Signal receiving circuit, receiver and communication equipment

Abstract

The utility model provides a signal receiving circuit, a receiver and communication equipment. The signal receiving circuit comprises a receiving module and an amplifying module which are connected in sequence, the amplification module at least comprises a first coupling unit, the first coupling unit is connected with the output end of the receiving module and used for distributing a first signal output by the receiving module and outputting a first coupling signal and a second coupling signal, and the first coupling signal and the second coupling signal have a phase difference; the first amplification unit is used for amplifying the first coupling signal and outputting a second signal; the second amplification unit is used for amplifying the second coupling signal and outputting a third signal; and the second coupling unit is used for combining the second signal and the third signal. By means of the mode, the two coupling units and the two amplifying units are used for coupling gain, the problems of performance loss and the like generated by a single-path amplifier are solved, and the communication performance of equipment is improved.

Description

TECHNICAL FIELD

[0001] The present application mainly relates to the field of communication technology, in particular to a signal receiving circuit, a receiver and a communication device. BACKGROUND

[0002] The receiving sensitivity is an important index in the private network communication, representing the ability of the minimum signal level that the receiver can correctly receive, and plays a very important role in the complex communication environment. In the actual circuit, the receiving sensitivity is realized by the design requirement of the noise figure (NF) index of the system, and the system NF is affected by the NF of each stage circuit.

[0003] In the prior art, an amplifier is usually used to improve the sensitivity of the device, but the gain improvement of the LNA (low noise amplifier) will cause poor input and output return loss or even self-excitation. The LNA interstage cascading before and after the poor standing wave will worsen the system noise, resulting in poor sensitivity, and the temperature change has a great influence on the overall performance of the amplifier. The stability will be poor or even self-excitation after a long time. CONTENT OF THE INVENTION

[0004] The main purpose of the present application is to provide a signal receiving circuit, a receiver and a communication device to solve the problem that the gain improvement of the single low noise amplifier in the prior art will cause poor input and output return loss or even self-excitation, so as to improve the gain of the low noise amplifier and improve the receiving sensitivity and overall receiving performance of the device.

[0005] To solve the above problems, the present application provides a signal receiving circuit, a receiver and a communication device, which comprises a receiving module and an amplifying module connected in sequence; wherein the amplifying module at least comprises: a first coupling unit connected to the output end of the receiving module, for distributing and outputting a first coupling signal and a second coupling signal from the first signal output by the receiving module, wherein the first coupling signal and the second coupling signal have a phase difference; a first amplifying unit connected to the first coupling unit, for amplifying the first coupling signal and outputting a second signal; a second amplifying unit connected to the first coupling unit, for amplifying the second coupling signal and outputting a third signal; and a second coupling unit connected to the first amplifying unit and the second amplifying unit, for combining the second signal and the third signal.

[0006] In an embodiment, the signal receiving circuit further comprises a detection module connected to the first amplifying unit and the second amplifying unit, for detecting the current value of the amplifying module; and a processing module connected to the detection module, for monitoring the working state of the amplifying module according to the current value.

[0007] In an embodiment, the signal receiving circuit further comprises a switch, a first end of the switch is connected to the receiving module, and a second end of the switch is connected to the amplifying module; wherein the switch is configured to control the on-off of the signal receiving circuit, and when the detecting module detects that the current value of the amplifying module is greater than the current threshold, the signal receiving circuit is controlled to be disconnected.

[0008] In an embodiment, the detecting module comprises a first resistor, a first end of the first resistor is connected to the first amplifying unit and the second amplifying unit, and a second end of the first resistor is connected to a voltage source; a subtractor, a negative input end of the subtractor is connected to the first end of the first resistor, a positive input end of the subtractor is connected to the second end of the first resistor, and an output end of the subtractor is connected to the processing module.

[0009] In an embodiment, the receiving module comprises an antenna, and a filtering unit, the filtering unit is connected to the antenna and the amplifying module, and is configured to filter the signal received by the antenna and output a first signal.

[0010] In an embodiment, the amplifying module further comprises a second resistor, a first end of the second resistor is connected to the isolation end of the first coupling unit, and a second end of the second resistor is grounded; and a third resistor, a first end of the third resistor is connected to the isolation end of the second coupling unit, and a second end of the third resistor is grounded.

[0011] In an embodiment, the signal amplitudes of the first coupling signal and the second coupling signal are the same, and the phase difference is 90°.

[0012] In an embodiment, the first amplifying unit and the second amplifying unit are low-noise amplifiers.

[0013] To solve the above problems, the present application further provides a receiver, comprising the signal receiving circuit as described in any one of the above embodiments.

[0014] To solve the above problems, the present application further provides a communication device, comprising a transmitter and a receiver, the transmitter is configured to transmit a radio frequency signal, and the receiver is configured to receive a radio frequency signal, and the receiver is as described in the above embodiments.

[0015] The application provides a signal receiving circuit, a receiver and a communication device, the signal receiving circuit comprising a receiving module and an amplifying module connected in sequence; the amplifying module at least comprises: a first coupling unit, which distributes and outputs a first coupling signal and a second coupling signal by distributing a first signal output by the receiving module through the first coupling unit, the first coupling signal and the second coupling signal having a phase difference; a first amplifying unit, which amplifies and outputs a second signal by amplifying the first coupling signal; a second amplifying unit, which amplifies and outputs a third signal by amplifying the second coupling signal; and a second coupling unit, which combines the second signal and the third signal, so that the gain effect of the amplifier is increased through linear conversion on the basis of ensuring the overall intermodulation index margin, thereby solving the problem of large input-output loss or even self-excitation caused by the gain increase of the single-path amplifier, and further solving the problem of poor sensitivity. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0017] Figure 1 is a structural schematic diagram of a first embodiment of the signal receiving circuit provided by the present application;

[0018] Figure 2 is a structural schematic diagram of a second embodiment of the signal receiving circuit provided by the present application;

[0019] Figure 3 is a structural schematic diagram of a third embodiment of the signal receiving circuit provided by the present application;

[0020] Figure 4 is a structural schematic diagram of a fourth embodiment of the signal receiving circuit provided by the present application;

[0021] Figure 5 is a structural schematic diagram of a fifth embodiment of the signal receiving circuit provided by the present application;

[0022] Figure 6 is a structural schematic diagram of a sixth embodiment of the signal receiving circuit provided by the present application;

[0023] Figure 7 is a structural schematic diagram of a seventh embodiment of the signal receiving circuit provided by the present application;

[0024] Figure 7a is a verification schematic diagram of the power-off S parameter in an embodiment of the signal receiving circuit provided by the present application;

[0025] Figure 7b is a verification schematic diagram about double-open S parameters in an embodiment of the signal receiving circuit provided in the present application;

[0026] Figure 7c is a verification schematic diagram about single-open S parameters in an embodiment of the signal receiving circuit provided in the present application;

[0027] Figure 8 is a control flow schematic diagram of an embodiment of the signal receiving circuit provided in the present application;

[0028] Figure 9 is a structural schematic diagram of an embodiment of the receiver provided in the present application;

[0029] Figure 10 is a structural schematic diagram of an embodiment of the communication device provided in the present application;

[0030] Figure 11 is a comparison diagram of IIP3 linear data in an embodiment of the signal receiving circuit provided in the present application.

[0031] Reference signs:

[0032] signal receiving circuit 100, receiving module 10, amplifying module 20, detecting module 30, processing module 40, switching switch 50, antenna 11, filtering unit 12, first coupling unit 21, first amplifying unit 22, second amplifying unit 23, second coupling unit 24, first resistor R1, second resistor R2, third resistor R3, subtracter M1, analog-to-digital conversion unit 41, processing unit 42, receiver 200, power supply 210, communication device 300, transmitter 310. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described clearly and completely in the present application with reference to the drawings in the embodiments of the present application. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0034] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0035] Reference herein to "embodiments" means that a particular feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily mutually exclusive of other embodiments. It is explicitly and implicitly understood that the embodiments described herein can be combined with other embodiments.

[0036] In existing communication processes, the requirement for receiving sensitivity is increasingly high, and in the field of communication, sensitivity is a key indicator of the performance of a receiver, which refers to the minimum signal strength that the receiver can correctly receive and demodulate, representing the ability of the receiver to correctly receive the minimum signal level. In other words, sensitivity is the lowest input signal power level that the receiver can achieve a certain predetermined performance standard (such as bit error rate BER) at a certain signal-to-noise ratio (SNR).

[0037] And improving the gain of the low noise amplifier (LNA) can effectively reduce the noise figure of the system and improve the receiving sensitivity. However, the gain improvement of the single low noise amplifier (LNA) will lead to poor input-output return loss and even self-excitation, and the inter-stage cascading of the low noise amplifier (LNA) with poor standing wave ratio will worsen the system noise, leading to worse sensitivity. Moreover, temperature changes have a great impact on the overall performance of the amplifier, and the stability will deteriorate over time or even self-excitation. The self-excitation phenomenon usually refers to the phenomenon of self-circulating amplification of signals due to internal feedback or external environmental factors. This phenomenon can seriously affect the performance of the communication system, causing the receiver to malfunction or even completely fail to work.

[0038] Referring to Figure 1 , Figure 1 is a structural schematic diagram of a first embodiment of a signal receiving circuit provided by the application; the signal receiving circuit 100 includes a receiving module 10 and an amplifying module 20 connected in sequence; wherein the amplifying module 20 at least includes a first coupling unit 21, a first amplifying unit 22, a second amplifying unit 23 and a second coupling unit 24.

[0039] Specifically, regarding the connection relationship between the modules: the first coupling unit 21 is connected to the output end of the receiving module 10, receives the first signal output by the receiving module 10 and distributes the first signal, outputs the first coupling signal and the second coupling signal, wherein the first coupling signal and the second coupling signal have a phase difference; the first amplification unit 22 is connected to the first coupling unit 21, receives the first coupling signal, and outputs the second signal; the second amplification unit 23 is connected to the first coupling unit 21, receives the second coupling signal, and outputs the third signal; the second coupling unit 24 is connected to the first amplification unit 22 and the second amplification unit 23 respectively, and combines the second signal and the third signal.

[0040] In an embodiment, the first coupling unit 21 and the second coupling unit 24 are directional couplers; in an embodiment, the first amplification unit 22 and the second amplification unit 23 are low-noise amplifiers.

[0041] Wherein, since the noise power is the noise floor of the 50 ohm system, the directional coupler also has a 50 ohm characteristic, so it cannot couple and distribute the noise; the directional coupling only averages the input signal and has no effect on the noise, so the noise figure of the identical dual-path LNA is unchanged compared with the single-ended LNA. The total noise figure is closely related to the noise figures of the two branches, and when the noise figures of the two branches are the same, the noise figure is the smallest.

[0042] Wherein, after the signal receiving circuit 100 receives the radio frequency signal through the receiving module 10, the useful signal obtained by it, i.e. the first signal, is output to the first coupling unit 21 for distribution through the first coupling unit 21; for example, in an embodiment, the a1 port of the first coupling unit 21 is the input port (A), the a2 port is the isolation port, and the b1 port is the through port The b2 port is the coupling port Wherein, the output signals of the through port and the coupling port have the same amplitude and opposite phases, i.e. a phase difference of 90 degrees, and the isolation port has no signal output; after the first signal passes through the first coupling unit 21, the first coupling signal and the second coupling signal are sent to the first amplification unit 22 and the second amplification unit 23 respectively for multiple amplification (e.g. G times amplification), respectively as And The two-way intermodulation component is reduced by 6dB (20log*((1 / 2A) / A)=-6dB), and then the signal enters the second coupling unit 24, and the total signal generated at the D2 port of the second coupling unit 24 is The total intermodulation branch is reduced by 6dB, and there is no output at the D1 port. Wherein, A is the first signal, and j is a constant.

[0043] It can be understood that the explanation about the four ports is as follows: input port (Port 1): this is the entrance for signals to enter the directional coupler. When a signal is input from this port, most of the signal will pass through to the next port output, and a small part of the signal will be coupled to the coupling port output. Usually, this port will receive the microwave signal to be processed. Straight-through port (Port 2): also known as the pass-through port, it allows signals to pass directly from the input port with essentially no change. This means that a signal can be input from Port 1 and output from Port 2 without being significantly attenuated or changed. Coupling port (Port 3): this port outputs the signal coupled from the input port. The amplitude of the coupled signal is usually a certain proportion of the amplitude of the input signal, and this proportion depends on the design of the coupler. The signal output from the coupling port is often used for power detection, gain control, etc. Isolation port (Port 4): in an ideal case, this port will not have power output to ensure minimal interference. But in reality, there will always be some power leakage from this port, which is an indicator of isolation.

[0044] In an embodiment, the signal amplitudes of the first coupling signal and the second coupling signal are the same, and the phase difference is 90°.

[0045] In an embodiment, as shown in Figure 2 , Figure 2 is a structural schematic diagram of a second embodiment of a signal receiving circuit provided by the present application; wherein the receiving module 10 comprises an antenna 11 and a filtering unit 12, the filtering unit 12 is connected to the antenna 11 and the amplifying module 20, and is used for filtering the signal received by the antenna 11 and outputting a first signal to the amplifying module 20.

[0046] In the above embodiment, the receiving module 10 receives a radio frequency signal through the antenna 11, and uses the filtering unit 12 to perform audio processing, signal purification, frequency band selection, etc. on the received radio frequency signal, and then can obtain a processed useful signal, so as to facilitate further operation of the subsequent circuit.

[0047] By the above manner, the dual-path amplification unit has the same gain as the single-path amplification unit, and the IIP3 is increased by 3dB. The innovation increases the gain of the amplification unit to improve the overall receiver NF on the basis of ensuring the intermodulation index margin, so as to improve the sensitivity. The IIP3 (Input Third-Order Intercept Point) is an important parameter in a wireless communication system, which refers to the third-order intercept point of an input signal. The higher the IIP3 is, the better the linearity of the system is, and the stronger the processing capability of the system for multi-frequency signals is. The noise figure (NF) is an important parameter for measuring the noise performance of an amplifier or a communication system. The noise figure is defined as the logarithm of the ratio of the noise power of the amplifier to the input signal noise power, and is usually expressed in decibels (dB). The smaller the noise figure is, the smaller the interference of the amplifier to the signal is, and the better the fidelity and clarity of the signal are.

[0048] In an embodiment, as shown in Figure 3 , Figure 3 is a structural schematic diagram of a third embodiment of a signal receiving circuit provided by the present application; the signal receiving circuit 100 further comprises a detection module 30 and a processing module 40; the detection module 30 is connected to the first amplification unit 22 and the second amplification unit 23, and is configured to detect the current value of the amplification module 20; and the processing module 40 is connected to the detection module 30, and is configured to monitor the working state of the amplification module 20 according to the current value.

[0049] In the above scheme, the detection module 30 and the processing module 40 are arranged to detect the current value change of the amplification module 20, so as to avoid the damage of components caused by excessive current during the working process of the circuit, which can be used for overcurrent protection, power management and other aspects.

[0050] Corresponding to the above scheme, in the specific schemes of other embodiments:

[0051] Scheme 1:

[0052] In an embodiment, as shown in Figure 4 , Figure 4 is a structural schematic diagram of a fourth embodiment of a signal receiving circuit provided by the present application; the detection module 30 comprises a first resistor R1 and a subtracter M1; wherein the first end of the first resistor R1 is connected to the first amplification unit 22 and the second amplification unit 23, the second end of the first resistor R1 is connected to a voltage source VCC; the negative input end of the subtracter M1 is connected to the first end of the first resistor R1, the positive input end of the subtracter M1 is connected to the second end of the first resistor R1, and the output end of the subtracter M1 is connected to the processing module 40.

[0053] Wherein, the voltage value across the first resistor R1 is detected by the subtracter M1 to obtain the voltage difference across the first resistor R1, and the current value is calculated according to Ohm's law by the processing module 40, and the working state of the amplification module 20 and the current value are detected in real time to avoid damage to components caused by excessive current.

[0054] Scheme 2:

[0055] In an embodiment, as shown in Figure 5 , Figure 5 is a structural schematic diagram of the fifth embodiment of the signal receiving circuit provided by the present application; the processing module 40 comprises: an analog-to-digital conversion unit 41 and a processing unit 42, the analog-to-digital conversion unit 41 is connected to the output end of the second coupling unit 24; and the processing unit 42 is connected to the analog-to-digital conversion unit 41 and the detection module 30 respectively.

[0056] It can be understood that after the voltage difference across the first resistor R1 is detected by the detection module 30, the processing unit 42 in the processing module 40 is used to realize the calculation function to obtain the current value and report the decoding data; in an embodiment, the processing unit 42 is a digital signal processor.

[0057] It can be understood that for the above-mentioned scheme of detecting the current, a specific application is further provided, and the scheme is as follows:

[0058] In an embodiment, as shown in Figure 6 , Figure 6 is a structural schematic diagram of the sixth embodiment of the signal receiving circuit provided by the present application; the signal receiving circuit 100 further comprises: a switching switch, the first end of the switching switch is connected to the receiving module 10, and the second end of the switching switch is connected to the amplification module 20; wherein the switching switch is used to control the on-off of the signal receiving circuit 100, and when the detection module 30 detects that the current value of the amplification module 20 is greater than the current threshold value, the switching switch is controlled to be disconnected.

[0059] Wherein, the switching switch is combined with the detection module 30 to realize the timely cutting off of the path to protect the rear-end circuit when the overcurrent condition occurs.

[0060] In combination with the above-mentioned embodiment scheme, the reflected power is absorbed by increasing the load to stabilize the standing wave in the signal receiving circuit 100, and the specific scheme is as follows:

[0061] In an embodiment, as shown in Figure 7 , Figure 7is a structural schematic diagram of a seventh embodiment of the signal receiving circuit provided in the application; the amplification module 20 further comprises a second resistor and a third resistor; wherein a first end of the second resistor is connected to the isolation end of the first coupling unit 21, and a second end of the second resistor is grounded; a first end of the third resistor is connected to the isolation end of the second coupling unit 24, and a second end of the third resistor is grounded.

[0062] Wherein, a part of the input signal, i.e., the first signal, is through a1 port to b2 port, and the power passing through b2 port will return to a1 port again, and the total phase shift is-360 degrees; another part of the signal is through a1 port to b1 port, and the power passing through b1 port will also return to a1 port again, and the total phase shift is-180 degrees; therefore, after the reflection of the two parts of the signal, the phases are opposite, and the power is cancelled, so there is no reflected signal at a1 port, but the signals reflected from b1 and b2 ports are superimposed at the port of the load resistor (the second resistor), and therefore a matching load at the port is needed to absorb the reflected power, so that the input standing wave is theoretically very good and stable, and the principle of the output standing wave is similar.

[0063] Further, refer to Figure 7a , Figure 7b and Figure 7c , wherein Figure 7a is a verification schematic diagram of the power-off S parameter in an embodiment of the signal receiving circuit provided in the application; Figure 7b is a verification schematic diagram of the double-on S parameter in an embodiment of the signal receiving circuit provided in the application; Figure 7c is a verification schematic diagram of the single-on S parameter in an embodiment of the signal receiving circuit provided in the application; wherein the single-on S parameter (similar to the state of burning one way). As can be seen from the above diagram, through the scheme in the application, the standing wave remains very good at rest or during work, and the gain isolation is stable; the single-on one way is similar to burning one way, and the standing wave amplifies stable and reliable signal output, because there are two amplifiers, if one of them is damaged, the circuit can still continue to use the other to work, although the output power is lowered by 6dB, in general, the reliability is higher than that of a single amplifier.

[0064] For the above embodiment, the application provides a corresponding control process on the basis of the above embodiment, refer to Figure 8 , Figure 8 is a control process schematic diagram of an embodiment of the signal receiving circuit provided in the application; wherein the specific mode comprises the following steps:

[0065] Step S10: Setting channel and switching to receive communication link. In an embodiment, after the flow starts, the channel number Band, n center frequency point are set, and the T / R switch is switched to RX end, TRX_ = 0, then the RX link is opened (LAN enables full open), the field strength threshold = -20 (i.e. the first threshold value) is set, and the current threshold Y = 20 (i.e. the second threshold value) is set. The main function of the T / R switch (Transmit / Receive Switch) is to quickly switch between transmission and reception modes while ensuring that the transmission signal will not be received by the receiver, thereby protecting the receiver from damage. When the T / R switch is switched to the RX end, it means that the switch has been set to the receiving mode.

[0066] Step S20: Detecting RSSI (signal strength) and current. The detection of RSSI (signal strength) and current is completed, and the values are compared with the corresponding threshold values in step S30.

[0067] Step S30: Whether RSSI is greater than or equal to the first threshold value, and the current value is greater than the second threshold value. When the determination of step S30 is satisfied (i.e. RSSI is greater than or equal to the first threshold value, and the current value is greater than the second threshold value), step S40 is executed: the first amplification unit enable = 1 and the second amplification unit enable = 0 (i.e. different enable outputs of the amplification unit are controlled), and further, after completing step S40, the current RSSI and current value are calculated according to the changes, and the current enable state, gain and current value changes are reported and stored. It can be understood that after the reporting and storage are completed, step S20 can be continued to jump and execute, realizing the continuous detection and adjustment of the circuit.

[0068] When the values of RSSI (signal strength) and current do not satisfy the determination of step S30, step S50 is further executed: whether RSS is less than or equal to the third threshold value. In an embodiment, the third threshold value is the difference between the first threshold value and 40; when the determination of step S50 is satisfied, step S60 is executed: the first amplification unit enable = 1 and the second amplification unit enable = 1, which is the same as the above. After completing step S60, the current RSSI and current value are calculated according to the changes, and the current enable state, gain and current value changes are reported and stored. It can be understood that after the reporting and storage are completed, step S20 can be continued to jump and execute, and when the condition determination of step S50 is not satisfied, it is also jumped to step S20 to continue to execute the detection and control.

[0069] It can be understood that the electric field strength detection is assisted by the current detection to improve the control logic accuracy. And when there is a large signal input, one LNA is turned off, the power saving strategy and large signal error-free code are executed.

[0070] In the above manner, on the basis of ensuring the overall intermodulation index margin, the excess linear conversion increases the LNA gain to improve the overall receiver NF, and the sensitivity is improved. For example, the IIP3 linearity can be increased by 3dB; the dynamic range is doubled (3dB); adjusting the linear gain can improve the sensitivity; the standing wave is good and the circuit is stable, even if one way is burned out, the receiver amplifier can still work; current detection; double LNA extended amplification frequency band, mainly limited by the bandwidth of the directional coupler; receiving +25dBm or less large signal without error code and other advantages.

[0071] Referring to Figure 9 , Figure 9 is a structural schematic diagram of an embodiment of a receiver provided by the present application; the receiver 200 includes a power supply 210 and a signal receiving circuit 100; the signal receiving circuit 100 is connected to the power supply 210, the power supply 210 supplies power to the signal receiving circuit 100, and the signal receiving circuit 100 is the signal receiving circuit 100 described in any one of the above embodiments.

[0072] Referring to Figure 10 , Figure 10 is a structural schematic diagram of an embodiment of a communication device provided by the present application; the communication device 300 includes a transmitter 310 and a receiver 200; the receiver 200 is connected to the transmitter 310, the transmitter 310 is used to transmit a radio frequency signal, and the receiver 200 is used to receive a radio frequency signal, and the receiver 200 is the receiver 200 described in the above embodiments.

[0073] Further, as Figure 11 , Figure 11 is an IIP3 linearity data comparison chart in an embodiment of a signal receiving circuit provided by the present application; after using the scheme of the present application, the IIP3 linearity is improved by 2.8-2.9dBc, in order to achieve better sensitivity, the gain of the low noise amplifier can be increased by about 2-3dB, which satisfies the intermodulation and improves the sensitivity.

[0074] The application provides a signal receiving circuit 100, a receiver and a communication device, the signal receiving circuit 100 comprises a receiving module 10 and an amplification module 20 connected in sequence; wherein the amplification module 20 at least comprises: a first coupling unit 21, the first coupling unit 21 is connected to the output end of the receiving module 10, receives the first signal output by the receiving module 10 and distributes the first signal, outputs a first coupling signal and a second coupling signal; a first amplification unit 22, the first amplification unit 22 is connected to the first coupling unit 21, receives the first coupling signal and outputs a second signal; a second amplification unit 23, the second amplification unit 23 is connected to the first coupling unit 21, receives the second coupling signal and outputs a third signal; a second coupling unit 24, the second coupling unit 24 is connected to the first amplification unit 22 and the second amplification unit 23 respectively, and combines the second signal and the third signal.

[0075] In the above manner, the coupling gain is achieved by using two coupling units and two amplification units, the performance loss caused by the single-path amplifier is solved, and the linear degree, dynamic range and other communication performances of the device are improved.

[0076] The above describes the embodiments of the application in detail, and the principles and implementation manners of the application are described by using specific examples; the above embodiment descriptions are only used to help understand the method of the application and the core idea thereof; meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation manner and application range can be changed, and the above description should not be understood as a limitation of the application.

Claims

1. A signal receiving circuit, characterized by comprising: The signal receiving circuit comprises a receiving module and an amplifying module connected in sequence; wherein the amplifying module comprises at least: a first coupling unit connected to the output end of the receiving module, for distributing the first signal output by the receiving module, and outputting a first coupling signal and a second coupling signal, wherein the first coupling signal and the second coupling signal have a phase difference; a first amplifying unit connected to the first coupling unit, for amplifying the first coupling signal, and outputting a second signal; a second amplifying unit connected to the first coupling unit, for amplifying the second coupling signal, and outputting a third signal; a second coupling unit connected to the first amplifying unit and the second amplifying unit respectively, for combining the second signal and the third signal.

2. The signal receiving circuit according to claim 1, characterized by The signal receiving circuit further comprises: a detection module connected to the first amplifying unit and the second amplifying unit, for detecting the current value of the amplifying module; a processing module connected to the detection module, for monitoring the working state of the amplifying module according to the current value.

3. The signal receiving circuit according to claim 2, characterized by The signal receiving circuit further comprises: a switching switch, the first end of the switching switch is connected to the receiving module, and the second end of the switching switch is connected to the amplifying module; wherein the switching switch is used for controlling the on-off of the signal receiving circuit, and when the detection module detects that the current value of the amplifying module is greater than a current threshold, the signal receiving circuit is controlled to be disconnected.

4. The signal receiving circuit according to claim 2, wherein The detection module comprises: a first resistor, the first end of the first resistor is connected to the first amplifying unit and the second amplifying unit, and the second end of the first resistor is connected to a voltage source; a subtracter, the negative input end of the subtracter is connected to the first end of the first resistor, the positive input end of the subtracter is connected to the second end of the first resistor, and the output end of the subtracter is connected to the processing module.

5. The signal receiving circuit of claim 1, wherein The receiving module comprises: an antenna; a filtering unit connected to the antenna and the amplifying module, for filtering the signal received by the antenna and outputting the first signal.

6. The signal receiving circuit of claim 1, wherein The amplifying module further comprises: a second resistor, the first end of the second resistor is connected to the isolation end of the first coupling unit, and the second end of the second resistor is grounded; a third resistor, the first end of the third resistor is connected to the isolation end of the second coupling unit, and the second end of the third resistor is grounded.

7. The signal receiving circuit according to any one of claims 1 to 6, characterized by, The signal amplitudes of the first coupling signal and the second coupling signal are the same, and the phase difference is 90°.

8. The signal receiving circuit of claim 1, wherein, The first amplifying unit and the second amplifying unit are low-noise amplifiers.

9. A receiver, characterized by The receiver comprises the signal receiving circuit according to any one of claims 1-8.

10. A communication device, characterized by The communication device comprises: a transmitter; a receiver, the transmitter is used for transmitting radio frequency signals, the receiver is used for receiving radio frequency signals, and the receiver is the receiver according to claim 9. The communication device comprises: a transmitter; a receiver, the transmitter is used for transmitting radio frequency signals, the receiver is used for receiving radio frequency signals, and the receiver is the receiver according to claim 9.

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