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

Abstract

The invention provides an L-band radio frequency front-end circuit and wireless communication equipment, 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 amplification circuit, a transmitting pre-stage amplification circuit and a power amplifier circuit, the input end of the low noise amplifier circuit is connected with the output end of the circulator, and the output end of the low noise amplifier circuit is connected with the output end of the switch filter bank circuit. 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 amplification circuit is connected with the first output end of the switch filter bank circuit, and the output end of the receiving post-stage amplification circuit outputs to a post-stage baseband. The input end of the transmitting pre-stage amplification circuit is used for accessing a broadband modulation radio frequency signal output by a baseband, the output end of the transmitting pre-stage amplification circuit is connected with the second input end of the switch filter bank circuit, and the input end of the power amplifier circuit is connected with the second output end of the switch filter bank circuit; and the output end of the power amplifier circuit is connected with the input end of the circulator.

Description

Technical Field

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

[0002] The existing L-band RF front-end often faces problems such as single function, limited receiving dynamic range, lack of front-end protection mechanism, insufficient transmit and receive switching speed, and low transmission efficiency. Summary of the Invention

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

[0004] To achieve the above objectives, the present invention provides an L-band radio frequency front-end circuit, the L-band radio frequency front-end circuit comprising: A circulator, the circulator is used to switch and isolate transmit and receive signals; a low noise amplifier circuit, wherein an input end of the low noise amplifier circuit is connected to an output end of the circulator, and the low noise amplifier circuit is used for low-noise amplification of broadband radio frequency signals; a switching filter bank circuit, wherein a first input terminal of the switching filter bank circuit is connected to an output terminal of the low noise amplifier circuit, and the switching filter bank circuit is used to perform frequency selective filtering on a broadband radio frequency signal; a receiving post-stage amplifier circuit, wherein the input end of the receiving post-stage amplifier circuit is connected to the first output end of the switching filter bank circuit, the output end of the receiving post-stage amplifier circuit outputs the processed radio frequency signal to the post-stage baseband, and the receiving post-stage amplifier circuit is used to amplify the frequency-selective signal after filtering to the level amplitude required by the post-stage baseband; a transmitting pre-stage amplifier circuit, wherein the input end of the transmitting pre-stage amplifier circuit is used to receive the broadband modulated RF signal output by the baseband, the output end of the transmitting pre-stage amplifier circuit is connected to the second input end of the switching filter bank circuit, and the transmitting pre-stage amplifier circuit is used to perform primary amplification on the broadband modulated RF signal output by the baseband; A power amplifier circuit, wherein the input end of the power amplifier circuit is connected to the second output end of the switch filter group circuit, the output end of the power amplifier circuit is connected to the input end of the circulator, and the power amplifier circuit is used to power amplify the frequency-selective signal after filtering.

[0005] Optionally, the low noise amplifier circuit includes: a limiter circuit, wherein an input end of the limiter circuit is connected to an output end of the circulator; a first low noise amplifier, wherein an input terminal of the first low noise amplifier is connected to an output terminal of the limiter circuit; A second low noise amplifier, wherein the input end of the second low noise amplifier is connected to the output end of the first low noise amplifier, and the output end of the second low noise amplifier is connected to the first input end of the switch filter bank circuit.

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

[0007] Optionally, the switch filter bank circuit includes: a first transceiver switch circuit, wherein a first input end of the first transceiver switch circuit is connected to the low noise amplifier circuit, and a first output end of the first transceiver switch circuit is connected to the input end of the power amplifier circuit; a first selection switch circuit, wherein a first output end of the first selection switch circuit is connected to a second input end of the first transceiver switch circuit, and a first input end of the first selection switch circuit is connected to a second output end of the first transceiver switch circuit; a radio frequency filter circuit, wherein a first input end of the radio frequency filter circuit is connected to the second output end of the first selection switch circuit, and a first output end of the radio frequency filter circuit is connected to the second input end of the first selection switch circuit; a second selection switch circuit, wherein a first input end of the second selection switch circuit is connected to the second output end of the radio frequency filter circuit, and a first output end of the second selection switch circuit is connected to the second input end of the radio frequency filter circuit; A second transceiver switch circuit, wherein the first input end of the second transceiver switch circuit is connected to the second output end of the second selection switch circuit, the first output end of the second transceiver switch circuit is connected to the second input end of the second selection switch circuit, the second input end of the second transceiver switch circuit is connected to the output end of the transmitting pre-stage amplifier circuit, and the second output end of the second transceiver switch circuit is connected to the input end of the receiving post-stage amplifier circuit.

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

[0009] Optionally, the transmitting pre-stage amplifier circuit includes: a second filtering circuit, wherein an input end of the second filtering circuit is used to receive a broadband modulated radio frequency signal output by a baseband; a first transmitting amplifier circuit, wherein an input end of the first transmitting amplifier circuit is connected to an output end of the second filtering circuit; a second transmitting amplifier circuit, wherein an input end of the second transmitting amplifier circuit is connected to an output end of the first transmitting amplifier circuit; A digitally controlled attenuation circuit, wherein the input end of the digitally controlled attenuation circuit is connected to the output end of the second transmitting amplification circuit, and the output end of the digitally controlled attenuation circuit is connected to the second input end of the switching filter group circuit.

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

[0011] Optionally, the L-band RF front-end circuit further includes: A power supply circuit, wherein the input end of the power supply circuit is used to connect to an external power supply, the first output end of the power supply circuit is connected to the power input end of the low-noise amplifier circuit, the second output end of the power supply circuit is connected to the power input end of the switching filter group circuit, the third output end of the power supply circuit is connected to the power input end of the receiving post-stage amplifier circuit, the fourth output end of the power supply circuit is connected to the power input end of the transmitting pre-stage amplifier circuit, and the fifth output end of the power supply circuit is connected to the power input end of the power amplifier circuit.

[0012] Optionally, the power supply circuit includes: An anti-reverse connection circuit, wherein the input end of the anti-reverse connection circuit is used to connect to an external power supply; an EMI circuit, wherein an input end of the EMI circuit is connected to an output end of the anti-reverse connection circuit; A power conversion circuit, wherein the input end of the power conversion circuit is connected to the output end of the EMI circuit, and the output end of the power conversion circuit is connected to the power input end of the power amplifier circuit; a voltage regulating circuit, wherein an input end of the voltage regulating circuit is connected to an output end of the power conversion circuit; a receiving switch circuit, wherein the output end of the receiving switch circuit is electrically connected to the low noise amplifier circuit and the receiving post-stage amplifier circuit respectively; A transmitting switch circuit, wherein the output end of the transmitting switch circuit is electrically connected to the switch filter group circuit and the transmitting pre-stage amplifier circuit respectively.

[0013] In addition, to achieve the above-mentioned object, the present invention also provides a wireless communication device, including the L-band radio frequency front-end circuit as described above.

[0014] The L-band RF front-end circuit of the embodiment of the present invention is provided with a circulator, a low-noise amplifier circuit, a switch filter group circuit, a receiving post-stage amplifier circuit, a transmitting pre-stage amplifier circuit and a power amplifier circuit, wherein the circulator is used to switch and isolate the receiving and transmitting signals, the low-noise amplifier circuit is used to low-noise amplify the broadband RF signal, the switch filter group circuit is used to perform frequency-selective filtering on the broadband RF signal, the receiving post-stage amplifier circuit is used to amplify the filtered frequency-selective signal to the level amplitude required by the post-stage baseband, the transmitting pre-stage amplifier circuit is used to perform primary amplification on the broadband modulated RF signal output by the baseband, and the power amplifier circuit is used to power amplify the filtered frequency-selective signal. In this embodiment, the input of the low-noise amplifier circuit is connected to the output of the circulator, the first input of the switched filter bank circuit is connected to the output of the low-noise amplifier circuit, the input of the receiving post-stage amplifier circuit is connected to the first output of the switched filter bank circuit, the output of the receiving post-stage amplifier circuit outputs the processed RF signal to the post-stage baseband, the input of the transmitting pre-stage amplifier circuit is used to receive the broadband modulated RF signal output by the baseband, the output of the transmitting pre-stage amplifier circuit is connected to the second input of the switched filter bank circuit, the input of the power amplifier circuit is connected to the second output of the switched filter bank circuit, and the output of the power amplifier circuit is connected to the input of the circulator. In this way, the circulator achieves transmit-receive isolation, and a multi-stage low-noise amplifier and limiter circuit combination is used to improve receive sensitivity and prevent overload damage. The switched filter bank is combined to achieve fast frequency selection filtering, and the hierarchical amplification structure is used to optimize the signal dynamic range. This has the advantages of enhanced anti-interference capability, expanded receive signal dynamic range, fast transmit-receive switching, improved power efficiency, and protection of the low-noise amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[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 diagram 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 yet another embodiment of the present invention; Figure 5 for Figure 4 A circuit schematic diagram of a first transceiver switch circuit and a first selection switch circuit; Figure 6 for Figure 4 Circuit diagram of the RF filter circuit; Figure 7 for Figure 4 A circuit schematic diagram of a second selection switch circuit and a second transceiver switch circuit; Figure 8 This is 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 schematic diagram of the receiving post-stage amplifier circuit; 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 diagram of the transmitting pre-stage amplifier circuit; Figure 12 for Figure 10 A circuit schematic diagram of the second filter circuit in FIG. Figure 13 This is a circuit block diagram of an L-band RF front-end circuit according to another embodiment of the present invention; Figure 14 for Figure 13 The circuit schematic 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 yet another embodiment of the present invention; Figure 16 This is a circuit block diagram of an L-band RF front-end circuit according to another embodiment of the present invention.

[0018] Description of Figure Numbers:

[0019] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0020] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments, and well-known modules, units and their connections, links, communications or operations are not shown or described in detail. In addition, the described features, architectures or functions can be combined in any way in one or more embodiments. It should be understood by those skilled in the art that the various embodiments described below are only for illustration and are not intended to limit the scope of protection of the present invention.

[0021] Existing L-band time-division RF front-ends (TD-RFFs) suffer from numerous technical deficiencies, severely hindering the performance of communication systems. First, traditional solutions suffer from limited functionality and lack advanced features like frequency-hopping reception, resulting in insufficient anti-interference capabilities and difficulty maintaining communication quality in complex electromagnetic environments. Second, the dynamic range of received signals is limited. When the input signal strength is high, the front-end low-noise amplifier (LNA) easily enters saturation, significantly degrading the noise figure and limiting the system's application scenarios. More seriously, existing designs lack effective limiting protection mechanisms in the front-end receive chain. High-power input signals can easily cause permanent damage to the LNA, severely impacting device reliability. Furthermore, traditional solutions exhibit long transmit-receive switching times, often reaching nanoseconds, failing to meet the fast switching requirements of modern communication systems. In the transmit chain, 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 issues collectively limit the performance and application scope of L-band RF front-ends in wireless communication systems.

[0022] The main solution of the embodiment of the present application is: the L-band RF front-end circuit of the embodiment of the present invention is provided with a circulator, a low-noise amplifier circuit, a switch filter group circuit, a receiving post-stage amplifier circuit, a transmitting pre-stage amplifier circuit and a power amplifier circuit, wherein the circulator is used to switch and isolate the receiving and transmitting signals, the low-noise amplifier circuit is used to low-noise amplify the broadband RF signal, the switch filter group circuit is used to perform frequency selection filtering on the broadband RF signal, the receiving post-stage amplifier circuit is used to amplify the filtered frequency-selective signal to the level amplitude required by the post-stage baseband, the transmitting pre-stage amplifier circuit is used to perform primary amplification on the broadband modulated RF signal output by the baseband, and the power amplifier circuit is used to perform frequency selection filtering on the filtered frequency-selective signal. Power amplification is performed. Then, in this embodiment, the input end of the low noise amplifier circuit is connected to the output end of the circulator, the first input end of the switch filter bank circuit is connected to the output end of the low noise amplifier circuit, the input end of the receiving post-stage amplifier circuit is connected to the first output end of the switch filter bank circuit, the output end of the receiving post-stage amplifier circuit outputs the processed RF signal to the post-stage baseband, the input end of the transmitting pre-stage amplifier circuit is used to receive the broadband modulated RF signal output by the baseband, the output end of the transmitting pre-stage amplifier circuit is connected to the second input end of the switch filter bank circuit, the input end of the power amplifier circuit is connected to the second output end of the switch filter bank circuit, and the output end of the power amplifier circuit is connected to the input end of the circulator.

[0023] The present application provides a solution that achieves transmit-receive isolation through a circulator, and adopts a combination of a multi-stage low-noise amplifier and a limiting circuit to improve receiving sensitivity and prevent overload damage. It combines a switching filter group to achieve fast frequency selection filtering, and cooperates with a hierarchical amplification structure to optimize the signal dynamic range. It has the advantages of enhancing anti-interference capability, expanding the dynamic range of the received signal, achieving fast transmit-receive switching, improving power efficiency and protecting the low-noise amplifier.

[0024] Existing technologies often face challenges with L-band RF front-ends, including limited functionality, limited dynamic range, a lack of front-end protection mechanisms, slow transmit / receive switching speeds, and low transmission efficiency. For example, in complex electromagnetic environments, traditional equipment struggles to achieve fast frequency-hopping communication. High-power signal inputs can easily saturate or damage the preamplifier, leading to reduced communication quality. Existing solutions are particularly limited in applications requiring high reliability, as they fail to meet the requirements for extended dynamic range and fast switching, hindering system performance.

[0025] To address these issues, and addressing the lack of functional integration, we attempted to modularize transmit / receive isolation, signal amplification, and filtering. To address the problem of preamplifier saturation caused by large signal inputs, we considered adding protection mechanisms to the signal chain. Analysis of the root causes of long transmit / receive switching times revealed signal path redundancy in the traditional architecture. We then switched to using a circulator 10 in conjunction with a switching filter to coordinate signal flow. To optimize transmission efficiency, we explored a hierarchical approach for power amplification and driver amplification to reduce overall power consumption.

[0026] Based on the above, refer to Figure 1 In one embodiment of the present invention, the L-band RF front-end circuit includes a circulator 10, a low-noise amplifier circuit 20, a switch filter bank circuit 30, a receiving post-stage amplifier circuit 40, a transmitting pre-stage amplifier circuit 50, and a power amplifier circuit 60, wherein: The circulator 10 is used to switch and isolate the receiving and transmitting signals; the input end of the low noise amplifier circuit 20 is connected to the output end of the circulator 10, and the low noise amplifier circuit 20 is used to low-noise amplify the broadband radio frequency signal; the first input end of the switch filter group circuit 30 is connected to the output end of the low noise amplifier circuit 20, and the switch filter group circuit 30 is used to perform frequency selection filtering on the broadband radio frequency signal; the input end of the receiving post-stage amplifier circuit 40 is connected to the first output end of the switch filter group circuit 30, and the output end of the receiving post-stage amplifier circuit 40 outputs the processed radio frequency signal to the post-stage baseband, and the receiving post-stage amplifier circuit 40 is used to filter the filtered radio frequency signal. The frequency-selective signal after the wave is amplified to the level amplitude required by the subsequent baseband; the input end of the transmitting pre-stage amplifier circuit 50 is used to access the broadband modulated RF signal output by the baseband, and the output end of the transmitting pre-stage amplifier circuit 50 is connected to the second input end of the switching filter group circuit 30, and the transmitting pre-stage amplifier circuit 50 is used to perform primary amplification on the broadband modulated RF signal output by the baseband; the input end of the power amplifier circuit 60 is connected to the second output end of the switching filter group circuit 30, and the output end of the power amplifier circuit 60 is connected to the input end of the circulator 10, and the power amplifier circuit 60 is used to power amplify the frequency-selective signal after filtering.

[0027] The circulator 10 is a microwave device that uses nonreciprocity to control signal flow. It can be made of ferrite material and uses a magnetic field to control the signal transmission path, thus solving the problem of mutual interference between transmitting and receiving signals. The low-noise amplifier circuit 20 includes a multi-stage amplifier structure, such as a two-stage cascade of low-noise amplifiers, which is used to amplify weak signals while maintaining a low noise figure to prevent premature saturation of the signal link. The switched filter bank is a frequency-selective network composed of RF switches and bandpass filters. By switching between filters in different frequency bands, frequency-hopping communication is achieved, improving anti-interference capabilities. The receiving post-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 pre-amplifier circuit 50 includes a broadband amplifier module that pre-amplifies the baseband modulated signal to provide an appropriate input level for subsequent power amplification. The power amplifier circuit 60 uses a combined driver stage and power stage structure, optimizing power transmission efficiency through an impedance matching network.

[0028] The received signal passes through the circulator 10 and enters the low-noise amplifier circuit 20 for initial amplification. After frequency selection by the switch filter bank circuit 30, it enters the receive post-amplifier circuit 40 for gain adjustment before being output to the baseband processing unit. After the transmit signal is output from the baseband, it is pre-amplified by the transmit pre-amplifier circuit 50, frequency selected by the switch filter bank, and enters the power amplifier circuit 60 for power boosting before being output through the circulator 10. The circulator 10 automatically changes the signal path when switching between transmit and receive modes to ensure isolation between the transmit and receive channels. The switch filter bank achieves dynamic frequency selection by switching between filters in different frequency bands, and cooperates with the pre- and post-amplifier circuits to form a complete signal processing chain.

[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 switch filter group, shortening the signal transmission path. The non-reciprocal nature of the circulator 10 significantly reduces the transmit / receive switching time to sub-microseconds compared to traditional switching devices. The multi-stage low-noise amplifier structure, combined with the switch filter group, expands the dynamic range of the received signal and avoids saturation of the previous stage caused by large input signals. The transmit chain utilizes a hierarchical amplification design, optimizing energy efficiency while maintaining output power, reducing power consumption by approximately 30% compared to traditional single-stage amplifier structures.

[0030] Through the above technical solutions, this embodiment effectively solves the problems of single function and weak anti-interference ability of traditional equipment, and realizes frequency-selective processing of broadband signals. The multi-stage amplification structure of the receiving link, combined with the limiting protection, expands the dynamic range to more than 80dB, avoiding performance degradation caused by large signals. The combined application of the circulator 10 and the switching filter group shortens the transmission and reception switching time to less than 500 nanoseconds, meeting the needs of fast frequency hopping communication. The pre-amplification and power amplification hierarchical design of the transmitting link improves the overall efficiency to more than 45% while maintaining an output power of 20W, significantly reducing the heat generated by the equipment.

[0031] The L-band RF front-end circuit of this embodiment is provided with a circulator 10, a low-noise amplifier circuit 20, a switch filter group circuit 30, a receiving post-stage amplifier circuit 40, a transmitting pre-stage amplifier circuit 50 and a power amplifier circuit 60, wherein the circulator 10 is used to switch and isolate the receiving and transmitting signals, the low-noise amplifier circuit 20 is used to low-noise amplify the broadband RF signal, the switch filter group circuit 30 is used to perform frequency-selective filtering on the broadband RF signal, the receiving post-stage amplifier circuit 40 is used to amplify the filtered frequency-selective signal to the level amplitude required by the post-stage baseband, the transmitting pre-stage amplifier circuit 50 is used to perform primary amplification of the broadband modulated RF signal output by the baseband, and the power amplifier circuit 60 is used to power amplify the filtered frequency-selective signal. Then, this embodiment For example, the input end of the low noise amplifier circuit 20 is connected to the output end of the circulator 10, the first input end of the switch filter bank circuit 30 is connected to the output end of the low noise amplifier circuit 20, the input end of the receiving post-stage amplifier circuit 40 is connected to the first output end of the switch filter bank circuit 30, and the output end of the receiving post-stage amplifier circuit 40 outputs the processed RF signal to the post-stage baseband. The input end of the transmitting pre-stage amplifier circuit 50 is used to receive the broadband modulated RF signal output by the baseband, the output end of the transmitting pre-stage amplifier circuit 50 is connected to the second input end of the switch filter bank circuit 30, the input end of the power amplifier circuit 60 is connected to the second output end of the switch filter bank circuit 30, and the output end of the power amplifier circuit 60 is connected to the input end of the circulator 10. In this way, the circulator 10 is used to achieve transmit and receive isolation, and a multi-stage low-noise amplifier and a limiting circuit 21 are used in combination to improve the receiving sensitivity and prevent overload damage. The switching filter group is combined to achieve fast frequency selection filtering, and the hierarchical amplification structure is used to optimize the signal dynamic range. It has the advantages of enhancing anti-interference ability, expanding the dynamic range of the received signal, achieving fast transmit and receive switching, improving power efficiency and protecting the low-noise amplifier.

[0032] Optionally, refer to Figure 2 Another embodiment of the present invention 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 limiter circuit 21, a first low noise amplifier 22, and a second low noise amplifier 23, wherein: The input end of the limiter circuit 21 is connected to the output end of the circulator 10; the input end of the first low noise amplifier 22 is connected to the output end of the limiter circuit 21; the input end of the second low noise amplifier 23 is connected to the output end of the first low noise amplifier 22, and the output end of the second low noise amplifier 23 is connected to the first input end of the switch filter group circuit 30.

[0033] The limiter circuit 21 is a protective circuit for limiting the amplitude of the input signal. It can be implemented by using a limiter chip N7 in series with a capacitor to prevent overload of the subsequent circuit by absorbing transient high-power signals. The first low-noise amplifier 22 is a circuit module that performs preliminary amplification of weak signals. It can be implemented by using a low-noise amplifier chip and a capacitor coupling structure to reduce the noise figure by optimizing the input matching. The second low-noise amplifier 23 is a circuit module that performs secondary gain boost on the signal after preliminary amplification. It can be implemented by using a cascaded amplifier chip and an inductor-capacitor matching network to expand the signal dynamic range through multi-stage amplification.

[0034] After the RF signal is output from circulator 10, it first passes through limiter circuit 21 to clamp abnormally high-power signals, preventing performance degradation or damage to first low-noise amplifier 22 due to input overload. The signal then undergoes two stages of low-noise amplification, sequentially through first and second low-noise amplifiers 22 and 23. The first stage primarily reduces the system noise figure, while the second stage provides additional gain to meet the signal amplitude requirements of subsequent circuits. Capacitive coupling is used to achieve DC isolation between the two amplifier stages, while an inductor-capacitor network optimizes impedance matching to ensure efficient signal transmission.

[0035] The existing low-noise amplifier circuit 20 usually lacks limiting protection and adopts a single-stage amplification structure, which makes the pre-amplifier easy to saturate when a large signal is input, and the dynamic range is limited. This embodiment eliminates the threat of instantaneous high voltage by adding a limiting circuit 21, and improves the signal gain in stages through a two-stage low-noise amplifier, thereby maintaining low noise performance while expanding the dynamic range, solving the problems of poor reliability and limited application scenarios in the existing technology. This embodiment can effectively suppress the impact of high-power input signals on the low-noise amplifier circuit 20, avoiding device damage; through the two-stage amplification structure, it can improve the signal gain while reducing the noise coefficient, thereby expanding the dynamic range of the received signal; and utilize the synergistic effect of limiting and amplification to enhance the circuit's anti-interference ability and stability in complex electromagnetic environments.

[0036] Optionally, refer to Figure 3 Another embodiment of the present invention provides an L-band radio frequency front-end circuit, based on the above Figure 2 In the embodiment shown, the limiter circuit 21 includes a limiter chip N7, wherein: A first capacitor C9 is connected in series between the RF signal input terminal of the limiter 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 end of the first low-noise amplifier chip U2 and the RF signal output end of the limiting chip N7; a first inductor L1 is connected in series between the second end of the first resistor R1 and the RF signal output end 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 the ground; a third capacitor C11 is connected in series between the first end of the second resistor R4 and the RF signal output end of the first low-noise amplifier chip U2, a third resistor R9 is connected in parallel between the first end of the second resistor R4 and the ground, and a fourth resistor R10 is connected in parallel between the second end of the second resistor R4 and the 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 end of the second low-noise amplifier chip U4 and the second end of the second resistor R4; a second inductor L3 is connected in series between the second end of the fifth resistor R2 and the output end of the second low-noise amplifier chip U4, and at least one capacitor is connected in parallel between the common node of the fifth resistor R2 and the second inductor L3 and the ground; a first end of the fifth capacitor C13 is connected to the output end of the second low-noise amplifier chip U4, and a second end of the fifth capacitor C13 is connected to the first input end of the switching filter group 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 the subsequent circuit. The first capacitor C9 refers to a DC blocking capacitor connected in series in the RF signal path. It can be implemented using a ceramic capacitor or a thin film capacitor. It 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. It is used for preliminary amplification of weak signals. The network formed by the first inductor L1 and the parallel capacitor refers to an impedance matching structure. It can be implemented using a winding inductor or a planar inductor to optimize signal transmission efficiency. The network formed by the second resistor R4, the third resistor R9, and the fourth resistor R10 refers to a bias circuit. It can be implemented using a voltage divider resistor or a current source structure to provide a stable operating point for the amplifier chip. The fourth capacitor C12 refers to an interstage coupling capacitor. It can be implemented using a multilayer ceramic capacitor to block DC and transmit RF signals. The network formed by the second inductor L3 and the parallel capacitor is the output matching circuit, which can be implemented using microstrip lines or lumped components and is used to increase 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 and is used to filter out the amplified DC component.

[0040] When the RF signal enters the receive link through the circulator 10, the limiter chip N7 quickly clamps high-power signals exceeding the threshold, preventing transient high voltage damage to downstream components. The first capacitor C9 blocks DC while allowing the RF signal to pass, preventing DC potential interference between the circulator 10 and the limiter chip N7. The limited signal passes through the second capacitor C10 and enters the first low-noise amplifier chip U2 for primary amplification. At this point, the matching network consisting of the first inductor L1 and the parallel capacitor adjusts the input impedance, improving signal transmission efficiency. The amplified signal is then coupled via the third capacitor C11 to the bias network consisting of the second resistor R4, the third resistor R9, and the fourth resistor R10. 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 formed by the second inductor L3 and the parallel capacitor optimizes high-frequency response characteristics. The final signal is output to the switched 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 cascade amplification structure. The combination of the limiting chip N7 and the multi-stage matching network can not only suppress sudden large signals, but also ensure the low-noise amplification characteristics of small signals. In addition, the discrete bias network design can avoid inter-stage interference, and multiple groups of matching circuits can optimize the working conditions of each stage respectively, which has better linearity and stability than the traditional single-stage structure. This embodiment effectively solves the problem that the front stage of the receiving link is susceptible to large signal impact. The limiting circuit 21 can quickly suppress the input power that exceeds the safety threshold and prevent damage to the low-noise amplifier device. The two-stage amplification structure cooperates with the impedance matching network to expand the receiving dynamic range, and improves the large signal processing capability while ensuring a low noise coefficient. The discrete bias design and inter-stage coupling structure reduce the mutual interference between circuits, so that the system can still maintain a stable working state in a complex electromagnetic environment.

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

[0043] Among them, the first transceiver switch circuit 31 refers to an electronic switching device for switching the transceiver signal path, which can be implemented by a PIN diode switch circuit, and the physical isolation of the receiving channel and the transmitting channel is achieved by controlling the signal. The first selection switch circuit 32 refers to a switching device for selecting different filtering channels, which can be implemented by a single-pole multi-throw radio frequency switch chip, and is used to guide the signal to the different frequency band processing modules of the radio frequency filter circuit 33. The radio frequency filter circuit 33 refers to a frequency selection network composed of multiple bandpass filters, which can be implemented by a dielectric filter or a surface acoustic wave filter, and is used to selectively attenuate or enhance the signal of a specific frequency band. The second selection switch circuit 34 refers to a reverse switching device that works in conjunction with the first selection switch circuit 32, and can be implemented by a single-pole multi-throw radio frequency switch chip of the same structure, and is used to reintegrate the filtered signal into the main signal link. The second transceiver switch circuit 35 refers to a device for completing the secondary path switching between the transmit signal and the receive signal, and can be implemented by an integrated transceiver switch module, and is used to establish a low-loss transmission path between the transmit and receive states.

[0044] In the receive mode, the first transceiver switch circuit 31 directs 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, it is transmitted to the receive post-amplifier circuit 40 via the second transceiver switch circuit 35. In the transmit mode, the second transceiver switch circuit 35 directs the signal from the transmit pre-amplifier circuit 50 to the second selection switch circuit 34. After filtering by the RF filter circuit 33, it is transmitted to the power amplifier circuit 60 via the first transceiver switch circuit 31. The RF filter circuit 33 uses a segmented design to achieve multi-band coverage, and the first and second selection switch circuits 32 and 34 use a symmetrical layout to ensure phase consistency in signal transmission. The transceiver switch circuits use a cascade structure to shorten the signal path, and a dual switching mechanism achieves complete isolation of the transmit and receive channels.

[0045] This embodiment sets up a two-stage selection switch and a transceiver switch to work together, so that the filter channel selection and the transceiver path switching can be independently controlled, which significantly shortens the state transition time. The RF filter circuit 33 adopts a distributed layout to avoid the cumulative insertion loss caused by the traditional cascade filter, and at the same time supports fast switching of multiple frequency bands through the flexible configuration of the selection switch. The double-layer structure design of the transceiver switch effectively isolates the crosstalk of the transmit signal to the receive channel, and improves the channel isolation compared to the traditional single switch structure. This embodiment realizes the fast switching and precise frequency selection functions of the transceiver channel, and solves the technical defects of the traditional RF front-end with long switching time and limited dynamic range. It can be manifested as the transceiver state transition time is shortened to the sub-microsecond level, which can support the fast frequency switching requirements of the frequency hopping communication system; the dynamic range of the received signal is expanded through the distributed filtering structure to avoid amplifier saturation caused by large signal input; the multi-stage switch collaborative control mechanism enhances the system's anti-interference ability, ensuring stable communication quality in complex electromagnetic environments.

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

[0047] The first receiving amplifier circuit 41 is a circuit module that performs preliminary amplification on the frequency-selective signal output by the switching filter bank. It can be implemented using a low-noise amplifier chip in conjunction with a matching circuit to boost signal strength to meet the input requirements of subsequent processing steps. The second receiving amplifier circuit 42 is a circuit module that performs secondary amplification on the signal after preliminary amplification. It can be implemented using an amplifier chip with adjustable gain to adjust the signal amplitude to the level range required for 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] The post-receiver amplifier circuit 40 uses a two-stage amplification structure to perform step-by-step gain control on the frequency-selected signal. A first receive amplifier circuit 41 initially amplifies the filtered signal output by the switched filter bank, and a second receive amplifier circuit 42 further adjusts the signal amplitude based on this initial amplification. The signal, after two amplifications, enters the first filter circuit 43, which filters out out-of-band noise and residual interference introduced by the amplification process, ultimately outputting an RF signal that meets baseband processing requirements. This structure avoids the saturation risk of a single-stage amplifier circuit through staged gain allocation. The introduction of filtering effectively suppresses noise accumulation in the signal chain.

[0049] This embodiment uses a two-stage amplification design with intermediate filtering to expand the signal processing dynamic range while suppressing inter-stage noise interference through the filtering process. This embodiment solves the problem of low-noise amplifier saturation caused by the limited dynamic range of the received signal and improves the linearity under large signal input through hierarchical gain control. At the same time, the introduction of the filtering process reduces the risk of noise coefficient deterioration and ensures that the signal-to-noise ratio of the output signal meets the baseband processing requirements. This structure also enhances the circuit's adaptability to different application scenarios through adjustable gain design, improving the overall reliability of the RF front end.

[0050] Optionally, refer to Figures 10 to 12 Another embodiment of the present invention provides an L-band radio frequency front-end circuit, based on the above Figure 1 In the embodiment shown, the transmission pre-stage amplifier circuit 50 includes a second filter circuit 51, a first transmission amplifier circuit 52, a second transmission amplifier circuit 53, and a digitally controlled attenuation circuit 54, wherein: The input end of the second filtering circuit 51 is used to access the broadband modulated RF signal output by the baseband; the input end of the first transmitting amplifier circuit 52 is connected to the output end of the second filtering circuit 51; the input end of the second transmitting amplifier circuit 53 is connected to the output end of the first transmitting amplifier circuit 52; the input end of the digitally controlled attenuation circuit 54 is connected to the output end of the second transmitting amplifier circuit 53, and the output end of the digitally controlled attenuation circuit 54 is connected to the second input end of the switching filter group circuit 30.

[0051] The second filter circuit 51 is a circuit used to filter out out-of-band interference from 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 transmit amplifier circuit 52 and the second transmit amplifier circuit 53 are amplifier units that sequentially increase the gain of the signal. They can be implemented using transistors or integrated amplifier chips. Their function is to gradually amplify the low-power baseband output signal 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 prevent saturation or distortion in subsequent circuits due to excessive signal strength.

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

[0053] This embodiment, by introducing a collaborative design of two-stage amplification and digitally controlled attenuation, not only expands the signal processing range but also enables flexible control of power output, thereby reducing overall power consumption and improving system adaptability. This embodiment effectively addresses the problems of low efficiency, high power consumption, and insufficient signal dynamic range in existing pre-transmitter amplification. 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 the present invention 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 driving amplifier circuit 61 and a power amplifier circuit 62, wherein: The input end of the driving amplifier circuit 61 is connected to the second output end of the switching filter group circuit 30 ; the input end of the power amplifier circuit 62 is connected to the output end of the driving amplifier circuit 61 , and the output end of the power amplifier circuit 62 is connected to the input end of the circulator 10 .

[0055] The driver amplifier circuit 61 is a circuit module that pre-amplifies the frequency-selective signal output by the switch filter bank. It can be implemented using a multi-stage gain-adjustable amplifier and is used 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 and can be implemented using GaN HEMT devices or LDMOS transistors. It is used to amplify the signal to the transmit power level required by the input of the circulator 10.

[0056] After the RF signal undergoes frequency selection processing by the switched filter bank, it undergoes primary amplification by the driver amplifier circuit 61, adjusting the signal amplitude to the optimal operating range for the power amplifier circuit 62. The power amplifier circuit 62 receives the optimized signal output by the driver stage and uses a high-efficiency amplification architecture to boost power. Ultimately, a signal that meets the required transmit power is transmitted to the antenna via the circulator 10. This hierarchical amplification structure optimizes the input level at the driver stage, allowing the power stage to operate within the high-efficiency range, thereby reducing overall power consumption.

[0057] The traditional power amplifier circuit 60 adopts a single-stage amplification structure. When the dynamic range of the input signal is limited, it is easy to enter the nonlinear region, resulting in a decrease in efficiency. This embodiment adopts a design that separates the driving stage and the power stage. The driving stage accurately controls the input signal amplitude so that the power stage is always in the best working state, thereby improving the power conversion efficiency while reducing the risk of heat loss. This embodiment effectively solves the technical problems of low transmission power efficiency and high power consumption of the traditional L-band RF front-end. The coordinated work of the driving amplifier circuit 61 and the power amplifier circuit 62 makes the signal amplification process more precise and controllable, and the working efficiency of the power amplifier circuit 62 is significantly optimized. Under the same output power conditions, it can reduce energy consumption by about 30%, while reducing the impact of heat accumulation on the life of the device.

[0058] Optionally, refer to Figure 15 Another embodiment of the present invention 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 end of the power supply circuit 70 is used to connect to an external power supply. The first output end of the power supply circuit 70 is connected to the power input end of the low noise amplifier circuit 20. The second output end of the power supply circuit 70 is connected to the power input end of the switching filter group circuit 30. The third output end of the power supply circuit 70 is connected to the power input end of the receiving post-stage amplifier circuit 40. The fourth output end of the power supply circuit 70 is connected to the power input end of the transmitting pre-stage amplifier circuit 50. The fifth output end of the power supply circuit 70 is connected to the power input end of the power amplifier circuit 60.

[0059] Among them, the power supply circuit 70 refers to a circuit system that provides stable power supply to each functional module of the RF front end, which can be implemented by a multi-stage power conversion and distribution architecture. For example, the anti-reverse connection circuit 71 prevents damage to the device due to reverse polarity of the power supply, and the EMI circuit 72 suppresses the conduction of electromagnetic interference on the power line. The voltage regulation circuit 74 refers to a circuit that adjusts the voltage according to the operating voltage requirements of each module, such as using a low-voltage difference linear regulator or a switching regulator chip to achieve output of different voltage values. The receiving switch circuit 76 and the transmitting switch circuit 75 refer to electronic switches that control the on and off of the power supply of the receiving link and the transmitting link respectively, such as using a MOS tube array to achieve independent control of the power path.

[0060] After the external power supply is protected against reverse connection by anti-reverse connection circuit 71, high-frequency interference signals are filtered out by EMI circuit 72. Subsequently, power conversion circuit 73 converts the input voltage into the high-voltage power supply required by power amplifier circuit 60. Voltage regulator circuit 74 derives different voltage levels from the converted power supply. Receiver switch circuit 76 distributes the adapted voltage to low-noise amplifier circuit 20 and receive post-amplifier circuit 40. Transmitter switch circuit 75 provides independent power to switch filter bank circuit 30 and transmit pre-amplifier circuit 50. This split-path power supply structure isolates power supply noise from each functional module. For example, the power supply paths of the receive and transmit chains are completely separated, preventing high-power transmit signals from interfering with the power supply of sensitive receive circuits.

[0061] This embodiment improves power supply reliability through the anti-reverse connection circuit 71 and the EMI circuit 72, achieves precise voltage matching through power conversion and voltage regulation, and achieves power supply isolation of the transceiver link through shunt switch control, effectively solving the problems of low power efficiency and weak anti-interference ability in the prior art. This embodiment realizes independent regulated power supply for each functional module of the RF front end, suppresses the interference of power supply noise on the RF signal link, and improves the reliability of the power supply system through anti-reverse connection and electromagnetic compatibility design. The shunt power supply structure enables the receiving and transmitting links to independently control the power supply timing. For example, when switching between transceiver and transmitter, the idle link power supply can be quickly cut off to reduce power consumption, solving the problem of inefficiency caused by extensive power management in traditional solutions.

[0062] Optionally, refer to Figure 16 Another embodiment of the present invention provides an L-band radio frequency front-end circuit, based on the above Figure 1 In the embodiment shown, the power supply circuit 70 includes an anti-reverse connection 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 end of the anti-reverse connection circuit 71 is used to connect to an external power supply; the input end of the EMI circuit 72 is connected to the output end of the anti-reverse connection circuit 71; the input end of the power conversion circuit 73 is connected to the output end of the EMI circuit 72, and the output end of the power conversion circuit 73 is connected to the power input end of the power amplifier circuit 60; the input end of the voltage regulating circuit 74 is connected to the output end of the power conversion circuit 73; the output end of the receiving switch circuit 76 is electrically connected to the low noise amplifier circuit 20 and the receiving post-stage amplifier circuit 40 respectively; the output end of the transmitting switch circuit 75 is electrically connected to the switching filter group circuit 30 and the transmitting pre-stage amplifier circuit 50 respectively.

[0063] Among them, the anti-reverse polarity circuit 71 refers to a circuit that prevents damage to the device caused by reverse polarity of the power supply. It can be implemented using a unidirectional conductive structure constructed with a diode or MOS transistor, automatically cutting off the current path when the external power supply is reversed. The EMI circuit 72 refers to 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 refers to a voltage conversion module, which can be implemented using a DC-DC switching power supply chip, and converts the input voltage into the operating voltage required by the power amplifier circuit 60. The voltage regulation circuit 74 refers to a voltage regulation module, which can be implemented using a low-dropout linear regulator or a programmable power management chip, and provides precise voltage values ​​for different functional modules. The receiving switch circuit 76 and the transmitting switch circuit 75 refer to power distribution control modules, which can be implemented using a MOS transistor switch array or a relay structure, and switch power supply to the receiving link or the transmitting link according to the operating mode.

[0064] The external power supply is protected against polarity reversal by an anti-reverse polarity circuit 71. Conducted interference is filtered out by an EMI circuit 72, and a power conversion circuit 73 converts the input voltage into the high-voltage power required by the power amplifier. A voltage regulator circuit 74 derives multiple regulated outputs from the converted power supply. The receive switch circuit 76 powers the low-noise amplifier and receive post-amplifier circuit 40 in the receive mode, while the transmit switch circuit 75 powers the switch filter bank and transmit pre-amplifier circuit 50 in the transmit mode. A time-sharing power supply mechanism activates only the power supply for the corresponding link during the transmit / receive switchover. The power amplifier circuit 60 is powered directly by the power conversion circuit 73 to meet its high power requirements.

[0065] This embodiment provides an independent power conversion module to match the high-voltage requirements of the power amplifier, employs a voltage regulator circuit 74 to derive multiple voltage regulators, and implements power time-sharing control in conjunction with the transceiver switching circuit, thereby improving power efficiency while reducing static power consumption. This embodiment effectively addresses the low efficiency and weak anti-interference capabilities of traditional RF front-end power systems, achieving power isolation control for the transceiver link, preventing equipment damage caused by reverse power connection and electromagnetic interference. The time-sharing power supply mechanism reduces overall system power consumption while providing stable and reliable high-voltage power support for the power amplifier circuit 60.

[0066] The present invention also provides a wireless communication device, which includes the L-band radio frequency front-end circuit according to the above embodiment.

[0067] It is worth noting that since the wireless communication device of the present invention is based on the above-mentioned L-band RF front-end circuit, the embodiments of the wireless communication device of the present invention include all technical solutions of all embodiments of the above-mentioned L-band RF front-end circuit, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0068] The L-band RF front-end circuit refers to a signal processing module operating in the 1-2 GHz frequency band. It uses a circulator 10 to achieve transmit and receive isolation, a low-noise amplifier 20 to improve receive sensitivity, and a switch 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. This RF front-end integrates the circuit to achieve interference-resistant communications.

[0069] In the receive path, a circulator 10 directs the antenna's received signal to a low-noise amplifier 20. After two stages of low-noise amplification, it enters a switched filter bank for frequency band selection. The filtered signal is then boosted to the required level for baseband processing by a receive post-amplifier 40. In the transmit path, the baseband modulated signal undergoes transmit pre-amplification, enters a switched filter bank for frequency selection, and then is boosted by a power amplifier 60 before being output to the antenna via the circulator 10. This structure achieves multi-band frequency hopping communication through independent amplification and filtering in the transmit and receive paths, combined with the fast switching capabilities of the switched filter bank.

[0070] Compared with existing technologies, traditional devices are limited by their single-band processing capabilities, making dynamic frequency hopping and interference mitigation impossible. Furthermore, the lack of limiting protection in the receiving channel can easily damage components. This embodiment achieves rapid multi-band switching through a switching filter bank, incorporates a limiting circuit 21 before the low-noise amplifier to prevent large signal impact, and employs a hierarchical amplification structure to extend the dynamic range. The independent design of the transmit and receive paths shortens switching time, and the matching design of the power amplifier circuit 60 and the driver stage improves transmission efficiency.

[0071] Through the above technical solutions, this embodiment effectively addresses the problems of traditional equipment, such as weak anti-interference capabilities, limited dynamic range, fragile components, slow switching speeds, and high power consumption. The frequency hopping function enhances adaptability to complex electromagnetic environments, while limiting protection improves device reliability. The independent amplification structure for both transmit and receive enables fast switching, while optimized power amplifier efficiency reduces system power consumption, expanding the device's application range in scenarios such as mobile communications and emergency command.

[0072] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An L-band radio frequency front-end circuit, characterized in that: The L-band radio frequency front-end circuit includes: A circulator, the circulator is used to switch and isolate transmit and receive signals; a low noise amplifier circuit, wherein an input end of the low noise amplifier circuit is connected to an output end of the circulator, and the low noise amplifier circuit is used for low-noise amplification of broadband radio frequency signals; a switching filter bank circuit, wherein a first input terminal of the switching filter bank circuit is connected to an output terminal of the low noise amplifier circuit, and the switching filter bank circuit is used to perform frequency selective filtering on a broadband radio frequency signal; a receiving post-stage amplifier circuit, wherein the input end of the receiving post-stage amplifier circuit is connected to the first output end of the switching filter bank circuit, the output end of the receiving post-stage amplifier circuit outputs the processed radio frequency signal to the post-stage baseband, and the receiving post-stage amplifier circuit is used to amplify the frequency-selective signal after filtering to the level amplitude required by the post-stage baseband; a transmitting pre-stage amplifier circuit, wherein the input end of the transmitting pre-stage amplifier circuit is used to receive the broadband modulated RF signal output by the baseband, the output end of the transmitting pre-stage amplifier circuit is connected to the second input end of the switching filter bank circuit, and the transmitting pre-stage amplifier circuit is used to perform primary amplification on the broadband modulated RF signal output by the baseband; A power amplifier circuit, wherein the input end of the power amplifier circuit is connected to the second output end of the switch filter group circuit, the output end of the power amplifier circuit is connected to the input end of the circulator, and the power amplifier circuit is used to power amplify the frequency-selective signal after filtering.

2. The L-band RF front-end circuit according to claim 1, wherein: The low noise amplifier circuit comprises: a limiter circuit, wherein an input end of the limiter circuit is connected to an output end of the circulator; a first low noise amplifier, wherein an input terminal of the first low noise amplifier is connected to an output terminal of the limiter circuit; A second low noise amplifier, wherein the input end of the second low noise amplifier is connected to the output end of the first low noise amplifier, and the output end of the second low noise amplifier is connected to the first input end of the switch filter bank circuit.

3. The L-band RF front-end circuit according to claim 2, wherein: The limiting circuit comprises: a limiter chip, wherein a first capacitor is connected in series between a radio frequency signal input terminal of the limiter chip and an output terminal of the circulator; The first low noise amplifier comprises: A first low-noise amplifier chip, wherein a second capacitor is connected in series between a radio frequency signal input terminal of the first low-noise amplifier chip and a radio frequency signal output terminal of the limiter chip; a first resistor, a first inductor connected in series between a second end of the first resistor and a radio frequency signal output end of the first low-noise amplifier chip, and at least one capacitor connected in parallel between a common node of the first resistor and the first inductor and ground; a second resistor, a third capacitor connected in series between a first end of the second resistor and the RF signal output end of the first low-noise amplifier chip, a third resistor connected in parallel between the first end of the second resistor and ground, and a fourth resistor connected in parallel between the second end of the second resistor and ground; The second low noise amplifier comprises: A second low-noise amplifier chip, a fourth capacitor connected in series between the input terminal of the second low-noise amplifier chip and the second end of the second resistor; a fifth resistor, wherein a second inductor is connected in series between a second end of the fifth resistor and an output end of the second low-noise amplifier chip, and at least one capacitor is connected in parallel between a common node of the fifth resistor and the second inductor and ground; A fifth capacitor, wherein a first end of the fifth capacitor is connected to the output end of the second low-noise amplifier chip, and a second end of the fifth capacitor is connected to the first input end of the switch filter group circuit.

4. The L-band RF front-end circuit according to claim 1, wherein: The switch filter bank circuit comprises: a first transceiver switch circuit, wherein a first input end of the first transceiver switch circuit is connected to the low noise amplifier circuit, and a first output end of the first transceiver switch circuit is connected to the input end of the power amplifier circuit; a first selection switch circuit, wherein a first output end of the first selection switch circuit is connected to a second input end of the first transceiver switch circuit, and a first input end of the first selection switch circuit is connected to a second output end of the first transceiver switch circuit; a radio frequency filter circuit, wherein a first input end of the radio frequency filter circuit is connected to the second output end of the first selection switch circuit, and a first output end of the radio frequency filter circuit is connected to the second input end of the first selection switch circuit; a second selection switch circuit, wherein a first input end of the second selection switch circuit is connected to the second output end of the radio frequency filter circuit, and a first output end of the second selection switch circuit is connected to the second input end of the radio frequency filter circuit; A second transceiver switch circuit, wherein the first input end of the second transceiver switch circuit is connected to the second output end of the second selection switch circuit, the first output end of the second transceiver switch circuit is connected to the second input end of the second selection switch circuit, the second input end of the second transceiver switch circuit is connected to the output end of the transmitting pre-stage amplifier circuit, and the second output end of the second transceiver switch circuit is connected to the input end of the receiving post-stage amplifier circuit.

5. The L-band RF front-end circuit according to claim 1, wherein: The receiving post-stage amplifier circuit comprises: a first receiving amplifier circuit, wherein an input terminal of the first receiving amplifier circuit is connected to a first output terminal of the switching filter bank circuit; a second receiving amplifier circuit, wherein an input end of the second receiving amplifier circuit is connected to an output end of the first receiving amplifier circuit; A first filtering circuit, wherein the input end of the first filtering circuit is connected to the output end of the second receiving amplifier circuit, and the output end of the first filtering circuit outputs the processed radio frequency signal to the subsequent baseband.

6. The L-band RF front-end circuit according to claim 1, wherein: The transmitting pre-stage amplifier circuit comprises: a second filtering circuit, wherein an input end of the second filtering circuit is used to receive a broadband modulated radio frequency signal output by a baseband; a first transmitting amplifier circuit, wherein an input end of the first transmitting amplifier circuit is connected to an output end of the second filtering circuit; a second transmitting amplifier circuit, wherein an input end of the second transmitting amplifier circuit is connected to an output end of the first transmitting amplifier circuit; A digitally controlled attenuation circuit, wherein the input end of the digitally controlled attenuation circuit is connected to the output end of the second transmitting amplification circuit, and the output end of the digitally controlled attenuation circuit is connected to the second input end of the switching filter group circuit.

7. The L-band RF front-end circuit according to claim 1, wherein: The power amplifier circuit comprises: a driving amplifier circuit, wherein an input terminal of the driving amplifier circuit is connected to the second output terminal of the switching filter bank circuit; A power amplifier circuit, wherein the input end of the power amplifier circuit is connected to the output end of the driving amplifier circuit, and the output end of the power amplifier circuit is connected to the input end of the circulator.

8. The L-band RF front-end circuit according to claim 1, wherein: The L-band RF front-end circuit further includes: A power supply circuit, wherein the input end of the power supply circuit is used to connect to an external power supply, the first output end of the power supply circuit is connected to the power input end of the low-noise amplifier circuit, the second output end of the power supply circuit is connected to the power input end of the switching filter group circuit, the third output end of the power supply circuit is connected to the power input end of the receiving post-stage amplifier circuit, the fourth output end of the power supply circuit is connected to the power input end of the transmitting pre-stage amplifier circuit, and the fifth output end of the power supply circuit is connected to the power input end of the power amplifier circuit.

9. The L-band RF front-end circuit according to claim 8, wherein: The power supply circuit comprises: An anti-reverse connection circuit, wherein the input end of the anti-reverse connection circuit is used to connect to an external power supply; an EMI circuit, wherein an input end of the EMI circuit is connected to an output end of the anti-reverse connection circuit; A power conversion circuit, wherein the input end of the power conversion circuit is connected to the output end of the EMI circuit, and the output end of the power conversion circuit is connected to the power input end of the power amplifier circuit; a voltage regulating circuit, wherein an input end of the voltage regulating circuit is connected to an output end of the power conversion circuit; a receiving switch circuit, wherein the output end of the receiving switch circuit is electrically connected to the low noise amplifier circuit and the receiving post-stage amplifier circuit respectively; A transmitting switch circuit, wherein the output end of the transmitting switch circuit is electrically connected to the switch filter group circuit and the transmitting pre-stage amplifier circuit respectively.

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

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