CN-224233669-U - Low-noise high-frequency sonar band-pass filter circuit

Abstract

The utility model relates to a low-noise high-frequency sonar band-pass filter circuit, which is constructed on the basis of LTC1562-2 and comprises input ports Vin1 and Vin2 for receiving weak echo signals of sonar transducer processed by a booster and output ports Out1 and Out2 for outputting signals to a variable gain amplifying circuit. The filter circuit is additionally provided with a plurality of element groups by taking the port as the center, wherein the input port Vin1 is externally connected with a first group of element groups, and the input port Vin2 is externally connected with a second group of element groups. The cooperative working mechanism of the elements in the high-frequency sonar bandpass filter circuit ensures that weak echo signals received by the sonar transducer can be accurately processed according to a preset filtering path, and finally achieves the effects of flat amplitude-frequency response and low circuit noise in a passband, thereby providing a high-quality signal processing foundation for a sonar receiver.

Inventors

• Niu yao

Assignees

• 海鹰企业集团有限责任公司

Dates

Publication Date

20260512

Application Date

20241224

Claims (3)

1. 1. A low-noise high-frequency sonar band-pass filter circuit, which is based on LTC1562-2 and is characterized by comprising input ports Vin1 and Vin2 for receiving weak echo signals of sonar transducer processed by a booster and output ports Out1 and Out2 for outputting signals to a variable gain amplifying circuit; The input port Vin1 is externally connected with a first group of element groups, and comprises resistors R2, R3 and R5 and specific pins of a chip LTC1562-2, the input port Vin1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to an INVB pin of the chip LTC1562-2, one end of the resistor R3 is connected to a V2B pin of the chip LTC1562-2, the other end of the resistor R3 is connected to AGND, one end of the resistor R5 is connected to a V2C pin of the chip LTC1562-2, and the other end of the resistor R5 is connected to AGND, namely, signals processed by the first group of element groups are transmitted into the chip LTC1562-2 for further processing and then output from Out 1; the input port Vin2 is externally connected with a second group of element groups, and the second group of element groups comprises resistors R8, R9, R10 and R12 and specific pins of a chip LTC1562-2, wherein the input port Vin2 is connected to one end of R8, the other end of R8 is connected to an INVA pin of the chip LTC1562-2, one end of R9 is connected to a V1B pin of the chip LTC1562-2, the other end is connected to AGND, one end of R10 is connected to a V1C pin of the chip LTC1562-2, the other end is connected to AGND, one end of R12 is connected to a V1D pin of the chip LTC1562-2, and the other end is connected to AGND.
2. 2. The high-frequency sonar bandpass filter circuit of claim 1 wherein resistor R2 is 4.22kΩ, resistor R5 is 10.2kΩ, resistor R3 is 7.87kΩ, resistor R2 and chip LTC1562-2 internal circuitry together form an input buffer stage for impedance matching the input signal after the signal at input port Vin1 enters the first set of components, and resistors R3, R5 and capacitor C together form an external feedback network.
3. 3. The high-frequency sonar bandpass filter circuit of claim 1 wherein resistors R9 and R10 are 7.87kΩ, R8 is 4.22kΩ, R12 is 10.2kΩ, and when the signal at input port Vin2 enters the second set of elements, resistor R8 also serves as part of the input buffer stage to match the impedance with chip LTC1562-2, and the feedback network of resistors R9, R10, R12 and capacitor C interacts with the internal circuitry of the chip.

Description

Low-noise high-frequency sonar band-pass filter circuit Technical Field The utility model relates to the technical field of electronic circuits in underwater acoustic signal detection, in particular to a low-noise high-frequency sonar bandpass filter circuit. Background Filter circuit technology has undergone significant advances and innovations from early simple components to the present complex systems. Early filter circuits were mainly dependent on passive components such as resistors, capacitors, and inductors to achieve frequency selection, and the combination and design of these components were relatively simple, and were capable of achieving basic filtering functions, but limited by the performance of the components and the complexity of the circuit, and the filtering effect and stability were relatively limited. As technology continues to evolve, filter circuit technology gradually transitions from passive components to active components and integrated circuit technology. Modern filter circuits widely adopt active devices, such as operational amplifiers, transistors and the like, and the introduction of the devices enables the frequency response of the filter circuit to be more accurate and the filtering effect to be better and more obvious. Meanwhile, the rapid development of the integrated circuit provides powerful support for miniaturization and integration of the filter circuit, and the filter circuit is widely applied to electronic equipment. Filters play a critical role in improving signal quality. During signal transmission and processing, noise and spurious components are unavoidable, which can interfere with the original signal and reduce the quality of the signal. Through the filter, noise and spurious components can be effectively removed, so that the quality of signals is improved. Therefore, a filtering scheme is needed, in underwater acoustic communication, components with different frequencies mixed in a signal can be separated through a filter, so that the quality of an original signal is improved, a high-quality sound chart is obtained after processing, the technical requirements of flat amplitude-frequency response and low circuit noise in a passband are met, and the signal processing quality in a sonar receiver is improved. Disclosure of utility model In order to solve the technical problem, the low-noise high-frequency sonar bandpass filter circuit of the utility model is a filter circuit constructed based on LTC1562-2, and comprises input ports Vin1 and Vin2 for receiving weak echo signals of sonar transducer processed by a booster, and output ports Out1 and Out2 for outputting signals to a variable gain amplifying circuit. In one embodiment of the present utility model, the filter circuit is additionally provided with a plurality of element groups around the port, wherein the input port Vin1 is externally connected with a first group of element groups, and the first group of element groups comprises resistors R2, R3, R5 and specific pins of the chip LTC1562-2, the input port Vin1 is connected to one end of R2, the other end of R2 is connected to the INVB pin of the chip LTC1562-2, one end of R3 is connected to the V2B pin of the chip LTC1562-2, the other end of R3 is connected to AGND, one end of R5 is connected to the V2C pin of the chip LTC1562-2, and the other end of R5 is connected to AGND, i.e. the signal processed by the first group of element groups is transmitted to the inside of the chip LTC1562-2 for further processing and then is output from Out 1. In one embodiment of the present utility model, the resistor R2 is 4.22kΩ, the resistor R5 is 10.2kΩ, and the resistor R3 is 7.87kΩ, and when the signal of the input port Vin1 enters the first group of elements, the resistor R2 and the internal circuit of the chip LTC1562-2 together form an input buffer stage to perform impedance matching on the input signal, so as to reduce signal reflection and ensure that the signal can be effectively transmitted to the inside of the chip for processing. The resistors R3 and R5 and the capacitor C form an external feedback network, the feedback network is combined with an amplifier in the chip LTC1562-2, and the amplitude and the phase of signals are adjusted through feedback action, so that the screening and the amplification of signals with specific frequencies are realized, and the characteristic of flat amplitude-frequency response in a passband is realized. In one embodiment of the present utility model, a second group of elements is connected outside the input port Vin2, including resistors R8, R9, R10, R12, and specific pins of the chip LTC1562-2, wherein the input port Vin2 is connected to one end of R8, the other end of R8 is connected to the INVA pin of the chip LTC1562-2, one end of R9 is connected to the V1B pin of the chip LTC1562-2, the other end is connected to AGND, one end of R10 is connected to the V1C pin of the chip LTC1562-2, the other end is connected to AGND, one