedance matching unit 111 can independently adjust its capacitance or inductance parameters to achieve impedance adaptation between the antenna 20 and the RF front end of the corresponding frequency band. The second end of each multi-channel impedance matching unit 111 is respectively connected to a different input end of the antenna tuning module 120 to form a frequency division processing structure to avoid mutual interference between signals of different frequency bands during the matching process. This design allows the matching parameters to be optimized separately for a specific frequency band, while reducing the equivalent insertion loss of the signal transmission path through multi-channel parallel processing.

[0072] Optionally, this embodiment further proposes that the impedance matching module 110 includes a multi-channel impedance matching unit 111, the first ends of the multi-channel impedance matching units 111 are connected in common and used to connect to the antenna 20, and the second ends of each multi-channel impedance matching unit 111 are respectively connected to a first end of the antenna tuning module 120.

[0073] This embodiment utilizes a distributed design of multiple impedance matching units 111 to simultaneously achieve matching in the main frequency band while also transferring the second harmonic suppression function to independent modules, eliminating the need for inserting lossy components into the main RF path. Furthermore, the co-connected structure of the multiple matching units reduces wiring complexity within the shielding enclosure, facilitating more compact device layouts compared to traditional solutions that require reserved space for resonant components.

[0074] In this embodiment, the above-described structural arrangement enables decoupling of multi-band impedance matching and harmonic suppression without increasing the insertion loss of the RF path 30. The discrete design of the multi-channel impedance matching unit 111 allows for independent adjustment of the matching parameters for each frequency band, avoiding the performance compromises typically associated with traditional single matching circuits due to multi-band requirements. Furthermore, the co-connected structure reduces signal distribution losses at the antenna 20 end, while the decentralized layout reduces space occupied within the main shield, facilitating the miniaturization of the communication device 1.

[0075] In an exemplary embodiment, Figure 2 As shown, a first end of the second harmonic suppression module 130 is connected to a first end of one of the impedance matching units 111 , and a second end of the second harmonic suppression module 130 is connected to a second end of the impedance matching unit 111 .

[0076] For example, the second harmonic suppression module 130 can be directly integrated into the connection path between the impedance matching unit 111 and the antenna tuning module 120. When the RF signal enters the impedance matching unit 111 through the antenna 20, the second harmonic suppression module 130 uses its frequency-selective characteristics to attenuate the second harmonics of the preset frequency band while allowing the main frequency band signal to be transmitted normally to the RF path 30. Because this module is not directly connected in series with the main RF path, the insertion loss it introduces only affects the harmonic frequency band, avoiding additional loss to the main frequency band signal.

[0077] Specifically, the first end of the second harmonic suppression module 130 is connected to the first end of one of the impedance matching units 111, and the second end of the second harmonic suppression module 130 is connected to the second end of the impedance matching unit 111. In this way, the second harmonic suppression module 130 can be connected to the matching network of the antenna tuning module 120, and the second harmonic suppression module 130 can be a structure connected in parallel with the impedance matching unit 111.

[0078] In practical applications, this embodiment embeds the harmonic suppression function into the connection node between the impedance matching unit 111 and the antenna tuning module 120. Without affecting the impedance matching performance of the main path, harmonic suppression can be achieved through path diversion, while reducing the space occupied by the internal space of the main shielding cover.

[0079] In this embodiment, the above-mentioned structural setting can effectively suppress the interference of the second harmonic of the RF path 30 on the GPS frequency band, while avoiding the deterioration of the insertion loss of the main frequency band signal caused by the additional filtering structure, thereby solving the technical problem of the contradiction between the degradation of the main RF performance and the harmonic suppression effect in the traditional solution.

[0080] In an exemplary embodiment, Figure 3 A schematic diagram of the specific structure of a second harmonic suppression module in a radio frequency interference suppression circuit provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the second harmonic suppression module 130 includes a series resonance unit 132 and a parallel resonance unit 131;

[0081] A first end of the series resonance unit 132 is used to connect to the antenna 20 , and a second end of the series resonance unit 132 is connected to a first end of one of the impedance matching units 111 ;

[0082] The first end of the parallel resonance unit 131 is connected to the first end of the series resonance unit 132 and is used to connect to the antenna 20 . The second end of the parallel resonance unit 131 is respectively connected to the second end of the impedance matching unit 111 and the first end of the antenna tuning module 120 .

[0083] The series resonant unit 132 may refer to a resonant circuit composed of an inductor and a capacitor, for example, a single-layer or multi-layer stacked inductor structure, with its resonant frequency configured to suppress the second harmonic frequency band of the RF path 30. The parallel resonant unit 131 may refer to a parallel resonant network composed of a capacitor and an inductor, for example, a combination of a chip capacitor and a wound inductor structure, with its resonant frequency configured to create a high impedance characteristic for the GPS frequency band. This structure achieves band-selective suppression in both the main path and the branch path through a dual resonant network.

[0084] For example, the first end of the series resonant unit 132 is connected to the antenna 20, and the second end of the series resonant unit 132 is connected to the first end of one of the impedance matching units 111. In this way, the series resonant unit 132 and the impedance matching unit 111 can be connected in series. The first end of the parallel resonant unit 131 is connected to the first end of the series resonant unit 132 and is connected to the antenna 20. The second end of the parallel resonant unit 131 is respectively connected to the second end of the impedance matching unit 111 and the first end of the antenna tuning module 120. In this way, the parallel resonant unit 131 can be connected in parallel with the impedance matching unit 111.

[0085] Specifically, the series resonant unit 132 can be connected directly in series between the antenna 20 and the impedance matching unit 111, creating a high impedance characteristic for the second harmonic frequency band, suppressing harmonic energy from reflecting toward the antenna 20. The parallel resonant unit 131 can be connected between the antenna 20 connection point and the impedance matching output terminal, forming a low-impedance path in the GPS frequency band, directing residual harmonic energy to ground. This topology ensures that the second harmonic is doubly attenuated before entering the main RF path, while avoiding additional loss to the main frequency band signal.

[0086] In practice, the resonant unit is integrated into the impedance matching network at the antenna 20 interface, and a branching structure is used to achieve harmonic suppression without changing the main path layout. This design maintains the low insertion loss characteristics of the RF main path while avoiding space occupation within the shielding case.

[0087] In this embodiment, the above-described configuration effectively suppresses interference from the B13 band's second harmonic on GPS reception while maintaining signal integrity in the main RF path. By optimizing the impedance matching network at the antenna 20 interface, this structure achieves harmonic suppression while avoiding the power compensation requirements associated with traditional solutions, ultimately reducing harmonic energy generation.

[0088] In an exemplary embodiment, Figure 3 As shown, the series resonant unit 132 includes an inductor unit.

[0089] A first end of the inductor is connected to a first end of the parallel resonant unit 131 and is used to connect to the antenna 20 .

[0090] The inductor unit may be a circuit unit composed of an inductor, such as a wire wound inductor or a laminated inductor, with an inductance value ranging from 1 to 10 nH. This unit forms a high impedance path for harmonics in a specific frequency band through series resonance, thereby suppressing the transmission of interfering signals.

[0091] Exemplarily, the first end of the inductor unit is directly connected to the first end of the parallel resonant unit 131 at the connection point of antenna 20, forming a series-parallel resonant circuit. When antenna 20 receives an RF signal, the inductor unit and parallel resonant unit 131 work together to produce a resonance effect in the 1554-1574 MHz frequency band corresponding to the second harmonic of the B13 frequency band, forming an equivalent open circuit state, preventing signals in this frequency band from entering RF path 30. At the same time, this structure maintains impedance matching in the main frequency band of 777-787 MHz, avoiding attenuation of the main RF signal.

[0092] In this embodiment, the aforementioned structure suppresses interference from the B13 second harmonic in the GPS band while also avoiding the RF performance degradation caused by insertion loss in conventional solutions. The coordinated layout of the inductor unit and parallel resonant unit 131 concentrates the interference suppression effect at the antenna 20 end, effectively blocking interference signals from entering subsequent circuits without requiring changes to the main RF path structure, thus addressing the challenge of limited device layout space.

[0093] In an exemplary embodiment, Figure 3 As shown, the parallel resonance unit 131 includes a capacitor unit;

[0094] The first end of the capacitor unit is connected to the first end of the series resonant unit 132 and is used to connect to the antenna 20;

[0095] The second end of the capacitor unit is connected to the second end of the impedance matching unit 111 and the first end of the impedance matching unit 111 respectively.

[0096] Among them, the capacitor unit can refer to a parallel resonant structure composed of capacitor elements. For example, it can be implemented using chip capacitors or ceramic capacitors, and its capacitance range can be adjusted according to the target suppression frequency band. The unit is connected in parallel between the antenna 20 and the impedance matching unit 111 to form a resonant suppression path for a specific frequency, thereby attenuating the second harmonic energy. The first end of the series resonant unit 132 is directly connected to the antenna 20, so that the high-frequency interference signal preferentially enters the resonant network for filtering.

[0097] Exemplarily, the capacitor unit and series resonant unit 132 together form a composite structure for second harmonic suppression. When a radio frequency signal enters the circuit through antenna 20, the second harmonic component of a preset frequency band forms a resonant circuit between the capacitor unit and the series resonant unit 132. At this point, the capacitor unit shunts and attenuates the high-frequency interference component through a parallel ground path. Because this structure is directly integrated within the impedance matching module 110, there is no need for additional independent filtering components. This maintains the low insertion loss characteristics of the main radio frequency path while effectively suppressing interference in the GPS band.

[0098] In this embodiment, through the above-mentioned structural setting, the signal transmission efficiency of the main RF path can be effectively maintained in the process of suppressing the interference of the second harmonic of the B13 band on the GPS band, avoiding the increase in power compensation demand caused by additional filtering devices, and optimizing the circuit layout space utilization.

[0099] In an exemplary embodiment, the second harmonic suppression module includes a harmonic suppression integrated component;

[0100] The first end of the harmonic suppression integrated component is connected to the first end of the harmonic suppression integrated component and is used to connect to the antenna;

[0101] The second terminal of the harmonic suppression integrated component is used for grounding.

[0102] Among them, integrated harmonic suppression components can refer to functional devices that integrate filtering circuits or resonant structures. For example, this can be achieved using surface-mount filters or miniaturized notch filters, whose built-in resonant networks can create impedance mismatches for specific frequency bands. Grounding can refer to forming a low-impedance connection between a circuit node and the device's reference potential point. For example, a metal casing or PCB ground plane can be used as the grounding point, and a current loop can be established through physical contact or welding.

[0103] Exemplarily, the harmonic suppression integrated component can be directly connected between the antenna and the ground terminal to form a bypass branch. When the second harmonic of the B13 frequency band exists in the radio frequency signal received by the antenna, the harmonic suppression integrated component exhibits a low impedance characteristic at its resonant frequency, so that the interference signal in the 1554-1574MHz frequency band is short-circuited to the ground point. The integrated component can act directly on the antenna port and complete harmonic suppression before the signal enters the radio frequency front end, thereby preventing the interference signal from entering the subsequent circuit and producing an amplification effect. Due to the use of integrated devices, there is no need to set up additional discrete resonant components in the main radio frequency path, which not only maintains the signal integrity of the main path, but also simplifies the circuit layout.

[0104] In this embodiment, without affecting the performance of the main RF path, the direct parallel connection structure of the harmonic suppression integrated components avoids the insertion loss caused by the series resonant unit in the traditional solution, and its integrated design saves circuit board space.

[0105] In an exemplary embodiment, the radio frequency interference suppression circuit further includes:

[0106] A GPS signal quality monitoring module, wherein a first end is connected to the GPS path, and a second end of the GPS signal quality monitoring module is connected to a second end of the antenna tuning module;

[0107] The antenna tuning module is used to adjust the matching parameters of the impedance matching module and the second harmonic suppression module based on the signal quality monitored by the GPS signal quality monitoring module, so as to adjust the frequency band interference intensity of the second harmonic.

[0108] The GPS signal quality monitoring module may refer to a circuit unit that obtains GPS path signal quality parameters in real time. For example, this may be implemented using a received signal strength indicator or a bit error rate detector to quantify the degree of GPS signal interference. The antenna tuning module may refer to a circuit unit that dynamically adjusts impedance matching and harmonic suppression parameters based on feedback signals. Specifically, this may be implemented using a programmable capacitor array or inductor array, optimizing the signal transmission path by changing matching network parameters.

[0109] Exemplarily, the GPS signal quality monitoring module continuously collects GPS channel signal quality data, such as signal strength or bit error rate, and transmits this data to the antenna tuning module. Based on the received signal quality parameters, the antenna tuning module can adjust the matching network parameters of the impedance matching module in real time, such as changing the capacitance or inductance value to better match the main frequency band impedance of the antenna and the RF channel. Simultaneously, it adjusts the resonant frequency or attenuation characteristics of the second harmonic suppression module, such as adjusting the inductance value of the series resonant unit or the capacitance value of the parallel resonant unit, to enhance the ability to suppress second harmonics in a preset frequency band. By dynamically adjusting the matching parameters, the interference intensity of the second harmonic on the GPS frequency band is kept to a minimum.

[0110] In practical applications, dynamic parameter optimization is achieved through GPS signal quality feedback, eliminating the need to add additional filtering components to the main RF path. This not only avoids the impact of increased insertion loss on the main RF performance, but also reduces the space occupied by hardware layout.

[0111] In this embodiment, through the above-mentioned structural setting, the harmonic suppression parameters can be accurately adjusted according to the real-time changes in the GPS signal quality, while ensuring the performance of the main RF path, effectively reducing the interference of the second harmonic on the GPS frequency band, and solving the problem of the traditional solution where the main RF performance is degraded due to the insertion loss introduced by the fixed filter device.

[0112] In an exemplary embodiment, the radio frequency path includes a B13 frequency band path, and the second harmonic of the preset frequency band is the second harmonic of the B13 frequency band; the radio frequency interference suppression circuit further includes:

[0113] A B13 signal strength detection module, a first end of which is connected to the B13 frequency band path, and a second end of which is connected to the second end of the antenna tuning module;

[0114] The antenna tuning module is used to adjust the matching parameters of the impedance matching module and the second harmonic suppression module based on the signal strength monitored by the B13 signal strength detection module, so as to adjust the frequency band interference intensity of the second harmonic.

[0115] The B13 frequency band path may refer to a radio frequency signal transmission link operating in the 777-787 MHz frequency range. For example, it may be implemented by combining a bandpass filter and a power amplifier to carry signals in the mobile communication frequency band. The B13 signal strength detection module may refer to a circuit unit that monitors the signal power in the B13 frequency band in real time. For example, it may be implemented by combining a coupler and a logarithmic detector to quantify the harmonic generation potential of the radio frequency path. The matching parameter adjustment may refer to changing the inductance, capacitance, and resonant frequency of the impedance matching network. Specifically, it may be implemented by using an adjustable capacitor array or a digitally tuned inductor to dynamically optimize the balance between the harmonic suppression depth and the main frequency signal transmission efficiency.

[0116] For example, when the signal strength of the B13 band path exceeds a preset threshold, the B13 signal strength detection module sends a control signal to the antenna tuning module, triggering the impedance matching module to adjust the inductor and capacitor parameters, shifting the resonance point of the second harmonic suppression module toward the 1554-1574MHz band while maintaining the impedance matching state of the main frequency band of 777-787MHz. This dynamic adjustment process is achieved through closed-loop control, suppressing the interference of the second harmonic on the GPS band while avoiding the deterioration of passband insertion loss caused by traditional fixed filtering networks.

[0117] In practical applications, the use of the B13 frequency band has become increasingly common in 5G communication systems, especially in densely populated urban areas. With the dense deployment of 5G base stations, the signal strength of the B13 frequency band has increased significantly, causing its second harmonic to interfere with GPS signals more severely. In certain locations with complex signal conditions, such as narrow streets between high-rise buildings or underground parking lots, the B13 signal may be abnormally enhanced due to multipath and signal reflections, causing its second harmonic to still significantly interfere with GPS signals. In such cases, signal strength monitoring of the B13 frequency band path can further improve the ability to suppress the second harmonic.

[0118] In some specific embodiments, the B13 signal strength detection module can be integrated into the RF front-end module. It extracts the forward power signal via a directional coupler, converts it into a DC voltage signal via a detection circuit, and then inputs it into the analog-to-digital conversion interface of the antenna tuning module. The antenna tuning module drives the varactor diode array in the impedance matching module to change its capacitance based on a preset power-tuning parameter mapping table, thereby simultaneously adjusting the LC resonant network parameters of the second harmonic suppression module.

[0119] In this embodiment, through the above-mentioned structural setting, the harmonic suppression strength can be adaptively adjusted under different transmission power scenarios, effectively solving the dynamic interference problem of the B13 second harmonic on the GPS frequency band. At the same time, it avoids the problems of passband insertion loss deterioration and device layout space occupation caused by the fixed filtering network in traditional solutions, and achieves the optimal balance between RF performance and harmonic suppression effect.

[0120] In an exemplary embodiment, Figure 4 This is a schematic diagram of the specific structure of a radio frequency interference suppression circuit 10 provided in this application, such as Figure 4 As shown, the radio frequency interference suppression circuit 10 includes: a multi-path impedance matching unit 111, an antenna 20 tuner and a second harmonic suppression module 130; the second harmonic suppression module 130 includes a capacitor.

[0121] For example, the antenna tuner 20 may be connected to the antenna tuning module 120. The multi-channel impedance matching unit 111 may form an impedance matching module 110, and its structure may refer to the structure of the radio frequency interference suppression circuit 10 in the above embodiments.

[0122] It can be understood that the implementation of this embodiment can be applied to various embodiments of the above-mentioned radio frequency interference suppression circuit 10, which will not be described in detail here.

[0123] In an exemplary embodiment, Figure 1 As shown, the present application further provides a communication device 1, which includes: an antenna 20; a radio frequency path 30; a GPS path 40; and the radio frequency interference suppression circuit 10 as described above.

[0124] This embodiment further provides a communication device 1, comprising an antenna 20, a radio frequency path 30, a GPS path 40, and a radio frequency interference suppression circuit 10. The radio frequency interference suppression circuit 10 includes an impedance matching module 110, an antenna tuning module 120, and a second harmonic suppression module 130. The impedance matching module 110 has a first end connected to the antenna 20 and has multiple second ends for matching the main frequency band impedance of the antenna 20 and the radio frequency path 30. The antenna tuning module 120 has multiple first ends correspondingly connected to the second ends of the impedance matching module 110, and its second end is connected to the radio frequency path 30 to adjust matching parameters. The second harmonic suppression module 130 has a first end connected to the antenna 20 and a second end connected to the first end of the antenna tuning module 120 to suppress interference of the second harmonic of the preset frequency band of the radio frequency path 30 on the GPS path 40.

[0125] Among them, the antenna 20 may refer to a device for receiving and transmitting electromagnetic waves, for example, it may be implemented by a metal conductor structure or a microstrip patch structure, and its function is to convert radio frequency signals into free-space electromagnetic waves. The radio frequency path 30 may refer to a transmission link for processing radio frequency signals in a specific frequency band, for example, it may be implemented by a combination of filters, amplifiers and transmission lines, and is used to carry signal transmission in the main communication frequency band. The GPS path 40 may refer to a receiving link for processing GPS frequency band signals, for example, it may be implemented by a combination of low-noise amplifiers, bandpass filters and mixers, and is used to receive 1575MHz satellite navigation signals. The radio frequency interference suppression circuit 10 may refer to a circuit structure that reduces interference through impedance matching and harmonic suppression, for example, it may be implemented by a combination of inductors, capacitors and resonant units, and is used to maintain the performance of the main radio frequency path 30 while suppressing the second harmonic.

[0126] Exemplarily, the impedance characteristics of the RF signal received by the antenna 20 are adjusted through the impedance matching module 110, so that the main frequency band signal is efficiently transmitted to the RF path 30. The antenna tuning module 120 can dynamically adjust the matching state of the impedance matching module 110 according to preset parameters to adapt to different operating frequencies or environmental changes. The second harmonic suppression module 130 filters out the second harmonic energy of the preset frequency band in the RF path 30 through a series or parallel resonant structure, for example, suppressing the second harmonic of the B13 band uplink signal to prevent it from falling into the GPS band and causing interference. The RF interference suppression circuit 10 is directly integrated into the communication device 1, and there is no need to add additional filtering devices in the main RF link, thereby reducing insertion loss and avoiding occupying the internal space of the shielding cover.

[0127] In this embodiment, through the above-mentioned structural setting, the interference of the second harmonic on the GPS frequency band can be effectively suppressed without affecting the performance of the main RF path 30, avoiding the problem of increasing the power amplifier power due to increased insertion loss, and reducing the space occupied by the internal device. Therefore, while ensuring the GPS positioning accuracy of the communication device 1, the transmission performance of the main frequency band in the RF path 30 can be improved.

[0128] It should be noted that Figures 1 to 4 The figure shows some ports and connection relationships of each module / unit, but in actual application, other connection relationships of ports of each module / unit can be set according to actual needs, and other pins or ports not shown can be set according to actual conditions. Figures 1 to 4 The examples shown in the accompanying drawings are not intended to limit the present application.

[0129] It can be understood that the above-mentioned impedance matching module 110, antenna tuning module 120 and second harmonic suppression module 130 and other modules can also adopt other forms, and are not limited to the forms mentioned in the above embodiments, as long as they can achieve the functions of completing impedance matching, antenna 20 tuning and second harmonic suppression.

[0130] The above circuit can be applied to electronic terminals or similar devices with communication functions, such as mobile phones, tablets, or video game devices.

[0131] In the description of this specification, the reference terms "some embodiments," "other embodiments," "specific implementation," "another implementation," etc., mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0132] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, article, or device comprising the element.

[0133] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referenced to each other.

[0134] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A radio frequency interference suppression circuit, characterized in that: Applicable to a communication device, the communication device including an antenna, a radio frequency path, and a GPS path; the radio frequency interference suppression circuit includes: an impedance matching module, having a first end for connecting to the antenna and a plurality of second ends for matching the impedance of the antenna and the main frequency band of the radio frequency path; an antenna tuning module, wherein the plurality of first ends are connected to a second end of the impedance matching module in a one-to-one correspondence, and the second end of the antenna tuning module is used to connect to the RF path and to adjust the matching parameters of the impedance matching module; A second harmonic suppression module, a first end of which is connected to the first end of the impedance matching module and is used to connect to the antenna, and a second end of the second harmonic suppression module is connected to the first end of the antenna tuning module, and is used to suppress the second harmonic of the preset frequency band of the RF path from interfering with the frequency band of the GPS path.

2. The radio frequency interference suppression circuit according to claim 1, characterized in that: The impedance matching module includes a multi-channel impedance matching unit; The first ends of the multiple impedance matching units are connected in common and used to be connected to the antenna; The second end of each anti-matching unit is correspondingly connected to a first end of the antenna tuning module.

3. The radio frequency interference suppression circuit according to claim 2, characterized in that: A first end of the second harmonic suppression module is connected to a first end of one of the impedance matching units, and a second end of the second harmonic suppression module is connected to a second end of the impedance matching unit.

4. The radio frequency interference suppression circuit according to claim 2, characterized in that: The second harmonic suppression module includes a series resonance unit and a parallel resonance unit; The first end of the series resonance unit is used to connect to the antenna, and the second end of the series resonance unit is connected to the first end of one of the impedance matching units; The first end of the parallel resonance unit is connected to the first end of the series resonance unit and is used to connect to the antenna. The second end of the parallel resonance unit is respectively connected to the second end of the impedance matching unit and the first end of the antenna tuning module.

5. The radio frequency interference suppression circuit according to claim 4, characterized in that: The series resonant unit includes an inductor unit; The first end of the inductor is connected to the first end of the parallel resonance unit and is used to connect to the antenna.

6. The radio frequency interference suppression circuit according to claim 4, characterized in that: The parallel resonance unit includes a capacitor unit; The first end of the capacitor unit is connected to the first end of the series resonant unit and is used to connect to the antenna; The second end of the capacitor unit is connected to the second end of the impedance matching unit and the first end of the impedance matching unit respectively.

7. The radio frequency interference suppression circuit according to claim 1, characterized in that: The second harmonic suppression module includes a harmonic suppression integrated component; The first end of the harmonic suppression integrated component is connected to the first end of the harmonic suppression integrated component and is used to connect to the antenna; The second terminal of the harmonic suppression integrated component is used for grounding.

8. The radio frequency interference suppression circuit according to claim 1, wherein: The radio frequency interference suppression circuit further includes: A GPS signal quality monitoring module, a first end of which is connected to the GPS path, and a second end of which is connected to the second end of the antenna tuning module; The antenna tuning module is used to adjust the matching parameters of the impedance matching module and the second harmonic suppression module according to the signal quality monitored by the GPS signal quality monitoring module, so as to adjust the frequency band interference intensity of the second harmonic.

9. The radio frequency interference suppression circuit according to claim 1, characterized in that: The radio frequency path includes a B13 frequency band path, and the second harmonic of the preset frequency band is the second harmonic of the B13 frequency band; The radio frequency interference suppression circuit further includes: A B13 signal strength detection module, a first end of which is connected to the B13 frequency band path, and a second end of which is connected to the second end of the antenna tuning module; The antenna tuning module is used to adjust the matching parameters of the impedance matching module and the second harmonic suppression module according to the signal strength monitored by the B13 signal strength detection module, so as to adjust the frequency band interference intensity of the second harmonic.

10. A communication device, characterized in that: The communication device comprises: antenna; RF pathway; GPS access; The radio frequency interference suppression circuit according to any one of claims 1 to 9.

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