Questions tagged [near-field]
The near-field tag has no usage guidance.
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Near-end scan different frequency magnetic field propagations in ideal DC source
I installed a simple PCB on Ansys siwave. I defined the power lines. And I defined an ideal voltage source that gives only 18 V on the pins. I set the near fields analysis as you can see.
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E field probe or H field probe to detect
I have a board that is failing radiated EMC tests. There are narrowband spikes with 50 MHz intervals (300 MHz, 350 MHz, 400 MHz, etc.)
I believe it has something to do with a clock (I suspect so since ...
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How should I use characteristic mode analysis for antennas that are needed for near field imaging?
I am designing an electrically small microstrip patch antenna, and its "radiative" near field (r = wavelength) reaches quite long enough for the whole imaging region. Basically, I don't need ...
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Why is the near-field radius of a small antenna lambda/2PI?
If I have a small antenna, the near-field is said to extend to \$\frac\lambda{2\pi}\$:
The outer boundary of the reactive near-field region is commonly
considered to be a distance of \${\textstyle {\...
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Can PN7150 NFC controller deactivate RF Interface?
I have used the PN7150 NFC chip from NXP in autonomous polling mode with LPCD disabled.
I can detect NFC Tag and can see NFC coil signals are changing as the NFC tag is detected.
PN7150 VDDTx current ...
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Near Field from a Dipole Antenna
What are the equations defining the near field of a half-wave dipole antenna? What is the rate of decay of E-field and H-field in the near field (both reactive and radiative zones)? How are the ...
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Near-field microwave antenna design
How to I design an antenna which produces a strong field within the antenna, but doesn't radiate out or reflect back to the source? (as much as possible)
I'd like ideally to have a planar structure (...
- 3,391
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Using a far field UHF RFID in the near field range
I have a 902 MHz to 928 MHz UHF 8dBi far-field RFID antenna connected to a reader. I want to read RFID tags.
What will be the consequences if I used this UHF antenna in the near field range when it is ...
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How to get rid of 19kHz electrical fields
The mains of my German flat has 19kHz electrical fields on hot, neutral and! ground wire.
I don't have to get rid of them entirely but I want to achieve 20dB reduction while sitting in front of my ...
- 111
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Does this sensor measure electrical or magnetic fields (with oscilloscope)
I want to measure electrical and magnetic fields of the frequency 50Hz to 1MHz with my oscilloscope.
For electrical fields I learned that any bunch of metal will work.
For magnetic field derivation ...
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NFC standards ISO 14443, ISO 15693 and ISO 18000-3. Which of them are most supported by smartphones?
I want to do this: mobile app <-> NFC <-> microcontroller, in order the MCU can communicate with Android or iOS apps via NFC hardware.
I have two options of low-cost NFC chips, these chips don'...
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Prevent Reception from an Extended Distance (Beyond Design)
I have a magnetic field that is being induced onto a power line by a transmitter, which is following the length of the power line to the receiver. The receiver communicates via a loosely coupled coil ...
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Implement a data protocol between a smartphone and a MCU via NFC hardware?
If I'm able to develop a mobile app which is able to use the NFC hardware of a smartphone to write/read through it. And if I have a board containing a MCU and a NFC transponder like the IC from ST ...
- 647
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Why do LF RFID tags use near field and why is reading distance longer with UHF RFID?
Why do LF/HF RFID tags use the near field (magnetic coupling) and not the far field?
Well, I guess it's easier. The two antennas can just be modeled as a "transformer" and power transfer is straight ...
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Designing 60hz antenna to detect electric field
I am working on designing an antenna to detect 60Hz electric field. I came across the microstrip antenna being used to detect the field. Before designing the antenna I wanted to maek sure this is the ...
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E fields and M fields in Near Field
I am reading a textbook that mentions that small loops with high dI/dt on a PCB tend to produce predominantly magnetic waves and stubs with high dV/dt tend to produce predominantly electric waves in ...
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