Adjustable amplitude limiter structure and radio frequency equipment

Abstract

The utility model provides an adjustable amplitude limiter structure and radio frequency equipment, and relates to the technical field of radio frequency. According to the invention, multiple stages of diode discharge links formed by forward series connection of multiple diodes are arranged, so that respective middle connection points of two adjacent stages of diode discharge links are connected through a microstrip line, and respective anode connection ends of the multiple stages of diode discharge links are externally connected with forward bias voltage signals through the same choke inductor; and meanwhile, the respective cathode connecting ends of the multistage diode discharge links are grounded, and at the moment, the actual voltage values of the forward bias voltage signals can be adjusted, so that the multistage diode discharge links can be grounded under the action of different forward bias voltage signals. And the amplitude limiting circuit is used for carrying out amplitude limiting processing of different degrees on the radio frequency input signal acquired by the input matching circuit so as to dynamically adjust the amplitude limiting level of the corresponding amplitude limiter structure, so that the corresponding radio frequency output signal meets the input power requirements of the rear-end amplifier of different degrees.

Description

Technical Field

[0001] This application relates to the field of radio frequency (RF) technology, and more specifically, to an adjustable limiter structure and a radio frequency device. Background Technology

[0002] With the continuous development of science and technology, radio frequency (RF) technology has been widely used in various industries (e.g., television, radio, mobile phones, radar, satellite positioning, automatic identification systems, etc.). In the actual application of RF technology, it is often necessary to use a limiter to limit the RF signal from the front end of the RF link so that the low-noise amplifier and / or power amplifier at the back end of the RF link can amplify the RF signal after the limiter to a state that meets the desired signal requirements.

[0003] It is worth noting that the current popular limiter structure in the industry is a passive limiter that uses PIN diodes or Schottky diodes. Its limiting level is relatively fixed in a high power range (e.g., 13-16dBm). As a result, the corresponding limiter structure is only suitable for use with high input power back-end amplifiers. It cannot effectively limit the RF signal power of the RF link front-end in use with low input power back-end amplifiers. This can easily cause the RF link back-end amplifier to enter an oversaturated state, reduce the amplifier's amplification efficiency, and deteriorate the amplifier's reliability. Utility Model Content

[0004] In view of this, the purpose of this application is to provide an adjustable limiter structure and RF device that can dynamically adjust the limiting level according to the requirements of different RF systems, so that the corresponding limiter structure is suitable for both high input power back-end amplifier application scenarios and low input power back-end amplifier application scenarios, ensuring that the RF link back-end amplifier can operate normally, thereby effectively expanding the adjustable range of the limiting level of the corresponding limiter structure and the application scenarios of the limiter.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0006] In a first aspect, this application provides an adjustable limiter structure, which includes a multi-stage diode leakage link, an input matching circuit, a choke inductor, and a decoupling filter capacitor, wherein each stage of the diode leakage link is formed by multiple diodes connected in forward series, and the intermediate connection points of adjacent two stages of the diode leakage link are connected by a microstrip line.

[0007] The anode terminals of each of the multi-stage diode leakage links are interconnected and connected to one end of the choke inductor. The other end of the choke inductor is connected to an externally adjustable forward bias voltage signal. One end of the choke inductor connected to the anode terminal is grounded through the decoupling filter capacitor, and the cathode terminals of each of the multi-stage diode leakage links are grounded respectively.

[0008] The intermediate connection point of the first-stage diode leakage link in the multi-stage diode leakage link is connected to an external radio frequency input signal via the input matching circuit, and the radio frequency output signal is output to the outside through the intermediate connection point of the last-stage diode leakage link in the multi-stage diode leakage link, wherein the radio frequency output signal is obtained by limiting the radio frequency input signal through the multi-stage diode leakage link.

[0009] In an optional implementation, all diodes in the same stage of the diode leakage link are symmetrically distributed about the corresponding intermediate connection point.

[0010] In an optional implementation, the final-stage diode leakage link includes an even number of target diodes, each connected in parallel with a first switch, and the number of target diodes on both sides of the corresponding intermediate connection point of the final-stage diode leakage link remains consistent.

[0011] In an optional implementation, one electrode of each target diode is connected to one end of a corresponding first switch via a second switch, and the other electrode of each target diode is connected to the other end of a corresponding first switch.

[0012] In an optional implementation, each of the multi-stage diode leakage links includes a Schottky diode.

[0013] In an optional implementation, the adjustable limiter structure further includes an interference signal filtering circuit;

[0014] The signal input terminal of the interference signal filtering circuit is connected to the intermediate connection point of the final stage diode leakage link, and is used to perform interference signal filtering processing on the received radio frequency output signal.

[0015] The signal output terminal of the interference signal filtering circuit is used to output the radio frequency output signal after interference signal filtering.

[0016] In an optional embodiment, the interference signal filtering circuit includes a first capacitor and a first inductor, wherein the first capacitor and the first inductor are connected in series to form a first series resonant network.

[0017] The network input terminal of the first series resonant network serves as the signal input terminal of the interference signal filtering circuit, and the network output terminal of the first series resonant network serves as the signal output terminal of the interference signal filtering circuit, wherein the first series resonant network is used to filter out low-frequency noise signals in the received radio frequency output signal.

[0018] In an optional embodiment, the interference signal filtering circuit further includes a second capacitor and a second inductor, wherein the second capacitor and the second inductor are connected in series to form a second series resonant network.

[0019] The network input terminal of the second series resonant network is connected to the network output terminal of the first series resonant network, and the network output terminal of the second series resonant network is grounded. The second series resonant network is used to filter out the second harmonic signal in the received radio frequency output signal.

[0020] In an optional embodiment, the interference signal filtering circuit further includes a third capacitor and a third inductor, wherein the third capacitor and the third inductor are connected in parallel to form a target parallel resonant network.

[0021] The network output terminal of the first series resonant network is connected in series with the target parallel resonant network, and the network output terminal of the target parallel resonant network serves as the signal output terminal of the interference signal filtering circuit, wherein the target parallel resonant network is used to filter out the third harmonic signal in the received radio frequency output signal.

[0022] Secondly, this application provides a radio frequency device, the radio frequency device including at least one adjustable limiter structure as described in any of the foregoing embodiments.

[0023] In this case, the beneficial effects of the embodiments of this application may include the following:

[0024] This application establishes a multi-stage diode leakage link formed by multiple diodes connected in forward series, connecting the intermediate connection points of adjacent diode leakage links via microstrip lines. The anode connections of each of the multi-stage diode leakage links are then interconnected and connected to one end of a choke inductor. An adjustable forward bias voltage signal is applied to the other end of the choke inductor. The anode connection of the choke inductor is grounded via a decoupling filter capacitor, while the cathode connections of each multi-stage diode leakage link are grounded. An external radio frequency input signal can be connected to the intermediate connection point of the first-stage diode leakage link via an input matching circuit. By adjusting the actual voltage value of the forward bias voltage signal, the multi-stage diode leakage link can operate without... Under the action of the same forward bias voltage signal, the received RF input signal is subjected to different degrees of limiting processing to dynamically adjust the limiting level of the corresponding limiter structure. This facilitates the output of the limited RF output signal through the intermediate connection point of the final diode in the multi-stage diode leakage link, thereby ensuring that the corresponding limiter structure can dynamically adjust the limiting level according to the needs of different RF systems. This allows the corresponding RF output signal to meet the input power requirements of the back-end amplifier at different levels, ensuring that the corresponding limiter structure can be used in both high-input-power and low-input-power back-end amplifier scenarios. This enables the RF link back-end amplifier to operate normally, effectively expanding the adjustable range of the limiting level and the application scenarios of the limiter structure.

[0025] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is one of the schematic diagrams of the adjustable limiter structure provided in the embodiments of this application;

[0028] Figure 2 for Figure 1 The diagram shows the simulation results of the limiting level of the adjustable limiter structure under different forward bias voltage values.

[0029] Figure 3 for Figure 1 The simulation results of DC power consumption of the adjustable limiter structure under different forward bias voltage values ​​are shown in the figure.

[0030] Figure 4 This is a second schematic diagram of the adjustable limiter structure provided in the embodiments of this application;

[0031] Figure 5 This is the third schematic diagram of the adjustable limiter structure provided in the embodiments of this application;

[0032] Figure 6 for Figure 5 The simulation results of the limiting level of the adjustable limiter structure under different switching modes and different forward bias voltage values ​​are shown in the figure.

[0033] Figure 7 for Figure 5 The simulation results of DC power consumption of the adjustable limiter structure under different switching modes and different forward bias voltage values ​​are shown in the figure.

[0034] Figure 8 Fourth schematic diagram of the adjustable limiter structure provided in the embodiments of this application;

[0035] Figure 9 Fifth schematic diagram of the adjustable limiter structure provided in the embodiments of this application;

[0036] Figure 10 A schematic diagram of the adjustable limiter structure provided in this application embodiment is shown in Figure 6.

[0037] Figure 11 for Figure 5 and Figure 10 The simulation comparison diagrams show the RF output signal waveforms of the adjustable limiter structures shown under the same operating conditions.

[0038] Icons: 10-Adjustable limiter structure; 11-Diode leakage link; 12-Input matching circuit; 13-Microstrip line; 14-Choke inductor; 15-Decoupling filter capacitor; 16-First switch; 17-Second switch; 18-Interference signal filtering circuit; 181-First capacitor; 182-First inductor; 183-Second capacitor; 184-Second inductor; 185-Third capacitor; 186-Third inductor. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0041] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0042] In the description of this application, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the equipment or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0043] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0044] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0045] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0046] Please refer to Figure 1 , Figure 1 This is one of the schematic diagrams of the adjustable limiter structure 10 provided in the embodiments of this application. In the embodiments of this application, the adjustable limiter structure 10 may include a multi-stage diode leakage link 11, an input matching circuit 12, a choke inductor 14, and a decoupling filter capacitor 15, wherein each stage of the diode leakage link 11 is composed of multiple diodes connected in forward series, and the anode connection terminal of each stage of the diode leakage link 11 (i.e., Figure 1Terminal A in the diagram corresponds to the anode of the diodes that are not connected to other diodes. The cathode connection terminal of each diode leakage link 11 (i.e., Figure 1 The K-terminal in the diagram represents the cathode of the diode that is not connected to other diodes. All diodes in the same stage of the diode leakage link 11 are symmetrically distributed about the corresponding intermediate connection point (i.e., the number of diodes in the same stage of the diode leakage link 11 is even, and the number of diodes on both sides of the corresponding intermediate connection point of the same stage of the diode leakage link 11 is consistent). The intermediate connection points of adjacent diode leakage links 11 are connected by microstrip lines 13, so as to effectively adjust the impedance matching between adjacent diode leakage links 11 using at least one microstrip line 13, reduce the insertion loss of the adjustable limiter structure 10 in actual use, improve the transmission efficiency of the adjustable limiter structure 10 for radio frequency signals, ensure the stability of the corresponding radio frequency signals during transmission, and thus improve the overall performance of the radio frequency system in which the adjustable limiter structure 10 is located.

[0047] In this embodiment, the anode connection terminals of each of the multi-stage diode leakage links 11 are interconnected and connected to one end of the choke inductor 14. The other end of the choke inductor 14 is externally connected to an adjustable forward bias voltage signal (i.e., Figure 1 The Vg in the multi-stage diode leakage link 11 allows the anode connection terminals of each multi-stage diode leakage link 11 to be externally connected to a forward bias voltage signal through the same choke inductor 14. Simultaneously, the anode connection terminals of each multi-stage diode leakage link 11 are interconnected and grounded through the decoupling filter capacitor 15. At this time, the choke inductor 14 and the decoupling filter capacitor 15 cooperate to form an LC filter circuit, enabling the forward bias voltage signal to act on the anode connection terminal of each stage of the diode leakage link 11. This ensures that each stage of the diode leakage link 11 can form a DC path to ground based on the unidirectional conduction characteristic of the diode under the action of the forward bias voltage signal. This allows input signal voltages exceeding the total threshold level of the corresponding diode leakage link 11 to be directly discharged to ground, thereby maintaining the output signal power of the corresponding diode leakage link 11 at a certain threshold value.

[0048] In this embodiment, the intermediate connection point of the first-stage diode leakage link (i.e., the diode leakage link 11 used to receive unlimited RF signals) in the multi-stage diode leakage link 11 is externally connected to the RF input signal (i.e., the input matching circuit 12) via the input matching circuit 12. Figure 1 The RFIN signal in the multi-stage diode leakage link 11 (i.e., the diode leakage link 11 furthest from the input matching circuit 12) is used to output the radio frequency output signal (i.e., the RFIN signal in the multi-stage diode leakage link 11). Figure 1The RFOUT signal is obtained by sequentially limiting the RF input signal through the multi-stage diode leakage link 11.

[0049] In this process, for any stage diode leakage link 11, the diodes included in the stage diode leakage link 11 have the same body size (i.e., the voltage received by each diode in the stage diode leakage link 11 is the same). When the voltage value of the forward bias voltage signal received by the stage diode leakage link 11 is larger, the voltage received by each diode in the stage diode leakage link 11 is higher, and the peak voltage of the input signal received by the stage diode leakage link 11 through the intermediate connection point is higher, which is closer to the diode threshold level. This makes it easier for each diode in the stage diode leakage link 11 to conduct under the action of the input signal and form a DC path to ground, thereby effectively reducing the limiting level of the corresponding diode leakage link 11. This makes the power attenuation of the output signal output by the corresponding diode leakage link 11 through its own intermediate connection point greater, further reducing the overall limiting level of the adjustable limiter structure 10.

[0050] by Figure 2 and Figure 3 For example, when Figure 1 The adjustable limiter structure 10 shown is implemented using a three-stage diode leakage link 11. Each stage of the diode leakage link 11 is formed by four diodes connected in forward direction. If a limiting operation simulation of the X-band (8-12GHz) RF input signal is performed on the adjustable limiter structure 10, the limiting level variation range of the adjustable limiter structure 10 when the forward bias voltage is 0-2V is 12-17dBm. When the RF input signal power is between 15-30dBm, the larger the forward bias voltage, the smaller the corresponding limiting level, and correspondingly, the greater the DC power consumption of the adjustable limiter structure 10.

[0051] Therefore, this application provides Figure 1 The adjustable limiter structure 10 shown can adjust the actual voltage value of the forward bias voltage signal, so that the multi-stage diode leakage link 11 can perform different degrees of limiting processing on the received RF input signal under different forward bias voltage signals. This dynamically adjusts the overall limiting level of the adjustable limiter structure 10, so that the RF output signal obtained by the adjustable limiter structure 10 can meet the input power requirements of the back-end amplifier at different levels. This ensures that the adjustable limiter structure 10 can be used in both high-input-power and low-input-power back-end amplifier scenarios, and can guarantee the normal operation of the RF link back-end amplifier in the corresponding RF system. This effectively expands the adjustable range of the limiting level and the application scenarios of the adjustable limiter structure 10.

[0052] It is understood that the diode sizes of the different diode leakage links 11 in the adjustable limiter structure 10 can be the same or different; the number of diodes in the different diode leakage links 11 in the adjustable limiter structure 10 can be the same or different; the diodes used in the multi-stage diode leakage links 11 in the adjustable limiter structure 10 are Schottky diodes, which do not require special PIN diode processes for fabrication, thus effectively reducing the production complexity and cost of the adjustable limiter structure 10, making the adjustable limiter structure 10 more competitive in the market. In one embodiment of this example, the diode sizes of each of the multi-stage diode leakage links 11 included in the adjustable limiter structure 10 are consistent, and the number of diodes in each of the multi-stage diode leakage links 11 is consistent.

[0053] Alternatively, please refer to Figure 4 , Figure 4 This is a second schematic diagram of the adjustable limiter structure 10 provided in this application embodiment. In this application embodiment, it is related to... Figure 1 Compared to the adjustable limiter structure 10 shown, Figure 4 The adjustable limiter structure 10 shown has an even number of target diodes at the final stage diode leakage link, each connected in parallel with a first switch 16. The number of target diodes on both sides of the corresponding intermediate connection point of the final stage diode leakage link is consistent. At the same time, there is at least one diode on both sides of the corresponding intermediate connection point of the final stage diode leakage link that is not connected in parallel with the first switch 16.

[0054] In this embodiment, for Figure 4 The adjustable limiter structure 10 shown can adjust the number of diodes connected in forward series to ground in the corresponding final-stage diode leakage link by controlling the on / off state of each first switch 16 (for example, when the first switch 16 corresponding to a target diode is turned on, the target diode is in a short-circuit state and cannot work normally; the target diode will not be used as a diode connected in forward series to ground; while when the first switch 16 corresponding to a target diode is turned off, the target diode can work normally and will be used as a diode connected in forward series to ground). This adjusts the voltage value received by each diode connected in forward series to ground in the corresponding final-stage diode leakage link, thereby further expanding the adjustable range of the limiting level of the corresponding limiter structure in conjunction with the forward bias voltage signal. Figure 4 In the final-stage diode leakage link, the number of first switches in the conducting state on both sides of the corresponding intermediate connection point remains consistent. Figure 4In the case of the adjustable limiter structure 10 shown, when the voltage value of the forward bias voltage signal is fixed, the more first switches in the conducting state there are, the fewer diodes in the forward series grounding in the corresponding final stage diode leakage link. However, the voltage value received by each diode in the forward series grounding is higher, and the peak voltage of the input signal received by the final stage diode leakage link through the intermediate connection point will also be raised higher and closer to the diode threshold level. This makes it easier for each diode in the current forward series grounding of the final stage diode leakage link to conduct under the action of the input signal and form a DC path to ground. This effectively and significantly reduces the limiting level of the final stage diode leakage link, and greatly increases the power attenuation of the RF output signal output through the final stage diode leakage link, further reducing the overall limiting level of the adjustable limiter structure 10.

[0055] Based on this, Figure 4 The adjustable limiter structure 10 shown is... Figure 1 The adjustable limiter structure 10 shown maintains the same limiting level when... Figure 4 The adjustable limiter structure 10 shown can be implemented using a lower forward bias voltage, enabling... Figure 4 The adjustable limiter structure 10 shown is compared to Figure 1 The adjustable limiter structure 10 shown has lower DC power consumption and higher RF signal limiting efficiency.

[0056] Alternatively, please refer to Figure 5 , Figure 5 This is the third schematic diagram of the adjustable limiter structure 10 provided in this application embodiment. In this application embodiment, it is related to... Figure 4 Compared to the adjustable limiter structure 10 shown, Figure 5The adjustable limiter structure 10 shown has a second switch 17 at each target diode, so that one electrode (e.g., anode or cathode) of each target diode is connected to one end of the corresponding first switch 16 via the second switch 17, and the other electrode (e.g., cathode or anode) of each target diode is connected to the other end of the corresponding first switch 16. The switching states of the first switch 16 and the second switch 17 corresponding to the same target diode are opposite (for example, when the first switch 16 corresponding to a target diode is turned on, the second switch 17 corresponding to the target diode will be turned off, and the target diode will be in an open circuit state, and the target diode cannot work normally and cannot be used as a diode in forward series grounding, and the distortion of the RF output signal waveform caused by the diode short circuit state can be effectively avoided; when the first switch 16 corresponding to a target diode is turned off, the second switch 17 corresponding to the target diode will be turned on, and the target diode can work normally and will be used as a diode in forward series grounding), so as to effectively avoid the distortion of the RF output signal waveform caused by the diode short circuit state.

[0057] by Figure 6 and Figure 7 For example, when Figure 5 The adjustable limiter structure 10 shown is implemented using a three-stage diode leakage link 11. Each stage of the diode leakage link 11 is formed by four diodes connected in forward direction. In the final stage diode leakage link 11, there are two target diodes connected in series with a second switch 17 and then in parallel with a first switch 16. If a limiting operation simulation of an X-band (8-12GHz) RF input signal is performed on this adjustable limiter structure 10, then the adjustable limiter structure 10 has two switching modes: a low limiting level mode (i.e., two first switches 17 and 16) and a low limiting level mode. When switch 6 is on and both second switches 17 are off, corresponding to V1 = -5), and in "high limiting level mode (i.e., both first switches 16 are off and both second switches 17 are on, corresponding to V1 = 0)," the adjustable limiter structure 10 in "high limiting level mode" has a limiting level variation range of 16-18 dBm when the forward bias voltage is 0-1V, and in "low limiting level mode," the adjustable limiter structure 10 has a limiting level variation range of 10-14 dBm when the forward bias voltage is 0-1V. Figure 5 The adjustable limiter structure 10 shown has an overall limiting level variation range of 10–18 dBm, which can be clearly achieved by utilizing switching mode switching and a small forward bias voltage range. Figure 2 The adjustable range of the limiting level shown (corresponding to) Figure 1 The effect of the adjustable limiter structure 10) shown is as follows. Specifically, when the RF input signal power is between 15 and 30 dBm, Figure 5The larger the positive bias voltage value of the adjustable limiter structure 10 shown in the same switching mode, the smaller the corresponding limiting level, and the greater the DC power consumption of the adjustable limiter structure 10. Figure 1 The adjustable limiter structure 10 shown requires approximately 0.2W of DC power to maintain a limiting level of 12dBm at an input signal power of 30dBm, while... Figure 5 The adjustable limiter structure 10 shown only needs to maintain a "low limit level mode" with a forward bias voltage of 1V to maintain a limiting level of 12dBm when the input signal power is 30dBm. At this point, the corresponding DC power consumption is close to 0.1W, which is approximately equivalent to not using a switching mode architecture (i.e.,...). Figure 1 The adjustable limiter structure 10 shown is half of the DC power consumption of the corresponding limiter structure, thereby effectively reducing the DC power consumption of the corresponding limiter structure and improving the RF signal limiting efficiency of the corresponding limiter structure.

[0058] In this application, conventional limiter structures are prone to power compression under high-power RF input signals, generating low-noise signals and / or high-order harmonic signals (e.g., second and third harmonic signals). This causes the RF output signal obtained from the limiting process to carry these low-noise and / or high-order harmonic signals when transmitted to the RF link back-end amplifier (at which point waveform distortion occurs in the RF output signal), leading to a decrease in the signal processing performance of the RF link back-end amplifier (e.g., weakening the P-1dB capability of the low-noise amplifier or deteriorating the linearity of the power amplifier). Therefore, this application addresses this issue... Figure 1 , Figure 4 or Figure 5 The adjustable limiter structure 10 shown is further improved, making the improved adjustable limiter structure 10 relative to... Figure 1 , Figure 4 or Figure 5 The adjustable limiter structure 10 shown additionally includes an interference signal filtering circuit 18 (e.g., Figure 8 The adjustable limiter structure 10 shown is relative to Figure 5 The adjustable limiter structure 10 shown includes an additional interference signal filtering circuit 18, which filters out interference signals passing through the interference signal filtering circuit 18. Figure 1 , Figure 4 or Figure 5 The RF output signal processed by the adjustable limiter structure 10 shown is subjected to interference signal filtering, so that the RF output signal after interference signal filtering can effectively avoid waveform distortion, thereby ensuring the quality of RF signal and ensuring that the signal processing performance of the corresponding RF link back-end amplifier does not decrease significantly, thereby improving the linearity of the corresponding RF system. At this time, the improved adjustable limiter structure 10 can clearly ensure that the corresponding RF system meets the requirements of high linearity and low signal distortion.

[0059] In this embodiment of the application, the signal input terminal of the interference signal filtering circuit 18 (i.e. Figure 8 The In terminal of the circuit is connected to the intermediate connection point of the final stage diode leakage link to filter out interference signals from the received RF output signal. Then, the signal is transmitted through the signal output terminal of the interference signal filtering circuit 18 (i.e.,...). Figure 8 The RF output signal, after interference signal filtering, is output from the Out terminal.

[0060] Optionally, in this embodiment, the interference signal filtering circuit 18 may include a first capacitor 181 and a first inductor 182, wherein the first capacitor 181 and the first inductor 182 are connected in series to form a first series resonant network, with the end of the first capacitor 181 furthest from the first inductor 182 serving as the network input terminal of the first series resonant network, and the end of the first inductor 182 furthest from the first capacitor 181 serving as the network output terminal of the first series resonant network. In this case, the network input terminal of the first series resonant network can be directly used as the signal input terminal of the interference signal filtering circuit 18, and the network output terminal of the first series resonant network can be used as the signal output terminal of the interference signal filtering circuit 18, thereby filtering out low-frequency noise signals in the received radio frequency output signal by the first series resonant network.

[0061] Alternatively, please refer to Figure 9 In this embodiment, the interference signal filtering circuit 18 may further include a second capacitor 183 and a second inductor 184, wherein the second capacitor 183 and the second inductor 184 are connected in series to form a second series resonant network. The end of the second capacitor 183 furthest from the second inductor 184 serves as the network input terminal of the second series resonant network, and the end of the second inductor 184 furthest from the second capacitor 183 serves as the network output terminal of the second series resonant network. The network input terminal of the second series resonant network is connected to the network output terminal of the first series resonant network, and the network output terminal of the second series resonant network is grounded. In this case, the second series resonant network can effectively filter out the second harmonic signal in the received radio frequency output signal by short-circuiting the second harmonic signal by transforming the impedance of the second harmonic signal in the received radio frequency output signal to a low-impedance state.

[0062] Alternatively, please refer to Figure 10In this embodiment, the interference signal filtering circuit 18 may further include a third capacitor 185 and a third inductor 186, wherein the third capacitor 185 and the third inductor 186 are connected in parallel to form a target parallel resonant network. One end of the third capacitor 185 connected to the third inductor 186 serves as the network input terminal of the target parallel resonant network, and the other end of the third capacitor 185 connected to the third inductor 186 serves as the network output terminal of the target parallel resonant network. The network output terminal of the first series resonant network is connected to the network input terminal of the target parallel resonant network to connect the target parallel resonant network in series. The network output terminal of the target parallel resonant network serves as the signal output terminal of the interference signal filtering circuit 18. In this case, the target parallel resonant network can effectively filter out the third harmonic signal in the received radio frequency output signal by transforming the impedance of the third harmonic signal in the received radio frequency output signal to a high-impedance state and thus performing open-circuit processing on the third harmonic signal.

[0063] by Figure 11 For example, Figure 11 (a) is Figure 5 The simulation diagram of the RF output signal waveform of the adjustable limiter structure 10 shown is shown. Figure 11 (b) is Figure 10 The simulation diagram of the RF output signal waveform of the adjustable limiter structure 10 shown is as follows: Figure 5 The adjustable limiter structure 10 shown directly outputs a high-power radio frequency output signal through the final-stage diode leakage link, which exhibits significant signal distortion due to interference. Figure 10 The adjustable limiter structure 10 shown has greatly improved the distortion problem of the RF output signal and improved the RF signal quality by adding the interference signal filtering circuit 18. It can ensure that the signal processing performance of the corresponding RF link back-end amplifier will not be significantly reduced.

[0064] Furthermore, it is understood that, for the aforementioned interference signal filtering circuit 18, since it employs filtering technology to ensure that only the fundamental signal can pass through the received RF output signal, the interference signal filtering circuit 18 can essentially be regarded as part of the output matching network. It can effectively reduce the use of devices related to the output matching network in the RF system, and can match the output impedance of the corresponding limiter structure with the system impedance (e.g., 50Ω) of the RF system while reducing signal insertion loss.

[0065] In this application, embodiments provide a radio frequency (RF) device. The RF device may include at least one of the aforementioned adjustable limiter structures 10, and uses the adjustable limiter structure 10 to limit the received frequency signal, so that the limited RF signal reaches the desired limiting level. The RF device may be, but is not limited to, an RF transmitter, an RF receiver, or an RF signal processing device.

[0066] The above descriptions are merely various embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An adjustable limiter structure, characterized in that, The adjustable limiter structure includes a multi-stage diode leakage link, an input matching circuit, a choke inductor, and a decoupling filter capacitor. Each stage of the diode leakage link is formed by multiple diodes connected in forward series, and the intermediate connection points of adjacent diode leakage links are connected by microstrip lines. The anode terminals of each of the multi-stage diode leakage links are interconnected and connected to one end of the choke inductor. The other end of the choke inductor is connected to an externally adjustable forward bias voltage signal. One end of the choke inductor connected to the anode terminal is grounded through the decoupling filter capacitor, and the cathode terminals of each of the multi-stage diode leakage links are grounded respectively. The intermediate connection point of the first-stage diode leakage link in the multi-stage diode leakage link is connected to an external radio frequency input signal via the input matching circuit, and the radio frequency output signal is output to the outside through the intermediate connection point of the last-stage diode leakage link in the multi-stage diode leakage link, wherein the radio frequency output signal is obtained by limiting the radio frequency input signal through the multi-stage diode leakage link.

2. The adjustable limiter structure according to claim 1, characterized in that, All diodes in the same level of diode leakage link are symmetrically distributed about the corresponding intermediate connection point.

3. The adjustable limiter structure according to claim 2, characterized in that, The final stage diode leakage link includes an even number of target diodes, each connected in parallel with a first switch, and the number of target diodes on both sides of the corresponding intermediate connection point of the final stage diode leakage link remains the same.

4. The adjustable limiter structure according to claim 3, characterized in that, One electrode of each target diode is connected to one end of the corresponding first switch via a second switch, and the other electrode of each target diode is connected to the other end of the corresponding first switch.

5. The adjustable limiter structure according to claim 1, characterized in that, Each of the diodes in the multi-stage diode leakage link is a Schottky diode.

6. The adjustable limiter structure according to any one of claims 1-5, characterized in that, The adjustable limiter structure also includes an interference signal filtering circuit; The signal input terminal of the interference signal filtering circuit is connected to the intermediate connection point of the final stage diode leakage link, and is used to perform interference signal filtering processing on the received radio frequency output signal. The signal output terminal of the interference signal filtering circuit is used to output the radio frequency output signal after interference signal filtering.

7. The adjustable limiter structure according to claim 6, characterized in that, The interference signal filtering circuit includes a first capacitor and a first inductor, wherein the first capacitor and the first inductor are connected in series to form a first series resonant network. The network input terminal of the first series resonant network serves as the signal input terminal of the interference signal filtering circuit, and the network output terminal of the first series resonant network serves as the signal output terminal of the interference signal filtering circuit, wherein the first series resonant network is used to filter out low-frequency noise signals in the received radio frequency output signal.

8. The adjustable limiter structure according to claim 7, characterized in that, The interference signal filtering circuit further includes a second capacitor and a second inductor, wherein the second capacitor and the second inductor are connected in series to form a second series resonant network. The network input terminal of the second series resonant network is connected to the network output terminal of the first series resonant network, and the network output terminal of the second series resonant network is grounded. The second series resonant network is used to filter out the second harmonic signal in the received radio frequency output signal.

9. The adjustable limiter structure according to claim 8, characterized in that, The interference signal filtering circuit also includes a third capacitor and a third inductor, wherein the third capacitor and the third inductor are connected in parallel to form a target parallel resonant network; The network output terminal of the first series resonant network is connected in series with the target parallel resonant network, and the network output terminal of the target parallel resonant network serves as the signal output terminal of the interference signal filtering circuit, wherein the target parallel resonant network is used to filter out the third harmonic signal in the received radio frequency output signal.

10. A radio frequency device, characterized in that, The radio frequency device includes at least one adjustable limiter structure as described in any one of claims 1-9.

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