Microwaves are radio waves with a frequency from 300MHz to 300GHz which corresponds to a wavelength of one meter down to one millimeter. Often in RF engineering however it is used to refer to a narrower region such as 1 to 100GHz.
Questions tagged [microwave]
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Why do microwave ovens, with metal walls, not blow up?
Why does a microwave oven with metal (?) walls work fine, but if I (theoretically) put a metal spoon in it, "bad things" may happen?
Maybe these internal walls are not conductive?
Kamil
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Is a microwave's output power proportional to the mass of its contents?
My friend and I are having a heated debate.
On the one hand, he thinks that a microwave oven that is empty, consumes almost no power (not considering lights, lcd, etc). He says that once you put an item in the oven, such as a glass of water, the…
Matthew Goulart
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Why does 1/4 wavelength have a ground plane and 1/2 wavelength needs none?
Why does 1/4 wavelength have to have a ground plane and 1/2 doesn't?
I know that an antenna that has half a wavelength does not need the ground plane (example a dipole antenna) and when using a wavelength of 1/4 it is usually necessary to have the…
LUFER
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Why do microwave ovens use magnetrons?
With a lot of advancement in solid state electronics and signal manipulation, isn't it easier to simply take high amplitude signals with frequencies near 1 MHz and multiply the signals using diodes and frequency filters(LC/RLC) than to use a…
Vishwa Mithra Tatta
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Are TV coaxial cables compatible with WiFi antennas?
If I replace an old, roof-mounted TV antenna with a 2.4GHz WiFi (IEEE 802.11) antenna; can I use the existing coax? Or will I need to run all new cable?
voices
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How dangerous is a magnetron?
I took apart a microwave, and when I saw the magnetron, I conviniently remembered that I had heard that magnetrons were dangerous. I decided to research this a bit further (I know, great timing) and I found that some magnetrons contains berilyum…
skillz21
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What causes loss of power over lifetime of a magnetron?
The power of a magnetron declines over time\$^1\$. While not noticable for most consumer applications (A 2000-hour lifetime would last over 20 years if the device is used only 15 minutes a day), this is a problem in industrial situations.
What…
Joren Vaes
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Big discrepancy between theoretical and actual power through my pulse generator
I am trying to acquire some skills about pulse generation, but that's not easy.
I've tried to derive the power dissipated by the input resistor in my pulse generator, but it turns out to be much lesser than the actual power (if I am correct).
Where…
MikeTeX
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90° Bend: Mitered vs Curved
On RF PCBs to bend a trace 90° you have many choices but among them Curved and Mitered bend considered as a good choice from performance POV (Both shown below).
For many years I thought that if you have enough space on your board, curved bend is a…
pazel1374
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A few questions on PIRs and other motion detectors
I grew up incorrectly believing that motion detectors (as part of burglar alarm systems) were designed to detect movement, when in actual fact it is the movement of a heated (like body heat) object which causes them to trip. I also understand there…
questioner
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What piece of technology is able to record the exact phase of microwaves?
I had this question on the physics community, but I thought this would be appropriate to cross-post here.
I read that in VLBI, the signals of microwaves (on the millimeter scale) are recorded and then later combined. A famous example of this is the…
Maximal Ideal
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Can I improve the directivity of an X-band radar module with integrated plane-patch antenna?
Lots of detail provided in case it's needed.
I'm continuing to tinker with remote proximity sensors driven by an Arduino (and eventually just an ATMEGA* chip and its safety buddies) and have a pretty good prototype so far. It picks up motion just…
Joshua Nozzi
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should I open a solder mask over a high speed microstrip line in a PCB?
Top layer of the PCB, 50 Ohm microstrip line transmitting 650 MHz/1.3 Gbps (corrected: 1.3 GHz) rectangular pulses.
To keep good signal integrity, should I remove a solder mask ink over the top of my trace?
Sergei Gorbikov
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Radio frequencies, what are the limits?
What is the correct range of frequencies for radio waves? Wikipedia's article on radio waves states that all frequencies below 300 GHz are radio waves, while the article on the radio spectrum states the upper limit is 3 THz. Additionally, the…
Tommaso Bendinelli
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Differences between a planar coil and coplanar waveguide to create a local 1D AC magnetic field
Coplanar waveguides (for example picture look here) are often used in research to create a local in-plane magnetic field. Now if compared to a planar microcoil like this,
driven by a AC voltage in the 1-5 GHz range, what would be the major…
James Last
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