WO2020243909A1

WO2020243909A1 - Standing wave detection apparatus and communication device

Info

Publication number: WO2020243909A1
Application number: PCT/CN2019/090009
Authority: WO
Inventors: 许锐生; 王清华
Original assignee: 海能达通信股份有限公司
Priority date: 2019-06-04
Filing date: 2019-06-04
Publication date: 2020-12-10

Abstract

A standing wave detection apparatus and a communication device. The standing wave detection apparatus comprises a signal strength detection circuit (11) and a controller (12). The signal strength detection circuit (11) is used for using a receiving link of a receiver to obtain a forward power and a reverse power of a transmitter in a transmission time slot so as to generate a corresponding forward voltage and reverse voltage. The controller (12) is connected to the signal strength detection circuit (11) and is used for receiving the forward voltage and the reverse voltage so as to obtain a voltage standing wave ratio of an antenna, determining, according to the voltage standing wave ratio of the antenna, whether to adjust a transmit power of the transmitter, and if yes, adjusting the transmit power of the transmitter by adjusting the value of a control voltage input to the transmitter. By means of the approach, the present application can perform forward power and reverse power detection in the transmission time slot by using the receiving link of the receiver, and thus performing standing wave detection to improve the detection accuracy and save hardware costs.

Description

Standing wave detection device and communication equipment

【Technical Field】

This application relates to the field of communication technology, and in particular to a standing wave detection device and communication equipment.

【Background technique】

In the RF transmission link of communication equipment, especially the high-power transmission circuit, in order to protect the RF power amplifier tube from being damaged by the reflected RF signal and shorten the service life, the voltage standing wave ratio is usually reserved between the final power amplifier tube and the antenna port. (VSWR, Voltage Standing Wave Ratio) The detection circuit monitors the standing wave in real time. When the standing wave is too large and the reflected signal exceeds the standard, the power amplifier is reduced or the power amplifier is turned off for protection; therefore, the standing wave detection and protection mechanism protects the power amplifier The service life of the tube plays a vital role.

In the long-term research and development, the inventor of the present application found that in existing practical applications, standing wave detection can be performed on the feedback link of high-power communication equipment predistortion, but this method is only suitable for digital predistortion (DPD, Digital Pre-Distortion) calibration system, and single-carrier digital trunking communication (DMR, Digital Mobile Radio) products do not need to perform DPD calibration, so there is no additional feedback channel; in addition, the current DMR vehicle standing wave detection method uses three operational amplifiers Realize the forward power and reverse power and standing wave detection of transmission with two detector tubes. The disadvantage is that there are more components, large layout space and high cost. Due to the use of hardware loop detection and control, the accuracy of the components affects each other and is consistent. The performance is relatively poor, and it is necessary to repeatedly test each frequency point to evaluate the fitting calibration factor; due to the frequency band and printed circuit board (PCB, Printed Circuit Board) design differences, each model requires a large amount of debugging work.

[Content of the invention]

The main problem to be solved by this application is to provide a standing wave detection device and communication equipment, which can use the receiver link to perform forward power and reverse power detection in the transmission time slot, and then perform standing wave detection to improve detection accuracy. Save hardware costs.

In order to solve the above technical problems, the technical solution adopted in this application is to provide a standing wave detection device. The standing wave detection device includes a signal strength detection circuit and a controller. The signal strength detection circuit is used for receiving by the receiver in the transmission time slot. The link obtains the forward power and reverse power of the transmitter to generate the corresponding forward voltage and reverse voltage; the controller is connected to the signal strength detection circuit to receive the forward voltage and reverse voltage to obtain the antenna Voltage standing wave ratio, and judge whether to adjust the transmitting power of the transmitter according to the voltage standing wave ratio of the antenna. If so, adjust the control voltage value input to the transmitter to adjust the transmitting power of the transmitter.

In order to solve the above technical problems, another technical solution adopted in this application is to provide a communication device, which includes: a first switch, a standing wave detection device, and a second switch. The first switch is connected to the transmitter, the receiver, and Antenna connection, used to connect the transmitter and antenna in the transmission time slot or the receiver and antenna in the receiving time slot; the standing wave detection device is connected to the receiver and the transmitter respectively, used to use the receiver in the transmission time slot The receiving link obtains the voltage standing wave ratio of the antenna, and adjusts the transmitting power of the transmitter according to the voltage standing wave ratio; the second switch is respectively connected with the transmitter, the receiver and the standing wave detection device to connect the transmitter and the standing wave Detection device; wherein, the standing wave detection device includes a signal strength detection circuit and a controller, the signal strength detection circuit is used to obtain the forward power and reverse power of the transmitter by using the receiving link of the receiver in the transmission time slot to generate the corresponding The controller is connected with the signal strength detection circuit to receive the forward voltage and the reverse voltage to obtain the voltage standing wave ratio of the antenna, and judge whether to adjust the transmission according to the voltage standing wave ratio of the antenna If yes, adjust the control voltage value input to the transmitter to adjust the transmitter’s transmit power.

Through the above solution, the beneficial effect of the present application is that the signal strength detection circuit of the transmission time slot uses the receiving link of the receiver to obtain the forward voltage and the reverse voltage corresponding to the output signal of the transmitter; Calculate the voltage standing wave ratio of the antenna and determine whether it is necessary to adjust the transmitting power of the transmitter according to the voltage standing wave ratio. If it is necessary to adjust the transmitting power of the transmitter, adjust the control input to the transmitter The voltage value is adjusted to change the transmission power of the transmitter. The forward power and reverse power detection are performed by using the receiver's receiving link in the transmission time slot, and then the standing wave detection is performed to improve the detection accuracy of the voltage standing wave ratio. , As the receiving link is multiplexed, the hardware cost is saved.

【Explanation of drawings】

In order to more clearly describe the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained from these drawings without creative work. among them:

FIG. 1 is a schematic structural diagram of an embodiment of a standing wave detection device provided by the present application;

Figure 2 is a schematic structural diagram of an embodiment of a communication device provided by the present application;

Fig. 3 is a schematic structural diagram of another embodiment of a communication device provided by the present application.

【Detailed ways】

The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present application.

Referring to FIG. 1, FIG. 1 is a schematic structural diagram of an embodiment of a standing wave detection device provided by the present application. The standing wave detection device includes a signal strength detection circuit 11 and a controller 12.

The signal strength detection circuit 11 is used to obtain the forward power and reverse power of the transmitter (not shown in the figure) by using the receiving link of the receiver (not shown in the figure) in the transmission time slot to generate the corresponding forward power. Voltage and reverse voltage.

The signal strength detection circuit 11 works in the transmission time slot of the transmitter. In the transmission time slot, the transmitter sends out radio frequency signals through an antenna (not shown in the figure). The receiver does not receive radio frequency signals. The signal strength detection circuit 11 can use the receiving The receiver link of the machine to obtain the power of the signal sent by the transmitter, and convert the power into a voltage value.

The controller 12 is connected to the signal strength detection circuit 11 for receiving forward voltage and reverse voltage to obtain the voltage standing wave ratio of the antenna, and judging whether to adjust the transmitting power of the transmitter according to the voltage standing wave ratio of the antenna, if necessary To adjust the transmitting power of the transmitter, adjust the control voltage value input to the transmitter to adjust the transmitting power of the transmitter.

The working principle of the voltage standing wave ratio detection is to obtain the forward power and reverse power first, and then calculate the voltage standing wave ratio VSWR according to the following formula:

VSWR=(1+Γ)/(1-Γ)

Among them, Γ is the reflection coefficient, and the reflection coefficient Γ is proportional to the ratio of the reverse voltage to the forward voltage.

According to the obtained forward voltage and reverse voltage, the controller 12 can obtain the voltage standing wave ratio of the antenna by calculation, and judge whether it is necessary to adjust the transmitting power of the transmitter according to the voltage standing wave ratio. Transmit power, the controller 12 can keep the output control voltage value unchanged. If the result of the judgment is that the transmitter’s transmit power needs to be adjusted, the controller 12 can adjust the transmitter’s transmit power by adjusting the output control voltage value, so that The transmitting power of the transmitter is adjusted according to specific needs to adapt to the current transmitting environment.

In the transmission time slot, the signal strength detection circuit 11 uses the receiving link of the receiver to obtain the forward voltage and the reverse voltage corresponding to the output signal of the transmitter; and receives the forward voltage and the reverse voltage through the controller 12, and calculates The voltage standing wave ratio of the antenna is used to determine whether it is necessary to adjust the transmitting power of the transmitter. If the transmitting power of the transmitter needs to be adjusted, it is adjusted by adjusting the control voltage value input to the transmitter, so that the When the transmission power changes, the forward power and reverse power detection are performed by using the receiver's receiving link in the transmission time slot, and then the standing wave detection is performed to improve the detection accuracy of the voltage standing wave ratio. Due to the multiplexing of the receiving link, Save hardware costs.

Continuing to refer to FIG. 1, the controller 12 includes a voltage standing wave ratio calculation and judgment circuit 121, a power adjustment circuit 122 and a power monitoring circuit 123.

The voltage standing wave ratio calculation and judgment circuit 121 is connected to the signal strength detection circuit 11, and is used to receive the forward voltage and the reverse voltage, calculate the voltage standing wave ratio, and judge whether the voltage standing wave ratio is greater than the preset voltage standing wave ratio, If the calculated voltage standing wave ratio is greater than the preset voltage standing wave ratio, a power adjustment command is sent to the power adjustment circuit 122.

The power adjustment circuit 122 is connected to the input end of the power amplifier of the transmitter, and is used to adjust the control voltage value of the input power amplifier to a preset voltage value after receiving an instruction to adjust the power, wherein the control voltage value is greater than the preset voltage value.

When the power adjustment circuit 122 receives the instruction to adjust the power, it indicates that the current voltage standing wave ratio obtained by the voltage standing wave ratio calculation and judgment circuit 121 is greater than the preset voltage standing wave ratio, and the current reflected power is large, which is not conducive to the radio frequency signal. Transmit, can reduce the transmitting power of the radio frequency signal, in order to reduce the reflected power, reduce the voltage standing wave ratio.

Further, the power amplifier of the transmitter includes at least one transistor, and the output end of the power adjustment circuit 122 is connected to the input end of the transistor for outputting a control voltage value to control the output power of the transistor; in a specific embodiment, the transistor is The field effect tube connects the output terminal of the power adjustment circuit 122 with the gate of the field effect tube to control the gate voltage of the field effect tube, so as to adjust the output power of the power amplifier by adjusting the control voltage value.

The power monitoring circuit 123 is respectively connected to the signal strength detection circuit 11 and the power adjustment circuit 122, and is used to obtain the forward voltage output by the signal strength detection circuit 11 to generate forward power, and determine whether the forward power is greater than the preset power. If the forward power is greater than the preset power, a power adjustment instruction is sent to the power adjustment circuit 122.

The power monitoring circuit 123 is used to determine whether the acquired forward power exceeds the preset power. When the acquired forward power is greater than the preset power, the power monitoring circuit 123 sends an instruction to adjust the power to the power adjustment circuit 122 so that the power adjustment circuit 122 adjusts the control voltage value of the power amplifier input to the transmitter to change the transmit power of the transmitter.

The voltage standing wave ratio calculation and judgment circuit 121, the power adjustment circuit 122, and the power monitoring circuit 123 are used to detect whether the transmitter's transmitting power and the current voltage standing wave ratio are within the normal range. If it exceeds the normal range, the power adjustment circuit 122 To control the output power of the power amplifier of the transmitter, thereby controlling the transmitting power of the transmitter, reducing the reflected power of the radio frequency signal, and increasing the safety of the transmitter, so as not to damage the circuit due to excessive power.

Referring to FIG. 2, FIG. 2 is a schematic structural diagram of an embodiment of a communication device provided by the present application. The communication device includes: an antenna 21, a transmitter 22, a receiver 23, a first switch 24, a standing wave detection device 25, and a second switch 26.

The antenna 21 is used to transmit or receive radio frequency signals.

The transmitter 22 is connected to the antenna 21 for generating radio frequency signals, and the antenna 21 is used to transmit the radio frequency signals.

The receiver 23 is connected to the antenna 21 for receiving radio frequency signals and processing the radio frequency signals to obtain baseband signals;

The first switch 24 is connected to the antenna 21, the transmitter 22, and the receiver 23, respectively, and is used to connect the transmitter 22 and the antenna 21 in the transmission time slot or the receiver 23 and the antenna 21 in the reception time slot.

In this embodiment, in order to use the receiving link 231 of the receiver 23 to obtain the forward power and the reverse power in the transmission time slot, the transmitter 22 and the receiver 23 share the same antenna 21, and the transmitter 22 and the receiver 23 cannot be simultaneously In other embodiments, when the transmitter 22 and the receiver 23 are respectively connected to an antenna 21, the first switch 24 can be connected to the receiver 23 only, and the first switch 24 can be controlled to be off during the transmission time slot. The on state prevents the receiver 23 from receiving radio frequency signals in the transmission time slot.

The standing wave detection device 25 is connected to the transmitter 22 and the receiver 23 respectively, and is used to obtain the voltage standing wave ratio of the antenna 21 by using the receiving link 231 of the receiver 23 in the transmission time slot, and adjust the transmitter 22 according to the voltage standing wave ratio. The transmit power.

The second switch 26 is respectively connected to the transmitter 22, the receiver 23 and the standing wave detection device 25, and is used to connect the transmitter 22 and the standing wave detection device 25, so that the standing wave detection device 25 can receive from the transmission through the receiving link 231. Receiver 23 does not receive radio frequency signals at this time.

The standing wave detection device 25 includes a signal strength detection circuit 251 and a controller 252. The signal strength detection circuit 251 is connected to the receiving link 231. The signal strength detection circuit 251 is used to obtain the transmission by using the receiving link 231 of the receiver 23 in the transmission time slot. The forward power and reverse power of the machine 22 to generate corresponding forward voltage and reverse voltage; the controller 252 is connected to the signal strength detection circuit 251 for receiving the forward voltage and reverse voltage to obtain the antenna 21 Voltage standing wave ratio, and judge whether to adjust the transmitting power of the transmitter 22 according to the voltage standing wave ratio of the antenna 21. If the transmitting power of the transmitter 22 needs to be adjusted, adjust the control voltage value input to the transmitter 22 to adjust the transmitter 22 The transmit power.

The transmitter 22 and the antenna 21 are connected through the first switch 24, and the signal strength detection circuit 251 in the transmission time slot of the transmitter 22 obtains the forward voltage and reverse voltage corresponding to the output signal of the transmitter 22 through the receiving link 231; the controller 252 The voltage standing wave ratio of the antenna 21 is calculated according to the forward voltage and the reverse voltage. When it is determined that the transmission power of the transmitter 22 needs to be adjusted according to the voltage standing wave ratio, the control voltage value input to the transmitter 22 is adjusted to adjust the transmission The transmission power of the transmitter 22 changes the transmission power of the transmitter 22. The receiving link 231 of the receiver 23 is used to detect the forward power and the reverse power in the transmission time slot, and then the standing wave detection is performed to improve the detection accuracy and save The hardware cost.

Referring to Figure 3, Figure 3 is a schematic structural diagram of another embodiment of a communication device provided by the present application. The communication device includes: an antenna 31, a transmitter 32, a receiver 33, a first switch 34, a standing wave detection device 35, and a second开关36。 Switch 36.

The first switch 34 is a one-of-two switch. The first end of the first switch 34 is connected to the antenna 31, the second end is connected to the output end of the transmitter 32, and the third end is connected to the input end of the receiver 33; When the terminal is connected to the second terminal, the antenna 31 is used to transmit the radio frequency signal generated by the transmitter 32, and when the first terminal is connected to the third terminal, the antenna 31 is used to receive the radio frequency signal.

The transmitter 32 includes a signal generation and modulation circuit 321, a power amplifier 322, and a bidirectional coupler 323 connected in sequence.

The signal generation and modulation circuit 321 is used to generate a baseband signal, modulate the baseband signal into a radio frequency signal, modulate the carrier signal with the baseband signal to form a passband signal, and move the passband signal to the required frequency band to form a radio frequency signal and use Enough power is emitted.

The power amplifier 322 is used to amplify the received radio frequency signal, and the bidirectional coupler 323 is used to couple the input amplified radio frequency signal, couple out a part of the radio frequency signal to generate a forward radio frequency signal and a reverse radio frequency signal, and The forward radio frequency signal and the reverse radio frequency signal are transmitted to the receiving link 331.

Further, the transmitter 32 further includes a first signal attenuator 324 and a second signal attenuator 325. The input end of the bidirectional coupler 323 is connected to the output end of the power amplifier 322, and the through end of the bidirectional coupler 323 is connected to the first switch 34. The first coupling end of the bidirectional coupler 323 is connected to the first signal attenuator 324, the first coupling end of the bidirectional coupler 323 is the same direction coupling end, and the second coupling end of the bidirectional coupler 323 is connected to the first signal attenuator 324. The two signal attenuators 325 are connected. The second coupling end of the bidirectional coupler 323 is a reverse coupling end. The bidirectional coupler 323 is used to send the forward radio frequency signal and the reverse radio frequency signal to the first signal attenuator 324 and the second signal attenuator 324, respectively. The signal attenuator 325, the first signal attenuator 324 and the second signal attenuator 325 are respectively used to attenuate the forward radio frequency signal and the reverse radio frequency signal output by the bidirectional coupler 323.

The receiver 33 includes a receiving link 331 and a low noise amplifier 332. The receiving link 331 includes at least a demodulation circuit (not shown in the figure). The input end of the low noise amplifier 332 is connected to the third end of the first switch 34. The output end of the noise amplifier 332 is connected to the second end of the second switch 36. The low noise amplifier 332 is used to amplify the received radio frequency signal. The second switch 36 is a radio frequency switch out of three. The three terminals and the fourth terminal are respectively connected to the first signal attenuator 324 and the second signal attenuator 325, the first terminal of the second switch 36 is connected to a demodulation circuit, and the demodulation circuit is used to demodulate the acquired signal, To get the demodulated signal.

Further, when the first end of the second switch 36 is connected to the second end of the second switch 36, the demodulation circuit is used to demodulate the amplified radio frequency signal output by the low noise amplifier 332 to obtain a baseband signal, where , The signal strength detection circuit 351 is in the off state; when the first end of the second switch 36 is connected to the third end of the second switch 36, the demodulation circuit is used to demodulate the signal output by the first signal attenuator 324, In order to obtain the forward signal, the signal strength detection circuit 351 outputs the forward voltage according to the forward signal; when the first terminal of the second switch 36 is connected to the fourth terminal of the second switch 36, the demodulation circuit is used for the second signal The signal output by the attenuator 325 is demodulated to obtain a reverse signal, and the signal strength detection circuit 351 outputs a reverse voltage according to the reverse signal.

The controller 352 includes a voltage standing wave ratio calculation and judgment circuit 3521, a power adjustment circuit 3522, and a power monitoring circuit 3523. The voltage standing wave ratio calculation and judgment circuit 3521 is connected to the signal strength detection circuit 351 for receiving forward and reverse voltages. Voltage, and calculate the voltage standing wave ratio, determine whether the voltage standing wave ratio is greater than the preset voltage standing wave ratio, if the voltage standing wave ratio is greater than the preset voltage standing wave ratio, send the power adjustment command to the power adjustment circuit 3522, and A warning can be issued to remind the user that the current voltage standing wave ratio is too large. For example, the voltage standing wave ratio calculation and judgment circuit 3521 can be connected to a speaker (not shown in the figure). When the voltage standing wave ratio is too large, the output voltage is The loudspeaker causes the loudspeaker to emit a warning sound; the power adjustment circuit 3522 is connected to the input end of the power amplifier 322 of the transmitter 32, and is used to adjust the control voltage value of the input power amplifier 322 to a preset voltage after receiving a power adjustment instruction Value, where the control voltage value is greater than the preset voltage value.

The power monitoring circuit 3523 is respectively connected to the signal strength detection circuit 351 and the power adjustment circuit 3522, and is used to obtain the forward voltage output by the signal strength detection circuit 351 to generate forward power, and determine whether the forward power is greater than the preset power, If the forward power is greater than the preset power, an instruction to adjust the power is sent to the power adjustment circuit 3522.

In the transmission time slot, the first end and the second end of the first switch 34 are connected, the signal generation and modulation circuit 321 generates a radio frequency signal, the power amplifier 322 amplifies the radio frequency signal, and the bidirectional coupler 323 performs the amplified radio frequency signal. Coupled, part of the radio frequency signal is output from the through end of the bidirectional coupler 323, part of the radio frequency signal (forward radio frequency signal) is output from the first coupling end, and another part of the radio frequency signal (reverse radio frequency signal) is output from the second coupling end. The signal attenuator 324 attenuates the forward radio frequency signal to obtain a forward radio frequency signal with reduced power, and the second signal attenuator 325 attenuates the reverse radio frequency signal to obtain a reverse radio frequency signal with reduced power.

At this time, the first terminal of the second switch 36 is connected to the third terminal or the fourth terminal. In a specific embodiment, it can be configured such that the first terminal of the second switch 36 is connected to the third terminal first, and then to the fourth terminal. Terminal connection, that is, first receive the signal output by the first signal attenuator 324, and then receive the signal output by the second signal attenuator 325, the demodulation circuit demodulates the received signal to obtain the forward signal and the reverse signal.

After the signal strength detection circuit 351 obtains the forward signal and the reverse signal, it detects the forward power and reverse power corresponding to the forward signal and the reverse signal, and outputs the forward voltage and reverse voltage to the controller 352. The controller 352 352 adjusts the control voltage value input to the power amplifier 322 as required.

In the receiving time slot of the receiver 33, the first end of the first switch 34 is connected to the third end, the antenna 31 receives the radio frequency signal, the radio frequency signal enters the low noise amplifier 332, and the low noise amplifier 332 amplifies the radio frequency signal, and the amplified signal The radio frequency signal is transmitted to the demodulation circuit for processing to obtain the baseband signal. At this time, the standing wave detection device 35 is in the off state, which does not affect the reception of the radio frequency signal.

Since the receiver 33 is connected to the second switch 36 after the low noise amplifier 332, it is necessary to evaluate whether the performance index of the receiver 33 has changed after the introduction of the second switch 36, and test whether there is no second switch 36 or the second switch 36 is provided. The sensitivity and intermodulation interference index, in a specific embodiment, the frequencies L, M and H are respectively 400.075MHz, 435.075MHz and 469.075MHz, and the test data shown in the following table is obtained:

It can be seen from the above table that the difference loss caused by the second switch 36 is less than 0.7dB, and the second switch 36 is located after the low noise amplifier 332. In theory, the deterioration of the receiving link 331 is negligible, and the sensitivity and intermodulation interference are basically negligible. There is no effect, so the second switch 36 can be added.

Since DMR is in Time Division Duplexing (TDD, Time Division Duplexing) mode, the transmit signal occupies one time slot, and the received signal occupies one time slot. In the transmit time slot, the receive link 331 after the low noise amplifier 332 can be reused for forward power. And reverse power detection for standing wave detection, protection and alarm measures. After the low noise amplifier 332, a radio frequency switch that selects one of three is added to switch between receiving radio frequency signals, forward signals, and reverse signals, using signal strength detection The circuit 351 obtains the forward power and the reverse power, and then sends them to the controller 352. The controller 352 calculates the voltage standing wave ratio. When the voltage standing wave ratio is higher than the set threshold, the controller 352 can reduce the power amplifier 322 Therefore, the output power of the power amplifier 322 is reduced, and the power amplifier 322 is protected in real time. When the voltage standing wave ratio is too large, an alarm will prompt the user that the voltage standing wave ratio of the antenna 31 is abnormal.

In a specific embodiment, a test is performed on the DMR vehicle platform, the low noise amplifier 332 is disconnected from the receiving link 331, and the second switch 36 is connected to introduce the forward RF signal and the reverse RF signal to the second switch At the first end of 36, the signal strength detection circuit 351 is used to detect the forward power and reverse power of the transmitter 32 to obtain the voltage standing wave ratio as shown in the following table:

In the prior art, it is necessary to repeatedly test each frequency point to evaluate the fitting calibration factor K. When the frequency is 400MHz, K=1.6; when the frequency is 435MHz, K=1.4; when the frequency is 470MHz, K=1.05; It can be seen from the above table that the error of the detection value is within ±0.2 using the solution in this embodiment, while the original detection value in the prior art is above ±0.5, and the calibration factor K needs to be multiplied to ensure the error of ±0.2. Therefore, this implementation Compared with the prior art, the detection accuracy of the solution in the solution is significantly improved.

This embodiment has advantages in cost control, layout space, and detection accuracy, saving hardware cost, PCB layout space, and debugging workload, and can accurately detect the current VSWR of antenna 31, and reduce power or shut down The protection measures of the power amplifier 322 reduce the damage to the power amplifier 322 caused by the transmitted signal.

The above are only examples of this application, and do not limit the scope of this application. Any equivalent structure or equivalent process transformation made by using the description and drawings of this application, or directly or indirectly applied to other related technical fields, The same reasoning is included in the scope of patent protection of this application.

Claims

A standing wave detection device, which includes:

The signal strength detection circuit is used to obtain the forward power and reverse power of the transmitter by using the receiving link of the receiver in the transmission time slot to generate the corresponding forward voltage and reverse voltage;

The controller is connected to the signal strength detection circuit and is used to receive the forward voltage and the reverse voltage to obtain the voltage standing wave ratio of the antenna, and determine whether to adjust the voltage standing wave ratio of the antenna according to the voltage standing wave ratio of the antenna. The transmitting power of the transmitter, if yes, adjust the control voltage value input to the transmitter to adjust the transmitting power of the transmitter.
The standing wave detection device according to claim 1, wherein:

The controller includes a voltage standing wave ratio calculation and judgment circuit and a power adjustment circuit. The voltage standing wave ratio calculation and judgment circuit is connected to the signal strength detection circuit for receiving the forward voltage and the reverse voltage. Voltage, and calculate the voltage standing wave ratio, determine whether the voltage standing wave ratio is greater than the preset voltage standing wave ratio, if so, send an instruction to adjust the power to the power adjustment circuit; the power adjustment circuit and the The input terminal of the power amplifier of the transmitter is connected to adjust the control voltage value input to the power amplifier to a preset voltage value after receiving the power adjustment instruction, wherein the control voltage value Greater than the preset voltage value.
The standing wave detection device according to claim 2, wherein:

The controller further includes a power monitoring circuit, which is connected to the signal strength detection circuit and the power adjustment circuit respectively, and is used to obtain the forward voltage output by the signal strength detection circuit to generate The forward power, and determine whether the forward power is greater than the preset power, and if so, send an instruction to adjust the power to the power adjustment circuit.
The standing wave detection device according to claim 2, wherein:

The power amplifier of the transmitter includes at least one transistor, and the output terminal of the power adjustment circuit is connected to the input terminal of the transistor for outputting the control voltage value to control the output power of the transistor.
A communication device, which includes:

The first switch is respectively connected to the transmitter, the receiver and the antenna, and is used to connect the transmitter and the antenna in the transmission time slot or the receiver and the antenna in the reception time slot;

The standing wave detection device is respectively connected with the receiver and the transmitter, and is used to obtain the voltage standing wave ratio of the antenna by using the receiving link of the receiver in the transmission time slot, and adjust the voltage standing wave ratio according to the voltage standing wave ratio. The transmit power of the transmitter;

The second switch is respectively connected with the transmitter, the receiver and the standing wave detection device, and is used to switch on the transmitter and the standing wave detection device;

Wherein, the standing wave detection device includes a signal strength detection circuit and a controller, and the signal strength detection circuit is used to obtain the forward power and reverse power of the transmitter by using the receiving link of the receiver in the transmission time slot, To generate corresponding forward voltage and reverse voltage; the controller is connected to the signal strength detection circuit, and is used to receive the forward voltage and the reverse voltage to obtain the voltage standing wave ratio of the antenna , And determine whether to adjust the transmitting power of the transmitter according to the voltage standing wave ratio of the antenna, and if so, adjust the control voltage value input to the transmitter to adjust the transmitting power of the transmitter.
The communication device according to claim 5, wherein:

The transmitter includes a signal generation and modulation circuit, a power amplifier, and a two-way coupler connected in sequence. The signal generation and modulation circuit is used to generate a baseband signal and modulate the baseband signal into the radio frequency signal. The amplifier is used to amplify the radio frequency signal, and the bidirectional coupler is used to generate a forward radio frequency signal and a reverse radio frequency signal, and transmit the forward radio frequency signal and the reverse radio frequency signal to the receiving link .
The communication device according to claim 6, wherein:

The transmitter further includes a first signal attenuator and a second signal attenuator, the input end of the two-way coupler is connected to the output end of the power amplifier, and the through end of the two-way coupler is connected to the first switch Is connected to the second end of the bidirectional coupler, the first coupling end of the bidirectional coupler is connected to the first signal attenuator, the second coupling end of the bidirectional coupler is connected to the second signal attenuator, and the bidirectional coupling The device is used to send the forward radio frequency signal and the reverse radio frequency signal to the first signal attenuator and the second signal attenuator, respectively, the first signal attenuator and the second signal attenuator They are respectively used to attenuate the forward radio frequency signal and the reverse radio frequency signal output by the bidirectional coupler.
The communication device according to claim 5, wherein:

The receiver includes a low noise amplifier and the receiving link, the receiving link at least includes a demodulation circuit, the input end of the low noise amplifier is connected to the third end of the first switch, and the low noise amplifier The output terminal of the amplifier is connected to the second terminal of the second switch. The low noise amplifier is used to amplify the received radio frequency signal. The third terminal and the fourth terminal of the second switch are connected to the The first signal attenuator and the second signal attenuator are connected, the first end of the second switch is connected to the demodulation circuit, and the demodulation circuit is used to demodulate the acquired signal to obtain Demodulate the signal.
The communication device according to claim 8, wherein:

When the first end of the second switch is connected to the second end of the second switch, the demodulation circuit is used to demodulate the amplified radio frequency signal output by the low noise amplifier to obtain In the baseband signal, the signal strength detection circuit is in a closed state; when the first end of the second switch is connected to the third end of the second switch, the demodulation circuit is used to The signal output by the first signal attenuator is demodulated to obtain a forward signal. The signal strength detection circuit outputs the forward voltage according to the forward signal; when the first terminal of the second switch is connected to the When the fourth terminal of the second switch is connected, the demodulation circuit is used to demodulate the signal output by the second signal attenuator to obtain a reverse signal, and the signal strength detection circuit is based on the reverse signal The reverse voltage is output.
The communication device according to claim 9, wherein:

The controller includes a voltage standing wave ratio calculation and judgment circuit and a power adjustment circuit. The voltage standing wave ratio calculation and judgment circuit is connected to the signal strength detection circuit for receiving the forward voltage and the reverse voltage. Voltage, and calculate the voltage standing wave ratio, determine whether the voltage standing wave ratio is greater than the preset voltage standing wave ratio, if so, send an instruction to adjust the power to the power adjustment circuit; the power adjustment circuit and the The input terminal of the power amplifier of the transmitter is connected to adjust the control voltage value input to the power amplifier to a preset voltage value after receiving the power adjustment instruction, wherein the control voltage value Greater than the preset voltage value.