# What's the shape of a microwave beam?

• kokophysics
In summary, In a microwave oven, the microwave beam takes the form of a standing wave that resonates throughout the entire cavity of the oven. This is similar to how a flute can fill a room with a steady note, without any specific "beam" shape. The food in the oven gets heated at varying intensities in different parts, which is why the oven has a turning plate to evenly distribute the heat. This also helps prevent superheating of certain parts of the food.
kokophysics
What's the shape of a microwave beam in a microwave oven? I wonder wether is a ray a small cone, a big cone a band...

Does this beam reflects on the inner walls of the microwave or get absorbed? I would say the second one because one side of the food, if it doesn't turn inside the microwave, doesn't get warm.

Thank you.

The entire cavity of the microwave is resonant, so the EM field effectively fills the entire space with a standing wave.

In much the same way, a flute can fill a room with a standing wave of a steady note, but it cannot be said that the sound leaves the flute in any particular direction or with any particular "beam" shape.

- Warren

Thanks for answering but i thin'k you're someway wrong. Food get hot in very different intensities in different parts if it doesn't turn, and because of that, there is a turning plate. (And I'm talking about homogeneous food).

Actually there is another curious effect. The part touching the plate gets hot very much quickly that the "free" part. I'm thinking of a steak, but happens with other things.

kokophysics said:
Thanks for answering but i thin'k you're someway wrong. Food get hot in very different intensities in different parts if it doesn't turn, and because of that, there is a turning plate. (And I'm talking about homogeneous food).

Think again. Look at an example of a standing wave. There are regions where there are nodes in the wave, meaning no oscillation or energy at that location in space.

Zz.

And the purpose of the rotation would be to run the food through each of those anti-nodes? (And of course prevent superheating)

## 1. What is the shape of a microwave beam?

The shape of a microwave beam is typically circular or oval, depending on the type and design of the antenna used to create the beam. However, the beam can also be shaped to be more directional or focused, depending on the specific application.

## 2. Are all microwave beams the same shape?

No, microwave beams can vary in shape depending on the type of antenna used, the frequency of the microwaves, and the desired application. Some beams may be circular, while others may be more rectangular or focused in a particular direction.

## 3. How is the shape of a microwave beam determined?

The shape of a microwave beam is determined by the design and construction of the antenna used to generate the beam. Different antenna designs can create different beam shapes, and the shape can also be manipulated through the use of reflectors or lenses.

## 4. Can the shape of a microwave beam be changed?

Yes, the shape of a microwave beam can be changed by adjusting the design of the antenna or using additional equipment such as reflectors or lenses. This can be done to achieve a specific beam shape or to improve the efficiency and focus of the beam.

## 5. Does the shape of a microwave beam affect its performance?

Yes, the shape of a microwave beam can greatly affect its performance. A more circular beam may have a wider coverage area but may not be as focused, while a more directional beam may have a narrower coverage area but can be more precise and efficient in its delivery of microwaves.

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