L-band radio frequency front-end circuit and wireless communication device

Abstract

The application provides an L-band radio frequency front-end circuit and a wireless communication device, and relates to the technical field of wireless communication.The L-band radio frequency front-end circuit comprises a circulator, a low-noise amplifier circuit, a switch filter bank circuit, a receiving post-stage amplifier circuit, a transmitting pre-stage amplifier circuit and a power amplifier circuit.The input end of the low-noise amplifier circuit is connected with the output end of the circulator.The first input end of the switch filter bank circuit is connected with the output end of the low-noise amplifier circuit.The input end of the receiving post-stage amplifier circuit is connected with the first output end of the switch filter bank circuit.The output end of the receiving post-stage amplifier circuit outputs to a post-stage baseband.The input end of the transmitting pre-stage amplifier circuit is used for connecting a wideband modulated radio frequency signal output by the baseband.The output end of the transmitting pre-stage amplifier circuit is connected with the second input end of the switch filter bank circuit.The input end of the power amplifier circuit is connected with the second output end of the switch filter bank circuit.The output end of the power amplifier circuit is connected with the input end of the circulator.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to an L-band radio frequency front-end circuit and wireless communication device. Background Technology

[0002] Existing L-band RF front-end technologies often face problems such as limited functionality, restricted receiving dynamic range, lack of front-end protection mechanisms, insufficient transmit / receive switching speed, and low transmission efficiency. Utility Model Content

[0003] The main purpose of this utility model is to provide an L-band radio frequency front-end circuit, which aims to achieve fast transmit / receive switching, improve power efficiency, and protect the low-noise amplifier, so that the L-band radio frequency front-end circuit has enhanced anti-interference capability and expanded dynamic range of received signals.

[0004] To achieve the above objectives, this utility model provides an L-band radio frequency front-end circuit, the L-band radio frequency front-end circuit comprising: Circulator, the circulator being used for switching and isolating transmit and receive signals; A low-noise amplifier circuit, the input of which is connected to the output of the circulator, is used for low-noise amplification of broadband radio frequency signals. A switching filter bank circuit, wherein the first input terminal of the switching filter bank circuit is connected to the output terminal of the low noise amplifier circuit, and the switching filter bank circuit is used to perform frequency selective filtering on broadband radio frequency signals. The receiving post-amplifier circuit has its input terminal connected to the first output terminal of the switching filter bank circuit, and its output terminal outputs the processed radio frequency signal to the post-baseband stage. The receiving post-amplifier circuit is used to amplify the filtered frequency-selective signal to the required level amplitude of the post-baseband stage. A pre-amplifier circuit is provided, wherein the input terminal of the pre-amplifier circuit is used to receive the broadband modulated radio frequency signal output from the baseband, and the output terminal of the pre-amplifier circuit is connected to the second input terminal of the switched filter bank circuit. The pre-amplifier circuit is used to perform primary amplification on the broadband modulated radio frequency signal output from the baseband. The power amplifier circuit has its input terminal connected to the second output terminal of the switching filter bank circuit, and its output terminal connected to the input terminal of the circulator. The power amplifier circuit is used to amplify the power of the filtered frequency-selective signal.

[0005] Optionally, the low-noise amplifier circuit includes: A limiting circuit, wherein the input terminal of the limiting circuit is connected to the output terminal of the circulator; A first low-noise amplifier, the input of which is connected to the output of the limiting circuit; A second low-noise amplifier is connected to the output of the first low-noise amplifier, and the output of the second low-noise amplifier is connected to the first input of the switched filter bank circuit.

[0006] Optionally, the limiting circuit includes: A limiting chip, wherein a first capacitor is connected in series between the radio frequency signal input terminal of the limiting chip and the output terminal of the circulator; The first low-noise amplifier includes: A first low-noise amplifier chip, wherein a second capacitor is connected in series between the radio frequency signal input terminal of the first low-noise amplifier chip and the radio frequency signal output terminal of the limiting chip; A first resistor, a first inductor connected in series between the second end of the first resistor and the RF signal output terminal of the first low-noise amplifier chip, and at least one capacitor connected in parallel between the common node of the first resistor and the first inductor and ground. The second resistor has a third capacitor connected in series between its first end and the RF signal output terminal of the first low-noise amplifier chip, a third resistor connected in parallel between its first end and ground, and a fourth resistor connected in parallel between its second end and ground. The second low-noise amplifier includes: A second low-noise amplifier chip is connected in series with a fourth capacitor between the input terminal of the second low-noise amplifier chip and the second terminal of the second resistor; The fifth resistor has a second inductor connected in series between its second end and the output terminal of the second low-noise amplifier chip, and at least one capacitor is connected in parallel between the common node of the fifth resistor and the second inductor and ground. The fifth capacitor has its first end connected to the output terminal of the second low-noise amplifier chip and its second end connected to the first input terminal of the switching filter bank circuit.

[0007] Optionally, the switching filter bank circuit includes: A first transceiver switch circuit, wherein the first input terminal of the first transceiver switch circuit is connected to the low-noise amplifier circuit, and the first output terminal of the first transceiver switch circuit is connected to the input terminal of the power amplifier circuit. A first selection switch circuit, wherein the first output terminal of the first selection switch circuit is connected to the second input terminal of the first transceiver switch circuit, and the first input terminal of the first selection switch circuit is connected to the second output terminal of the first transceiver switch circuit. The radio frequency (RF) filter circuit has its first input terminal connected to the second output terminal of the first selection switch circuit, and its first output terminal connected to the second input terminal of the first selection switch circuit. A second selection switch circuit, wherein the first input terminal of the second selection switch circuit is connected to the second output terminal of the radio frequency filter circuit, and the first output terminal of the second selection switch circuit is connected to the second input terminal of the radio frequency filter circuit; The second transceiver switch circuit has its first input terminal connected to the second output terminal of the second selection switch circuit, its first output terminal connected to the second input terminal of the second selection switch circuit, its second input terminal connected to the output terminal of the pre-transmitter amplifier circuit, and its second output terminal connected to the input terminal of the post-receiver amplifier circuit.

[0008] Optionally, the receiving stage amplifier circuit includes: A first receiving amplifier circuit, wherein the input terminal of the first receiving amplifier circuit is connected to the first output terminal of the switched filter bank circuit; A second receiving amplifier circuit, wherein the input terminal of the second receiving amplifier circuit is connected to the output terminal of the first receiving amplifier circuit; A first filtering circuit is connected to the output of the second receiving amplifier circuit, and the output of the first filtering circuit outputs the processed radio frequency signal to the subsequent baseband stage.

[0009] Optionally, the pre-transmission amplifier circuit includes: The second filter circuit has its input terminal used to receive the broadband modulated radio frequency signal output from the baseband. A first transmitting amplifier circuit, wherein the input terminal of the first transmitting amplifier circuit is connected to the output terminal of the second filtering circuit; A second transmitting amplifier circuit, wherein the input terminal of the second transmitting amplifier circuit is connected to the output terminal of the first transmitting amplifier circuit; The numerically controlled attenuation circuit has its input terminal connected to the output terminal of the second transmitting amplifier circuit, and its output terminal connected to the second input terminal of the switching filter bank circuit.

[0010] Optionally, the power amplifier circuit includes: A driving amplifier circuit, wherein the input terminal of the driving amplifier circuit is connected to the second output terminal of the switched filter bank circuit; A power amplifier circuit, wherein the input terminal of the power amplifier circuit is connected to the output terminal of the drive amplifier circuit, and the output terminal of the power amplifier circuit is connected to the input terminal of the circulator.

[0011] Optionally, the L-band radio frequency front-end circuit further includes: The power supply circuit has an input terminal for connecting to an external power source, a first output terminal connected to the power input terminal of the low-noise amplifier circuit, a second output terminal connected to the power input terminal of the switching filter bank circuit, a third output terminal connected to the power input terminal of the receiving post-amplifier circuit, a fourth output terminal connected to the power input terminal of the transmitting pre-amplifier circuit, and a fifth output terminal connected to the power input terminal of the power amplifier circuit.

[0012] Optionally, the power supply circuit includes: A reverse connection protection circuit, wherein the input terminal of the reverse connection protection circuit is used to connect to an external power supply; An EMI circuit, wherein the input terminal of the EMI circuit is connected to the output terminal of the reverse connection protection circuit; A power conversion circuit, wherein the input terminal of the power conversion circuit is connected to the output terminal of the EMI circuit, and the output terminal of the power conversion circuit is connected to the power input terminal of the power amplifier circuit; A voltage regulating circuit, wherein the input terminal of the voltage regulating circuit is connected to the output terminal of the power conversion circuit; A receiving switch circuit, the output of which is electrically connected to the low-noise amplifier circuit and the receiving post-amplifier circuit, respectively. The transmitter switch circuit has its output terminal electrically connected to the switch filter bank circuit and the transmitter preamplifier circuit, respectively.

[0013] In addition, to achieve the above objectives, this utility model also provides a wireless communication device, including the L-band radio frequency front-end circuit described above.

[0014] The L-band RF front-end circuit of this embodiment includes a circulator, a low-noise amplifier circuit, a switched filter bank circuit, a receiving post-amplifier circuit, a transmitting pre-amplifier circuit, and a power amplifier circuit. The circulator is used to switch and isolate the transmitting and receiving signals; the low-noise amplifier circuit amplifies the broadband RF signal with low noise; the switched filter bank circuit performs frequency-selective filtering on the broadband RF signal; the receiving post-amplifier circuit amplifies the filtered frequency-selective signal to the required level amplitude of the subsequent baseband stage; the transmitting pre-amplifier circuit performs primary amplification of the broadband modulated RF signal output from the baseband; and the power amplifier circuit amplifies the filtered frequency-selective signal. In this embodiment, the input terminal of the low-noise amplifier circuit is first connected to the output terminal of the circulator. The first input terminal of the switching filter bank circuit is connected to the output terminal of the low-noise amplifier circuit. The input terminal of the receiving stage amplifier circuit is connected to the first output terminal of the switching filter bank circuit. The output terminal of the receiving stage amplifier circuit outputs the processed RF signal to the subsequent baseband stage. The input terminal of the transmitting stage amplifier circuit is used to receive the broadband modulated RF signal output from the baseband stage. The output terminal of the transmitting stage amplifier circuit is connected to the second input terminal of the switching filter bank circuit. The input terminal of the power amplifier circuit is connected to the second output terminal of the switching filter bank circuit. The output terminal of the power amplifier circuit is connected to the input terminal of the circulator. Thus, the circulator achieves transmit / receive isolation, and the combination of multi-stage low-noise amplifiers and limiting circuits improves receiving sensitivity and prevents overload damage. Combined with the switching filter bank, fast frequency selection filtering is achieved. The hierarchical amplification structure optimizes the signal dynamic range, resulting in advantages such as enhanced anti-interference capability, expanded received signal dynamic range, fast transmit / receive switching, improved power efficiency, and protection of the low-noise amplifier. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a circuit block diagram of an L-band radio frequency front-end circuit according to an embodiment of the present invention. Figure 2 This is a circuit block diagram of an L-band radio frequency front-end circuit according to another embodiment of the present invention; Figure 3 for Figure 2 The circuit schematic of the low-noise amplifier circuit; Figure 4 This is a circuit block diagram of an L-band radio frequency front-end circuit according to another embodiment of the present invention. Figure 5 for Figure 4 The circuit diagram of the first transceiver switch circuit and the first selection switch circuit; Figure 6 for Figure 4 The circuit schematic of the radio frequency filter circuit; Figure 7 for Figure 4 The circuit diagram of the second selection switch circuit and the second transceiver switch circuit; Figure 8 A circuit block diagram of an L-band radio frequency front-end circuit according to another embodiment of the present invention; Figure 9 for Figure 8 The circuit diagram of the receiving amplifier stage; Figure 10 This is a circuit block diagram of an L-band radio frequency front-end circuit according to another embodiment of the present invention; Figure 11 for Figure 10 The circuit schematic of the pre-amplifier circuit; Figure 12 for Figure 10 The circuit diagram of the second filter circuit in the diagram; Figure 13 This is a circuit block diagram of an L-band radio frequency front-end circuit according to another embodiment of the present invention. Figure 14 for Figure 13 The circuit diagram of the power amplifier circuit; Figure 15 This is a circuit block diagram of an L-band radio frequency front-end circuit according to another embodiment of the present invention. Figure 16 The present invention provides a circuit block diagram of an L-band radio frequency front-end circuit according to another embodiment.

[0018] Explanation of icon numbers:

[0019] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Well-known modules, units, and their connections, links, communications, or operations are not shown or described in detail. Furthermore, the described features, architectures, or functions can be combined in any way in one or more embodiments. Those skilled in the art should understand that the various embodiments described below are only for illustrative purposes and are not intended to limit the scope of protection of the present invention.

[0021] The existing L-band time-division RF front-end technology suffers from numerous technical defects, severely restricting the performance improvement of communication systems. Firstly, traditional solutions are functionally limited, lacking advanced features such as frequency-hopping reception, resulting in insufficient anti-interference capabilities and difficulty in guaranteeing communication quality in complex electromagnetic environments. Secondly, the dynamic range of the received signal is limited; when the input signal strength is high, the front-end low-noise amplifier is prone to saturation, causing a significant deterioration in the noise figure and limiting the system's application scenarios. More seriously, existing designs lack effective amplitude limiting protection mechanisms in the front-end receiving link, making the low-noise amplifier highly susceptible to permanent damage when encountering high-power signal input, severely impacting equipment reliability. Furthermore, the traditional solution has a long transmit / receive switching time, typically on the nanosecond level, which cannot meet the rapid switching requirements of modern communication systems. On the transmit link side, existing technologies suffer from low power efficiency and excessive energy consumption, which not only increases system power consumption but also complicates heat dissipation design. These problems collectively limit the performance and application scope of L-band RF front-ends in wireless communication systems.

[0022] The main solution of this application embodiment is as follows: The L-band RF front-end circuit of this utility model embodiment is provided with a circulator, a low-noise amplifier circuit, a switched filter bank circuit, a receiving post-amplifier circuit, a transmitting pre-amplifier circuit, and a power amplifier circuit. The circulator is used to switch and isolate the transmitting and receiving signals; the low-noise amplifier circuit is used to amplify the broadband RF signal with low noise; the switched filter bank circuit is used to perform frequency selective filtering on the broadband RF signal; the receiving post-amplifier circuit is used to amplify the filtered frequency-selective signal to the required level amplitude of the subsequent baseband stage; the transmitting pre-amplifier circuit is used to perform primary amplification on the broadband modulated RF signal output from the baseband stage; and the power amplifier circuit is used to amplify the filtered frequency-selective signal... For power amplification, in this embodiment, the input terminal of the low-noise amplifier circuit is first connected to the output terminal of the circulator, the first input terminal of the switching filter bank circuit is connected to the output terminal of the low-noise amplifier circuit, the input terminal of the receiving stage amplifier circuit is connected to the first output terminal of the switching filter bank circuit, the output terminal of the receiving stage amplifier circuit outputs the processed RF signal to the subsequent baseband stage, the input terminal of the transmitting stage amplifier circuit is used to receive the broadband modulated RF signal output from the baseband stage, the output terminal of the transmitting stage amplifier circuit is connected to the second input terminal of the switching filter bank circuit, the input terminal of the power amplifier circuit is connected to the second output terminal of the switching filter bank circuit, and the output terminal of the power amplifier circuit is connected to the input terminal of the circulator.

[0023] This application provides a solution that achieves transmit-receive isolation through a circulator, and uses a combination of multi-stage low-noise amplifiers and limiting circuits to improve receiving sensitivity and prevent overload damage. It also combines a switching filter bank to achieve fast frequency selection filtering and a graded amplification structure to optimize the signal dynamic range. This solution has the advantages of enhanced anti-interference capability, expanded received signal dynamic range, fast transmit-receive switching, improved power efficiency, and protection of the low-noise amplifier.

[0024] In existing technologies, L-band RF front-ends often face problems such as limited functionality, restricted receiving dynamic range, lack of front-end protection mechanisms, insufficient transmit / receive switching speed, and low transmission efficiency. For example, in complex electromagnetic environments, traditional equipment struggles to achieve fast frequency hopping communication, and the preamplifier is prone to saturation or damage when high-power signals are input, leading to a decline in communication quality. Especially in applications requiring high reliability, existing solutions cannot meet the demands for dynamic range extension and fast switching, thus limiting system performance improvements.

[0025] To address the aforementioned issues and the problem of insufficient functional integration, an attempt was made to modularly integrate transmit / receive isolation, signal amplification, and filtering functions. To address the saturation of the preamplifier caused by large signal inputs, a protection mechanism was added to the signal link. Analysis of the root cause of long transmit / receive switching times revealed signal path redundancy in the traditional structure; therefore, a circulator 10 and a switching filter were used to collaboratively control the signal flow. Regarding transmit efficiency optimization, a staged processing scheme for power amplification and drive amplification was explored to reduce overall power consumption.

[0026] Based on the above, referring to Figure 1 In one embodiment of this utility model, the L-band radio frequency front-end circuit includes a circulator 10, a low-noise amplifier circuit 20, a switched filter bank circuit 30, a receiver post-amplifier circuit 40, a transmitter pre-amplifier circuit 50, and a power amplifier circuit 60, wherein: Circulator 10 is used for switching and isolating transmit and receive signals; the input terminal of low-noise amplifier circuit 20 is connected to the output terminal of circulator 10, and low-noise amplifier circuit 20 is used for low-noise amplification of broadband radio frequency signals; the first input terminal of switched filter bank circuit 30 is connected to the output terminal of low-noise amplifier circuit 20, and switched filter bank circuit 30 is used for frequency selective filtering of broadband radio frequency signals; the input terminal of receiver-stage amplifier circuit 40 is connected to the first output terminal of switched filter bank circuit 30, and the output terminal of receiver-stage amplifier circuit 40 outputs the processed radio frequency signal to the subsequent baseband stage, and receiver-stage amplifier circuit 40 is used to filter... The frequency-selective signal after the wave is amplified to the required level amplitude of the subsequent baseband stage; the input terminal of the pre-transmitter amplifier circuit 50 is used to receive the broadband modulated RF signal output from the baseband stage, and the output terminal of the pre-transmitter amplifier circuit 50 is connected to the second input terminal of the switched filter bank circuit 30. The pre-transmitter amplifier circuit 50 is used to perform primary amplification of the broadband modulated RF signal output from the baseband stage; the input terminal of the power amplifier circuit 60 is connected to the second output terminal of the switched filter bank circuit 30, and the output terminal of the power amplifier circuit 60 is connected to the input terminal of the circulator 10. The power amplifier circuit 60 is used to perform power amplification of the filtered frequency-selective signal.

[0027] The circulator 10 is a microwave device that uses non-reciprocal characteristics to control signal flow. It can be made of ferrite material and controls the signal transmission path through a magnetic field, solving the problem of mutual interference between transmitted and received signals. The low-noise amplifier circuit 20 includes a multi-stage amplifier structure, such as cascading two low-noise amplifiers, to amplify weak signals while maintaining a low noise figure and preventing premature saturation of the signal link. The switching filter bank is a frequency-selective network composed of RF switches and bandpass filters. It achieves frequency-hopping communication by switching different frequency band filters, improving anti-interference capability. The receiving stage amplifier circuit 40 uses a multi-stage gain-adjustable amplifier to adjust the filtered signal to the level required for baseband processing, ensuring signal integrity. The transmitting stage amplifier circuit 50 includes a broadband amplification module to pre-amplify the baseband modulated signal, providing a suitable input level for subsequent power amplification. The power amplifier circuit 60 adopts a combination of driver and power stages, optimizing power transmission efficiency through an impedance matching network.

[0028] The received signal is initially amplified by the low-noise amplifier circuit 20 after passing through the circulator 10. After frequency selection by the switched filter bank circuit 30, it enters the receiving post-amplifier circuit 40 for gain adjustment, and is finally output to the baseband processing unit. The transmitted signal, after being output from the baseband, is pre-amplified by the transmitting pre-amplifier circuit 50, then frequency-selected by the switched filter bank before entering the power amplifier circuit 60 for power boosting, and finally output through the circulator 10. The circulator 10 automatically changes the signal path during transmit / receive mode switching to ensure isolation between the transmit and receive channels. The switched filter bank achieves dynamic frequency selection by switching different frequency band filters, forming a complete signal processing link in conjunction with the pre- and post-amplifier circuits.

[0029] Compared to existing technologies, this solution integrates traditional discrete transceiver modules into a unified architecture through the collaborative operation of the circulator 10 and the switching filter bank, shortening the signal transmission path. The non-reciprocal nature of the circulator 10 significantly reduces the transmit / receive switching time to sub-microsecond levels compared to traditional switching devices. The multi-stage low-noise amplifier structure, combined with the switching filter bank, expands the dynamic range of the received signal and avoids pre-stage saturation caused by large signal inputs. The transmit link employs a graded amplification design, optimizing energy efficiency while ensuring output power, reducing power consumption by approximately 30% compared to traditional single-stage power amplifier structures.

[0030] Through the above technical solutions, this embodiment effectively solves the problems of traditional equipment having limited functionality and weak anti-interference capabilities, achieving frequency-selective processing of broadband signals. The multi-stage amplification structure of the receiving link, combined with amplitude limiting protection, extends the dynamic range to over 80dB, avoiding performance degradation caused by large signals. The combined application of the circulator 10 and the switching filter bank shortens the transmit / receive switching time to within 500 nanoseconds, meeting the requirements of fast frequency-hopping communication. The pre-amplification and power amplification staged design of the transmitting link maintains 20W output power while increasing the overall efficiency to over 45%, significantly reducing equipment heat generation.

[0031] The L-band RF front-end circuit of this embodiment includes a circulator 10, a low-noise amplifier circuit 20, a switched filter bank circuit 30, a receiver post-amplifier circuit 40, a transmitter pre-amplifier circuit 50, and a power amplifier circuit 60. The circulator 10 is used to switch and isolate the transmit and receive signals; the low-noise amplifier circuit 20 is used to amplify the broadband RF signal with low noise; the switched filter bank circuit 30 is used to perform frequency-selective filtering on the broadband RF signal; the receiver post-amplifier circuit 40 is used to amplify the filtered frequency-selective signal to the required level amplitude of the subsequent baseband stage; the transmitter pre-amplifier circuit 50 is used to perform primary amplification of the broadband modulated RF signal output from the baseband; and the power amplifier circuit 60 is used to amplify the filtered frequency-selective signal. This embodiment... For example, the input terminal of the low-noise amplifier circuit 20 is first connected to the output terminal of the circulator 10, the first input terminal of the switching filter bank circuit 30 is connected to the output terminal of the low-noise amplifier circuit 20, the input terminal of the receiving stage amplifier circuit 40 is connected to the first output terminal of the switching filter bank circuit 30, the output terminal of the receiving stage amplifier circuit 40 outputs the processed RF signal to the subsequent baseband stage, the input terminal of the transmitting stage amplifier circuit 50 is used to receive the broadband modulated RF signal output from the baseband stage, the output terminal of the transmitting stage amplifier circuit 50 is connected to the second input terminal of the switching filter bank circuit 30, the input terminal of the power amplifier circuit 60 is connected to the second output terminal of the switching filter bank circuit 30, and the output terminal of the power amplifier circuit 60 is connected to the input terminal of the circulator 10. Thus, the circulator 10 achieves transmit-receive isolation, and the combination of multi-stage low-noise amplifier and limiting circuit 21 improves the receiving sensitivity and prevents overload damage. Combined with the switching filter bank, fast frequency selection filtering is achieved, and the hierarchical amplification structure optimizes the signal dynamic range. This has the advantages of enhanced anti-interference capability, expanded received signal dynamic range, fast transmit-receive switching, improved power efficiency, and protection of the low-noise amplifier.

[0032] Optionally, refer to Figure 2 Another embodiment of this utility model provides an L-band radio frequency front-end circuit, based on the above... Figure 1 In the embodiment shown, the low-noise amplifier circuit 20 includes a limiting circuit 21, a first low-noise amplifier 22, and a second low-noise amplifier 23, wherein: The input terminal of the limiting circuit 21 is connected to the output terminal of the circulator 10; the input terminal of the first low-noise amplifier 22 is connected to the output terminal of the limiting circuit 21; the input terminal of the second low-noise amplifier 23 is connected to the output terminal of the first low-noise amplifier 22, and the output terminal of the second low-noise amplifier 23 is connected to the first input terminal of the switching filter bank circuit 30.

[0033] Among them, the limiting circuit 21 is a protection circuit used to limit the amplitude of the input signal. It can be implemented using a limiting chip N7 in series with a capacitor, and prevents the subsequent circuit from overloading by absorbing instantaneous high-power signals. The first low-noise amplifier 22 is a circuit module that performs preliminary amplification of weak signals. It can be implemented using a low-noise amplifier chip and a capacitor coupling structure, and reduces the noise figure by optimizing input matching. The second low-noise amplifier 23 is a circuit module that performs secondary gain enhancement on the pre-amplified signal. It can be implemented using cascaded amplifier chips and an inductor-capacitor matching network, and expands the dynamic range of the signal through multi-stage amplification.

[0034] In this circuit, after the radio frequency signal is output from the circulator 10, it first passes through the limiting circuit 21 to clamp abnormally high-power signals, preventing the first low-noise amplifier 22 from deteriorating or being damaged due to input overload. Subsequently, the signal undergoes two stages of low-noise amplification, passing through the first low-noise amplifier 22 and the second low-noise amplifier 23. The first stage amplifier primarily reduces the system noise figure, while the second stage amplifier provides additional gain to meet the signal amplitude requirements of subsequent circuits. DC isolation is achieved between the two amplifier stages via capacitive coupling, and impedance matching is optimized using an inductor-capacitor network to ensure signal transmission efficiency.

[0035] Existing low-noise amplifier circuits 20 typically lack limiting protection and employ a single-stage amplification structure, leading to easy saturation of the preamplifier under large signal input and limited dynamic range. This embodiment eliminates the threat of instantaneous high voltage by adding a limiting circuit 21 and improves signal gain in stages through a two-stage low-noise amplifier, maintaining low-noise performance while expanding the dynamic range, thus solving the problems of poor reliability and limited application scenarios in existing technologies. This embodiment can effectively suppress the impact of high-power input signals on the low-noise amplifier circuit 20, avoiding device damage; improve signal gain while reducing the noise figure through a two-stage amplification structure, expanding the dynamic range of the received signal; and enhance the circuit's anti-interference capability and stability in complex electromagnetic environments by utilizing the synergistic effect of limiting and amplification.

[0036] Optionally, refer to Figure 3 Another embodiment of this utility model provides an L-band radio frequency front-end circuit, based on the above... Figure 2 In the embodiment shown, the limiting circuit 21 includes a limiting chip N7, wherein: A first capacitor C9 is connected in series between the RF signal input terminal of the limiting chip N7 and the output terminal of the circulator 10.

[0037] The first low-noise amplifier 22 includes a first low-noise amplifier chip U2, a first resistor R1, and a second resistor R4, wherein: A second capacitor C10 is connected in series between the RF signal input terminal of the first low-noise amplifier chip U2 and the RF signal output terminal of the limiting chip N7; a first inductor L1 is connected in series between the second terminal of the first resistor R1 and the RF signal output terminal of the first low-noise amplifier chip U2, and at least one capacitor is connected in parallel between the common node of the first resistor R1 and the first inductor L1 and ground; a third capacitor C11 is connected in series between the first terminal of the second resistor R4 and the RF signal output terminal of the first low-noise amplifier chip U2, a third resistor R9 is connected in parallel between the first terminal of the second resistor R4 and ground, and a fourth resistor R10 is connected in parallel between the second terminal of the second resistor R4 and ground.

[0038] The second low-noise amplifier 23 includes a second low-noise amplifier chip U4, a fifth resistor R2, and a fifth capacitor C13, wherein: A fourth capacitor C12 is connected in series between the input terminal of the second low-noise amplifier chip U4 and the second terminal of the second resistor R4; a second inductor L3 is connected in series between the second terminal of the fifth resistor R2 and the output terminal of the second low-noise amplifier chip U4; at least one capacitor is connected in parallel between the common node of the fifth resistor R2 and the second inductor L3 and ground; the first terminal of the fifth capacitor C13 is connected to the output terminal of the second low-noise amplifier chip U4, and the second terminal of the fifth capacitor C13 is connected to the first input terminal of the switching filter bank circuit 30.

[0039] Among them, the limiting chip N7 refers to a device that limits the amplitude of the input signal through a voltage clamping mechanism. It can be implemented using a PIN diode or an integrated limiter, and is used to suppress the impact of high-power signals on subsequent circuits. The first capacitor C9 is a DC blocking capacitor connected in series in the RF signal path. It can be implemented using a ceramic capacitor or a film capacitor, and is used to isolate the DC component and maintain RF signal transmission. The first low-noise amplifier chip U2 refers to an amplifier module with a low noise figure. It can be implemented using gallium arsenide or silicon-based integrated circuits, and is used to initially amplify weak signals. The network formed by the first inductor L1 and the parallel capacitor is an impedance matching structure. It can be implemented using a wire-wound inductor or a planar inductor, and is used to optimize signal transmission efficiency. The network formed by the second resistor R4, the third resistor R9, and the fourth resistor R10 is a bias circuit. It can be implemented using a voltage divider resistor or a current source structure, and is used to provide a stable operating point for the amplifier chip. The fourth capacitor C12 is an interstage coupling capacitor. It can be implemented using a multilayer ceramic capacitor, and is used to block DC and transmit RF signals. The network formed by the second inductor L3 and the parallel capacitor refers to the output matching circuit, which can be implemented using microstrip lines or lumped elements to enhance the signal output power. The fifth capacitor C13 is the output DC blocking capacitor, which can be implemented using a capacitor with excellent high-frequency characteristics to filter out the amplified DC component.

[0040] In this process, when the radio frequency (RF) signal enters the receiving link through the circulator 10, the limiting chip N7 can quickly clamp high-power signals exceeding the threshold, preventing instantaneous high voltage from damaging downstream devices. The first capacitor C9 blocks DC while allowing the RF signal to pass through, preventing DC potential interference between the circulator 10 and the limiting chip N7. The limited signal enters the first low-noise amplifier chip U2 for primary amplification via the second capacitor C10. At this stage, the matching network composed of the first inductor L1 and parallel capacitors adjusts the input impedance, improving signal transmission efficiency. The amplified signal is coupled to a bias network composed of the second resistor R4, the third resistor R9, and the fourth resistor R10 via the third capacitor C11. This structure provides a stable bias voltage for the second low-noise amplifier chip U4. The fourth capacitor C12 transmits the signal to the second-stage amplifier chip for secondary amplification. The output matching network composed of the second inductor L3 and parallel capacitors optimizes high-frequency response characteristics. Finally, the signal is output to the switching filter bank via the fifth capacitor C13, completing the two-stage low-noise amplification process.

[0041] This embodiment expands the dynamic range through a two-stage cascaded amplification structure. The combination of the limiting chip N7 and the multi-stage matching network can suppress sudden large signals while ensuring low-noise amplification characteristics for small signals. Furthermore, the discrete bias network design avoids inter-stage interference, and multiple matching circuits can optimize the operating state of each stage independently, resulting in better linearity and stability compared to traditional single-stage structures. This embodiment effectively solves the problem of the receiving link's front-end being susceptible to large signal impacts. The limiting circuit 21 can quickly suppress input power exceeding the safety threshold, preventing damage to the low-noise amplifier components. The two-stage amplification structure, combined with the impedance matching network, expands the receiving dynamic range, improving large-signal processing capabilities while maintaining a low noise figure. The discrete bias design and inter-stage coupling structure reduce mutual interference between circuits, enabling the system to maintain stable operation even in complex electromagnetic environments.

[0042] Optionally, refer to Figures 4 to 7 Another embodiment of this utility model provides an L-band radio frequency front-end circuit, based on the above... Figure 1 The embodiment shown includes a first transceiver switch circuit 30, a first selection switch circuit 32, an RF filter circuit 33, a second selection switch circuit 34, and a second transceiver switch circuit 35, wherein: The first input terminal of the first transceiver switch circuit 31 is connected to the low-noise amplifier circuit 20, and the first output terminal of the first transceiver switch circuit 31 is connected to the input terminal of the power amplifier circuit 60; the first output terminal of the first selection switch circuit 32 is connected to the second input terminal of the first transceiver switch circuit 31, and the first input terminal of the first selection switch circuit 32 is connected to the second output terminal of the first transceiver switch circuit 31; the first input terminal of the RF filter circuit 33 is connected to the second output terminal of the first selection switch circuit 32, and the first output terminal of the RF filter circuit 33 is connected to the second input terminal of the first selection switch circuit 32; the second selection switch... The first input terminal of the switching circuit 34 is connected to the second output terminal of the RF filter circuit 33, and the first output terminal of the second selection switch circuit 34 is connected to the second input terminal of the RF filter circuit 33; the first input terminal of the second transceiver switch circuit 35 is connected to the second output terminal of the second selection switch circuit 34, the first output terminal of the second transceiver switch circuit 35 is connected to the second input terminal of the second selection switch circuit 34, the second input terminal of the second transceiver switch circuit 35 is connected to the output terminal of the pre-transmitter amplifier circuit 50, and the second output terminal of the second transceiver switch circuit 35 is connected to the input terminal of the post-receiver amplifier circuit 40.

[0043] The first transceiver switch circuit 31 is an electronic switch device used to switch the transmit and receive signal paths. It can be implemented using a PIN diode switch circuit and achieves physical isolation between the receive and transmit channels through control signals. The first selection switch circuit 32 is a switching device used to select different filter channels. It can be implemented using a single-pole multi-throw (SPMD) RF switch chip and is used to guide signals to different frequency band processing modules of the RF filter circuit 33. The RF filter circuit 33 is a frequency selection network composed of multiple bandpass filters. It can be implemented using a dielectric filter or a surface acoustic wave (SAW) filter and is used to selectively attenuate or enhance signals in specific frequency bands. The second selection switch circuit 34 is a reverse switching device that works in conjunction with the first selection switch circuit 32. It can be implemented using a SPMD RF switch chip with the same structure and is used to reintegrate the filtered signal into the main signal link. The second transceiver switch circuit 35 is a device used to complete the secondary path switching between transmit and receive signals. It can be implemented using an integrated transceiver switch module and is used to establish a low-loss transmission path between transmit and receive states.

[0044] In the receiving mode, the first transceiver switch circuit 31 guides the signal output from the low-noise amplifier circuit 20 to the first selection switch circuit 32. After frequency selection by the RF filter circuit 33, the signal is transmitted to the receiving post-amplifier circuit 40 via the second transceiver switch circuit 35. In the transmitting mode, the second transceiver switch circuit 35 guides the signal from the transmitting pre-amplifier circuit 50 to the second selection switch circuit 34. After filtering by the RF filter circuit 33, the signal is transmitted to the power amplifier circuit 60 via the first transceiver switch circuit 31. The RF filter circuit 33 achieves multi-band coverage through a segmented design, and the first and second selection switch circuits 32 and 34 are symmetrically arranged to ensure signal transmission phase consistency. The transceiver switch circuits adopt a cascaded structure to shorten the signal path, and complete isolation of the transmitting and receiving channels is achieved through a dual switching mechanism.

[0045] This embodiment achieves independent control of filter channel selection and transmit / receive path switching by setting up a two-stage selection switch and a transmit / receive switch working in tandem, significantly shortening the state transition time. The RF filter circuit 33 adopts a distributed layout, avoiding the cumulative insertion loss caused by traditional cascaded filters, and supports fast switching of multiple frequency bands through flexible configuration of the selection switch. The dual-layer structure design of the transmit / receive switch effectively isolates the crosstalk of the transmitted signal to the receiving channel, improving channel isolation compared to the traditional single-switch structure. This embodiment realizes fast switching and precise frequency selection of the transmit / receive channel, solving the technical defects of long switching time and limited dynamic range of traditional RF front-ends. This can be manifested in the reduction of transmit / receive state transition time to the sub-microsecond level, supporting the fast frequency switching requirements of frequency hopping communication systems; the distributed filtering structure expands the dynamic range of the received signal, avoiding amplifier saturation caused by large signal input; and the multi-stage switch collaborative control mechanism enhances the system's anti-interference capability, ensuring stable communication quality in complex electromagnetic environments.

[0046] Optionally, refer to Figure 8 and Figure 9 In another embodiment, this utility model provides an L-band radio frequency front-end circuit, based on the above... Figure 1 The embodiment shown includes a receiving amplifier circuit 40 comprising a first receiving amplifier circuit 41, a second receiving amplifier circuit 42, and a first filtering circuit 43, wherein: The input terminal of the first receiving amplifier circuit 41 is connected to the first output terminal of the switching filter bank circuit 30; the input terminal of the second receiving amplifier circuit 42 is connected to the output terminal of the first receiving amplifier circuit 41; the input terminal of the first filtering circuit 43 is connected to the output terminal of the second receiving amplifier circuit 42, and the output terminal of the first filtering circuit 43 outputs the processed radio frequency signal to the subsequent baseband stage.

[0047] The first receiving amplification circuit 41 is a circuit module that initially amplifies the frequency-selective signal output from the switched filter bank. It can be implemented using a low-noise amplifier chip in conjunction with a matching circuit to enhance the signal strength to meet the input requirements of subsequent processing stages. The second receiving amplification circuit 42 is a circuit module that performs secondary amplification on the initially amplified signal. It can be implemented using a gain-adjustable amplifier chip to adjust the signal amplitude to the level range required by the subsequent baseband processing. The first filtering circuit 43 is a circuit module that performs out-of-band noise suppression on the amplified signal. It can be implemented using an LC filter or a surface acoustic wave filter to filter out high-frequency harmonics and interference signals.

[0048] In this design, the receiving amplifier circuit 40 uses a two-stage amplification structure to perform step-by-step gain control on the frequency-selective signal. The first receiving amplifier circuit 41 initially amplifies the filtered signal output from the switched filter bank, and the second receiving amplifier circuit 42 further adjusts the signal amplitude based on this. The signal after two amplifications enters the first filtering circuit 43, which filters out out-of-band noise and residual interference components introduced during the amplification process, ultimately outputting an RF signal that meets the baseband processing requirements. This structure avoids the saturation risk of a single-stage amplifier circuit through staged gain allocation, while the introduction of the filtering stage effectively suppresses noise accumulation in the signal link.

[0049] This embodiment employs a two-stage amplification combined with intermediate filtering to expand the dynamic range of signal processing while suppressing inter-stage noise interference through the filtering stage. This embodiment addresses the low-noise amplifier saturation problem caused by the limited dynamic range of the received signal, and improves linearity under large signal input through graded gain control. Simultaneously, the introduction of the filtering stage reduces the risk of noise figure degradation, ensuring that the signal-to-noise ratio of the output signal meets the baseband processing requirements. Furthermore, the adjustable gain design enhances the circuit's adaptability to different application scenarios and improves the overall reliability of the RF front-end.

[0050] Optionally, refer to Figures 10 to 12 Another embodiment of this utility model provides an L-band radio frequency front-end circuit, based on the above... Figure 1 The embodiment shown includes a pre-amplifier circuit 50 comprising a second filter circuit 51, a first transmitter amplifier circuit 52, a second transmitter amplifier circuit 53, and a digitally controlled attenuation circuit 54, wherein: The input terminal of the second filter circuit 51 is used to receive the broadband modulated radio frequency signal output from the baseband; the input terminal of the first transmitting amplifier circuit 52 is connected to the output terminal of the second filter circuit 51; the input terminal of the second transmitting amplifier circuit 53 is connected to the output terminal of the first transmitting amplifier circuit 52; the input terminal of the digitally controlled attenuation circuit 54 is connected to the output terminal of the second transmitting amplifier circuit 53, and the output terminal of the digitally controlled attenuation circuit 54 is connected to the second input terminal of the switching filter bank circuit 30.

[0051] The second filter circuit 51 is used to filter out out-of-band interference in the baseband output signal. It can be implemented using a bandpass filter or a low-pass filter. Its function is to suppress spurious signals and ensure the spectral purity of the input signal. The first transmitting amplifier circuit 52 and the second transmitting amplifier circuit 53 are amplification units that sequentially boost the signal gain. They can be implemented using transistors or integrated amplifier chips. Their function is to amplify the low-power signal output from the baseband step by step to a level suitable for subsequent processing. The digitally controlled attenuation circuit 54 is a circuit that adjusts the signal attenuation through digital control. It can be implemented using an adjustable resistor network or a digital potentiometer. Its function is to dynamically adjust the signal amplitude to avoid saturation or distortion of subsequent circuits due to excessively strong signals.

[0052] The broadband modulated RF signal output from the baseband first enters the second filter circuit 51 for out-of-band noise suppression, then undergoes preliminary amplification by the first transmit amplifier circuit 52, and further increases the signal power by the second transmit amplifier circuit 53. The signal after two stages of amplification enters the digitally controlled attenuation circuit 54, where the attenuation is adjusted according to system requirements, and finally outputs to the switched filter bank circuit 30. This structure, through a combination of multi-stage amplification and dynamic attenuation, ensures signal strength while avoiding overload risks and optimizing signal transmission efficiency.

[0053] This embodiment, by introducing a synergistic design of two-stage amplification and digitally controlled attenuation, not only expands the signal processing range but also achieves flexible control of power output, thereby reducing overall power consumption and improving system adaptability. This embodiment effectively solves the problems of low efficiency, high power consumption, and insufficient signal dynamic range in existing pre-transmitter amplification stages. Through multi-stage gain adjustment and dynamic attenuation mechanisms, it significantly improves the stability and energy efficiency of the transmit link while avoiding the risk of circuit damage caused by signal overload.

[0054] Optionally, refer to Figure 13 and Figure 14 Another embodiment of this utility model provides an L-band radio frequency front-end circuit, based on the above... Figure 1 In the embodiment shown, the power amplifier circuit 60 includes a driver amplifier circuit 61 and a power amplifier circuit 62, wherein: The input terminal of the drive amplifier circuit 61 is connected to the second output terminal of the switch filter bank circuit 30; the input terminal of the power amplifier circuit 62 is connected to the output terminal of the drive amplifier circuit 61, and the output terminal of the power amplifier circuit 62 is connected to the input terminal of the circulator 10.

[0055] The drive amplifier circuit 61 is a circuit module that pre-amplifies the frequency-selective signal output from the switched filter bank. It can be implemented using a multi-stage gain-adjustable amplifier to boost the filtered RF signal to the input level required by the power amplifier circuit 62. The power amplifier circuit 62 is a circuit module that boosts the power of the pre-amplified signal. It can be built using GaN HEMT devices or LDMOS transistors to amplify the signal to the transmit power level required at the input of the circulator 10.

[0056] In this process, after the radio frequency signal is frequency-selected by the switching filter bank, it is first amplified by the driver amplifier circuit 61 to adjust the signal amplitude to the optimal operating range of the power amplifier circuit 62. The power amplifier circuit 62 receives the optimized signal output from the driver stage, uses a high-efficiency amplification architecture to boost the power, and finally transmits the signal that meets the transmission power requirements to the antenna end through the circulator 10. This hierarchical amplification structure optimizes the input level through the driver stage, enabling the power stage to operate in the high-efficiency range and reducing overall power consumption.

[0057] Traditional power amplifier circuit 60 employs a single-stage amplification structure, which is prone to entering the nonlinear region and causing efficiency degradation when the dynamic range of the input signal is limited. This embodiment adopts a separate design for the driver stage and power stage. By precisely controlling the amplitude of the input signal through the driver stage, the power stage is always in an optimal operating state, improving power conversion efficiency while reducing the risk of heat loss. This embodiment effectively solves the technical problems of low transmit power efficiency and high power consumption in traditional L-band RF front-ends. The coordinated operation of the driver amplifier circuit 61 and the power amplifier circuit 62 makes the signal amplification process more precise and controllable, and the operating efficiency of the power amplifier circuit 62 is significantly optimized. Under the same output power conditions, energy consumption can be reduced by about 30%, while reducing the impact of heat accumulation on device lifespan.

[0058] Optionally, refer to Figure 15 Another embodiment of this utility model provides an L-band radio frequency front-end circuit, based on the above... Figure 1 In the embodiment shown, the L-band RF front-end circuit further includes a power supply circuit 70, wherein: The input terminal of the power supply circuit 70 is used to connect to an external power supply. The first output terminal of the power supply circuit 70 is connected to the power input terminal of the low noise amplifier circuit 20. The second output terminal of the power supply circuit 70 is connected to the power input terminal of the switching filter bank circuit 30. The third output terminal of the power supply circuit 70 is connected to the power input terminal of the receiving stage amplifier circuit 40. The fourth output terminal of the power supply circuit 70 is connected to the power input terminal of the transmitting stage amplifier circuit 50. The fifth output terminal of the power supply circuit 70 is connected to the power input terminal of the power amplifier circuit 60.

[0059] The power supply circuit 70 refers to the circuit system that provides stable power to the various functional modules of the RF front-end. It can be implemented using a multi-stage power conversion and distribution architecture. For example, a reverse polarity protection circuit 71 prevents damage to components caused by reverse polarity connection, and an EMI circuit 72 suppresses electromagnetic interference conducted on the power lines. The voltage regulation circuit 74 is a circuit that adjusts the voltage according to the operating voltage requirements of each module. For example, a low-dropout linear regulator or a switching regulator chip can be used to achieve different voltage output values. The receiver switch circuit 76 and the transmitter switch circuit 75 are electronic switches that control the power supply on / off of the receiver and transmitter links respectively. For example, a MOSFET array can be used to achieve independent control of the power path.

[0060] In this system, after the external power supply is protected against reverse connection risks by the reverse connection protection circuit 71, high-frequency interference signals are filtered out by the EMI circuit 72. Subsequently, the power conversion circuit 73 converts the input voltage into the high-voltage power supply required by the power amplifier circuit 60. The voltage regulation circuit 74 derives different voltage levels from the converted power supply. The receiving switch circuit 76 distributes the appropriate voltage to the low-noise amplifier circuit 20 and the receiving post-amplifier circuit 40, while the transmitting switch circuit 75 provides independent power to the switching filter bank circuit 30 and the transmitting pre-amplifier circuit 50. This branched power supply structure isolates the power supply noise of each functional module from each other. For example, the power supply paths of the receiving link and the transmitting link are completely separated, avoiding power supply interference from high-power transmitting signals to sensitive receiving circuits.

[0061] This embodiment improves power supply reliability through reverse connection protection circuit 71 and EMI circuit 72, achieves precise voltage matching through power conversion and regulation, and implements power supply isolation for the transmit and receive links through branch switch control, effectively solving the problems of low power supply efficiency and weak anti-interference capability in the prior art. This embodiment realizes independent regulated power supply for each functional module of the RF front end, suppresses power supply noise interference to the RF signal link, and improves the reliability of the power system through reverse connection protection and electromagnetic compatibility design. The branch power supply structure allows independent control of the power supply timing of the receive and transmit links. For example, during transmit / receive switching, the power supply of idle links can be quickly cut off to reduce power consumption, solving the problem of low efficiency caused by the crude power management in traditional solutions.

[0062] Optionally, refer to Figure 16 In another embodiment, this utility model provides an L-band radio frequency front-end circuit, based on the above... Figure 1 In the illustrated embodiment, the power supply circuit 70 includes a reverse connection protection circuit 71, an EMI circuit 72, a power conversion circuit 73, a voltage regulation circuit 74, a transmitting switch circuit 75, and a receiving switch circuit 76, wherein: The input terminal of the reverse connection protection circuit 71 is used to connect to an external power supply; the input terminal of the EMI circuit 72 is connected to the output terminal of the reverse connection protection circuit 71; the input terminal of the power conversion circuit 73 is connected to the output terminal of the EMI circuit 72, and the output terminal of the power conversion circuit 73 is connected to the power input terminal of the power amplifier circuit 60; the input terminal of the voltage regulation circuit 74 is connected to the output terminal of the power conversion circuit 73; the output terminal of the receiving switch circuit 76 is electrically connected to the low noise amplifier circuit 20 and the receiving post-amplifier circuit 40 respectively; the output terminal of the transmitting switch circuit 75 is electrically connected to the switching filter bank circuit 30 and the transmitting pre-amplifier circuit 50 respectively.

[0063] Among them, the reverse connection protection circuit 71 is a circuit to prevent damage to the equipment caused by reverse power polarity connection. It can be implemented using a unidirectional conduction structure built with diodes or MOSFETs, automatically cutting off the current path when the external power supply is reversed. The EMI circuit 72 is an electromagnetic interference suppression circuit, which can be implemented using an LC filter network or a common-mode inductor structure to filter out high-frequency noise interference in the power line. The power conversion circuit 73 is a voltage conversion module, which can be implemented using a DC-DC switching power supply chip to convert the input voltage to the operating voltage required by the power amplifier circuit 60. The voltage regulation circuit 74 is a voltage regulation module, which can be implemented using a low-dropout linear regulator or a programmable power management chip to provide precise voltage values ​​for different functional modules. The receiver switch circuit 76 and the transmitter switch circuit 75 are power distribution control modules, which can be implemented using a MOSFET switch array or a relay structure, switching between receiving and transmitting power supply according to the operating mode.

[0064] The external power supply undergoes polarity protection via a reverse connection protection circuit 71, followed by EMI circuit 72 filtering out conducted interference. A power conversion circuit 73 then converts the input voltage to the high-voltage power required by the power amplifier. A voltage regulation circuit 74 derives multiple regulated outputs from the converted power supply. A receiving switch circuit 76 powers the low-noise amplifier and the receiving-to-amplifier circuit 40 in receiving mode, while a transmitting switch circuit 75 powers the switching filter bank and the transmitting-to-amplifier circuit 50 in transmitting mode. Through a time-sharing power supply mechanism, only the power supply to the corresponding link is activated during transmit / receive switching. The power amplifier circuit 60 is directly powered by the power conversion circuit 73 to match its high power requirements.

[0065] This embodiment sets up an independent power conversion module to match the high-voltage requirements of the power amplifier, uses a voltage regulation circuit 74 to derive multiple regulated power sources, and coordinates with the transceiver switching circuit to achieve time-sharing power control, thereby improving power efficiency while reducing static power consumption. This embodiment effectively solves the problems of low efficiency and weak anti-interference capability in traditional RF front-end power systems, realizes power isolation control of the transceiver link, prevents equipment damage caused by reverse power connection and electromagnetic interference, reduces the overall power consumption of the system through the time-sharing power supply mechanism, and provides stable and reliable high-voltage power support for the power amplifier circuit 60.

[0066] This utility model also proposes a wireless communication device, which includes an L-band radio frequency front-end circuit as described in the above embodiments.

[0067] It is worth noting that since the wireless communication device of this utility model is based on the above-mentioned L-band radio frequency front-end circuit, the embodiments of the wireless communication device of this utility model include all the technical solutions of all the embodiments of the above-mentioned L-band radio frequency front-end circuit, and the technical effects achieved are exactly the same, so they will not be repeated here.

[0068] The L-band RF front-end circuit refers to the signal processing module operating in the 1-2 GHz frequency band. It can use a circulator 10 to achieve transmit / receive isolation, a low-noise amplifier circuit 20 to improve receiving sensitivity, and a switching filter bank to achieve multi-band switching. Wireless communication equipment refers to terminal devices with RF signal transmission and reception capabilities, such as satellite communication terminals or military tactical radios, which integrate this RF front-end to achieve anti-interference communication.

[0069] In the receiving path, circulator 10 directs the antenna-received signal to low-noise amplifier circuit 20. After two stages of low-noise amplification, the signal enters the switching filter bank for frequency band selection. The filtered signal is then boosted to the level required for baseband processing by the receiving stage amplifier circuit 40. In the transmitting path, the baseband modulated signal is amplified before transmission and then enters the switching filter bank for frequency selection. The power amplifier circuit 60 then boosts the power before outputting the signal to the antenna via circulator 10. This structure, through independent amplification and filtering in the transmitting and receiving paths, combined with the fast switching capability of the switching filter bank, enables multi-band frequency hopping communication.

[0070] Compared to existing technologies, traditional equipment is limited by its single-band processing capability, making dynamic frequency hopping interference suppression impossible, and the lack of amplitude limiting protection in the receiving channel can easily lead to device damage. This embodiment achieves rapid multi-band switching through a switching filter bank, incorporates an amplitude limiting circuit 21 in the low-noise amplifier pre-stage to prevent large signal impacts, and employs a graded amplification structure to extend the dynamic range. Independent transmit and receive path design shortens switching time, and the matching design between the power amplifier circuit 60 and the driver stage improves transmission efficiency.

[0071] Through the above technical solutions, this embodiment effectively solves the problems of weak anti-interference capability, limited dynamic range of reception, easy damage of components, slow switching speed and high power consumption of traditional equipment. Frequency hopping function enhances adaptability to complex electromagnetic environments, amplitude limiting protection improves equipment reliability, independent transmit and receive amplification structure enables fast switching, and power amplifier efficiency optimization reduces system power consumption, expanding the application range of the equipment in mobile communication, emergency command and other scenarios.

[0072] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. An L-band radio frequency front-end circuit, characterized in that, The L-band radio frequency front-end circuit includes: Circulator, the circulator being used for switching and isolating transmit and receive signals; A low-noise amplifier circuit, the input of which is connected to the output of the circulator, is used for low-noise amplification of broadband radio frequency signals. A switching filter bank circuit, wherein the first input terminal of the switching filter bank circuit is connected to the output terminal of the low noise amplifier circuit, and the switching filter bank circuit is used to perform frequency selective filtering on broadband radio frequency signals. The receiving post-amplifier circuit has its input terminal connected to the first output terminal of the switching filter bank circuit, and its output terminal outputs the processed radio frequency signal to the post-baseband stage. The receiving post-amplifier circuit is used to amplify the filtered frequency-selective signal to the required level amplitude of the post-baseband stage. A pre-amplifier circuit is provided, wherein the input terminal of the pre-amplifier circuit is used to receive the broadband modulated radio frequency signal output from the baseband, and the output terminal of the pre-amplifier circuit is connected to the second input terminal of the switched filter bank circuit. The pre-amplifier circuit is used to perform primary amplification on the broadband modulated radio frequency signal output from the baseband. The power amplifier circuit has its input terminal connected to the second output terminal of the switching filter bank circuit, and its output terminal connected to the input terminal of the circulator. The power amplifier circuit is used to amplify the power of the filtered frequency-selective signal.

2. The L-band RF front-end circuit as described in claim 1, characterized in that, The low-noise amplifier circuit includes: A limiting circuit, wherein the input terminal of the limiting circuit is connected to the output terminal of the circulator; A first low-noise amplifier, the input of which is connected to the output of the limiting circuit; A second low-noise amplifier is connected to the output of the first low-noise amplifier, and the output of the second low-noise amplifier is connected to the first input of the switched filter bank circuit.

3. The L-band RF front-end circuit as described in claim 2, characterized in that, The limiting circuit includes: A limiting chip, wherein a first capacitor is connected in series between the radio frequency signal input terminal of the limiting chip and the output terminal of the circulator; The first low-noise amplifier includes: A first low-noise amplifier chip, wherein a second capacitor is connected in series between the radio frequency signal input terminal of the first low-noise amplifier chip and the radio frequency signal output terminal of the limiting chip; A first resistor, a first inductor connected in series between the second end of the first resistor and the RF signal output terminal of the first low-noise amplifier chip, and at least one capacitor connected in parallel between the common node of the first resistor and the first inductor and ground. The second resistor has a third capacitor connected in series between its first end and the RF signal output terminal of the first low-noise amplifier chip, a third resistor connected in parallel between its first end and ground, and a fourth resistor connected in parallel between its second end and ground. The second low-noise amplifier includes: A second low-noise amplifier chip is connected in series with a fourth capacitor between the input terminal of the second low-noise amplifier chip and the second terminal of the second resistor; The fifth resistor has a second inductor connected in series between its second end and the output terminal of the second low-noise amplifier chip, and at least one capacitor is connected in parallel between the common node of the fifth resistor and the second inductor and ground. The fifth capacitor has its first end connected to the output terminal of the second low-noise amplifier chip and its second end connected to the first input terminal of the switching filter bank circuit.

4. The L-band RF front-end circuit as described in claim 1, characterized in that, The switched filter bank circuit includes: A first transceiver switch circuit, wherein the first input terminal of the first transceiver switch circuit is connected to the low-noise amplifier circuit, and the first output terminal of the first transceiver switch circuit is connected to the input terminal of the power amplifier circuit. A first selection switch circuit, wherein the first output terminal of the first selection switch circuit is connected to the second input terminal of the first transceiver switch circuit, and the first input terminal of the first selection switch circuit is connected to the second output terminal of the first transceiver switch circuit. The radio frequency (RF) filter circuit has its first input terminal connected to the second output terminal of the first selection switch circuit, and its first output terminal connected to the second input terminal of the first selection switch circuit. A second selection switch circuit, wherein the first input terminal of the second selection switch circuit is connected to the second output terminal of the radio frequency filter circuit, and the first output terminal of the second selection switch circuit is connected to the second input terminal of the radio frequency filter circuit; The second transceiver switch circuit has its first input terminal connected to the second output terminal of the second selection switch circuit, its first output terminal connected to the second input terminal of the second selection switch circuit, its second input terminal connected to the output terminal of the pre-transmitter amplifier circuit, and its second output terminal connected to the input terminal of the post-receiver amplifier circuit.

5. The L-band RF front-end circuit as described in claim 1, characterized in that, The receiving post-amplification circuit includes: A first receiving amplifier circuit, wherein the input terminal of the first receiving amplifier circuit is connected to the first output terminal of the switched filter bank circuit; A second receiving amplifier circuit, wherein the input terminal of the second receiving amplifier circuit is connected to the output terminal of the first receiving amplifier circuit; A first filtering circuit is connected to the output of the second receiving amplifier circuit, and the output of the first filtering circuit outputs the processed radio frequency signal to the subsequent baseband stage.

6. The L-band RF front-end circuit as described in claim 1, characterized in that, The pre-transmission amplifier circuit includes: The second filter circuit has its input terminal used to receive the broadband modulated radio frequency signal output from the baseband. A first transmitting amplifier circuit, wherein the input terminal of the first transmitting amplifier circuit is connected to the output terminal of the second filtering circuit; A second transmitting amplifier circuit, wherein the input terminal of the second transmitting amplifier circuit is connected to the output terminal of the first transmitting amplifier circuit; The numerically controlled attenuation circuit has its input terminal connected to the output terminal of the second transmitting amplifier circuit, and its output terminal connected to the second input terminal of the switching filter bank circuit.

7. The L-band RF front-end circuit as described in claim 1, characterized in that, The power amplifier circuit includes: A driving amplifier circuit, wherein the input terminal of the driving amplifier circuit is connected to the second output terminal of the switched filter bank circuit; A power amplifier circuit, wherein the input terminal of the power amplifier circuit is connected to the output terminal of the drive amplifier circuit, and the output terminal of the power amplifier circuit is connected to the input terminal of the circulator.

8. The L-band RF front-end circuit as described in claim 1, characterized in that, The L-band radio frequency front-end circuit also includes: The power supply circuit has an input terminal for connecting to an external power source, a first output terminal connected to the power input terminal of the low-noise amplifier circuit, a second output terminal connected to the power input terminal of the switching filter bank circuit, a third output terminal connected to the power input terminal of the receiving post-amplifier circuit, a fourth output terminal connected to the power input terminal of the transmitting pre-amplifier circuit, and a fifth output terminal connected to the power input terminal of the power amplifier circuit.

9. The L-band RF front-end circuit as described in claim 8, characterized in that, The power supply circuit includes: A reverse connection protection circuit, wherein the input terminal of the reverse connection protection circuit is used to connect to an external power supply; An EMI circuit, wherein the input terminal of the EMI circuit is connected to the output terminal of the reverse connection protection circuit; A power conversion circuit, wherein the input terminal of the power conversion circuit is connected to the output terminal of the EMI circuit, and the output terminal of the power conversion circuit is connected to the power input terminal of the power amplifier circuit; A voltage regulating circuit, wherein the input terminal of the voltage regulating circuit is connected to the output terminal of the power conversion circuit; A receiving switch circuit, the output of which is electrically connected to the low-noise amplifier circuit and the receiving post-amplifier circuit, respectively. The transmitter switch circuit has its output terminal electrically connected to the switch filter bank circuit and the transmitter preamplifier circuit, respectively.

10. A wireless communication device, characterized in that, Includes the L-band radio frequency front-end circuit as described in any one of claims 1 to 9.

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