A radio frequency link for improving the dynamic range of signal reception in complex electromagnetic environments

Abstract

This invention discloses a radio frequency (RF) link for improving the dynamic range of signal reception in complex electromagnetic environments, comprising: an RF link circuit, a mixer link circuit, and an intermediate frequency (IF) gain circuit, which are connected sequentially; it also includes a detection and control circuit, which is disposed between the mixer link circuit and the IF gain circuit, for judging and calculating the voltage value of the detected signal, and thereby controlling the IF link gain and the magnitude of the mixer input signal. This invention effectively solves the problems of link saturation caused by strong interference signals and the decrease in effective dynamic range caused by mismatch between the input range of the ADC acquisition link and the link.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a radio frequency link for improving the dynamic range of signal reception in complex electromagnetic environments. Background Technology

[0002] With the rapid development of modern radio communication technologies such as 4G / 5G communication, low-altitude drone monitoring and suppression, low-orbit internet satellites, high-throughput satellites, navigation satellites, and communication countermeasures and interference, and based on practical application verification, insufficient consideration in receiver link gain allocation and control design has led to a series of problems, including signal-to-noise ratio compression, RF link spurious emissions, ADC chip self-spurious emissions, and ADC saturation. These issues affect the receiver's ability to adapt to complex electromagnetic environments. Therefore, a receiver link that can adapt to the increasing complexity and congestion of the electromagnetic spectrum, and that can handle both strong interference and weak signals, is needed. Summary of the Invention

[0003] The purpose of this invention is to provide a radio frequency link that improves the dynamic range of signal reception in complex electromagnetic environments, so as to effectively solve the technical problems of signal compression or saturation and weak signal detection sensitivity in environments where strong interference and weak signals coexist.

[0004] This invention is achieved using the following technical solution: a radio frequency link for improving the dynamic range of signal reception in complex electromagnetic environments, comprising: a radio frequency link circuit, a mixer link circuit, and an intermediate frequency gain circuit, wherein the radio frequency link circuit, the mixer link circuit, and the intermediate frequency gain circuit are connected in sequence; it also includes a detection and control circuit, wherein the detection and control circuit is disposed between the mixer link circuit and the intermediate frequency gain circuit, and is used to judge and calculate the voltage value of the detection, thereby controlling the intermediate frequency link gain and the magnitude of the mixer input signal in a coordinated manner.

[0005] Furthermore, the radio frequency link circuit includes a limiter, a first switch, a second switch, and a first attenuator connected in sequence, with a bypass circuit and a variable amplifier connected in parallel between the first switch and the second switch.

[0006] Furthermore, the gain of the RF link circuit is 5dB~10dB, and the signal passing through the RF link circuit is within the input range guaranteed by the dynamic range of the subsequent mixer circuit, thus preventing the mixer link circuit from saturating.

[0007] Furthermore, the mixing link circuit includes a second attenuator and a mixer connected in sequence, wherein the second attenuator is used to adjust the signal strength entering the mixer; and the mixer is used to shift the input radio frequency to the intermediate frequency band signal.

[0008] Furthermore, the detection and control circuit is used to detect and measure the signal strength of the signal entering the mixing link circuit, and to control the gain of the second attenuator and the intermediate frequency link circuit in conjunction with it.

[0009] Furthermore, the detection and control circuit includes a detector, a level acquisition circuit, and a control circuit connected in sequence. The input terminal of the detector is connected to the output terminal of the second attenuator, and the output terminal of the control circuit is connected to the input terminals of the second attenuator and the intermediate frequency link circuit, respectively.

[0010] Furthermore, the intermediate frequency gain circuit includes a third attenuator and an amplifier circuit connected in sequence. The third attenuator is used to adjust the strength of the incoming signal; the amplifier circuit is used to amplify the intermediate frequency signal to match the input range of the subsequent ADC acquisition link.

[0011] Furthermore, the intermediate frequency gain circuit has an intermediate frequency gain value of 15dB~115dB, which can amplify and match any input signal to the input range of the ADC acquisition link, thereby maximizing the dynamic range.

[0012] Furthermore, the intermediate frequency gain value is controlled based on the signal strength output by the detection and control circuit, amplifying the signal output by the intermediate frequency gain circuit to a specified power level. The intermediate frequency gain value G = P1 - P2, where P1 is the intermediate frequency output setting value, P2 is the detection output value, and G is the intermediate frequency gain value.

[0013] The beneficial effects of this invention are as follows: In complex electromagnetic environments where strong interference and weak signals coexist, this invention effectively solves the problems of link saturation caused by strong interference signals and the decrease in effective dynamic range caused by mismatch between the input range of the ADC acquisition link and the above-mentioned RF / IF link gain range allocation design, as well as the linkage closed-loop control of the detection control circuit and the RF / IF link gain. This effectively improves the detection sensitivity, the accuracy of weak signal detection, and the signal monitoring distance. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0017] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0018] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0019] See Figure 1 A radio frequency (RF) link for improving the dynamic range of signal reception in complex electromagnetic environments includes: an RF link circuit, a mixer link circuit, and an intermediate frequency (IF) gain circuit, which are connected sequentially; it also includes a detection and control circuit, which is located between the mixer link circuit and the IF gain circuit, and is used to judge and calculate the voltage value of the detected signal, thereby controlling the IF link gain and the magnitude of the mixer input signal.

[0020] In this embodiment, the RF link circuit includes a limiter, a first switch, a second switch, and a first attenuator connected in sequence. Both the first and second switches can be single-pole double-throw (SPDT) switches. A bypass circuit and a variable amplifier are also connected in parallel between the first and second switches. The limiter limits large signals to a certain size; the bypass circuit is used for large signal transmission; the variable amplifier is used for amplifying and transmitting small signals; and the first attenuator is used to adjust the signal power. This invention can design the RF link gain to be 5-10dB (default 5dB) through the coordinated adjustment of the variable amplifier and the first attenuator. The amplified signal meets the input range requirements of the subsequent mixer circuit under the dynamic range guarantee, preventing the mixer circuit from saturating.

[0021] In addition, in some embodiments, a preselection network may be set up to suppress signals outside the bandwidth.

[0022] In this embodiment, the mixing link circuit includes a second attenuator and a mixer connected in sequence. The second attenuator is used to adjust the signal strength entering the mixer, and the mixer is used to shift the input RF frequency to the intermediate frequency band. Further, the detection and control circuit is used to detect and measure the signal strength of the signal entering the mixing link circuit, and to control the gain of the second attenuator and the intermediate frequency link circuit in conjunction. The detection and control circuit includes a detector, a level acquisition circuit, and a control circuit connected in sequence. The input terminal of the detector is connected to the output terminal of the second attenuator, and the output terminal of the control circuit is connected to the input terminals of both the second attenuator and the intermediate frequency link circuit. Specifically, the output terminal of the control circuit is connected to the input terminal of the third attenuator of the intermediate frequency gain circuit. The detector is used to detect the power intensity of the input signal of the mixer and outputs a voltage value corresponding to the power level; the level acquisition circuit is used to digitally sample the output voltage value of the detector and output the corresponding value; the control circuit is used to judge and calculate the voltage value detected, and control the second attenuator at the input of the mixer link circuit and the third attenuator of the intermediate frequency link circuit respectively, so as to achieve the purpose of controlling the intermediate frequency link gain and the input signal of the mixer in conjunction with the signal power of the mixer.

[0023] Specifically, the second attenuator is used to adjust the signal strength entering the mixer; the mixer is used to shift the input RF frequency to the intermediate frequency band; the detection and control circuit is used to detect and measure the signal strength of the signal entering the mixing link, and to control the gain of the attenuator and the intermediate frequency link in conjunction with it. This invention adds a detection and control circuit and a second attenuator design, forming a closed-loop linkage control design between the detection and control circuit and the second attenuator (and a linkage design with the third attenuator of the intermediate frequency link). The specific design is as follows: 1) When the output value of the detector is higher than a certain set value (e.g., -10dBm), the value of the second attenuator will be adjusted within the range M = P. 设定值 – P 检波输出 1) Ensure that the signal strength entering the mixer does not exceed the mixer's input threshold (e.g., -10dBm); 2) When the detector's output value is lower than a certain set value (e.g., -10dBm), it will not control the attenuator's value, thus ensuring the mixer's linear operating dynamic range.

[0024] In this embodiment, the intermediate frequency (IF) gain circuit includes a third attenuator and an amplifier circuit connected in sequence. The third attenuator is used to adjust the strength of the incoming signal; the amplifier circuit is used to amplify the IF signal to match the input range of the subsequent ADC acquisition link. Further, this invention: 1) designs the IF gain to 15dB-115dB (default is 40dB), which can amplify and match any input signal (e.g., -115dBm to -10dBm) to the input range of the ADC acquisition link (e.g., -70dBm to 5dBm), maximizing the dynamic range; 2) the IF link gain control and the detector and control circuit of the mixer circuit are linked for control. The IF gain value is controlled according to the signal strength output by the detector, amplifying the signal output by the IF link to a specified power level. The IF link gain value G = P1 - P2, where P1 is the IF output setpoint and P2 is the detector output value. Assuming P1 = IF output setpoint... The specific design is as follows: 1) When the detector output signal strength P is -35dBm, the intermediate frequency (IF) gain is adjusted to 35dB; 2) When the detector output signal strength P is -25dBm, the IF gain is adjusted to 25dB; 3) When the detector output signal strength P is -10dBm, the IF gain is adjusted to 10dB. By controlling the IF link gain through closed-loop linkage, the magnitude of the IF link output signal strength can be automatically matched to the input range of the subsequent ADC acquisition link.

[0025] Based on the above embodiments, the present invention has at least the following technical effects:

[0026] In complex electromagnetic environments where strong interference and weak signals coexist, this invention effectively solves the problems of link saturation caused by strong interference signals and the decrease in effective dynamic range caused by mismatch between the input range of the ADC acquisition link and the detection control circuit and the RF / IF link gain through the above-mentioned RF / IF link gain range allocation design and the linkage closed-loop control of the detection control circuit and the RF / IF link gain. It effectively improves the detection sensitivity, the accuracy of weak signal detection and the signal monitoring distance.

[0027] For the foregoing embodiments, in order to simplify the description, they are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, because according to this application, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to this application.

[0028] The above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Modifications and variations made by those skilled in the art without departing from the spirit and scope of the invention should be within the protection scope of the appended claims.

Claims

1. A radio frequency link for improving the dynamic range of signal reception in complex electromagnetic environments, characterized in that, include: The system includes an RF link circuit, a mixer link circuit, and an intermediate frequency gain circuit, which are connected in sequence. It also includes a detection and control circuit, which is located between the mixer link circuit and the intermediate frequency gain circuit. The detection and control circuit is used to judge and calculate the voltage value of the detected signal, and then control the gain of the intermediate frequency gain circuit and the magnitude of the input signal of the mixer. The detection and control circuit includes a detector, a level acquisition circuit, and a control circuit connected in sequence. The input terminal of the detector is connected to the output terminal of the second attenuator, and the output terminal of the control circuit is connected to the input terminals of the second attenuator and the intermediate frequency gain circuit, respectively. Specifically, the output terminal of the control circuit is connected to the input terminal of the third attenuator of the intermediate frequency gain circuit.

2. The radio frequency link for improving the dynamic range of signal reception in a complex electromagnetic environment as described in claim 1, characterized in that, The radio frequency link circuit includes a limiter, a first switch, a second switch, and a first attenuator connected in sequence. A bypass circuit and a variable amplifier are provided in parallel between the first switch and the second switch.

3. The radio frequency link for improving the dynamic range of signal reception in a complex electromagnetic environment as described in claim 2, characterized in that, The gain of the radio frequency link circuit is 5dB~10dB. The signal passing through the radio frequency link circuit is within the input range guaranteed by the dynamic range of the subsequent mixing circuit to prevent the mixing link circuit from saturating.

4. The radio frequency link for improving the dynamic range of signal reception in a complex electromagnetic environment as described in claim 1, characterized in that, The mixing link circuit includes a second attenuator and a mixer connected in sequence. The second attenuator is used to adjust the signal strength entering the mixer, and the mixer is used to shift the input radio frequency to the intermediate frequency band signal.

5. The radio frequency link for improving the dynamic range of signal reception in a complex electromagnetic environment as described in claim 4, characterized in that, The detection and control circuit is used to detect and measure the signal strength of the signal entering the mixing link circuit, and to control the gain of the second attenuator and the intermediate frequency gain circuit in conjunction.

6. The radio frequency link for improving the dynamic range of signal reception in a complex electromagnetic environment as described in claim 1, characterized in that, The intermediate frequency gain circuit includes a third attenuator and an amplifier circuit connected in sequence. The third attenuator is used to adjust the strength of the incoming signal; the amplifier circuit is used to amplify the intermediate frequency signal to match the input range of the subsequent ADC acquisition link.

7. The radio frequency link for improving the dynamic range of signal reception in a complex electromagnetic environment as described in claim 6, characterized in that, The intermediate frequency gain value of the intermediate frequency gain circuit is 15dB~115dB.

8. The radio frequency link for improving the dynamic range of signal reception in a complex electromagnetic environment as described in claim 7, characterized in that, The intermediate frequency (IF) gain value is controlled based on the signal strength output by the detection and control circuits. The signal output by the IF gain circuit is amplified to a specified power level. The IF gain value G = P1 - P2, where P1 is the IF output setting value, P2 is the detection output value, and G is the IF gain value.

Images