Development of chipless, wireless current sensor system based on giant magnetoimpedance magnetic sensor and surface acoustic wave transponder

by:AIRWOLF     2020-06-16
A giant magnetoimpance used in a chip-free, wireless current sensor system (GMI)
Magnetic sensor and one
Port surface sound waves (SAW)
Real reflection extension line
Time power monitoring in current-
High GMI sensor
Each layer has a high quality crystal structure, which helps to achieve high sensitivity and good linearity in the magnetic field of 3-16 oe.
400 mhz RF energy generated from the fork finger sensor (IDT)-
Type reflector on 1-
The port saw extension cord is used as an activation source for the GMI magnetic sensor. The one-
The port saw extension cable replaces the existing transceiver system consisting of thousands of transistors, thus realizing chip-less and wireless operation.
We confirm the large change in the amplitude of the saw reflection peak due to the change in the impedance of the GMI sensor caused by the current flowing through the conductor.
Good linearity and ~ Sensitivity of 0.
For the current in the range of 1-12 u2009 A, 691db/A was observed.
Mode Coupling (COM)
In order to predict the performance of the device in advance, the modeling and impedance matching analysis were also carried out and compared with the experimental results.
In modern electrical technology, a system is needed that can monitor the real situation.
Use the time power supply at any location and then wirelessly transmit the information to the portable reader.
By monitoring the real
Unnecessary energy consumption can be prevented and necessary measures can be taken to prevent any major accidents in the distribution infrastructure.
When charging an electric car or household appliance, real
Time monitoring of charging status; i. e.
, Whether the charger has proper current flow or any contact failure or aging problems.
In order to achieve such a system, current and voltage sensors with high sensitivity and reliability are required.
Various current sensors with different designs and working mechanisms, including resistance shunt current sensors, Hall sensors, induction sensors, Rogovsky coil sensors, are reported.
The resistance shunt sensor based on Ohm\'s law measures the current by directly touching the current path.
It is easy to measure DC and low frequency current with this sensor;
However, it requires complex signals.
The circuit is regulated and heating and safety issues are raised.
Hall sensors are based on non-
Contact Information, relatively safe.
However, in order to measure the external current, the knowledge of the magnetic field generated from the current
It is necessary to carry the current flowing through the path and the sensor itself.
In addition, due to the use of semiconductors and non-semiconductors, it has the problem of low breakdown voltage
Linearity in high external current measurement.
Rogoski coil sensors wrap copper wire around air or non-air
Magnetic core and measure the external current by using an integrator at the output.
Large volume, large weight, high power consumption and complex wireless communication technology are all key problems to be solved.
Current sensor based on GMI and giant magnetic resistance (GMR)
It has been reported in the literature that as a result of high sensitivity, wide frequency range, small size, low power consumption and easy compatibility with CMOS technology, it is the first choice.
Over the years, the development of this current sensor has benefited from advances in theoretical and technical methods.
Compared to conventional sensors, GMI and GMR sensors are compatible with many other statesof-the-
Art and Technology.
Sending the measured current to a remote reader requires a wireless transceiver system.
The existing wireless transceiver systems include battery, antenna, voltage regulator, amplifier, de-
A/D converter and digital processor.
This kind of wireless system will have problems such as signal distortion and noise increase when passing through the wireless electronic circuit,
Start the charging battery installation of the circuit and current sensor.
In addition, the existing wireless receiving and receiving systems need to be processed twice.
Signal processing is done first at the forefront of the wireless system and then again in the remote reader unit.
Most importantly, when multiple sensors are integrated in one system, these systems are expensive, heavy, high power consumption, and difficult to use.
In recent years, reflective surface acoustic devices have been used as passive transponder to overcome these shortcomings. Fu .
Reported wireless passive saw sensor using single electrode
The IDT-type structure acts as a reflector and is connected as a load impedance to external capacitance and resistance sensors. Schimetta .
Develop wireless pressure-
Measurement system combined with saw reflection extension line and high
Q capacitor pressure sensor. Li .
Integrate the magnetic field, temperature and humidity sensors with the saw sensor for both passive and wireless multi-functional sensors. Jung .
A wireless neural probe is developed in which a varicap diode connected with a sharp metal handle is electrically connected to the SAW device. Karilainen .
Biomedical applications of voltage sensors in developed countries are based on the belief that delay, voltage
Relevant impedance loading on reflector IDT.
We propose a wireless current sensing system without a chip, which consists of a GMI magnetic sensor and-
Port surface sound waves (SAW)delay line.
The picture shows the overall view of the developed sensor and measurement system.
The developed system consists of a GMI magnetic sensor for current sensing,-
Port saw extension cord without chip and battery-
Free transceiver system, large sensitivity impedance matching element, two antennas, one clip
On the packaging platform, as the network analyzer of the reader.
When IDT on one-
The port saw reflection extension line receives RF energy through the antenna, and the saw generated on the piezoelectric substrate travels to the two reflector.
Some saw energy is reflected by the reflector and returned to the input IDT and re-
The sensor is converted into an EM wave, which is transmitted to a remote measurement system via an antenna.
There are two reflection peaks in the reader system.
The GMI magnetic sensor is connected to the second IDT-
Type reflector on 1-
The port saw reflects the extension cord.
The conductor line carrying current produces a magnetic field, which affects the impedance change of GMI;
This leads to a change in the second reflection peak of the reader unit.
By evaluating the amplitude change of the second reflection peak, data related to the current value in the conductor can be evaluated.
Compared with the existing wireless current sensor system, the system has many advantages: no chip and battery
Free, so no need for any complicated transceiver system and heavy re-
Start the charging battery of the circuit. The one-
The port saw extension cord replaces the currently available transceiver system consisting of thousands of transistors. A clip-
On the packaging platform for controlling the distance, angle and tilt between current-current
With conductor and GMI sensor.
Mode Coupling (COM)
Modeling and impedance matching analysis were performed to predict one-
The port saw the extension cord and, depending on the size of the current flowing in the wire, made the amplitude change of the second reflection peak larger and linear.
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