Multi-band radio frequency power real-time monitoring device

Abstract

The invention provides a multi-band radio frequency power real-time monitoring device which comprises a broadband antenna, a radio frequency amplifier, a power divider, a microstrip filter, a power detector and an acquisition processor. The radio-frequency amplifier comprises a broadband matching circuit and a low-noise amplifier and is used for amplifying radio-frequency signals received by the broadband antenna, and the power divider is used for dividing output signals of the radio-frequency amplifier into N equal parts and respectively sending the N equal parts into the microstrip filters with filtering characteristics of different frequency bands, the power detector converts an output signal of the microstrip filter into a voltage signal, outputs the voltage signal to the acquisition processor for sampling and quantification, and calculates the average power in each frequency band within a specified time. The device can quickly acquire the power information of each frequency band of the radio frequency signal, has the characteristics of good real-time performance and high accuracy, and can monitor the non-single-frequency complex radio frequency signal in real time.

Description

TECHNICAL FIELD

[0001] The present application relates to the radio frequency power monitoring technology in wireless communication system, especially a kind of multi-band radio frequency signal power monitoring device of real-time monitoring. BACKGROUND

[0002] Radio frequency power monitoring technology originally originated from wireless communication, in recent years the technology is widely applied to other scientific fields, such as global positioning technology, navigation technology, electronic countermeasure, aerospace, etc.For radio frequency electronic system, high accuracy, real-time power monitoring can make electronic system more intelligent and automated, thereby improving stability and reliability.However, in the receiver system of wideband antenna, radio frequency signal source is often non-single frequency weak signal, and it is difficult to accurately obtain the power information at each frequency.

[0003] CN1529523A "mobile communication system transmit power detection device", the power monitoring of single frequency radio frequency signal is clearly defined, the intermediate frequency signal is sent into high-speed A / D converter after the measured signal passes through down-conversion unit, then the data is processed, but the frequency band that can be processed is narrow due to the limitation of A / D converter, and multi-band monitoring cannot be carried out.CN101368986A "a wideband radio frequency power detection device" expands the bandwidth of power monitoring through compensation circuit and scaling algorithm, but only covers the frequency range of UHF 470-860MHz digital television.

[0004] CN117768042A "a radio frequency power detection device and equipment" realizes wideband power monitoring with radio frequency signal detection chip LT5534, but only the total power size can be obtained by single monitoring, and the power size of each frequency band in complex radio frequency signal cannot be obtained.

[0005] For the power monitoring of non-single frequency complex radio frequency signal, a common idea is: on the basis of the method described in CN1529523A "mobile communication system transmit power detection device", the monitoring frequency band is widened by frequency sweeping.But this method also has obvious defects: since frequency sweeping needs a long time, this method cannot guarantee real-time monitoring, greatly limits the monitoring bandwidth, and when the target frequency cannot be predicted, the monitoring accuracy of this method is not high.

[0006] Therefore, it is necessary to provide a radio frequency power detection real-time monitoring device capable of overcoming the above-mentioned defects to realize real-time, multi-band monitoring of complex radio frequency signal. SUMMARY

[0007] The purpose of the present application is to provide a multi-band radio frequency power real-time monitoring device, which can overcome the above-mentioned defects and realize real-time, multi-band monitoring of complex radio frequency signal.

[0008] To achieve the above-mentioned purposes, the multi-band radio frequency power real-time monitoring device provided by the application comprises a broadband antenna, a radio frequency amplifier, a power divider, a microstrip filter, a power detector and an acquisition processor. The broadband amplifier comprises a broadband matching circuit and a low-noise amplifier, and amplifies the radio frequency signals received by the broadband antenna. The power divider divides the output signals of the radio frequency amplifier into N parts, respectively sends them into the microstrip filters with different frequency band filtering characteristics, and the power detector converts the output signals of the microstrip filters into voltage signals, outputs them into the acquisition processor for sampling and quantization, and calculates the average power in each frequency band within a specified time. Wherein:

[0009] The radio frequency amplifier comprises a low-noise amplifier and a broadband matching circuit. Before the signal enters the low-noise amplifier, the broadband matching circuit is needed to realize the maximum power transmission of the radio frequency signal, which comprises inductors L1, L2, L3 and L4, and open-circuit microstrip lines TL1, TL2 and TL3. The inductors L1, L2, L3 and L4 are connected in series at the head and tail, and the open-circuit microstrip lines are placed at the connection of the inductors. The broadband matching circuit widens the matching bandwidth, and the series inductors facilitate physical debugging.

[0010] The low-noise amplifier of the radio frequency amplifier is a broadband and high-gain low-noise amplifier chip, with a -3dB bandwidth not less than 4GHz, a gain not less than 10dB, and an in-band gain ripple not higher than 3dB.

[0011] The microstrip filter filters the required real-time monitoring frequency band, has three parallel coupling sections TLIN1, TLIN2 and TLIN3, each of which has three parameters of metal line width, inner edge spacing and metal line length. By adjusting these parameters, the center frequency and -3dB bandwidth of the real-time monitoring frequency band can be accurately controlled.

[0012] The power divider can select different structures according to the number of required real-time monitoring frequency bands, including but not limited to a Wilkinson structure microstrip power divider and a T-shaped structure microstrip power divider, which can realize 1-to-N (N=2, 4, 8) power average distribution under a given frequency band.

[0013] The power detector realizes power detection of the radio frequency signal, which is composed of an RMS detection chip. By the method of effective value detection, the radio frequency power signal is converted into a voltage signal.

[0014] The acquisition processor can sample and quantize the output signals of the power detector, and calculate the average power in each frequency band within a specified time. The number of sampling channels is not less than 2, the number of sampling bits is not less than 12, the sampling frequency is not less than 500Hz, and the specified time is not less than 4ms. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The whole structural diagram of a multi-band radio frequency power real-time monitoring device.

[0016] Figure 2 The structure diagram of a wideband matching circuit in the multi-band radio frequency power real-time monitoring device.

[0017] Figure 3 The structure diagram of a microstrip filter in the multi-band radio frequency power real-time monitoring device.

[0018] Figure 4 The structure diagram of a power divider and a microstrip filter in the case of N=2. DETAILED DESCRIPTION

[0019] The application will be further described in detail below in combination with the accompanying drawings and embodiments. However, the embodiments in the following description are only descriptive, but not restrictive.

[0020] ATTACHMENT Figure 1 The schematic diagram of the multi-band radio frequency power real-time monitoring device, specifically comprising: a wideband antenna, a radio frequency amplifier, a power divider, a microstrip filter, a power detector, and a sampling processor. After the radio frequency signal to be measured enters the monitoring system, it is first amplified in power by the wideband radio frequency amplifier. The power divider can divide the radio frequency signal into two paths, and the two paths of signals are processed by the microstrip filter to complete the filtering of different frequency bands. The power detection unit converts the power signal into a voltage signal and outputs it to the sampling processor. The sampling processor samples and quantizes the analog voltage signal and processes and stores the digital signal. The application of the power divider and the multi-band filter enables the application to perform multi-band power real-time monitoring on the radio frequency signal in real time.

[0021] The radio frequency amplifier comprises a low-noise amplifier and a wideband matching circuit. Before the signal enters the low-noise amplifier, the wideband matching circuit is needed to realize the maximum power transmission of the radio frequency signal. In actual application, the corresponding matching circuit needs to be designed according to the requirements. The wideband matching circuit is as shown in the attached Figure 2The broadband matching circuit comprises inductors L1, L2, L3 and L4, and open-circuit microstrip lines TL1, TL2 and TL3, the inductors L1, L2, L3 and L4 are connected in series, and the open-circuit microstrip lines are arranged at the connection positions of the inductors, the matching degree and the frequency range can be adjusted by adjusting the values of the four inductors and the metal length and width of the three open-circuit microstrip lines, the broadband matching circuit retains the inductor elements connected in series, reduces the area of the matching network, and can correct the deviation of the circuit by adjusting the sizes of the inductors L1, L2, L3 and L4, the circuit debugging can be conveniently performed, and the broadband matching circuit has remarkable engineering value and economic effect.

[0022] The low-noise amplifier of the radio frequency amplifier is a broadband high-gain low-noise amplifier chip, the reference device is ADL8104, the -3dB bandwidth is 0.4GHz-7.5GHz, and the gain is 15dB.

[0023] The power divider is a T-shaped microstrip power divider, and can realize power average distribution of two frequency bands.

[0024] The microstrip filter has the structure as shown in the accompanying drawings Figure 3 The microstrip filter is a parallel-coupled line structure band-pass filter, and comprises three parallel-coupled sections. The cut-off frequency and -3dB bandwidth of the filter are mainly determined by the length L, width W and spacing D of the coupled sections, and a total of nine parameters in the three coupled sections can be optimized. The filter is printed on a ZYF300CA board material, the dielectric constant of the board material is 3, and the thickness is 0.76. The filter realizes filtering of two frequency bands, and the -3dB cut-off frequencies of the two frequency bands are 1.9GHz-4.2GHz and 3.9GHz-6.2GHz respectively. The size of the 1.9GHz-4.2GHz filter is designed as follows: the size of the first coupled section is W11=15mil, L11=427mil and S11=5mil, the size of the second coupled section is W12=17mil, L12=383mil and S12=5mil, and the size of the third coupled section is W13=15mil, L13=423mil and S13=5mil, and the in-band attenuation is 0.3dB; the size of the 3.9GHz-6.2GHz filter is designed as follows: the size of the first coupled section is W21=4mil, L21=732mil and S21=5mil, the size of the second coupled section is W22=4mil, L22=587mil and S22=5mil, and the size of the third coupled section is W23=4mil, L23=732mil and S23=5mil, and the in-band attenuation is 0.7dB.

[0025] The accompanying drawings show that Figure 4It is the connection diagram of power divider and microstrip filter in the embodiment, and the number of frequency bands is 2. If the two filters are close on the printed circuit board, signal crosstalk will be caused, so the filters of two frequency bands are placed on the left and right of the power divider, and better isolation effect can be obtained.

[0026] The power detector is an RMS detection chip, and the method of effective value detection is used to convert the radio frequency power signal into a voltage signal. After the signal passes through the filter, the signals in the two frequency bands are separated, and then two power detection chips are used to detect the power signals of the two frequency bands. The reference device is LTC5596, which can realize RMS power monitoring in a wide frequency band from 100MHz to 40GHz.

[0027] The acquisition processor is an MCU, which samples and quantizes the output signal of the power detector, and calculates the average power in each frequency band within a specified time. The number of sampling channels is 2, the number of sampling bits is 12, the sampling frequency is 100kHz, and the data is summed within 4ms. The reference device is STM32F103C8T6.

[0028] It can be understood that those skilled in the art can replace or change the technical solutions and concepts of the present application to realize real-time monitoring of radio frequency power in more frequency bands, and these changes or replacements shall belong to the protection scope of the claims attached to the present application.

Claims

1. A multi-band radio frequency power real-time monitoring device, characterized in that: The device includes a broadband antenna, a radio frequency amplifier, a power divider, a microstrip filter, a power detector, and a data acquisition processor. The radio frequency amplifier includes a broadband matching circuit and a low-noise amplifier, which amplifies the radio frequency signal received by the broadband antenna. The power divider divides the output signal of the radio frequency amplifier into N equal parts and sends them to microstrip filters with different frequency band filtering characteristics. The power detector converts the output signal of the microstrip filter into a voltage signal and outputs it to the data acquisition processor for sampling and quantization, and calculates the average power in each frequency band within a specified time.

2. The multi-band radio frequency power real-time monitoring device according to claim 1, characterized in that: The broadband matching circuit of the radio frequency amplifier realizes the maximum power transmission of radio frequency signals. It includes inductors L1, L2, L3, L4 and open-circuit microstrip lines TL1, TL2, TL3. L1, L2, L3, L4 are connected in series. The open-circuit microstrip lines are placed at the connection points of the inductors. The broadband matching circuit is easy to debug.

3. The multi-band radio frequency power real-time monitoring device according to claim 1, characterized in that: The low-noise amplifier of the radio frequency amplifier is a wideband, high-gain low-noise amplifier chip with a -3dB bandwidth of not less than 4GHz, a gain of not less than 10dB, and an in-band gain ripple of not more than 3dB.

4. The multi-band radio frequency power real-time monitoring device according to claim 1, characterized in that: The power divider can be selected with different structures depending on the number of frequency bands to be monitored in real time, including but not limited to: Wilkinson microstrip power dividers and T-type microstrip power dividers. Under a given frequency band, it can achieve 1 to N (N=2, 4, 8) power average distribution.

5. The multi-band radio frequency power real-time monitoring device according to claim 1, characterized in that: The microstrip filter filters the required real-time monitoring frequency band and has three parallel coupling sections TLIN1, TLIN2, and TLIN3. Each parallel coupling section has three parameters: wire width, inner edge spacing, and wire length. By adjusting these parameters, precise control of the center frequency and -3dB bandwidth of the monitored frequency band can be achieved.

6. The multi-band radio frequency power real-time monitoring device according to claim 1, characterized in that: The power detector, composed of an RMS detector chip, realizes the power detection of the radio frequency signal and converts the radio frequency power signal into a voltage signal through the effective value detection method.

7. The multi-band radio frequency power real-time monitoring device according to claim 1, characterized in that: The acquisition processor can sample and quantize the output signal of the power detector and calculate the average power in each frequency band within a specified time. The number of sampling channels is not less than 2, the number of sampling bits is not less than 12, the sampling frequency is not less than 500Hz, and the specified time is not less than 4ms.

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