CN222719719U - Dual-polarized array type multi-frequency microwave band electromagnetic detection device - Google Patents

Abstract

The utility model discloses dual-polarized array type multi-frequency microwave band electromagnetic detection equipment which comprises a high-directivity dual-polarized transmitting antenna and more than two high-directivity dual-polarized receiving antennas, wherein the high-directivity dual-polarized transmitting antenna is electrically connected with a microwave broadband transmitting system, and each high-directivity dual-polarized receiving antenna is electrically connected with a broadband superheterodyne receiving circuit system. The detection equipment disclosed by the utility model adopts high-directivity, dual-polarization (horizontal, vertical) and array antennas, so that the acquisition of scattered multi-component microwave electromagnetic signals is realized, the detection capability of weak scattered signals is effectively improved, the limitation of the traditional geological prospecting instrument on shallower detection depth of an underground target is broken through, and the high-resolution detection of the target in a complex space at a deeper part of the underground can be realized.

Description

Dual-polarized array type multi-frequency microwave band electromagnetic detection device

Technical Field

The utility model belongs to the field of geological exploration, and particularly relates to dual-polarized array type multi-frequency microwave electromagnetic detection equipment in the field, which is used for measuring an underground complex space target body based on an electromagnetic reflection basic principle and has high sensitivity.

Background

In recent years, the development and utilization of urban underground space are increasing, and with the rapid development of non-excavation technology, the technical problem of underground construction of urban cross-building, street, river, railway and other complex areas is not existed. Because the existence information of underground space targets (gas pipelines, water supply and power supply pipe networks and the like) is unknown, the gas pipelines, the water supply and power supply pipe networks are broken and broken accidents frequently occur in the non-excavation technical construction. In order to avoid damage to the front target during trenchless construction driving, accurate detection of urban underground targets (gas pipelines, water supply, power supply networks, etc.) is required.

The current detection methods of urban underground targets (gas pipelines, water supply pipes, power supply pipe networks and the like) commonly used at home and abroad include a gyroscope inertial positioning method, a tracing detection method, an active sound wave method, a ground penetrating radar method, a direct current resistivity method and the like. The gyroscope inertial positioning method has large detection depth and high detection precision, is suitable for pipelines made of various materials, but needs to open a window on the pipeline/pipeline so as to place the gyroscope in the pipeline, which can lead to the pipeline/pipeline to stop running. The tracing detection method is based on the principle that a metal wire or a tracing probe capable of exciting electromagnetic wave is fed into a pipeline, and a receiver positioned on the ground surface receives electromagnetic signals. However, the trace detection method is not suitable for metal pipes because metal shields the propagation of electromagnetic waves. Active sonic methods also require that the pipe leave a sound source access. The ground penetrating radar method is commonly used for fine detection of underground targets, is simple and convenient to construct, low in cost, high in efficiency, high in resolution and capable of imaging, but because the ground penetrating radar adopts high-frequency pulse waves for detection, the attenuation of high-frequency electromagnetic waves is large, and meanwhile, the directivity of the ground penetrating radar antenna is relatively poor, so that the underground targets in deep cities cannot be detected and are indistinct.

Disclosure of utility model

The utility model aims to overcome the defect that the traditional earth surface electromagnetic detection equipment and method cannot perform nondestructive high-precision and large-depth detection on urban underground targets (nonmetal pipelines such as gas pipelines, water supply pipelines, power supply pipelines and the like), and provides dual-polarized array type multi-frequency microwave electromagnetic detection equipment with detection resolution precision reaching millimeter level and nondestructive detection depth reaching tens of meters.

The utility model adopts the following technical scheme:

The dual-polarized array type multi-frequency microwave band electromagnetic detection device is improved by comprising a high-directivity dual-polarized transmitting antenna and more than two high-directivity dual-polarized receiving antennas, wherein the high-directivity dual-polarized transmitting antenna is electrically connected with a microwave broadband transmitting circuit, each high-directivity dual-polarized receiving antenna is electrically connected with a broadband superheterodyne receiving circuit system, the broadband superheterodyne receiving circuit system comprises a front low-noise amplifier, a mixer, an emitter follower amplifier, a narrow-band filter, a low-noise variable gain amplifier and a driving amplifier which are electrically connected together in sequence, the mixer of each broadband superheterodyne receiving circuit system is electrically connected with a microwave broadband local oscillator system, the driving amplifier is electrically connected with a multipath synchronous analog-to-digital conversion circuit, and the multipath synchronous analog-to-digital conversion circuit is electrically connected with a digital signal processing circuit, and the high-precision clock synchronization circuit is electrically connected with the microwave broadband local oscillator transmitting circuit, the microwave broadband local oscillator system and the digital signal processing circuit respectively.

Further, the microwave broadband transmitting system comprises a frequency agile microwave signal generator, a digital program controlled tunable resonant frequency filter and a high gain high power amplifier.

Further, the microwave broadband local oscillation system comprises a frequency agile microwave signal generator, a digital program controlled tunable oscillation frequency filter and a high-gain high-power driver.

Further, the multipath synchronous analog-to-digital conversion circuit comprises Gao Wengui pair rail operational amplifiers, a high-precision reference power supply and a multichannel high-precision synchronous acquisition analog-to-digital converter.

Further, the digital signal processing circuit comprises a high-speed signal processing main controller, a high-precision reference voltage device, a high-speed crystal oscillator and a large-capacity memory.

A dual-polarized array type multi-frequency microwave band electromagnetic detection method uses the equipment and is characterized in that after a microwave broadband transmitting system generates a broadband microwave signal, the broadband microwave signal is transmitted to the underground by a high-directionality dual-polarized transmitting antenna, scattered signals caused by underground abnormal bodies are transmitted by a stratum and received by a high-directionality dual-polarized receiving antenna, the scattered signals are amplified by a front low-noise amplifier of a broadband superheterodyne receiving circuit system in sequence, the lower side frequency of a mixer is mixed, an emitter follower amplifier is amplified, a narrow-band filter is used for filtering, a low-noise variable gain amplifier and a driving amplifier are amplified, the signals are transmitted to a multi-channel synchronous analog-to-digital conversion circuit and are converted into digital signals, finally, the digital signal processing circuit processes and stores data, the broadband microwave local oscillation system provides broadband microwave local oscillation signals for the mixer of the broadband superheterodyne receiving circuit system, and the high-precision clock synchronization circuit realizes clock synchronization among the microwave broadband transmitting system, the microwave broadband local oscillation system and the digital signal processing circuit.

Further, the frequency ranges of the broadband microwave signals and the broadband microwave local oscillation signals are 1-10 GHz.

The beneficial effects of the utility model are as follows:

The detection equipment disclosed by the utility model adopts high-directivity, dual-polarization (horizontal, vertical) and array antennas, so that the acquisition of scattered multi-component microwave electromagnetic signals is realized, the detection capability of weak scattered signals is effectively improved, the limitation of the traditional geological prospecting instrument on shallower detection depth of an underground target is broken through, and the high-resolution detection of the target in a complex space at a deeper part of the underground can be realized. Different antenna array combination forms can adapt to the requirements of different detection scenes, and the nondestructive, high-precision and high-resolution interface detection of urban underground space targets (nonmetal pipelines such as gas pipelines, water supply pipelines, power supply pipelines and the like) is realized.

The detection equipment disclosed by the utility model eliminates the influence of background interference signals by utilizing the higher resolution capability of time-harmonic and multi-frequency microwave signals, through strong directional signal transmission, weak signal detection, strong interference suppression and acquisition of multi-component electromagnetic field information of scattered echoes, and greatly improves the nondestructive, non-contact and large-depth detection capability of underground nonmetallic pipelines.

The detection method disclosed by the utility model utilizes the electromagnetic detection and identification technology of the high-directionality and array microwave section to realize the rapid positioning and inversion of the urban underground nonmetallic pipeline, and greatly improves the imaging resolution capability. The broadband microwave signal of 1-10 GHz is adopted, and the broadband microwave signal has a plurality of working frequencies, so that the scanning detection can be carried out on the interfaces of the urban underground space targets (nonmetal pipelines such as gas pipelines, water supply pipelines, power supply pipelines and the like) with different depths.

Drawings

Fig. 1 is a block diagram of the components of the disclosed detection apparatus.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

In embodiment 1, the embodiment discloses a dual-polarized array type multi-frequency microwave electromagnetic detection device, which utilizes multi-frequency microwave band signals generated by a transmitting antenna, wherein the microwave signals encounter an abnormal body in the underground propagation process, and the electric parameters of the abnormal body and surrounding stratum are different to generate scattering, so that the scattering signals have a certain relationship with the size, the position and the electric parameters of the abnormal body. And measuring scattered echo information by using an array and directional antenna, and performing geologic body interpretation and imaging on geometric and electrical parameters of abnormal bodies in the stratum.

As shown in FIG. 1, the system comprises a high-directivity dual-polarized (vertical and horizontal) transmitting antenna and more than two high-directivity dual-polarized (vertical and horizontal) receiving antennas, wherein a plurality of horizontal and vertical polarized electric field and magnetic field transmitting and receiving antenna arrays are assembled by adopting high-directivity microwave antennas, so that the transmitting and collecting of scattered multi-component electromagnetic wave signals with different depths can be realized, the influence of direct coupling signals is eliminated, and meanwhile, the multi-component microwave scattering signals of urban underground targets (nonmetal pipelines such as gas pipelines, water supply pipelines, power supply pipelines and the like) can be finely detected by adopting the antenna arrays consisting of a plurality of antennas with different transmitting-receiving intervals and the working frequencies of a plurality of microwaves (1 GHz-10 GHz).

The high-directivity dual-polarized transmitting antenna is electrically connected with the microwave broadband transmitting system, each high-directivity dual-polarized receiving antenna is electrically connected with a broadband superheterodyne receiving circuit system, the broadband superheterodyne receiving circuit system comprises a front low-noise amplifier, a mixer, an emitter follower amplifier, a narrow-band filter, a low-noise variable gain amplifier and a driving amplifier which are electrically connected together in sequence, the mixer of each broadband superheterodyne receiving circuit system is electrically connected with the microwave broadband local oscillation system, the driving amplifier is electrically connected with a multipath synchronous analog-to-digital conversion circuit, the multipath synchronous analog-to-digital conversion circuit is electrically connected with the digital signal processing circuit, and the high-precision clock synchronization circuit is electrically connected with the microwave broadband transmitting system, the microwave broadband local oscillation system and the digital signal processing circuit respectively.

In this embodiment, the microwave broadband transmitting system includes a frequency agile microwave signal generator, a digitally programmable tunable resonant frequency filter, and a high gain high power amplifier.

The microwave broadband local oscillation system comprises a frequency agile microwave signal generator, a digital program controlled tunable oscillation frequency filter and a high-gain high-power driver.

The multi-channel synchronous analog-to-digital conversion circuit is a multi-channel high-precision analog-to-digital conversion circuit and comprises a high Wen Gui pair rail operational amplifier, a high-precision reference power supply and a multi-channel high-precision synchronous acquisition analog-to-digital converter.

The digital signal processing circuit comprises a high-speed signal processing main controller, a high-precision reference voltage device, a high-speed crystal oscillator and a large-capacity memory.

The embodiment also discloses a dual-polarized array type multi-frequency microwave band high-sensitivity electromagnetic detection method, after the equipment is used, a microwave broadband transmitting system generates a broadband microwave signal, the broadband microwave signal is transmitted to underground by a high-directionality dual-polarized transmitting antenna, scattered signals caused by underground abnormal bodies are transmitted by a stratum to be received by a high-directionality dual-polarized receiving antenna, the scattered signals are sequentially amplified by a front low-noise amplifier of a broadband superheterodyne receiving circuit system, the lower side frequency of a mixer is mixed, an emitter follower amplifier is amplified, a narrow-band filter is filtered, a low-noise variable gain amplifier is amplified and subjected to frequency conversion by a driving amplifier, and the like, the signals are transmitted to a plurality of synchronous analog-to-digital conversion circuits, the signals convert the multipath scattered echo electromagnetic analog signals into digital signals, finally, the digital signal processing circuits process and store the data, the broadband microwave broadband local oscillation signals are provided by a microwave broadband local oscillation system for a mixer of the broadband superheterodyne receiving circuit system, and clock synchronization between the microwave broadband local oscillation system (receiving system) and the digital local oscillation signal processing circuit is realized by a high-precision clock synchronization circuit.

The frequency range of the broadband microwave signal and the broadband microwave local oscillator signal is 1-10 GHz. The microwave multi-frequency transmitting antenna transmits a plurality of time-harmonic microwave section working electromagnetic signals within the range of 1-10 GHz to the stratum, the transmitting signals excite the microwave frequency range and the time-harmonic field (primary field) through the dual-polarized (horizontal and vertical) transmitting antenna, and as the density of the underground target body and the surrounding interface is different, the underground deep abnormal body and the surrounding stratum interface cause microwave electromagnetic signal scattering, and the scattered signals (multi-component electromagnetic echo signals) are transmitted through the stratum and are received by the array receiving antenna in the dual-polarized direction (horizontal and vertical), so that the receiving of multi-component microwave signals scattered by the multipath urban underground target bodies (gas pipelines, water supply pipelines, power supply pipelines and other nonmetallic pipelines) is completed.

Claims (5)

1. A dual-polarization array multi-frequency microwave band electromagnetic detection equipment, characterized in that: it comprises a high-directional dual-polarization transmitting antenna and more than two high-directional dual-polarization receiving antennas, the high-directional dual-polarization transmitting antenna is electrically connected to a microwave broadband transmitting system, each high-directional dual-polarization receiving antenna is electrically connected to a broadband superheterodyne receiving circuit system, the broadband superheterodyne receiving circuit system comprises a pre-low noise amplifier, a mixer, an emitter follower amplifier, a narrowband filter, a low-noise variable gain amplifier and a driving amplifier that are electrically connected together in sequence, the mixers of each broadband superheterodyne receiving circuit system are electrically connected to a microwave broadband local oscillator system, the driving amplifiers are electrically connected to a multi-channel synchronous analog-to-digital conversion circuit, the multi-channel synchronous analog-to-digital conversion circuit is electrically connected to a digital signal processing circuit, and a high-precision clock synchronization circuit is electrically connected to the above-mentioned microwave broadband transmitting system, the microwave broadband local oscillator system and the digital signal processing circuit respectively. 2. According to claim 1, the dual-polarization array multi-frequency microwave band electromagnetic detection equipment is characterized in that the microwave broadband transmission system includes a frequency agile microwave signal generator, a digital programmable adjustable resonant frequency filter and a high-gain high-power amplifier. 3. According to claim 1, the dual-polarization array multi-frequency microwave band electromagnetic detection equipment is characterized in that the microwave broadband local oscillator system includes a frequency agile microwave signal generator, a digital programmable adjustable resonant frequency filter and a high-gain high-power driver. 4. According to claim 1, the dual-polarization array multi-frequency microwave band electromagnetic detection equipment is characterized in that the multi-channel synchronous analog-to-digital conversion circuit includes a high-temperature rail-to-rail operational amplifier, a high-precision reference power supply and a multi-channel high-precision synchronous acquisition analog-to-digital converter. 5. According to claim 1, the dual-polarization array multi-frequency microwave band electromagnetic detection equipment is characterized in that the digital signal processing circuit includes a high-speed signal processing main controller, a high-precision reference voltage device, a high-speed crystal oscillator and a large-capacity memory.