CN213750360U

CN213750360U - Receiving circuit of interwell electromagnetic imaging system

Info

Publication number: CN213750360U
Application number: CN202022515934.2U
Authority: CN
Inventors: 张庆乐; 杨爱锋; 姬勇力; 王华雄; 孙刚
Original assignee: China Institute of Radio Wave Propagation CETC 22 Research Institute
Current assignee: China Institute of Radio Wave Propagation CETC 22 Research Institute
Priority date: 2020-11-03
Filing date: 2020-11-03
Publication date: 2021-07-20
Anticipated expiration: 2030-11-03

Abstract

The utility model discloses an electromagnetic imaging system receiving circuit between well, including the preamplification circuit who receives external signal, the different filtering channel of a plurality of filtering frequency range of being connected with the preamplification circuit electricity respectively, analog switch with each filtering channel electricity is connected respectively, the programme-controlled amplifier circuit who is connected with the analog switch electricity, the high pass filter who is connected with programme-controlled amplifier circuit electricity, the low pass filter who is connected with the high pass filter electricity, the AD collection system who is connected with the low pass filter electricity, DSP control circuit then respectively with foretell analog switch, programme-controlled amplifier circuit and AD collection system electricity are connected. The utility model discloses a receiving circuit can select different filtering channel according to the received signal frequency of difference, has reduced the noise to the interference of useful signal, has improved the suppression ability of filtering circuit to the noise, can suppress out of band signal by great degree.

Description

Receiving circuit of interwell electromagnetic imaging system

Technical Field

The utility model belongs to the signal receiving circuit field, in particular to electromagnetic imaging system receiving circuit between well in this field.

Background

The receiving frequency range of the interwell electromagnetic imaging system is between 1Hz and 1KHz, the frequency range is wider, if only one band-pass filter is used, the bandwidth of the filter is wider, the attenuation effect on noise is limited, particularly when shallow well measurement is carried out, the interference of 50Hz is very large, and the high attenuation degree of out-of-band noise in all frequency ranges cannot be met by only one conventional band-pass filter.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that an electromagnetic imaging system receiving circuit between well that SNR is high is provided exactly.

The utility model adopts the following technical scheme:

in a receiver circuit for an interwell electromagnetic imaging system, the improvement comprising: the device comprises a pre-amplifying circuit for receiving external signals, a plurality of filtering channels which are respectively and electrically connected with the pre-amplifying circuit and have different filtering frequency ranges, analog switches respectively and electrically connected with the filtering channels, a program-controlled amplifying circuit electrically connected with the analog switches, a high-pass filter electrically connected with the program-controlled amplifying circuit, a low-pass filter electrically connected with the high-pass filter, and an AD acquisition system electrically connected with the low-pass filter, wherein a DSP control circuit is respectively and electrically connected with the analog switches, the program-controlled amplifying circuit and the AD acquisition system.

Furthermore, the number of the filtering channels is 5, and the filtering frequency ranges are 1-50 Hz, 50-100 Hz, 100-150 Hz, 150-200 Hz and 250Hz in sequence.

Furthermore, the filtering channel is a band-pass filter.

In a method of operating a receiver circuit for use in an above-described interwell electromagnetic imaging system, the improvement comprising: after a weak signal received by the receiving circuit is amplified by the preamplification circuit, the DSP control circuit controls the analog switch to be connected with a filtering channel with corresponding filtering frequency according to a signal frequency range, the signal enters the program control amplification circuit after being subjected to denoising processing by the filtering channel, the DSP control circuit controls the amplification factor of the program control amplification circuit, the signal amplified by the program control amplification circuit enters the AD acquisition system through the high-pass filter and the low-pass filter in sequence to be converted into a digital signal, and the digital signal is transmitted into the DSP control circuit to be subjected to software filtering.

The utility model has the advantages that:

the utility model discloses a receiving circuit can select different filtering channel according to the received signal frequency of difference, has reduced the noise to the interference of useful signal, has improved the suppression ability of filtering circuit to the noise, can suppress out of band signal by great degree. The amplification factor of the program-controlled amplifying circuit can be set according to the size of the received signal so as to adjust the received signal to a range suitable for the acquisition of the AD acquisition system. In the actual use process, digital filters with different orders can be selected according to different sampling sample quantities, and corresponding filtering algorithms can be selected according to different conditions, so that the operation speed is improved, and the signal-to-noise ratio is increased to the maximum extent.

The utility model discloses an operation method adopts multichannel band-pass filter circuit to carry out the filtering of first order, carries out the software filtering of second level again behind the signal entering DSP control circuit, and the software filtering is favorable to the suppression of noise and improvement SNR at the inside joining of DSP control circuit.

Drawings

Fig. 1 is a block diagram of a receiving circuit disclosed in embodiment 1 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Embodiment 1, as shown in fig. 1, this embodiment discloses a receiving circuit of an interwell electromagnetic imaging system, which includes a preamplifier circuit 1 for receiving an external signal, a plurality of filter channels 2 with different filter frequency ranges electrically connected to the preamplifier circuit, analog switches 3 electrically connected to the filter channels, a programmable amplifier circuit 4 electrically connected to the analog switches, a high pass filter 5 electrically connected to the programmable amplifier circuit, a low pass filter 6 electrically connected to the high pass filter, an AD acquisition system 7 electrically connected to the low pass filter, and a DSP control circuit 8 electrically connected to the analog switches, the programmable amplifier circuit, and the AD acquisition system.

In this embodiment, there are 5 filtering channels, and the filtering frequency ranges are 1 to 50Hz, 50 to 100Hz, 100 to 150Hz, 150 to 200Hz, and 250Hz in sequence. The filtering channel is a band-pass filter.

The embodiment also discloses an operation method, which is suitable for the receiving circuit of the interwell electromagnetic imaging system, after a weak signal received by the receiving circuit is amplified by the preamplification circuit, the DSP control circuit controls the analog switch to be connected with a filtering channel with corresponding filtering frequency according to the signal frequency range, the signal enters the program-controlled amplification circuit after being subjected to denoising treatment by the filtering channel, the DSP control circuit controls the amplification factor of the program-controlled amplification circuit, the signal amplified by the program-controlled amplification circuit enters the AD acquisition system through the high-pass filter and the low-pass filter in sequence to be converted into a digital signal, and the digital signal is transmitted into the DSP control circuit to be subjected to software filtering.

Different signal frequencies select different filtering channels, and the noise suppression capability of the filtering circuit can be effectively improved. The DSP control circuit can set different amplification times of the program control amplifying circuit according to the size of the received signal. And the digital signals converted by the AD acquisition system are subjected to software filtering again, and different digital filters and corresponding filtering algorithms can be selected according to different conditions, so that the signal-to-noise ratio is increased to the maximum extent.

Claims

1. A receiving circuit of an interwell electromagnetic imaging system is characterized in that: the device comprises a pre-amplifying circuit for receiving external signals, a plurality of filtering channels which are respectively and electrically connected with the pre-amplifying circuit and have different filtering frequency ranges, analog switches respectively and electrically connected with the filtering channels, a program-controlled amplifying circuit electrically connected with the analog switches, a high-pass filter electrically connected with the program-controlled amplifying circuit, a low-pass filter electrically connected with the high-pass filter, and an AD acquisition system electrically connected with the low-pass filter, wherein a DSP control circuit is respectively and electrically connected with the analog switches, the program-controlled amplifying circuit and the AD acquisition system.

2. The interwell electromagnetic imaging system receiving circuit of claim 1, wherein: the number of the filtering channels is 5, and the filtering frequency ranges are 1-50 Hz, 50-100 Hz, 100-150 Hz, 150-200 Hz and 250Hz in sequence.

3. The interwell electromagnetic imaging system receiving circuit of claim 1, wherein: the filtering channel is a band-pass filter.