Physics of Microwaves

The magnetron was also used mainly in the microwave oven, which changed everything. It was first discovered and used in 1921, and it improved again in 1940 with the time. The reason for using a magnetron is that it allows pulsed or continuous microwave generation with increased power to frequencies between 1 megawatt and 1 to 40 GHz. . The percentage of efficiency is also about 80%, the average life expectancy is about 5000 hours. In order for food to actually begin to heat up, the microwave oven has to go through the food, so we have to investigate the magnetron in detail.

Abstract This is the first of two articles on microwave physics. This article describes the problem of generating microwaves in an oven, including the operation of standing waves in magnetrons, waveguides, and resonant cavities. Next, we consider chemical changes that can occur during food microwave absorption, water dielectric relaxation, penetration depth of electromagnetic waves in materials, microwave heating, multiphoton ionization or dissociation.

The actual picture of the microwave oven represents a typical microwave oven (there are many details). Microwaves are generated in the magnetron and the magnetron enters the cooking chamber through the waveguide. This rectangular parallelepiped has a metal wall so it can be used as a Faraday crate. Glass front doors and bulb cavities are covered with metal mesh. Since the holes in the grid are small compared to the wavelength of the microwave, the grid is like a metal plate. The microwave incident on the metal wall of the oven behaves like a visible light hitting a silver mirror, for example. Microwaves are absorbed very efficiently because the electric field of the waves interacts very strongly with the metal's almost free electrons. In a simple model, the electronic behavior is described as damped forced oscillation. These accelerating electrons re-radiate electromagnetic waves at the same frequency

The oven is a microwave oven. But you should not call it a microwave oven. In fact, they said from now, you said you would never use the word "microwave" at the store. Whether you are in the registry, barbecue area, or lounge. Whether your shift has already begun. If you hear the word "microwave oven", you will be dismissed immediately and escorted from the building. Mark is a "big" manager of speech. A person who went to Hamburg University. The degree is set to the office with the mop bucket and the old Tandy PC. This is the way you know that this is a serious absurdity - he talks to us like a presidential speech. Mark is too much, Mark seems to be afraid to say "microwave" even though "you can not say the word" microwave ".