What are the characteristics of microwave radiation?

What are the characteristics of microwave radiation?

Microwave radiation is commonly defined as that portion of the electromagnetic spectrum with wavelengths between 1 mm and 1 m (or the equivalent frequency range from 300 GHz to 300 MHz). Even at the highest frequency, the energy per photon is less than 10−3 eV which is too low to produce ionization.

What are the properties of a microwaves?

Properties of Microwaves Microwaves are the waves that radiate electromagnetic energy with shorter wavelength. Microwaves are not reflected by Ionosphere. Microwaves travel in a straight line and are reflected by the conducting surfaces. Microwaves are easily attenuated within shorter distances.

How does a magnetron produce microwaves?

The microwave oven uses a magnetron to generate microwave energy. The microwave energy travels through a waveguide and is distributed into a metal cavity where the food is cooked. The waves are absorbed by the food and excite water molecules in the food. This heat then transfers throughout the food cooking it.

What are 3 characteristics of microwaves?

Microwave ovens heat food using microwaves, a form of electromagnetic radiation similar to radio waves. Microwaves have three characteristics that allow them to be used in cooking: they are reflected by metal; they pass through glass, paper, plastic, and similar materials; and they are absorbed by foods.

What kind of magnets are used in a cavity magnetron?

Modern tubes use rare-earth magnets, electromagnets or ferrite magnets which are much less bulky. The cavity magnetron is a high-power vacuum tube that generates microwaves using the interaction of a stream of electrons with a magnetic field while moving past a series of cavity resonators which are small, open cavities in a metal block.

How are microwaves produced in a cavity magnetron?

The tube is embraced between the poles of two horseshoe-shaped alnico magnets (top, bottom), which create a magnetic field along the axis of the tube. The microwaves are emitted from the waveguide aperture (top) which in use is attached to a waveguide conducting the microwaves to the radar antenna.

How is the resonant frequency of a cavity magnetron determined?

The resonant frequency of the arrangement is determined by the cavities’ physical dimensions.

How is the curvature of the path of a magnetron controlled?

The curvature of the path can be controlled by varying either the magnetic field, using an electromagnet, or by changing the electrical potential between the electrodes. At very high magnetic field settings the electrons are forced back onto the cathode, preventing current flow.