Transmit-receive switching automatic switching device applied to broadband ADCP

Abstract

The utility model provides a transmit-receive switching automatic switching device applied to a broadband ADCP, comprising a transducer, a high-speed electronic switch connected with two ends of the transducer, a full-wave rectification circuit connected with two ends of the transducer, and a threshold control circuit connected with the full-wave rectification circuit. Wherein the high-speed electronic switch is connected with the transmitting circuit or the receiving circuit through a corresponding isolation transformer, the other end of the threshold control circuit is connected with the high-speed electronic switch, and the active switching electronic switch is designed to automatically block high voltage in a transmitting stage and keep lower conduction impedance in a receiving stage. Therefore, the influence on the noise of the broadband ADCP is reduced.

Description

Technical Field

[0001] The utility model relates to the field of underwater acoustic electronics applications, in particular to an automatic switching device for transmitting and receiving transfers applied to broadband ADCP. Background Art

[0002] Broadband Acoustic Doppler Current Profiler (Broadband ADCP) is an advanced hydrological measuring instrument, mainly used to measure the three-dimensional velocity distribution of water flow. It works based on the principle of acoustic Doppler effect, can provide high-precision, high-resolution velocity data, and can measure the velocity and direction of different water layers without interfering with the flow field. Broadband ADCP system usually uses the same transducer (or a group of transducers) that both transmits sound waves and receives echoes, which requires that the system needs to be equipped with an automatic switching device for transmitting and receiving to effectively isolate the transmitting signal from the receiving signal to avoid the transmitting signal from interfering with the sensitive receiving circuit. And the automatic switching device for transmitting and receiving will directly affect the signal crosstalk, which is crucial to improving the accuracy and resolution of flow velocity measurement.

[0003] The circuit diagram of the automatic switching circuit for transmitting and receiving in the current broadband ADCP is as follows: Figure 1 As shown in the figure, this type of automatic switching circuit for transmitting and receiving combined generally adopts resistive or capacitive coupling and is limited by a diode. In order to limit the conduction current of the diode to reduce power consumption, the impedance of the series resistor or capacitor in this type of automatic switching circuit for transmitting and receiving is generally high. The high-impedance series element will introduce additional signal attenuation, especially for low-impedance transducers, which may cause the received echo signal strength to decrease, thereby affecting the signal-to-noise ratio (SNR) of the data and the final flow velocity measurement accuracy, which undoubtedly reduces the noise factor (NF) of the system. Utility Model Content

[0004] The utility model aims to provide an automatic switching device for transmitting and receiving switching applied to broadband ADCP, which realizes self-blocking of high voltage in the transmitting stage and maintains a low on-resistance in the receiving stage by designing an active switching electronic switch, so as to reduce the influence of noise on the broadband ADCP.

[0005] To achieve the above objectives, the present technical solution provides an automatic switching device for transmitting and receiving switching applied to broadband ADCP, including: a transducer, a high-speed electronic switch connected to both ends of the transducer, a full-wave rectifier circuit connected to both ends of the transducer, and a threshold control circuit connected to the full-wave rectifier circuit, wherein the high-speed electronic switch switches to connect the transmitting circuit or the receiving circuit through the corresponding isolation transformer, and the other end of the threshold control circuit is connected to the high-speed electronic switch.

[0006] Compared with the prior art, this technical solution has the following characteristics and beneficial effects: This solution adopts an active switching electronic switch, which is different from the current-limiting coupling method of the traditional circuit and can reduce the additional impedance when the receiving circuit is coupled with the transducer, thereby reducing the equivalent input noise. In circuit design, the optimal noise coefficient can be obtained by adjusting the transformer ratio. Specifically, the automatic switching device for transmitting and receiving transfers applied to broadband ADCP designed in this solution can automatically block the high voltage according to the voltage amplitude in the transmitting stage to protect the receiving end, and can maintain a low on-impedance in the receiving stage to reduce the impact on the system noise, which has certain advantages in the noise matching of broadband ADCP low source resistance transducers. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a circuit diagram of a traditional resistor or capacitor current limiting coupled transceiver switching circuit.

[0008] Figure 2 The present invention is a block diagram of a transmitting and receiving automatic switching device applied to a broadband ADCP.

[0009] Figure 3 The present invention is a schematic diagram of the realization principle of the automatic switching device for transmitting and receiving transfers applied to broadband ADCP.

[0010] Figure 4 It is a schematic diagram of control signals of a receiving / transmitting automatic switching device applied to a broadband ADCP. DETAILED DESCRIPTION

[0011] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the utility model.

[0012] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0013] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0014] The present invention provides a device for automatically switching transmission and reception applied to broadband ADCP, including:

[0015] A transducer, a high-speed electronic switch connected to both ends of the transducer, a full-wave rectifier circuit connected to both ends of the transducer, and a threshold control circuit connected to the full-wave rectifier circuit, wherein the high-speed electronic switch is switched to connect the transmitting circuit or the receiving circuit through a corresponding isolation transformer, and the other end of the threshold control circuit is connected to the high-speed electronic switch.

[0016] Different from the resistive or capacitive current limiting coupled transmit-receive switching circuit in the prior art, this solution designs an active automatic switching high-speed electronic switch to achieve the effect of automatically blocking the high voltage according to the voltage amplitude when the transmitting circuit is in the transmitting stage, thereby protecting the receiving end, and maintaining a low on-impedance in the receiving stage.

[0017] Specifically, the transmitting transformer T2 and the de-transmitter constitute a transmitting circuit, and the high-speed electronic switch and the de-transmitter are respectively connected to both sides of the transmitting transformer T2; the receiving transformer T1 and the de-receiving mechanism constitute a receiving circuit, and the high-speed electronic switch and the de-receiver are respectively connected to both sides of the receiving transformer T1.

[0018] In a specific embodiment of the present scheme, MAX14805 is selected as a high-speed electronic switch. MAX14805 is a high-performance integrated circuit designed and manufactured by Analog Devices Inc. (formerly Maxim Integrated) and optimized for high-voltage signal switching in ultrasonic imaging applications. At this time, two input logic control switch groups DIN1 and DIN2 and two switches SW 1 and SW 2 are provided in the high-speed electronic switch, wherein the input logic control switch groups DIN1 and DIN2 are connected to the threshold control circuit, the switch SW1 in the high-speed electronic switch is connected to the transmitting circuit, the switch SW2 in the high-speed electronic switch is connected to the receiving circuit, and the conduction state of the switches SW1 and SW2 is affected by the signals of the input logic control switch groups DIN1 and DIN2.

[0019] The conduction logic table of the high-speed electronic switch is shown in Table 1 below:

[0020] Table 1 High-speed electronic switch conduction logic table

[0021]

[0022] That is to say, when the signal of the input logic control switch group DIN1 and the input logic control switch group DIN2 is 0, switch SW1 and switch SW2 are both in the off state; when the signal of the input logic control switch group DIN1 and the input logic control switch group DIN2 is 1, switch SW1 and switch SW2 are both in the on state; when the signal of the input logic control switch group DIN1 is 0 and the signal of the input logic control switch group DIN2 is 1, switch SW1 is in the off state and switch SW2 is in the on state; when the signal of the input logic control switch group DIN1 is 1 and the signal of the input logic control switch group DIN2 is 0, switch SW1 is in the on state and switch SW2 is in the off state.

[0023] Specifically, refer to Figure 3 It can be seen that one end of the switch SW1 of the high-speed electronic switch is connected to the transducer, and the other end is connected to the transmitting transformer through a parallel transmitting switch diode group, and the transmitting transformer is also connected to the transducer. The transmitting switch diode group includes a switch diode D8 and a switch diode D9 with different conduction directions and arranged in parallel.

[0024] One end of the switch SW9 of the high-speed electronic switch is connected to the transducer, and the other end is connected to the receiving transformer through a parallel receiving switch diode group, and the receiving transformer is also connected to the transducer. The receiving switch diode group includes a switch diode D6 and a switch diode D7 with different conduction directions and arranged in parallel.

[0025] In some embodiments, an enable terminal EN of the high-speed electronic switch is grounded.

[0026] In a specific embodiment, the model of the switching diode D6 , the switching diode D7 , the switching diode D8 , and the switching diode D9 is 1N4148.

[0027] The full-wave rectifier circuit provided by the present solution includes a high-speed diode D1, a high-speed diode D2, a high-speed diode D3, a high-speed diode D4, a resistor R1, a resistor R2 and a capacitor C1, wherein the high-speed diode D1 is connected in series with the high-speed diode D2 to form a first branch, the high-speed diode D3 and the high-speed diode D4 form a second branch, the resistor R1 and the resistor R2 are connected in series to form a third branch, the first branch, the second branch and the third branch are connected in parallel, the capacitor C1 is connected in parallel on both sides of the resistor R2, and the first branch and the second branch are respectively connected to the two ends of the transducer.

[0028] In the embodiment of the present scheme, the circuit formed by the high-speed diode D1, the high-speed diode D2, the high-speed diode D3, and the high-speed diode D4 plays the role of full-wave rectification, and the circuit structure composed of the resistor R1, the resistor R2 and the capacitor C1 forms the role of envelope detection in the transmitting state.

[0029] The threshold control circuit provided by the present solution includes a first threshold control branch connected to the input logic control switch group DIN1 and a second threshold control branch connected to the input logic control switch group DIN2, wherein the first threshold control branch includes a resistor R4, a photocoupler Q1 and a resistor R5, the photosensitive diode in the photocoupler Q1 is connected to the full-wave rectifier circuit, the transistor of the photocoupler Q1 is connected to the resistor R5 and the resistor R4, wherein the second threshold control branch includes a connected NMOS tube Q2 and a resistor R3, and the output end of the NMOS tube Q2 is connected to the first threshold control branch.

[0030] Specifically, Figure 3 As shown, the photosensitive diode of the photocoupler Q1 is connected in parallel to the TVS tube T5 and then connected in parallel to both sides of the capacitor C1. At this time, the TVS tube T5 plays a role in protecting the photocoupler Q1. The base of the transistor of the photocoupler Q1 corresponds to the photosensitive diode, the collector is connected to VDD, the emitter is connected to the resistor R5, and the resistor R5 is grounded. One end of the resistor R4 is connected to the input logic control switch group DIN1, and the other end is connected to the resistor R5, and the circuit between the resistor R4 and the input logic control switch group DIN1 is connected to the ground through the capacitor C2.

[0031] In the embodiment of the present solution, the voltage VDD is a positive voltage of 5V.

[0032] The source of the NMOS transistor Q2 is connected to the input logic control switch group DIN 2 and the resistor R 3 , the drain of the NMOS transistor Q2 is grounded, the gate of the NMOS transistor Q2 is connected to the first threshold control branch, and the resistor R 3 is grounded.

[0033] The working principle of the automatic switching device for transmitting and receiving applied to broadband ADCP is as follows:

[0034] When the broadband ADCP is in the receiving state of receiving signals, the transmitting transformer T1 does not transmit signals, the full-wave rectifier circuit will not affect the reception due to the blocking effect of the switching diode, the emitter voltage of the photocoupler Q1 is the ground voltage, and the output of the corresponding NMOS tube Q2 is the voltage VDD. At this time, the signal of the input logic control switch group DIN1 in the high-speed electronic switch is 0, and the signal of the input logic control switch group DIN2 is 1, the corresponding switch SW9 is turned on, and the switch SW1 is turned off.

[0035] When the broadband ADCP is in the transmitting state of the transmitting signal, the full-wave rectifier circuit performs full-wave rectification on the transmitting signal, and the resistor R1, the resistor R2 and the capacitor C1 form an envelope detection to obtain a rectified signal. The rectified signal is connected through the resistor R1 and the photodiode to turn on the photocoupler Q1. At this time, the voltage of the drain of the NMOS tube Q2 is reduced to 0. At this time, the resistor R4 and the capacitor C2 on the first threshold control branch play a delay role. The signal of the input logic control switch group DIN1 in the corresponding high-speed electronic switch is 1, and the signal of the input logic control switch group DIN2 is 0. The corresponding switch SW9 is turned off and the switch SW1 is turned on.

[0036] like Figure 4 As shown, Figure 4 A pulse signal is injected into the broadband ADCP input: frequency: 100kHz, Vpp=200V, and the control signal after envelope detection. It can be seen that the automatic switching device for transmitting and receiving applied to the broadband ADCP of this solution realizes automatic switching of transmitting and receiving.

[0037] The present utility model is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present utility model. However, no matter what changes are made in the shape or structure, all those having the same or similar technical solutions as the present application fall within the protection scope of the present utility model.

Claims

1. A transceiver automatic switching device applied to broadband ADCP, characterized in that: include: A transducer, a high-speed electronic switch connected to both ends of the transducer, a full-wave rectifier circuit connected to both ends of the transducer, and a threshold control circuit connected to the full-wave rectifier circuit, wherein the high-speed electronic switch is switched to connect the transmitting circuit or the receiving circuit through a corresponding isolation transformer, and the other end of the threshold control circuit is connected to the high-speed electronic switch.

2. The automatic switching device for transmitting and receiving according to claim 1, wherein: The transmitting transformer T2 and the de-transmitter constitute a transmitting circuit, and the high-speed electronic switch and the de-transmitter are respectively connected to the two sides of the transmitting transformer T2; the receiving transformer T1 and the de-receiver constitute a receiving circuit, and the high-speed electronic switch and the de-receiver are respectively connected to the two sides of the receiving transformer T1.

3. The automatic switching device for transmitting and receiving according to claim 1, wherein: The high-speed electronic switch is provided with two input logic control switch groups DIN1 and DIN2, and two switches SW 1 and SW 2, wherein the input logic control switch groups DIN1 and DIN2 are connected to the threshold control circuit, the switch SW1 in the high-speed electronic switch is connected to the transmitting circuit, the switch SW2 in the high-speed electronic switch is connected to the receiving circuit, and the conduction states of the switches SW1 and SW2 are affected by the signals of the input logic control switch groups DIN1 and DIN2.

4. The automatic switching device for transmitting and receiving and switching applied to broadband ADCP according to claim 3 is characterized in that: When the signal of the input logic control switch group DIN1 is 0 and the signal of the input logic control switch group DIN2 is 1, the switch SW1 is in the off state and the switch SW2 is in the on state; when the signal of the input logic control switch group DIN1 is 1 and the signal of the input logic control switch group DIN2 is 0, the switch SW1 is in the on state and the switch SW2 is in the off state.

5. The automatic switching device for transmitting and receiving and switching applied to broadband ADCP according to claim 1 is characterized in that: The full-wave rectifier circuit includes a high-speed diode D1, a high-speed diode D2, a high-speed diode D3, a high-speed diode D4, a resistor R1, a resistor R2 and a capacitor C1, wherein the high-speed diode D1 is connected in series with the high-speed diode D2 to form a first branch, the high-speed diode D3 and the high-speed diode D4 form a second branch, the resistor R1 and the resistor R2 are connected in series to form a third branch, the first branch, the second branch and the third branch are connected in parallel, the capacitor C1 is connected in parallel on both sides of the resistor R2, and the first branch and the second branch are respectively connected to the two ends of the transducer.

6. The automatic switching device for transmitting and receiving and switching applied to broadband ADCP according to claim 3 is characterized in that: The threshold control circuit includes a first threshold control branch connected to the input logic control switch group DIN1 and a second threshold control branch connected to the input logic control switch group DIN2, wherein the first threshold control branch includes a resistor R4, a photocoupler Q1 and a resistor R5, the photosensitive diode in the photocoupler Q1 is connected to the full-wave rectifier circuit, the transistor of the photocoupler Q1 is connected to the resistor R5 and the resistor R4, wherein the second threshold control branch includes a connected NMOS tube Q2 and a resistor R3, and the output end of the NMOS tube Q2 is connected to the first threshold control branch.

7. The automatic switching device for transmitting and receiving and switching applied to broadband ADCP according to claim 6 is characterized in that: The photosensitive diode of the photocoupler Q1 is connected in parallel to the TVS tube T5 and then connected in parallel to both sides of the capacitor C1. The base of the transistor of the photocoupler Q1 is set corresponding to the photosensitive diode, the collector is connected to VDD, the emitter is connected to the resistor R5, and the resistor R5 is grounded.

8. The automatic switching device for transmitting and receiving and switching applied to broadband ADCP according to claim 6 is characterized in that: The source of the NMOS transistor Q2 is connected to the input logic control switch group DIN 2 and the resistor R 3 , the drain of the NMOS transistor Q2 is grounded, the gate of the NMOS transistor Q2 is connected to the first threshold control branch, and the resistor R 3 is grounded.

9. The automatic switching device for transmitting and receiving and switching applied to broadband ADCP according to claim 6, characterized in that: The emitter voltage of the photocoupler Q1 is the ground voltage, the output of the NMOS tube Q2 is the voltage VDD, the signal of the input logic control switch group DIN1 in the high-speed electronic switch is 0, the signal of the input logic control switch group DIN2 is 1, the corresponding switch SW9 is turned on, and the switch SW1 is turned off.

10. The automatic switching device for transmitting and receiving and switching applied to broadband ADCP according to claim 6, characterized in that: When the broadband ADCP is in the transmitting state of the transmitting signal, the full-wave rectifier circuit performs full-wave rectification on the transmitting signal, and the resistor R1, the resistor R2 and the capacitor C1 form an envelope detection to obtain a rectified signal. The rectified signal is connected through the resistor R1 and the photodiode to turn on the photocoupler Q1, and the voltage of the drain of the NMOS tube Q2 is reduced to 0. The signal of the input logic control switch group DIN1 in the high-speed electronic switch is 1, and the signal of the input logic control switch group DIN2 is 0, and the corresponding switch SW9 is turned off, and the switch SW1 is turned on.

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