Filter circuit, low-noise receiver front-end assembly and low-noise receiver front-end device

Abstract

This application provides a filter circuit, a low-noise receiving front-end component, and a low-noise receiving front-end device, belonging to the field of filter technology. The filter circuit includes: a radio frequency input terminal, a first frequency-tunable resonant unit, a low-noise amplifier, a second frequency-tunable resonant unit, and a radio frequency output terminal connected in sequence. The frequency-tunable resonant unit includes a PIN diode switched capacitor array circuit. The PIN diode switched capacitor array circuit includes multiple parallel PIN diode switched capacitor circuits, each including a resonant capacitor and a PIN diode switch control unit. Under the drive of a high-voltage signal group, the PIN diode switched capacitor array circuit determines the switching state of each switch control unit in the multiple PIN diode switched capacitor circuits to determine the number of resonant capacitors participating in the resonant operation. This application embeds the low-noise amplifier within the frequency hopping filter, which can simultaneously ensure the frequency selectivity of the radio frequency link and reduce the noise figure of the radio frequency link, thereby improving the receiving performance of the communication system.

Description

Technical Field

[0001] This application relates to the field of filter technology, and in particular to a filter circuit, a low-noise receiving front-end component, and a low-noise receiving front-end device. Background Technology

[0002] There are two main ways to implement the receiver RF front-end in communication systems: post-low noise amplifier (LNA) and pre-low noise amplifier (LNA).

[0003] The low-noise amplifier post-amplifier approach, where the pre-stage is a filter and the post-stage is a low-noise amplifier, has the advantages of simple architecture, good frequency selectivity of communication system, and strong anti-interference capability. However, the disadvantage is that the link noise figure is relatively large, which has a significant impact on the receiving sensitivity of communication system.

[0004] The low-noise amplifier (LNOA) pre-amplifier method uses a high-power LNOA for the RF front end, and then filters are connected to the subsequent stages. It has the advantages of low link noise figure and high receiving sensitivity of communication system, but the disadvantages are weak anti-interference capability, poor frequency selectivity, and high requirements for P-1 of LNOA. It requires LNOA with high P-1 and low gain, resulting in poor device selectivity and high cost.

[0005] Therefore, it is necessary to provide a low-cost and high-efficiency implementation method for the receiver's radio frequency front-end. Utility Model Content

[0006] This application provides a filter circuit, a low-noise receiver front-end component, and a low-noise receiver front-end device to overcome the deficiencies of low-noise amplifier post-positioning and low-noise amplifier pre-positioning in the prior art, and to achieve a low-cost and high-efficiency receiver RF front-end.

[0007] This application provides a filter circuit, including: The radio frequency input terminal, the first frequency adjustable resonant unit, the low noise amplifier, the second frequency adjustable resonant unit, and the radio frequency output terminal are connected in sequence. Both the first frequency-tunable resonant unit and the second frequency-tunable resonant unit include a PIN diode switched capacitor array circuit. The PIN diode switched capacitor array circuit includes multiple parallel PIN diode switched capacitor circuits; the PIN diode switched capacitor circuit includes a resonant capacitor and a PIN diode switching control unit; The PIN diode switched capacitor array circuit is used to determine the switching state of each PIN diode switch control unit in the multi-channel PIN diode switched capacitor circuit under the drive of the high voltage signal group, so as to determine the number of resonant capacitors participating in the resonant operation.

[0008] According to a filter circuit provided in this application, the PIN diode switch control unit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first PIN diode, a second PIN diode, a first capacitor, and a second capacitor; The first end of the resonant capacitor is connected to the first end of the first resistor, the first end of the second resistor, the cathode of the first PIN diode, and the anode of the second PIN diode; The first end of the third resistor is connected to the second end of the first resistor, the anode of the first PIN diode, and the first end of the first capacitor; the second end of the third resistor is connected to the power supply. The first end of the fourth resistor is connected to the second end of the second resistor, the cathode of the second PIN diode, and the first end of the second capacitor; the second end of the fourth resistor is connected to a high-voltage signal. The second terminal of the first capacitor and the second terminal of the second capacitor are grounded.

[0009] According to a filter circuit provided in this application, the first frequency-tunable resonant unit further includes a first inductor, a second inductor, and a third inductor; The first end of the first inductor is connected to the radio frequency input terminal; the second end of the first inductor is connected to the first end of the second inductor and the first end of the third inductor; the second end of the second inductor is grounded; the second end of the third inductor is connected to the second end of each of the resonant capacitors in the PIN diode switched capacitor array circuit and the input terminal of the low noise amplifier. The second frequency-tunable resonant unit also includes a fourth inductor, a fifth inductor, a sixth inductor, and a seventh inductor; The first end of the fourth inductor is connected to the output of the low-noise amplifier; the second end of the fourth inductor is connected to the first ends of the fifth inductor, the sixth inductor, and the seventh inductor; the second end of the fifth inductor is grounded; the second end of the sixth inductor is connected to the second end of each of the resonant capacitors in the PIN diode switched capacitor array circuit; and the second end of the seventh inductor is connected to the RF output.

[0010] According to the filter circuit provided in this application, a third frequency adjustable resonant unit is included. The input terminal of the third frequency-tunable resonant unit is connected to the output terminal of the second frequency-tunable resonant unit; the output terminal of the third frequency-tunable resonant unit is connected to the radio frequency output terminal. The third frequency-tunable resonant unit includes the PIN diode switched capacitor array circuit.

[0011] According to a filter circuit provided in this application, the third frequency-tunable resonant unit further includes an eighth inductor, a ninth inductor, a tenth inductor, and an eleventh inductor. The first end of the eighth inductor is connected to the output end of the second frequency-tunable resonant unit; the second end of the eighth inductor is connected to the first end of the ninth inductor, the first end of the tenth inductor, and the first end of the eleventh inductor; the second end of the ninth inductor is grounded; the second end of the tenth inductor is connected to the second end of each of the resonant capacitors in the PIN diode switched capacitor array circuit; and the second end of the eleventh inductor is connected to the RF output end.

[0012] According to the filter circuit provided in this application, it further includes: a fourth frequency-tunable resonant unit; The input terminal of the fourth frequency-tunable resonant unit is connected to the radio frequency input terminal; the output terminal of the fourth frequency-tunable resonant unit is connected to the input terminal of the first frequency-tunable resonant unit. The fourth frequency-tunable resonant unit includes the PIN diode switched capacitor array circuit.

[0013] According to a filter circuit provided in this application, the fourth frequency-tunable resonant unit further includes a twelfth inductor, a thirteenth inductor, a fourteenth inductor, and a fifteenth inductor; The first end of the twelfth inductor is connected to the radio frequency input terminal; the second end of the twelfth inductor is connected to the first end of the thirteenth inductor, the first end of the fourteenth inductor, and the first end of the fifteenth inductor; the second end of the thirteenth inductor is grounded; the second end of the fourteenth inductor is connected to the second end of each of the resonant capacitors in the PIN diode switched capacitor array circuit; and the second end of the fifteenth inductor is connected to the input terminal of the first frequency-adjustable resonant unit.

[0014] This application also provides a low-noise receiving front-end component, including: Filter circuits as described in any of the above; The numerical control module is used to output high-voltage signal groups to the filter circuit.

[0015] According to a low-noise receiving front-end component provided in this application, the numerical control module includes: A memory circuit is used to store the control matrix data of the PIN diode switched capacitor array circuit of the filter circuit; A driver isolation chip is used to generate the high-voltage signal group based on the control matrix data under the drive of external control commands, and output the high-voltage signal group to the filter circuit.

[0016] This application also provides a low-noise receiving front-end device, characterized in that it includes: The low-noise receiver front-end component as described in any of the above.

[0017] The filter circuit, low-noise receiver front-end component, and low-noise receiver front-end device provided in this application adopt a design method in which the low-noise amplifier is embedded in the filter circuit. The low-noise amplifier is embedded between the second-order resonance of the frequency hopping filter, which balances the advantages and disadvantages of placing the low-noise amplifier before and after the filter. This method can ensure the frequency selectivity of the RF link and reduce the noise figure degradation caused by filter insertion loss, thereby reducing the noise figure of the RF link and providing a better frequency response in the passband. This improves the receiving performance of the communication system and is widely applicable to microwave communication, broadband communication systems, radar, and electronic warfare systems. The design method of embedding the low-noise amplifier in the filter circuit also has the advantages of simple design, small size, simple manufacturing process and structure, low assembly difficulty, reliability and ease of use, and low production cost. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is one of the structural schematic diagrams of the filter circuit provided in this application.

[0020] Figure 2 This is a circuit diagram of the PIN diode switched capacitor array circuit provided in this application.

[0021] Figure 3 This is one of the circuit diagrams of the filter circuit provided in this application.

[0022] Figure 4 This is the second schematic diagram of the filter circuit provided in this application.

[0023] Figure 5 This is the second circuit diagram of the filter circuit provided in this application.

[0024] Figure 6 This is the third schematic diagram of the filter circuit provided in this application.

[0025] Figure 7 This is the third circuit diagram of the filter circuit provided in this application.

[0026] Figure 8 This is a schematic diagram of the structure of the low-noise receiving front-end component provided in this application.

[0027] Figure 9 This is a structural schematic diagram of the CNC module provided in this application.

[0028] Figure 10This is a schematic diagram of the low-noise receiving front-end device provided in this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions 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, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] It should be noted that, in the description of this application, the term "comprising" or any other variations thereof is intended to cover a non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Those skilled in the art will understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and that the objects distinguished by "first," "second," etc., are generally of the same class and are not limited in number.

[0032] The following is combined Figures 1-10 This application describes the filter circuit, low-noise receiving front-end assembly, and low-noise receiving front-end device provided in this application.

[0033] Figure 1 This is one of the structural schematic diagrams of the filter circuit provided in this application, such as... Figure 1 As shown, the filter circuit includes, but is not limited to, the RF input terminal 110, the first frequency adjustable resonant unit 120, the low noise amplifier (LNA) 130, the second frequency adjustable resonant unit 140 and the RF output terminal 150 connected in sequence.

[0034] The RF input terminal 110 is connected to the input terminal of the first frequency adjustable resonant unit 120, the output terminal of the first frequency adjustable resonant unit 120 is connected to the input terminal of the low noise amplifier 130, the output terminal of the low noise amplifier 130 is connected to the input terminal of the second frequency adjustable resonant unit 140, and the output terminal of the second frequency adjustable resonant unit 140 is connected to the RF output terminal 150.

[0035] The first frequency-tunable resonant unit 120 and the second frequency-tunable resonant unit 140 both include a PIN diode switched capacitor array circuit 200. The PIN diode switched capacitor array circuit 200 includes multiple parallel PIN diode switched capacitor circuits 210; each PIN diode switched capacitor circuit 210 includes a resonant capacitor 211 and a PIN diode switching control unit 212, with the resonant capacitor 211 connected to the PIN diode switching control unit 212.

[0036] The PIN diode switched capacitor array circuit 200 is used to determine the switching state of each PIN diode switch control unit 212 in the multi-channel PIN diode switched capacitor circuit 210 under the drive of an externally input high voltage signal group, so as to determine the number of resonant capacitors 211 participating in the resonant operation.

[0037] It is understood that the externally input high-voltage signal group includes multiple high-voltage signals; each high-voltage signal can control one PIN diode switched capacitor circuit 210 in any frequency adjustable resonant unit, that is, one high-voltage signal simultaneously controls the switching state of one PIN diode switched capacitor circuit 210; each high-voltage signal can also simultaneously control one PIN diode switched capacitor circuit 210 in different frequency adjustable resonant units, that is, one high-voltage signal simultaneously controls the switching state of two or more PIN diode switched capacitor circuits 210.

[0038] Specifically, when the filter circuit is working, the radio frequency (RF) signal is input from the RF input terminal 110. As it passes through the first frequency-tunable resonant unit 120, the PIN diode switched capacitor circuit 210 of the first frequency-tunable resonant unit 120, driven by an externally input high-voltage signal, determines the switching state of the PIN diode switch control unit 212, thereby determining the number of resonant capacitors 211 participating in the resonant operation. This allows for adjustment of the capacitor values ​​involved in the resonant operation, achieving frequency changes in the RF signal. The RF signal processed by the first frequency-tunable resonant unit 120 is input to the low-noise amplifier 130, and the output from the low-noise amplifier 130 is then input to the second frequency-tunable resonant unit 140.

[0039] Driven by an externally input high-voltage signal, the PIN diode switched capacitor circuit 210 of the second frequency-tunable resonant unit 140 determines the switching state of the PIN diode switch control unit 212, thereby determining the number of resonant capacitors 211 participating in the resonant operation. This allows for adjustment of the capacitor values ​​involved in the resonant operation, achieving frequency variation of the radio frequency signal. The radio frequency signal processed by the second frequency-tunable resonant unit 140 is finally output via the radio frequency output terminal.

[0040] By adjusting the capacitance value involved in the resonant operation, the corresponding frequency point can be selected to achieve frequency variation of the radio frequency signal, making the filter's operating frequency vary from 225MHz to 678MHz.

[0041] In the post-low noise amplifier (LDA) approach, the pre-stage filter has a direct impact on the link noise figure. When the filter insertion loss is large, the noise figure is high, which directly affects the receiving sensitivity of the communication system. In the pre-low noise amplifier approach, the frequency selectivity is poor, the anti-interference capability is weak, and the requirements for the LDA are high. High P-1 and low gain LDAs are expensive and have poor versatility.

[0042] The filter circuit provided in this application employs a design method where the low-noise amplifier (LNOA) is embedded within the filter circuit. By embedding the LNOA between the second-order resonances of the frequency-hopping filter, the advantages and disadvantages of placing the LNOA before and after the filter are balanced. This approach ensures the frequency selectivity of the RF link while reducing noise figure degradation caused by filter insertion loss, thereby lowering the noise figure of the RF link. It also exhibits good frequency response within the passband, thus improving the receiving performance of the communication system. This design is widely applicable to microwave communication, broadband communication systems, radar, and electronic warfare systems. Furthermore, the LNOA embedded design method also offers advantages such as simple design, small size, simple manufacturing process and structure, low assembly difficulty, reliability, ease of use, and low production cost.

[0043] As an optional embodiment, Figure 2 This is a circuit diagram of the PIN diode switched capacitor array circuit provided in this application, such as... Figure 2 As shown, each PIN switch control unit 212 in each PIN switch capacitor circuit 210 of the PIN switch capacitor array circuit 200 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first PIN diode D1, a second PIN diode D2, a first capacitor (Cn+1, ..., C2n) and a second capacitor (C2n+1, ..., C3n).

[0044] Taking the PIN diode switched capacitor circuit 210 containing the resonant capacitor C1 as an example, the first end of the resonant capacitor C1 is connected to the first end of the first resistor R1, the first end of the second resistor R2, the cathode of the first PIN diode D1, and the anode of the second PIN diode D2, respectively; the first end of the third resistor R3 is connected to the second end of the first resistor R1, the anode of the first PIN diode D1, and the first end of the first capacitor Cn+1, respectively; the second end of the third resistor R3 is connected to the power supply, which provides a voltage of 3.3V; the first end of the fourth resistor R4 is connected to the second end of the second resistor R2, the cathode of the second PIN diode D2, and the first end of the second capacitor C2n+1, respectively; the second end of the fourth resistor R4 is connected to the externally input high-voltage signal HV1; the second end of the first capacitor Cn+1 and the second end of the second capacitor are grounded.

[0045] Therefore, in each PIN diode switched capacitor array circuit 200, each resonant capacitor 211 (C1, ..., Cn) constitutes a capacitor array, and each PIN diode switch control unit 212 constitutes a switch control array. Under the control of the externally input high voltage signal group (HV1, ..., HVn), each PIN diode switch control unit 212 presents different switching states, so that the number of resonant capacitors 211 participating in the resonant operation is different under the control of different high voltage signal groups, thereby adjusting the capacitance value participating in the resonant operation and realizing the frequency change of the radio frequency signal.

[0046] As an optional embodiment, Figure 3 This is one of the circuit diagrams of the filter circuit provided in this application, such as... Figure 3 As shown, in the filter circuit, the first frequency-tunable resonant unit 120 further includes a first inductor L1, a second inductor L2, and a third inductor L3; the first end of the first inductor L1 is connected to the RF input terminal 110, the second end of the first inductor L1 is connected to the first end of the second inductor L2 and the first end of the third inductor L3, the second end of the second inductor L2 is grounded, and the second end of the third inductor L3 is connected to the second end of each resonant capacitor (C1, ..., Cn) in the PIN diode switched capacitor array circuit of the first frequency-tunable resonant unit 120 and the input terminal of the low-noise amplifier 130.

[0047] The second frequency-tunable resonant unit 140 also includes a fourth inductor L4, a fifth inductor L5, a sixth inductor L6, and a seventh inductor L7; the first end of the fourth inductor L4 is connected to the output terminal of the low-noise amplifier 130; the second end of the fourth inductor L4 is connected to the first end of the fifth inductor L5, the first end of the sixth inductor L6, and the first end of the seventh inductor L7, respectively; the second end of the fifth inductor L5 is grounded; the second end of the sixth inductor L6 is connected to the second end of each resonant capacitor (C1, ..., Cn) in the PIN diode switched capacitor array circuit of the second frequency-tunable resonant unit 140; the second end of the seventh inductor L7 is connected to the RF output terminal 150.

[0048] By embedding a low-noise amplifier between the two resonants of a frequency-hopping filter, matching and cascading the low-noise amplifier with the filter's resonant inductor, and using a PIN diode matrix switch to control the filter's resonant capacitor, frequency variation can be achieved.

[0049] As an optional embodiment, Figure 4 This is the second schematic diagram of the filter circuit provided in this application, as shown below. Figure 4 As shown, the filter circuit also includes a third frequency-tunable resonant unit 160.

[0050] The input terminal of the third frequency-tunable resonant unit 160 is connected to the output terminal of the second frequency-tunable resonant unit 140; the output terminal of the third frequency-tunable resonant unit 160 is connected to the RF output terminal 150; the third frequency-tunable resonant unit 160 includes a PIN diode switched capacitor array circuit 200.

[0051] It is understandable that the structure of the PIN diode switched capacitor array circuit 200 in the third frequency adjustable resonant unit 160 is the same as that of the PIN diode switched capacitor array circuit 200 in the first frequency adjustable resonant unit 120 and the second frequency adjustable resonant unit 140, and will not be described in detail here.

[0052] This embodiment provides a third-order frequency hopping filter circuit, in which a low-noise amplifier is embedded. Specifically, the low-noise amplifier is located after the first-order resonant stage and followed by two resonants, which helps to better leverage the advantages of a pre-positioned low-noise amplifier. Furthermore, using a third-order PIN diode switched capacitor array circuit as the main component, the frequency parameters can be adjusted according to actual usage requirements, significantly reducing debugging work.

[0053] As an optional embodiment, Figure 5 This is the second circuit diagram of the filter circuit provided in this application, as shown below. Figure 5 As shown, the third frequency-tunable resonant unit 160 also includes an eighth inductor L8, a ninth inductor L9, a tenth inductor L10, and an eleventh inductor L11; the first end of the eighth inductor L8 is connected to the output terminal of the second frequency-tunable resonant unit 140 (that is, the second end of the seventh inductor L7); the second end of the eighth inductor L8 is connected to the first end of the ninth inductor L9, the first end of the tenth inductor L10, and the first end of the eleventh inductor L11; the second end of the ninth inductor L9 is grounded; the second end of the tenth inductor L10 is connected to the second end of each resonant capacitor (C1, ..., Cn) in the PIN diode switched capacitor array circuit of the third frequency-tunable resonant unit 160; the second end of the eleventh inductor L11 is connected to the RF output terminal 150.

[0054] By embedding a low-noise amplifier between the first and second resonants of a third-order frequency hopping filter, matching and cascading the low-noise amplifier with the filter's resonant inductor, and using a PIN diode matrix switch to control the filter's resonant capacitor, the frequency variation can better leverage the advantages of pre-amplifying the low-noise amplifier.

[0055] As an optional embodiment, Figure 6 This is the third schematic diagram of the filter circuit provided in this application, as shown below. Figure 6 As shown, the filter circuit also includes a fourth frequency-tunable resonant unit 170.

[0056] The input terminal of the fourth frequency-tunable resonant unit 170 is connected to the radio frequency input terminal 110; the output terminal of the fourth frequency-tunable resonant unit 170 is connected to the input terminal of the first frequency-tunable resonant unit 120; the fourth frequency-tunable resonant unit 170 includes a PIN diode switched capacitor array circuit 200.

[0057] It is understood that the structure of the PIN diode switched capacitor array circuit 200 in the fourth frequency adjustable resonant unit 170 is the same as the structure of the PIN diode switched capacitor array circuit 200 in the first frequency adjustable resonant unit 120, the second frequency adjustable resonant unit 140, and the third frequency adjustable resonant unit 160 in the aforementioned embodiments, and will not be described again.

[0058] This embodiment provides another third-order frequency hopping filter circuit, in which a low-noise amplifier is embedded. Specifically, the low-noise amplifier is located after the second-order resonant stage and followed by the first-order resonant stage, which helps to better utilize the advantages of post-positioning the low-noise amplifier. Furthermore, using a third-order PIN diode switched capacitor array circuit as the main component, the frequency parameters can be adjusted according to actual usage requirements, greatly reducing debugging work.

[0059] As an optional embodiment, Figure 7 This is the third circuit diagram of the filter circuit provided in this application, as shown below. Figure 7 As shown, the fourth frequency-tunable resonant unit 170 also includes a twelfth inductor L12, a thirteenth inductor L13, a fourteenth inductor L14, and a fifteenth inductor L15; the first end of the twelfth inductor L12 is connected to the RF input terminal 110; the second end of the twelfth inductor L12 is connected to the first end of the thirteenth inductor L13, the first end of the fourteenth inductor L14, and the first end of the fifteenth inductor L15, respectively; the second end of the thirteenth inductor L13 is grounded; the second end of the fourteenth inductor L14 is connected to the second end of each resonant capacitor (C1, ..., Cn) in the PIN diode switched capacitor array circuit of the fourth frequency-tunable resonant unit 170; the second end of the fifteenth inductor L15 is connected to the input terminal of the first frequency-tunable resonant unit 120 (that is, the first end of the first inductor L1).

[0060] By embedding a low-noise amplifier between the second and third resonants of a third-order frequency hopping filter, matching and cascading the low-noise amplifier with the filter's resonant inductor, and using a PIN diode matrix switch to control the filter's resonant capacitor, the frequency variation can better leverage the advantages of a post-positioned low-noise amplifier.

[0061] Figure 8 This is a schematic diagram of the structure of the low-noise receiving front-end component provided in this application, as shown below. Figure 8 As shown, the low-noise receiving front-end component includes the filter circuit 810 and the numerical control module 820 provided in any of the above embodiments.

[0062] The numerical control module 820 is used to output a high-voltage signal group to the filter circuit 810, so that the PIN tube switched capacitor array circuit of each frequency adjustable resonant unit in the filter circuit 810 determines the switching state of each PIN tube switch control unit in the multi-channel PIN tube switched capacitor circuit under the drive of the high-voltage signal group, so as to determine the number of resonant capacitors participating in the resonant operation, and then adjust the capacitor value participating in the resonant operation to realize the frequency change of the radio frequency signal.

[0063] It should be noted that the low-noise receiving front-end component provided in this application is implemented based on the filter circuit described in any of the above embodiments, and will not be described in detail in this embodiment.

[0064] Figure 9 This is a structural schematic diagram of the CNC module provided in this application, as shown below. Figure 9 As shown, the CNC module 820 includes, but is not limited to, a memory circuit (also known as a memory FLASH circuit) 821 and a driver isolation chip 822.

[0065] The memory circuit 821 is used to store the control matrix data of the PIN diode switched capacitor array circuit of the filter circuit; the drive isolation chip 822 is used to generate a high voltage signal group based on the control matrix data under the drive of external control commands, and output the high voltage signal group to the filter circuit.

[0066] Specifically, combined Figure 9 As shown, the memory circuit 821 stores the control matrix data of the PIN diode switched capacitor array circuit of the filter circuit (including the control data of the aforementioned capacitor array and the control data of the switch control array). Through external control instructions controlling address codes A0-A7, the control matrix data D0-D11 of the memory circuit 821 is called, so that the drive isolation chip 822 generates a high voltage signal group HV0-HV11 based on the control matrix data D0-D11, and outputs the high voltage signal group HV0-HV11 to the PIN diode switched capacitor array circuit of each frequency adjustable resonant unit of the filter circuit 810. This correspondingly changes the switching state of the PIN diode switch control unit in the 12 parallel PIN diode switched capacitor circuits in each PIN diode switched capacitor array circuit, thereby adjusting the selection of the resonant capacitor.

[0067] By using a storage control method, which uses a memory circuit to store parameter data, the matching between the filter resonance and the low-noise amplifier is adjusted, and the resonant frequency is adjusted to achieve RF frequency changes. Parameters can be retrieved at any time during use. It has the advantages of low cost, simple and easy process, wide application range and high reliability.

[0068] Figure 10 This is a schematic diagram of the low-noise receiving front-end device provided in this application, as shown below. Figure 10As shown, the low-noise receiving front-end device 1000 includes, but is not limited to, the low-noise receiving front-end component 1010 provided in any of the above embodiments.

[0069] Optionally, the low-noise receiving front-end device further includes an external structural component, and the low-noise receiving front-end component 1010 is fixedly disposed inside the external structural component.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A filter circuit, characterized in that, include: The radio frequency input terminal, the first frequency adjustable resonant unit, the low noise amplifier, the second frequency adjustable resonant unit, and the radio frequency output terminal are connected in sequence. Both the first frequency-tunable resonant unit and the second frequency-tunable resonant unit include a PIN diode switched capacitor array circuit. The PIN diode switched capacitor array circuit includes multiple parallel PIN diode switched capacitor circuits; the PIN diode switched capacitor circuit includes a resonant capacitor and a PIN diode switching control unit; The PIN diode switched capacitor array circuit is used to determine the switching state of each PIN diode switch control unit in the multi-channel PIN diode switched capacitor circuit under the drive of the high voltage signal group, so as to determine the number of resonant capacitors participating in the resonant operation.

2. The filter circuit according to claim 1, characterized in that, The PIN diode switch control unit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first PIN diode, a second PIN diode, a first capacitor, and a second capacitor; The first end of the resonant capacitor is connected to the first end of the first resistor, the first end of the second resistor, the cathode of the first PIN diode, and the anode of the second PIN diode; The first end of the third resistor is connected to the second end of the first resistor, the anode of the first PIN diode, and the first end of the first capacitor; the second end of the third resistor is connected to the power supply. The first end of the fourth resistor is connected to the second end of the second resistor, the cathode of the second PIN diode, and the first end of the second capacitor; the second end of the fourth resistor is connected to a high-voltage signal. The second terminal of the first capacitor and the second terminal of the second capacitor are grounded.

3. The filter circuit according to claim 1 or 2, characterized in that, The first frequency-tunable resonant unit further includes a first inductor, a second inductor, and a third inductor; The first end of the first inductor is connected to the radio frequency input terminal; the second end of the first inductor is connected to the first end of the second inductor and the first end of the third inductor; the second end of the second inductor is grounded; the second end of the third inductor is connected to the second end of each of the resonant capacitors in the PIN diode switched capacitor array circuit and the input terminal of the low noise amplifier. The second frequency-tunable resonant unit also includes a fourth inductor, a fifth inductor, a sixth inductor, and a seventh inductor; The first end of the fourth inductor is connected to the output of the low-noise amplifier; the second end of the fourth inductor is connected to the first ends of the fifth inductor, the sixth inductor, and the seventh inductor; the second end of the fifth inductor is grounded; the second end of the sixth inductor is connected to the second end of each of the resonant capacitors in the PIN diode switched capacitor array circuit; and the second end of the seventh inductor is connected to the RF output.

4. The filter circuit according to claim 1, characterized in that, Also includes: Third frequency adjustable resonant unit; The input terminal of the third frequency-tunable resonant unit is connected to the output terminal of the second frequency-tunable resonant unit; the output terminal of the third frequency-tunable resonant unit is connected to the radio frequency output terminal. The third frequency-tunable resonant unit includes the PIN diode switched capacitor array circuit.

5. The filter circuit according to claim 4, characterized in that, The third frequency-tunable resonant unit also includes an eighth inductor, a ninth inductor, a tenth inductor, and an eleventh inductor; The first end of the eighth inductor is connected to the output end of the second frequency-tunable resonant unit; the second end of the eighth inductor is connected to the first end of the ninth inductor, the first end of the tenth inductor, and the first end of the eleventh inductor; the second end of the ninth inductor is grounded; the second end of the tenth inductor is connected to the second end of each of the resonant capacitors in the PIN diode switched capacitor array circuit; and the second end of the eleventh inductor is connected to the RF output end.

6. The filter circuit according to claim 1, characterized in that, Also includes: Fourth frequency adjustable resonant unit; The input terminal of the fourth frequency-tunable resonant unit is connected to the radio frequency input terminal; the output terminal of the fourth frequency-tunable resonant unit is connected to the input terminal of the first frequency-tunable resonant unit. The fourth frequency-tunable resonant unit includes the PIN diode switched capacitor array circuit.

7. The filter circuit according to claim 6, characterized in that, The fourth frequency-tunable resonant unit also includes a twelfth inductor, a thirteenth inductor, a fourteenth inductor, and a fifteenth inductor; The first end of the twelfth inductor is connected to the radio frequency input terminal; the second end of the twelfth inductor is connected to the first end of the thirteenth inductor, the first end of the fourteenth inductor, and the first end of the fifteenth inductor; the second end of the thirteenth inductor is grounded; the second end of the fourteenth inductor is connected to the second end of each of the resonant capacitors in the PIN diode switched capacitor array circuit; and the second end of the fifteenth inductor is connected to the input terminal of the first frequency-adjustable resonant unit.

8. A low-noise receiving front-end component, characterized in that, include: The filter circuit as described in any one of claims 1 to 7; The numerical control module is used to output high-voltage signal groups to the filter circuit.

9. The low-noise receiving front-end assembly according to claim 8, characterized in that, The numerical control module includes: A memory circuit is used to store the control matrix data of the PIN diode switched capacitor array circuit of the filter circuit; A driver isolation chip is used to generate the high-voltage signal group based on the control matrix data under the drive of external control commands, and output the high-voltage signal group to the filter circuit.

10. A low-noise receiving front-end device, characterized in that, include: The low-noise receiver front-end component as described in any one of claims 8 or 9.

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