Microwave Definition and 349 Threads

I took about 100 ml of distilled water, put a small, clean rock in it (to prevent "bumping" or explosion) and heated it repeatedly in a microwave oven on high for 45 seconds. After each heating I checked the temperature of the water with a digital temperature probe. I did this 7 or 8 times...

Why do people worry so much about microwave radiation if it has less energy than infrared (heat) radiation? Why do they worry about STANDING near microwaves versus standing near heat sources? Why do they worry about using it to heat up their food if it's lower in energy than infrared?

How does a microwave receiver works? I can connect it to a multimeter and when a transmitter beam microwave to it, I received voltage and current output. When I put them closer, the output increase. How did the receiver convert intensity of the microwave to voltage and current? I assume the...

Microwave wave guide Davenn stated: as a rule of thumb, the width of a wave guide needs to be of the same order of magnitude as the wavelength of the guided wave. Will a 100+GHz wave guide fit down a 6 inch pipe? what shape would it be? Round, Square, Other?

Dear friends! What is your openion about validity of the following information: " When was the last time you checked your microwave for radiation leakage? Yes, I did say radiation leakage, because any microwave can start leaking radiation any time, for whatever reasons. And such a leakage...

If I tightly packed oily sand in my microwave and turned it on would it heat the sand and oil? If paraffin and salt water were present would it heat everything? Could I send the microwaves to the oven from 1 mile away thru a piece of metal conduit?

Speaking about single photons, the shorter the wavelength (or the higher the frequency) the more energy the wave carries. But for "real life EM waves", next to the frequency there is also the amplitude, the number of photons making the wave. Given 2 waves of the same frequency, the bigger the...

Hello, Microwaves are classified as non-ionizing radiation, so my question is, how do microwaves separate atoms into positive ions and electrons? I've heard of multi-photon ionization, is this what happens?

Hey guys, I am currently self studying some microwave engineering through Pozar's textbook, and I have a couple of conceptual questions. 1.What is the point of defining a generalized reflection coefficient \tau(0) e^{-2j\beta l} if real reflections happen at boundaries? 2. Is there an analog to...

So, I'm new around here and I'm not entirely sure if this is in the right section, but today I noticed something which I found thought-provoking. Before I go into this, I should point out that I'm 16, so all of my physics knowledge above high-school level is entirely self-taught, so I still have...

I always understood that a microwave oven heated things by the microwaves (wavelength about 10cm) vibrating the polar water molecules so they try to line up with the flipping electromagnetic field and they then impart their agitation to the surrounding matter of the food. Now if this story...

How do we know that the cmb is not just related to just our galaxy, and that all galaxies have there own cmb?

I want to get a input impedance from microwave. if the attanuation constant is 0.13, the value is 0.13dB/m. for get the Zin, the dB have to disappear. 0.13dB=10log(X) 0.013dB=log(X) 10^(0.013)dB=X ?? I don't sure about this solution. please help me! google didn't help me.

Is it possible to convert light in the visible spectrum to infrared or microwave light. What processes would be used to do this? Thanks, EJ

Why are raidowaves used for Wifi and Bluetooth but microwaves for satellite communication among other things. I was under the assumption that radiowaves are used for communication only. What are the factors which play into this decision. Also, is there a link between frequency of a wave and the...

Hi, I am taking a course in Microwave Engineering and we were given the following problem to solve An amplifier with a gain of 12 dB, a bandwidth of 150 MHz, and a noise figure of 4 dB feeds a receiver with a noise temperature of 900 K. Find the noise figure of the overall system. Need I to use...

Homework Statement I am putting the picture of the equation given to me in book , I feel it to be wrong please tell me that is the equation written in book correct or not ! Homework EquationsThe Attempt at a Solution

I'm not sure if I should be asking this in the EE section, but here goes. I'm trying to understand more about resonant cavities and how they act to filter out frequencies other than the resonant frequency. In the case where a cavity resonator is coupled between two transmission lines, how...

I probably have the wrong idea, but we learn by asking I guess. I just microwaved some pizza and while doing so I remembered that microwaves are electromagnetic radiation. I then got to thinking that microwaves work by using a frequency of light that interacts with the water molecules in the...

Can an aging microwave oven reaching the end of it life result in a change in its power draw? I've had this microwave for many years, and I know they do wear out, but it has begun blowing a breaker when used. I can't think of any changes to our electrical draw in the house that might affect it...

Hello, Is there any specific element that would absorb x-ray and emit radiation roughly in microwave band (not thermal radiation, fluorescence). Or could it be achieved by mixtures and gradual wavelength increase? Thank you.

I see a lot of information posted on the inefficiencies of heating water to steam with microwave energy. I was wondering if anybody has thoughts on super heating steam with microwave energy? For example, could you run steam through a turbine at 300 psi (417 degrees F), return steam at 100 psi...

I guess we all know laser beams. I wonder if we can make beams in the microwave frequency range and how the beam width relates to the frequency, e.g what is the minimum beam width we can achieve with a frequeny of 50Ghz.

For a science fair experiment me and my partner are working on creating plasma in a microwave.Our hypothesis is that if the manipulability of plasma is affected by the type of gas used, then plasma will react to magnetic fields differently depending on the gas that has been ionised. Because...

Hi everyone, I am about to enter a local Science Fair and my project revolves around creating plasma in a microwave. This is a great experiment, all you do is stick a lighted match in a cork, (or something to hold the match in place) put it in the microwave with a glass beaker over the match...

I understand that the electromagnetic waves inside a microwave can induce a current (terminology?) on a metal object within it. What I don't understand is why, when my fork touched the interior casing of the microwave, it made a lot of sparks and an arc-welder like black mark on the wall. If...

Hello. Do you know that if you take grape to the microwave, you can make some plasma? I think so. () However, on internet is a lot of explanation why does thegrape in microwave produce plasma, but they are not good or they are different. I don't know some official theory. So, I have a...

I have a need for a microwave oven which uses a specific wave length to heat a specific part of a composite sample more than another part of the sample. Normal microwave ovens have a random frequency and amplitude and the frequency is not adjustable. A radio like a short wave radio would...

Dear friends; People say that using of Microwave oven is harmful for human body as the high frequency raise of microwave oven destroy the internal structure of food. Some people say that the person who daily use the microwave oven, can be faced blood cancer. Please share your comments as now...

People always tell me that microwave ovens heat food by exciting the water molecules in food. This is done by blasting food with 2.4 Ghz radiation, the people that say this, also say that the frequency that is used is critical because that frequency interacts with the water molecules. I wonder...

This question is about the interference pattern observed when the waves from two microwave transmitters interfere. The first parts of the question involve the wavelengths of microwaves being the same for each transmitter. For the last part the question proposes that the wavelength of one of...

I have been working under a supervisor in the field of microwave circuits and devices. I have been told that he would be willing to supervise me in the graduate program, and if I am interested, I should begin to think about what I would like to do. I have some confusions regarding this. Is...

I was going over some past papers ( OCR Physics A2 ) and I came across this question about cosmic microwave background radiation-the topic I seem to be struggling with the most :/ and I wasn't sure how to structure my answer. It's worth 5 marks. The question is : Describe the important...

Homework Statement Assume that the transmission lines are lossless (hence all characteristic impedances are real). I am told that there is 6 dB coupling at port 3 from port 1. We are supposed to design the coupler to be matched at port 1. Is port 4 still isolated from port 1? Would this...

Hey all, Refer to page 5 in the pdf in the link (http://whites.sdsmt.edu/classes/ee481/notes/481Lecture26.pdf) I am having a little bit of a hard time understanding a portion of a derivation. You will notice that when determining the ABCD paramters of the shunt stubs they merely use A=1...

Our Panasonic has finally given up the ghost, with a broken internal door catch mechanism. I have a go at most things but I really believe this one is not 'user serviceable' (:cry:) Time for a new one and I can see advantages in using a flat bed model. We had one without a turntable, several...

Hi all, I need a proper software for designing microwave cavities. I intend to use simple base geometries (e.g. closed box) with some modifications, like holes for optical access or for feeding the MW. These modifications however may seriously affect the Q factor, the frequency or might...

Got the following from a friend who teaches HS physics... Measuring the speed of light with chocolate and a microwave oven http://morningcoffeephysics.com/measuring-the-speed-of-light-with-chocolate-and-a-microwave-oven/

I don't really know how to quantify EM waves when it comes to amplitude, but I understand that MRI rf waves are measured in units of tesla. What is the amplitude of a typical microwave oven EM wave in Tesla (mT, uT)??

Hello It would be awesome if anyone can help me with this. The center of the top wall of my microwave oven seems to have melted and the coating has formed boils about 1cm in radius. My roommate thinks its because of the evaporation of oil in the food that someone microwaved for too long...

I have the transformer from a microwave that has the few turns and big windings on one side and the other side must have smaller turns I was just wondering if you apply 115 volt ac to the larger number of windings what would come out the heavier windings? I am just wondering if this can be used...

Hello All, Does microwave radiation cause change in protein chain structure?

"Reverse Microwave" There's some buzz going around about this product, http://www.businessinsider.com/this-reverse-microwave-chills-beer-in-45-seconds-2013-10 which claims to be able to cool drinks rapidly. Honestly, I'm a bit unimpressed. It looks like it's just a refrigerator that...

I made the experiment up myself so my errors may be a result of this, but I heated up marshmallows, eggs and cheese in the microwave and measured the distance between the hotspots in order to get the wavelengths. For the marshmallows I got 0.13cm, for the eggs I got 0.16cm and for the cheese I...

"The cosmic microwave background radiation" is an electromagnetic radiation observed in all directions of the sky and presents a profile type black body with about 3 K temperature. The fact that this allows us to infer the conditions of evolution of matter with radiation of the universe?

And if so, at a rate faster or slower or the same compared to at earlier times of the universe?

Homework Statement A plastic plate with refraction index of 1.5 is placed in the interior of a micro-wave oven which operates with a frequency of 2.5 x 10^9 Hz. If the micro-waves are perpendicular to the surface of the plate, what is the minimum thickness of the plate so that the maximum...

Hellooos! My Question is: How can a Microwave be run/Powered through an inverter? i.e. if I want to power a Microwave of 800 Watts through a 1000 Watts inverter with a 100 AH Battery, could it be possible or would I have to use a Higher Watts inverter? Assuming the Battery (above mentioned)...

Just a thought because of the anomalous Planck satellite cmb data, and the second largest continuous structure in our solar system that almost fried the pioneer probe... Jupiter's magnetosphere which is known emitting radiowaves.

i haven't been able to obtain a simple answer