Can we get Higher Frequencies from an Oven Magnetron?

[tade]

Is it possible, and if so, how should we modify a typical oven magnetron so as to produce higher frequencies of EM radiation?

 

[davenn]

Is it possible, and if so, how should we modify a typical oven magnetron so as to produce higher frequencies of EM radiation?

no, they are designed to oscillate at a specific frequency

and what dangerous things were you planning to do with 100's of Watts of microwave power ?Dave

 

[tade]

no, they are designed to oscillate at a specific frequency

I know, but with modifications?

and what dangerous things were you planning to do with 100's of Watts of microwave power ?

change the frequency so as to resonate with the other components of food, besides the water in food.

 

[Daniel Petka]

I guess you could decrease the Brownian motion by freezing it with liquid nitrogen and thus increase the photon energy aka frequency. It works with lasers and leds, I doubt it will with a magnetron, though.

 

[Baluncore]

… change the frequency so as to resonate with the other components of food, besides the water in food.

https://en.wikipedia.org/wiki/Microwave_oven#Principles

Sometimes, microwave heating is explained as a resonance of water molecules, but this is incorrect; such resonances occur only at above 1 terahertz (THz).

https://en.wikipedia.org/wiki/Microwave_oven#Design

The microwave frequencies used in microwave ovens are chosen based on regulatory and cost constraints. The first is that they should be in one of the industrial, scientific, and medical (ISM) frequency bands set aside for non-communication purposes. For household purposes, 2.45 GHz has the advantage over 915 MHz in that 915 MHz is only an ISM band in the ITU Region 2 while 2.45 GHz is available worldwide. Three additional ISM bands exist in the microwave frequencies, but are not used for microwave cooking. Two of them are centered on 5.8 GHz and 24.125 GHz, but are not used for microwave cooking because of the very high cost of power generation at these frequencies. The third, centered on 433.92 MHz, is a narrow band that would require expensive equipment to generate sufficient power without creating interference outside the band, and is only available in some countries.

 

[tade]

https://en.wikipedia.org/wiki/Microwave_oven#Principleshttps://en.wikipedia.org/wiki/Microwave_oven#Design

i need magnetron specifics though

 

[Baluncore]

i need magnetron specifics though

What specifics ?
The legal restriction on frequency is decided by licensing of radiation sources.

Wavelength is set by the dimensions of the resonant cavity, if you make it bigger it will have a proportionally longer wavelength = lower frequency. Every time a magnetron is turned on it heats up and physically expands, so the frequency chirps slightly downwards in the ISM band.

Magnetic field is unimportant as it simply sets the direction of curvature of the electron paths. Variation of field can give maybe a one percent change in frequency, but extreme changes will lead to higher internal losses and cooling problems.

Internal “Pi strapping” effectively short circuits all modes, (except for the most efficient), by forcing the phase between cavities to be Pi radians = 180°. Only a small proportion of the circulating internal resonant energy is extracted per cycle so the frequency cannot be pulled by changing the external tuning to select another mode or harmonic at a different frequency.

 

[tech99]

I know, but with modifications?change the frequency so as to resonate with the other components of food, besides the water in food.

A microwave oven does not operate at a resonant frequency of water. Any frequency will do.