CN209949099U - A wireless DC-free sensor information transmission circuit - Google Patents

Abstract

A wireless direct current-free sensing information transmission circuit belongs to the technical field of electronics. The transmission circuit comprises a receiving and transmitting antenna, a drain electrode matching circuit, an open circuit line, a sensor, a transistor containing a heterojunction and a resonant network, wherein one end of the drain electrode matching circuit is connected with the receiving and transmitting antenna, the other end of the drain electrode matching circuit is connected with a drain electrode of the transistor containing the heterojunction, a source electrode of the transistor containing the heterojunction is connected with the open circuit line, a grid electrode of the transistor containing the heterojunction is grounded through the resonant network, and an output end of the sensor is connected between the drain electrode matching circuit and the transistor containing the heterojunction; the drain electrode matching circuit receives pumping microwaves through the receiving and transmitting antenna and transmits microwave signals modulated by the sensing information to the receiving and transmitting antenna. The utility model discloses circuit structure is simple, can realize the long-range wireless transmission of information under the condition of small size, light weight, convenient to use, application range is wide.

Description

A wireless DC-free sensor information transmission circuit

technical field

The invention belongs to the technical field of electronics, and particularly relates to a wireless non-direct current sensing information transmission circuit.

Background technique

Sensor information is usually output in the form of voltage or current signal, and the signal is generally weak, which puts forward higher requirements for wireless transmission of sensor information. In the sensor system network, the signal output by the sensor needs to be processed by the signal conditioning circuit, and then the conditioned signal is analyzed and processed by the information acquisition center to realize the networking of the sensor. The typical processing of the conditioning circuit includes circuit isolation, impedance transformation, level conversion, amplification, filtering, linearization and various calculations. Especially in the wireless transmission system of sensor information, the conditioning circuit usually requires various radio frequency circuits. Components such as oscillators, amplifiers, filters, isolators, etc. In order for each component to work normally, DC power supply is often required, which requires adding power supply equipment such as batteries to the system, which will increase the size, weight, and circuit complexity of the system, and limit the application range of sensor equipment to a certain extent, especially It is a battery-powered sensor device, and its working time is limited by the battery capacity. If wired power supply is used, it will hinder the extensive or intensive deployment of sensor devices, which will have a greater impact on the sensor network.

A typical sensor signal conditioning circuit flow [Weak signal conditioning circuit design and noise analysis, Zhang Jinli, Northwestern Polytechnical University, 2007], as shown in Figure 1. The basic process is: the sensor output electrical signal is pre-amplified first, then the second-stage amplification is performed, and then the signal is pre-processed (filtering, rectification, amplitude adjustment, etc.), and then input to the A/D converter, and finally enters the data processing and analysis center. However, such a conditioning transmission circuit for sensing information has a complex structure, cannot be transmitted wirelessly, and is inconvenient to use.

SUMMARY OF THE INVENTION

Aiming at the technical problems existing in the background technology, the present invention provides a wireless DC-free sensing information transmission circuit, which realizes the wireless DC-free transmission of sensing information.

The technical scheme adopted in the present invention is as follows:

A wireless DC-free sensing information transmission circuit includes a transceiver antenna, a drain matching circuit, an open line, a sensor, a transistor including a heterojunction and a resonant network. One end of the drain matching circuit is connected to the transceiver antenna, and the other end is connected to the transceiver antenna. It is connected to the drain of the transistor with heterojunction, and the source of the transistor with heterojunction is connected to the open line, so that the modulated microwave signal generated by the polariton transition is reflected back to the drain matching circuit and transmitted through the transceiver antenna , the gate of the transistor containing the heterojunction is grounded through the resonant network, and the output end of the sensor is connected between the drain matching circuit and the transistor containing the heterojunction; the drain matching circuit receives the pumping microwave through the transceiver antenna, And transmit the microwave signal modulated by the sensing information to the transceiver antenna.

A method for realizing a wireless non-direct current sensing information transmission circuit, a transceiver antenna receives a pumping microwave signal, and then feeds it into a transistor containing a heterojunction through a drain matching circuit; The junction capacitance is used to control the resonant frequency of the resonant network, so that the transistor containing the heterojunction outputs the microwave signal modulated by the sensor information corresponding to the resonant frequency. The drain matching circuit and the transceiver antenna are sent out to realize the wireless DC-free transmission of sensing information.

Further, the heterojunction-containing transistor may be a heterojunction bipolar transistor or a field effect transistor (FET), etc.; wherein, the field effect transistor may be a metal-oxide semiconductor field effect transistor (MOSFET) or High Electron Mobility Transistor (HEMT).

Compared with the prior art, the beneficial effects of the present invention are:

1. The present invention provides a wireless DC-free sensing information transmission circuit. The circuit generates a microwave signal with a frequency of _fr by receiving the pumping microwave. The microwave signal will be modulated by the electrical signal output by the sensor in the circuit. The modulated signal The signal is transmitted from the circuit through the antenna in a wireless manner, and the signal is demodulated through the receiving circuit to recover the electrical signal output by the sensor, thus realizing the wireless transmission of sensing information without direct current.

2. The present invention provides a wireless DC-free sensing information transmission circuit, which has a simple circuit structure, can realize long-distance wireless transmission of information under the condition of small size and light weight, is convenient to use, and has a wide range of use. The circuit does not need DC power supply, that is, it does not need a battery or a limited way to supply energy, so the energy supply is no longer limited, and the device has a long service life. When in use, it is only necessary to transmit the pump microwave to the circuit, and the microwave signal carrying the sensing information can be received, showing good timeliness, and when there is no pump microwave irradiation, the device is in a completely silent state without electricity , will not actively transmit microwave signals, will not interfere with other equipment, and has good concealment and coexistence. Compared with the traditional sensing information transmission circuit, this circuit loads the sensing information on the microwave signal, so that the sensing information can be transmitted through the antenna, and the frequency of the pumping microwave is different from that of the information carrier signal, and its carrier frequency _fr It can also be controlled by adjusting the pump microwave or circuit structure according to its own needs, which is convenient for signal reception and processing, and shows excellent anti-interference ability.

Description of drawings

FIG. 1 is a structural diagram of a typical sensor signal conditioning circuit mentioned in the background art;

2 is a schematic structural diagram of a wireless DC-free sensing information transmission circuit provided by the present invention;

Figure 3 is a diagram of the test results of the wireless non-DC sensing information transmission circuit of the present invention; a DC voltage with a step of 0.01V is used to simulate the sensor voltage output, and the change process of the output modulated microwave signal frequency _fr with DC is displayed.

Detailed ways

In order to facilitate those skilled in the art to understand the technical content of the present invention, the content of the present invention will be further explained below with reference to the accompanying drawings.

As shown in FIG. 2, it is a schematic structural diagram of a wireless DC-free sensing information transmission circuit provided by the present invention; it includes a transceiver antenna, a drain matching circuit, an open circuit, a sensor, a transistor containing a heterojunction, and a resonant network. One end of the drain matching circuit is connected to the transceiver antenna, and the other end is connected to the drain of the transistor containing the heterojunction, and the source of the transistor containing the heterojunction is connected to the open line, so that the modulated signal generated by the polariton transition can be generated. The microwave signal is reflected back to the drain matching circuit and transmitted through the transceiver antenna, the gate of the transistor with heterojunction is grounded through the resonant network, and the output end of the sensor is connected between the drain matching circuit and the transistor with the heterojunction. Among them, the drain matching circuit realizes the matching between the output impedance of the antenna and the impedance of the transistor, so that the pumping microwave can be fed into the transistor more efficiently, and the microwave signal carrying the sensing information can be smoothly emitted from the matching circuit to realize the integration of the transceiver and the antenna.

The invention provides a wireless DC-free sensing information transmission circuit, which receives pumping microwaves through a transceiver antenna, excites the polariton in the transistor containing heterojunctions to a high energy level, and excites the polariton to a high energy level According to the feedback of the resonant network, it transitions to a specified energy level, and generates a microwave signal corresponding to the resonant frequency of the resonant network. The signal will be modulated by the sensor, and the signal modulated by the sensor information is finally transmitted through the transceiver antenna. The modulated microwave signal has a linear corresponding relationship with the output voltage of the sensor, which realizes the wireless transmission of sensing information without direct current. Among them, the output voltage of the sensor connected in parallel between the drain matching circuit and the transistor with the heterojunction will change the junction capacitance inside the transistor, so as to control the resonant frequency of the resonant network and form a frequency modulation signal carrying the sensor information. Assuming the fed pumping microwave frequency f _p and the resonant frequency _fr of the resonant network, the main frequency of the signal output by the sensing information transmission circuit is also _fr but is modulated by the sensing information. When the voltage U output by the sensor increases, the junction capacitance of the resonant network becomes smaller, and its resonant frequency increases. It shows that the signal frequency _{fr (f r is} the main frequency of the modulated signal) output by the circuit after being modulated by the sensing information has a positive linear relationship with the output voltage U of the sensor.

The present invention provides a wireless DC-free sensing information transmission circuit. After the pump microwave is input, in the transistor with heterojunction, the polariton of the ground state energy level E ₀ is excited to a higher energy level E _h =E _c +h f _p (h is Planck's constant, f _p is the pump frequency). When the unstable polariton on the E _h energy level transitions to the specified energy level, the microwave energy is radiated outward. A fixed energy path is realized by determining the specified energy level at the resonant frequency _fr of the _resonant network, which is controlled by the sensor output voltage, as shown in Figure 2. In this way, the excited polariton transitions from E _h to E _r , and the signal frequency generated by the radiation is f _a , where f _a =f _p -f _r , the signal frequency has a linear correspondence with the sensor output voltage, f The signals of the two frequencies _a and f _r both carry the modulated signal, and finally carry the sensing information and are emitted from the input port of the pumping microwave.

Figure 3 is a diagram of the test results of the wireless non-DC sensing information transmission circuit of the present invention; a DC voltage with a step of 0.01V is used to simulate the sensor voltage output, and the change process of the output modulated microwave signal frequency _fr with DC is displayed. It can be seen from Figure 3(a) to (f) that the DC voltage U increases from 0.01V to 0.06V, and the output frequency fr increases from 64.047MHz to _66.547MHz , indicating that the frequency changes linearly with the voltage.

The present invention provides a wireless DC-free sensing information transmission circuit, which has a simple circuit structure, receives pumping microwaves through an antenna and modulates the output voltage of the sensor to realize wireless DC-free sensing information transmission, and can be widely used in Medicine, security, sensing, quantum technology and electronics.

Those of ordinary skill in the art will appreciate that the embodiments described herein are intended to assist readers in understanding the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific statements and embodiments. Various modifications and variations of the present invention are possible for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims (2)

1. A wireless non-direct current sensing information transmission circuit comprises a receiving and transmitting antenna, a drain electrode matching circuit, an open circuit line, a sensor, a transistor with a heterojunction and a resonant network, wherein one end of the drain electrode matching circuit is connected with the receiving and transmitting antenna, the other end of the drain electrode matching circuit is connected with the drain electrode of the transistor with the heterojunction, the source electrode of the transistor with the heterojunction is connected with the open circuit line, the grid electrode of the transistor with the heterojunction is grounded through the resonant network, and the output end of the sensor is connected between the drain electrode matching circuit and the transistor with the heterojunction; the drain electrode matching circuit receives pumping microwaves through the receiving and transmitting antenna and transmits microwave signals modulated by the sensing information to the receiving and transmitting antenna.

2. The wireless non-direct current sensing information transmission circuit according to claim 1, wherein the transistor with the heterojunction is a heterojunction bipolar transistor or a field effect transistor, and wherein the field effect transistor is a metal-oxide semiconductor field effect transistor or a high electron mobility transistor.

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